WADC TR 54-120 Part 2 APRIL 1955 AN INVESTIGATION OF INTERGRANULAR OXIDATION IN STAINLESS STEELS AND HIGH-NICKEL ALLOYS Clarence A. Siebert Maurice J. Sinnott Lynn H. DeSmyter Robert E. Keith University of Michigan Engineering Research Institute Project No. 2110-5-F Materials Laboratory Contract No. AF 33(616)-353 Project No. 7351 Task No. 73512 United States Air Force Wright Air Development Center Air Research and Development Command Wright-Patterson Air Force Base, Ohio

FOREWORD This report was prepared by the University of Michigan, under USAF Contract No. AF 53(616)-555. The contract was initiated under Project No. 7551, "Metallic Materials", Task No. 73512, "High Temperature Alloys", formerly RDO No. 615-135 "High Temperature Alloys", and was administered under the direction of the Materials Laboratory, Directorate of Research, Wright Air Development Center with Lt J. R. Miller acting as project engineer. WADC TR 54-120 Pt 2 iii

ABSTRACT Chromel alloys ASM, ARM, and D, and type 310 stainless steels were oxidized for 100-hour periods in the stressed condition. The above alloys and Inconel were oxidized for times up to 500 hours in the unstressed condition. Intergranular oxidation measurements were obtained microscopically. The influence of stress was to cause an increase in the intergranular penetration when a minimum stress was reached. In general, the intergranular penetration increased with increasing time and temperature. Increasing the water-vapor content of the air increased the:intergranular penetration slightly. The effect of a preferred orientation decreased the intergranular penetration slightly. The weight gained during oxidation was determined. It was found that in the alloys tested that a plot of the square of the specific weight gain versus temperature resulted in a straight-line relationship. Visual and magnetic examinations were made on the oxidized specimens and their oxides. No correlation between these observations and oxidation properties could be determined. X-ray diffraction patterns were made on representative oxides. This analysis showed the scales encountered to be of a protective nature by Randall and Robbs criteria of the presence of Cr203 or highparameter spinel. Electron diffraction examination of the subsurface structure was performed on type 3510 stainless steels oxidized in the unstressed condition. It was found that the oxidation products in the subsurface region were substantially the same as the surface oxides as determined by x-ray diffraction techniques. PUBLICATION REVIEW This report has been reviewed and is approved. FOR THE COMMANDER: M. R. WHITMORE Technical Director Materials Laboratory Directorate of Research WADC TR 54-120 Pt 2 iv

TABLE OF CONTENTS Page FOREWORD............. iii ABSTRACT.. iv LIST OF ILLUSTRATIONS........................ vi LIST OF TABLES...x.................x INTRODUCTION.......................... 1 EQUIPMENT. ~. ~ ~ ~ ~ ~ ~. ~ ~ ~ ~ ~. 4 1 Stressed Oxidation Equipment.............. 1 Humidifying Equipment.... 2 Weight-Gain Equipment................,,....... 2 PROCEDURE. 3 Specimen Preparation........ Equipment Operation.................. 3 Evaluation of Specimens......................,.. 4 Evaluation of Oxide Scales............ 4 Electron Diffraction..................... 4 MATERIAL........................ 6 RESULTS AND DISCUSSION..................... 6 Weight-Gain Investigation.................. 6 Effect of Stress....... *..... 7 Commercial Type 310 Alloys, Heats X27258 and X46572. ~ ~.. 7 Vacuum-Melted Type 310 Alloy; Heats Vt-5, Vt-7, and J10......... 9 Chromel Alloys D, ASM, and ARM (Heats A and B)........10 Unstressed Studies..............11 Electron Diffraction........................... 13 X-ray Analysis................ 15 SUMMARY AND CONCLUSIONS...................... 15 BIBLIOGRAPHY... 0.0..a.. O 16 WADCBIBLIOGRAPHY..............2. v........ WADC TR 54-120 Pt 2 v

LIST OF ILLUSTRATIONS Figure Page 1. Line Drawing. Schematic Drawing of Stress Oxidation Unit. 26 2. Photograph. Suspension Mechanism. 27 5. Line Drawing. Schematic Drawing of Humidifier Unit. 28 4. Line Drawing, Schematic Drawing of Weight-Gain Unit. 29 5 Photograph. Cut Specimens and Mount. 30 6. Photomicrograph. Pre-rupture Fissures; Chromel D Alloy. 31 7. Photomicrograph. Intergranular Penetrations; Type 310 Alloy, Heat X46572. 31 8. Photomicrograph. Intergranular Penetrations; Type 310 Alloy, Heat X46572. 31 9. Photomicrograph. Pre-rupture Fissures; Type 310 Alloy, Heat X46572. 31 10. Photomicrograph, Pre-rupture Fissures and Excess Constituent; Type 310 Alloy, Heat Vt-5, 52 11. Photomicrograph. Pre-rupture Fissures and Excess Constituent; Type 510 Alloy, Heat X46572. 32 12. Photomicrograph. Inclusions and Grain Size; Type 310 Alloy, Heat Vt-7. 32 15. Photomicrograph. Pre-rupture Fissures; Type 310 Alloy, Heat Vt-7. 32 14. Photomicrograph. Pre-rupture Fissures; Type 310 Alloy, Heat Vt-7, 33 15. Photomicrograph. Grain Size of Chromel Alloy ASM. 33 16. Photomicrograph. Intergranuar Penetrations;Chromel Alloy ARM. 33 17. Photomicrograph. Intergranular Penetrations; Chromel Alloy ARM. 55 18. Photomicrograph. Pre-rupture Fissures and Excess Constituent; Chromel Alloy ARM. 34 19. Photomicrograph. Intergranular Penetrations; Type 310 Alloy, Heat X27258. 34 20. Photomicrograph. Intergranular Penetrations; Type 310 Alloy, Heat X27258. 34 21. X-ray Transmission Pattern; Type 310 Alloy, Heat 31372. 54 22. X-ray Transmission Pattern; Type 310 Alloy, Heat 31372. 55 23. Photomicrograph. Intergranular Penetrationj Type 310 Alloy, Heat 51372. 35 24. Photomicrograph. Intergranular Penetration; Type 310 Alloy, Heat 31372. 55 25. Electron Diffraction Pattern; Rhombohedral Phase. 35 26. Electron Diffraction Pattern; Spinel Phase. 56 27. Photomicrograph. Oxidized Specimen Surface. 37 28. Photomicrograph. Oxidized Specimen Surface. 37 29. Photomicrograph. Oxidized Specimen Surface. 37 50. Photomicrograph. Oxidized Specimen Surface. 57 314 Graph. Square of Specific Weight Gain vs. Time; Type 310 Alloy, Heat J10. 38 32. Graph. Square of Specific Weight Gain vs. Time; Chromel ARM Alloy, Heat A. 39 533. Graph. Square of Specific Weight Gain vs. Time; Type 310 Alloy, Heat Vt-7. 40 34. Graph. Square of Specific Weight Gain vs. Time; Chromel ASM Alloy, 41 WADC TR 54-120 Pt 2 vi

LIST OF ILLUSTRATIONS (continued) Figure Page 35. Graph. Square of Specific Weight Gain vs. Time; Type 310 Alloy, Heat Vt-5. 42 36. Graph. Square of Specific Weight Gain vs. Time; Chromel D Alloy. 43 37. Graph. Square of Specific Weight Gain vs. Time; Type 310 Alloy, Heat X46572. 44 38. Chart. Ratings of Alloys Tested on the Basis of Parabolic Rate Constant. 45 39. Graph. Penetration vs. Depth Below Surface; Type 310 Alloy, Heat X27258, 1600~F. 46 40. Graph. Penetration vs. Depth Below Surface; Type 310 Alloy, Heat X27258, 1700~F. 47 41. Graph. Penetration vs. Depth Below Surface; Type 310 Alloy, Heat X27258, 1800~F. 48 42. Graph. Summary Penetration-Frequency Curves; Type 310 Alloy, Heat X27258, 1600~, 17000, and 18000F. 49 43. Graph. Summary Penetration Depth Curves; Type 310 Alloy, Heat X27258, 1600~, 17000, and 1800~F. 49 44. Graph. Penetration vs. Depth Below Surface; Type 310 Alloy, Heat X46572, 1800~F. 50 45. Graph. Penetration vs. Depth Below Surface; Type 310 Alloy, Heat X46572, 1900~F. 51 46. Graph. Summary Penetration-Frequency Curves; Type 310 Alloy, Heat X46572, 1800~F. 52 47. Graph. Summary Penetration Depth Curves; Type 310 Alloy, Heat X46572, 1800~F. 52 48. Graph. Summary Penetration-Frequency Curves; Type 310 Alloy, Heat X46572, 1900~F. 53 49. Graph. Summary Penetration Depth Curves; Type 310 Alloys Heat X46572, 1900~F. 53 50. Graph. Penetration vs. Depth Below Surface; Type 310 Alloy, Heat J10, Unstressed' 54 51. Graph. Penetration vs. Depth Below Surface; Type 310 Alloy, Heat Vt-5, Unstressed. 55 52. Graph. Penetration vs. Depth Below Surface; Type 310 Alloy, Heat Vt-7. 56 53. Graph. Summary Penetration-Frequency Curve; Type 310 Alloy, Heat J10. 57 54. Graph. Summary Penetration Depth Curve; Type 310 Alloy, Heat JlO. 57 55. Graph. Summary Penetration-Frequency Curve; Type 310 Alloy, Heat Vt-5. 58 56. Graph. Summary Penetration Depth Curve; Type 310 Alloy, Heat Vt-5. 58 57. Graph. Summary Penetration-Frequency Curve; Type 310 Alloy, Heat Vt-7. 59 58. Graph. Summary Penetration Depth Curve; Type 310 Alloy, Heat Vt-7. 59 59. Graph. Penetration vs. Depth Below Surface; Type 310 Alloy, Heat Vt-5, 1800~F. 60 60. Graph. Penetration vs. Depth Below Surface; Type 310 Alloy, Heat Vt-5, 1900~F. 60 61. Graph. Penetration vs. Depth Below Surface; Type 310 Alloy, Heat Vt-7, 1800~F. 61 WADC TR 54-120 Pt 2 vii

LIST OF ILLUSTRATIONS (continued) Figure Page 62. Graph. Penetration vs. Depth Below Surface; Type 310 Alloy, Heat Vt-7, 1900~F. 62 63. Graph. Summary Penetration-Frequency Curves; Type 310 Alloys, Heats Vt-5 and Vt-7 18000F. 63 64. Graph. Summary Penetration Depth Curves; Type 310 Alloys, Heats Vt-5 and Vt-7, 1800~F. 63 65. Graph. Summary Penetration-Frequency Curves; Type 310 Alloys, Heats Vt-5 and Vt-7, 1900~F. 64 66, Graph. Summary Penetration Depth Curves; Type 310 Alloys- Heats Vt-5 and Vt-7, 1900~F. 64 67. Graph. Penetration vs. Depth Below Surface; Chromel ARM Alloy, Heat A. 65 68. Graph. Penetration vs. Depth Below Surface; Chromel ARM Alloy, Heat B. 66 69. Graph. Penetration vs. Depth Below Surface; Chromel ASM Alloy. 67 70. Graph. Penetration vs. Depth Below Surface; Chromel D Alloy. 68 71. Graph. Summary Penetration-Frequency Curves; Chromel Alloys. 69 72. Graph. Summary Penetration Depth Curves; Chromel Alloys 70 73. Graph. Penetration vs. Depth Below Surface; Chromel ARM Alloy, Heat A, 1800~F. 71 74. Graph. Penetration vs. Depth Below Surface; Chromel ARM Alloy, Heat A, 1900~F. 72 75. Graph, Penetration vs. Depth Below Surface; Chromel ARM Alloy, Heat A, 2000~F. 73 76. Graph, Penetration vs. Depth Below Surface; Chromel ASM Alloy, 18000F. 74 77. Graph. Penetration vs. Depth Below Surface; Chromel ASM Alloy, 1900~F, 75 78. Graph. Penetration vs. Depth Below Surface; Chromel ASM Alloy, 2000~F. 76 79. Graph. Penetration vs. Depth Below Surface; Chromel D Alloy, 1800QF. 77 80. Graph. Penetration vs. Depth Below Surface; Chromel D Alloy, 1900~F. 78 81. Graph. Penetration vs. Depth Below Surface; Chromel D Alloy, 2000~F* 79 82. Graph. Summary Penetration-Frequency Curves; Chromel ARM Alloy, Heat A, 1800~F. 80 835 Graph. Summary Penetration Depth Curves; Chromel ARM Alloy, Heat A, 1800~F. 80 84. Graph. Summary Penetration-Frequency Curves; Chromel ARM Alloy, Heat A, 1900~F. 81 85. Graph. Summary Penetration Depth Curves; Chromel ARM Alloy, Heat A, 1900~F. 81 86. Graph. Summary Penetration-Frequency Curves; Chromel ARM Alloy, Heat A, 2000~F 82 87. Graph. Summary Penetration Depth Curves; Chromel ARM Alloy, Heat A, 20000F. 82 88. Graph. Summary Penetration-Frequency Curves; Chromel ASM Alloy, 1800~F. 83 89, Graph. Summary Penetration Depth Curves; Chromel ASM Alloy, 1800~F. 83 90. Graph. Summary Penetration.Frequeney Curves; Chromel ASM Alloy, 1900~F. 84 91. Graph. Summary Penetration Depth Curves; Chromel ASM Alloy, 1900~F. 84 WADC TR 54-120 Pt 2 viii

LIST OF ILLUSTRATIONS (concluded) Figure Page 92. Graph. Summary Penetration-Frequency Curves; Chromel ASM Alloy, 2000~F. 85 93. Graph. Summary Penetration Depth Curves; Chromel ASM Alloy, 2000~F. 85 94. Graph. Summary Penetration-Frequency Curves; Chromel D Alloy, 1800~F. 86 95. Graph. Summary Penetration Depth Curves; Chromel D Alloy, 1800~F. 86 96* Graph. Summary Penetration-Frequency Curves; Chromel D Alloy, 1900~F. 87 97. Graph. Summary Penetration Depth Curves; Chromel D Alloy, 1900~F. 87 98. Graph. Summary Penetration-Frequency Curves; Chromel D Alloy, 2000~F. 88 99. Graph. Summary Penetration Depth Curves; Chromel D Alloy, 2000~F. 88 100. Graph. Penetration vs. Depth Below Surface; Inconel Alloy, 10 Hours, Effect of Time. 89 101. Graph. Penetration vs. Depth Below Surface; Inconel- Alloy, 0 Hours, Effect of Time. 90 102. Graph. Penetration vs. Depth Below Surface; Inconel Alloy, 100 Hours, Effect of Time. 91 105. Graph. Summary Penetration-Frequency Curves; Inconel Alloy, Effect of Time. 92 104. Graph. Summary Penetration Depth Curves; Inconel Alloy, Effect of Time. 92 105. Graph. Penetration vs. Depth Below Surface; Inconel, Chromel ARM, and Type 310 (Heat X27258) Alloys, 1900~Fy 500 Hours. 93 106. Graph. Penetration vs. Depth Below Surface; Type 310 Alloy, Heat X46572, Effect of Moisture Content. 94 107. Graph. Penetration vs. Depth Below Surface; Type 310 Alloy, Heat J1O, Effect of Moisture Content. 95 108. Graph. Penetration vs. Depth Below Surface; Chromel ASM Alloy, Effect of Moisture Content. 96 109. Graph. Summary-Penetration-Frequency Curves; Chromel and Type 510 Alloys, Effect of Moisture Content. 97 110. Graph. Summary Penetration Depth Curves; Chromel and Type 310 Alloys, Effect of Moisture Content. 97 111. Graph. Penetration vs. Depth Below Surface; Type 310 Alloy, Heat 31372, Effect of Preferred Orientation (As-Received). 98 112. Graph. Penetration vs. Depth Below Surface; Type 310 Alloy, Heat 31372, Effect of Preferred Orientation (97% Reduced). 99 113. Graph. Summary Penetration-Frequency Curves; Type 310 Alloy, Heat 31372, Effect of Preffered Orientation. 100 114. Graph. Summary Penetration Depth Curves; Type 310 Alloy, Heat 31572, Effect of Preferred Orientation. 100 WADC TR 54-120 Pt 2 ix

LIST OF TABLES No. Page 1. Chemical Analysis of Materials, Weight Percent 18 2. Specific Weight Gained in Milligrams per Square Inch 19 3. Explanation of Symbols Used in Oxidation Data Tabulations 20 4. Results of Oxidation Tests 21 5. Penetration Distribution 24 6. Analyses of Intergranular Oxides of Stainless Steels Obtained by Electron Diffraction. 25 WADC TR 54-120 Pt 2 x

INTRODUCTION It has been established by numerous investigators that grain-boundary diffusion can be greater than the lattice or volume diffusion. Since the oxidation process is primarily controlled by diffusion rates, it is not surprising that the oxidation rates of the grain boundary can be greater than that of the metal matrix.. This report is primarily concerned with this grain-boundary oxidation although the volume or lattice oxidation rate will affect the measured grain-boundary oxidation rate and therefore must be considered as well, Compared with the total volume of literature concerning the subject of oxidation, the portion concerned with intergranular oxidation is small. Intergranular oxidation becomes an important factor when thin sections are exposed to an oxidizing medium, since under these conditions the portion of the metal influenced by these oxide fissures is a significant percentage of the whole. Because of these facts the.program outlined below used materials of about 0.05 of an inch thick. The present program arose from the need of the U. S. Air Force for information concerning intergranular oxidation in the temperature range of 16000 to 2000~F. There were six objectives in this research program: 1. to determine the effect of temperatures between 1600~ and 2000~F on intergranular oxidation, 2. to examine the effects of alloy composition on intergranular oxidation, 3. to determine the nature of the penetrating material in areas of intergranular attack, 4- to determine the effect of stress on intergranular oxidation, 5. to determine the effect of moisture content of air on intergranular oxidation, and 6. to determine the effect of a preferred orientation on intergranular oxidation. During the past year the major efforts have been concentrated on objectives through 4. EQUIPMENT In addition to the unstressed oxidation equipment used during the previous year (1) the oxidation equipment consisted of stressed oxidation units, progres.sive weight-gain equipment, and apparatus for humid atmosphere generation. Stressed Oxidation Equipment The stressed oxidation equipment consisted of three direct load units as shown schematically in Fig. 1. This type of unit was considered more applicable than a beam-loaded unit because the loads used were small, and because the in-line WADC TR 54-120 Pt 2 1

suspension resulted in less eccentricity in the sample. The sample and suspension were entirely suspended on ball and socket joints as shown in Fig. 2. To determine the eccentricity of the system a 1/8- x x 18inch flatground stock was made into a standard sheet specimen and equipped with SR4-A12 strain gauges attached to both flat surfaces of the test specimen.. The stress-strain curve, which was obtained by progressively loading the system, had essentially the same slope for each gauge position. This system was a:considerable improvement over the clamp-type grips tested. The ground stock was used to assure that the suspension was being tested and not the specimen flatness. The vertical-stress oxidation furnaces, although shorter, were similar to the horizontal furnaces used in the previous work with the following two:exceptions: (1) more windings were placed on the bottom and top of the furnace to correct for draft effects; and (2) the furnace core consisted of Chromel wire covered inside and out with alundum cement. A temperature survey showed the 2-inch oxidation zone to be essentially flat (+ 53F) and little variation for the next inch above and below this zone. The furnaces were controlled from a control thermocouple placed close to the furnace windings. This type of control demonstrated no thermal cycling on a recorder sensitive to a temperature change of 3~F. It was estimated that natural convection in the furnace roughly corresponded to the low flow rates used in the horizontal furnace. Since no variation in intergranular penetration was observed with varying flow rates (1) this natural convection was considered adequate. Humidifying Equipment A humidifier was constructed for producing air of various dewpoints. The air was humidified by passing it countercurrently through heated water sprayed over a column packed with porcelain saddles as shown in Fig. 53 It was found that humidity could be controlled to + 2~F over a 100-hour run, and maintained at any mean value from minus 60~F to plus 120~F by mixing the humidified air with dry- air. Weight.Gain Equipment The equipment for the determination of the increase in weight of a material while it is being oxidized consists principally of a vertical furnace, an analytical balance, a sample suspension, and an atmosphere system, as shown in Fig. 4. The furnace was duplicate of the furnaces used in unstressed oxidation studies previously described (1). The specimen to be oxidized was suspended from the balance by the platinum wire, and dry air was metered through the furnace, being heated by the porcelain chips in the lower portion. This method of obtaining oxidation data has been criticized in the past since scale may flake off during the test. The scales encountered in the alloys used in this investigation were very adherent at the testing temperature. Since no significant jumps were encountered in the weight-gain data, this factor was considered to be a minor one. WADC TR 54-120 Pt 2 2

PROCEDURE Specimen Preparation The specimens for the unstressed oxidation and electron diffraction tests were standard 1-1/2-inch samples of the type used during the previous investigation (1). Stressed oxidation specimens were prepared as standard strip specimens, as illustrated in Fig. 2. Special care was used to keep foreign materials and scratches from the 1/2- x 2-inch gauge portion of the specimen since the samples for intergranular penetration measurements were taken from this section. Texture specimens for work on preferred orientation were prepared by coldrolling the 310 RA alloy 97-98%, and shearing the material into standard, unstressed oxidation specimens. In order to indicate the oxidation in specimens without a texture, control samples were made by cutting the 1/2-inch as-received stock lengthwise and cold-working about 10% to.produce a material with a surface similar to that of the textured specimens. This resulted in samples about 3/16-inch thick in the 10f reduced reference material and 1/32 inch in thickness in the 97% reduced material. Both samples were given a 2000~F anneal for 4-1/2 hours in dry argon (dewpoint, minus 600F) in an attempt to produce an annealing texture in the highly reduced material., The specimens for the weight-gain measurements were 2- x 1-inch rectangles of the as-received material containing a 1/64-inch hole near the top for the insertion of the platinum suspension wire, Equipment Operation When the furnaces had reached thermal equilibrium the specimens were loaded into the furnace. At the conclusion of the run the stressed and unstressed samples were quenched in distilled water. This was done to help preserve the high-temperature phases for x-ray and electron diffraction studies. After the samples were quenched the contents were filtered through coarse filter paper and washed with acetone and then ether to accelerate the drying of the loose scale which flaked off on quenching. When the filter paper had dried, the contents were bottled along with any scale which could be removed by gentle scraping with a surgical scalpel. The total elapsed time between quenching and bottling was about 45 minutes. The visual appearance of the samples was recorded. The percentage elongation which occurred during the test, was determined by measuring the extension of gauge punch marks placed 2 inches apart in the reduced section of the specimen. The samples used for penetration evaluation were sectioned as shown in Fig. 5, and bent 90~ to assure perpendicularity in mounting. The bent samples were given a qualitative magnetic test (1), mounted in bakelite, and polished on a water-cooled belt sander using 120- and 240-grit silicon carbide paper. This was followed by a semifinal polish on 1-micron diamond paste which resulted in a sample with a good edge, retained inclusions and oxide stringers, and was reasonably free of scratches. A final polish consisting of Linde A (levigated alumna) paste, of sufficient thickWADC TR 54-120 Pt 2 5

ness to avoid contact with the polishing cloth, removed the remaining scratches and did not tear out inclusions or oxide stringers. Evaluation of Specimens 2he mounted and polished samples were measured to determine the extent of intergranular penetration. The mean depth (X)and the total number of penetrations (N) were then determined from the penetration measurements. A complete description of the method of taking penetration data as well as a development of the penetration parameters is given in the previous year's report (1). In brief, the method consisted of- examining the polished specimen at 500 diameters using a calibrated, No. 6 grain-size eye piece. The grid, containing 6 squares on the side was aligned with the specimen edge,- and the number of penetrations and their depths were obtained by traversing the edge over a distance of approximately 2 inches. As was expected, the greatest uncertainty was encountered in the very small penetrations, that is, those less than 1 grid in depth. Repeated measurements by various operators indicated that individual variability, -onsidering the first grid penetrations, was approximately 20% in samples extremely difficult to evaluate, and about 10% in the more easily counted samples. The variability encountered in penetrations extending deeper (those in the second, third, etc., -grids) was approximately 5%0 After the penetration measurements were completed, the specimens were given a careful metallographic examination in the etched and unetched conditions. Unusual or significant areas were examined under oblique, polarized, and dark field illumination. Some of the specimens exhibited fissures throughout the matrix as shown in Fig. 6, which made it impossible to determine intergranular penetrations due to oxidation, Evaluation of Oxide Scales The oxide scale was examined visually and tested for magnetism (1). Powdered oxide samples were prepared for x-ray examination, and diffraction patterns obtained using either a 57.5 or 114-mm camera. The values of interplaner spacings were obtained from the film by use of a transparent Nelson Nies x-ray diffraction scale. The values obtained with this method compared favorably with the values obtained by the more laborious direct reading of the film using a comparator, or by the use of a photometer trace. Electron Diffraction In an effort to determine the nature of the intergranular compounds, a technique was developed for examining the subsurface regions of oxidized specimens by means of reflection electron diffraction, a method well suited for the study of solid surface layers. The procedure which was followed on previously oxidized specimens consisted of the following steps: 1o All the external scale possible was removed by scraping, without WADC TR 54-120 Pt 2. 4

actually disturbing the metal surface itself. The scale thus collected was powdered and analyzed by x-ray diffraction. 2. Thickness measurements were made on the specimen at two points on the surface. One of these points was. later to be subject to etching action while the other was to be protected from etching by Scotch tape, and thus, served as a reference standard for later thickness measurements. These measurements were made on a Pratt and Whitney supermicrometer accurate to 0O0001 inch. The assumption was that the etching attack on the exposed underside of the specimen was essentially uniform, 3. An electron diffraction pattern was made of the specimen surface, using an RCA Type EMD-2 electron diffraction apparatus. 4, The specimen was electrolytically etched for 15 to 30 sec in a mixture of 10o perchloric and 90% glacial acetic acids at a temperature of 15~C and a current density of 6 amp/in.2 This etching treatment has the property of removing the metal without disturbing the intergranular compounds (2). 5. An electron diffraction pattern was made of the exposed compounds. 6. The exposed compounds were brushed off the surface using a rotary wire brush on a hand-power tool. The brush did not damage the surface} and in addition, was much less likely to cause contamination than was an abrasive compound. The Scotch tape covering the unetched portion of the specimen was then removed. 7. Thickness measurements were made of the etched and unetched portions of the specimen as described in Step 2. By appropriate subtractions, the amount of metal removed in the etching operation could then be determined. A fresh piece of Scotch tape was then applied to the unetched portion of the surface and Steps 4 through 7 were repeated as many times as necessary to reach the depth in the specimen where diffraction patterns from the intergranular compounds no longer appeared. The electron diffraction procedure outlined above made it possible to show any changes in the overall composition of the intergranular compounds resulting from oxidation as a function of their depth below the metal-oxide interface. For this part of the program, six heats were selected from the nine studied in the oxidation runs. In the case of the type 309 plus Nb and type 310, heats 64177 and 64270, specimens were studied following 100 hours of oxidation at 1600~, 1700~, 1800~, and 1900~F. For the heats X11306, X11338, and X27258, 2000~F specimens were studied in addition to the other four temperatures. In connection with the electron diffraction studies, it should be mentioned that this method also has its limitations, although it is capable of use with extremely small amounts of materials, and is especially useful for thin films. The smallest uncertainty in interplanar spacing which can be expected using the reflection, electron diffraction technique is about 24. Since this uncertainty is of the same order as the change in interplanar spacing between the diffraction patterns of Fe203 and Cr2O3, and between spinels having low and high lattice parameters the electron diffraction studies: can do little more in the present case than to indicate the presence or absence of the rhombohedral or cubic phases. In evaluating the diffraction patterns obtained, the relative proportions of WADC TR 54-120 Pt 2 5

spinel and rhombohedral phases shown in individual patterns were indicated by specifying whether the patterns of specific phases were strong (S), medium (M), weak (W), very weak (VW), or very, very weak (VVW) [see Table 5]. In addition, a qualitative attempt was made to show the diminution of diffracted intensity from intergranular oxides on individual specimens accompanying successive etches by referring intensities to those obtained in patterns taken prior to etching. It must be remembered, however, that comparison of relative intensities obtained in different exposures can be misleading, since many factors related to exposure and specimen surface preparation and alignment can influence the intensity obtained in a given pattern; and these factors vary among exposures. MATERIAL The material for this investigation (Table 1) was received in sheet and strip form and tested as described below: 1. Type 310 alloy, heats 64177, 64270, X11306, X11338, and X27258; and type 309 plus Nb,.-This material was oxidized in the unstressed condition in horizontal tube furnaces and used for electron diffraction studies. 2. Type 310 alloy, heats X27258, X46572, 31372, J10, Vt-5, Vt-7; Inconel; and Chromel alloys ARM (heats A and B), ASM, and D.-These alloys were oxidized in the unstressed condition in horizontal tube furnaces and under stress in the stress units, and the intergranular penetration determined. 3. Type 510 alloy, heats X46572, J10 Vt-5, and Vt-7; and Chromel alloys ARM (heat A), ASM, and D. —These alloys were tested in the progressive weight-gain equipment. RESULTS AND DISCUSSION For the purposes of discussion the results of this investigation are divided into three parts, namely: (1) weight-gain investigation, (2) effect of stress, and (3) unstressed studies. Weight-Gain Investigation Since an apparently low rate of intergranular penetration may result from a small difference in the rates of grain-boundary and volume oxidation, it was necessary to determine a measure of the volume oxidation. The progressive weight-gain equipment was assembled to give an answer to this problem. Table 2 indicates the progressive gain in weight per square inch of sample with increasing time, The experimental data were plotted as conventional weight-gain vs. time curves, and the data shown in Table 5 were taken from these curves. In general these curves follow the parabolic law of oxidation as is evidenced by the straight WADC TR 54-120 Pt 2 6

lines obtained in plots of the square of the specific weight gained vs. time shown in Figs. 31 through 37. Alloy ASM showed a considerable deviation from this relationship at 2000~F. The line drawn through the 2000~F points is admittedly only a rough estimation of the weight gained, but it is useful for weight-gain rate comparisons with other alloys. Most samples show some deviation from the parabolic oxidation in the early stages. This initial deviation is to be expected for a number of reasons, some of which have been listed by Gulbransen (3); they are: 1. the effect of the decrease in roughness or surface area as the re-: action proceeds, 2. the effect of the heat evolved in the reaction on the rate of reaction, 3. the effect of the solution of oxygen in the metal on the rate of reaction, 4. the effect of the concentration of impurities in the oxide during the early stages of the reaction, 5. the change in oxide composition, and 6. the influence of potential fields at the gas interface due to absorbed oxygen ions. In addition to these theoretical deviations there were also some experimental variables which influenced the initial stages of the process, such as speed of loading, and the fact that a finite time is necessary to bring the metal to temperature. Because of these and other related factors the parabolic rate constant (slope of AW vs. time curve) is probably a better indication of the volume oxidation than the other parameters. A slight inaccuracy is involved by ascribing all the weight gain to volume oxidation since the intergranular oxidation will also increase the weight of the sample, although this is thought to be a slight factor. Figure 38 is a rating of the alloys tested on the basis of the parabolic rate constant. A small value of this constant is indicative of a slow rate of oxidation. It is notable that the ASM alloy is significantly superior to the other alloys tested at all the temperatures used in this investigation. This difference is especially pronounced at 2000~F. Heat X46572, a commercial heat of type 310 stainless steel, showed the highest rate of oxidation at 18000 and 1900~F while its oxidation resistance is better than some of the other alloys at 20000F. Effect of Stress In this phase of the work it was desired to determine the effect of stress on intergranular oxidation. Since each material has its own characteristic attributes, the alloys will be considered individually. All the data obtained for the stressed studies are summarized in Table 4; the key to the symbols used is given in Table 35. Included in this table are the results of the visual observations and magnetic measurements made on the oxidized samples and on the oxides which were removed from these samples. As in the previous investigation no correlation between these data and oxidation characteristics could be found. Commercial Type 310 Alloys, Heats X27258 and X46572 Heat X27258 was the first material investigated under stressed conditions. WADC TR 54-120 Pt 2 7

Unstressed studies during the previous year showed that this heat had comparatively good intergranular oxidation resistance. and subsequent tests showed it to have exceptional high-temperature properties. The highest stresses used are approximately the 100-hour rupture strength listed in the ASTM publication concerning the hightemperature properties of stainless steels-(4). However, this heat showed little elongation even at the higher stresses and therefore does not adequately illustrate the effect of stress. The stress region, where elongation becomes appreciable and where the effect of stress on oxidation would be expected to increase. was only roughly determined when the available supply of material was exhausted. Figures 59 through 41 and Table 4 show the number of penetrations per inch vs. the depth curves, as well as all the other penetration-frequency vs. depth curves.encountered in this investigation, are of the general decay type described in the previous yearly report (1). Figure 42 illustrates the effect of stress on the number of intergranular penetrations, and Fig,. 43 shows the effect of stress on the mean depth of penetration. The mean depth curves show a decrease in the mean depth of the slightly stressed samples over the unstressed values. Although this decrease is slight, it is consistent in all samples.. At present no explanation for this observation has been found. It is to be emphasized that 0.0032 inch represents the smallest mean depth which can be determined with the present counting method., Therefore the relatively straight line in the 16000F mean depth graph as shown in Fig. 43 indicates that most of the penetrations counted were in the first grid and not necessarily of the same depth. In an effort to determine the reproducibility of the results, samples were run at 2460 and 2480 psi, respectively. As can be seen from Figs. 42 and 435, the reproducibility of the results is quite good. Heat X46572 showed approximately the same unstressed intergranular penetration behavior as heat X27258, but relatively poor high-temperature properties. The test temperatures of 1800~ and 1900~F were used, since the previous run indicated that the effect of stress would be more noticeable at these temperatures. Figures 44 and 45 indicate the penetration frequency at various depths and stress levels, and Figs. 46 through 49 show the variation in penetration number and mean depth. with stress as well as the elongation encountered at the various stress levels. The penetration-frequency curves show a general increase in penetration depth with increasing stress, especially in the case of the deeper penetrations. The 1500-psi graph is an exception in that the sample contained considerably more penetrations; and penetrations of a greater depth on one side of the specimen compared with the other side. This persisted:even after repeated polishing. When fissures of considerable depth are present there is a tendency to overlook some of the very small penetrations. This, in addition to the greater uncertainty in the small fissures. can account in part for the small number of shallow fissures counted in the 1500and 1650-psi samples. The mean depth graphs show a considerable increase in depth when the elongation becomes greater than approximately 15%. These depth graphs are probably more significant than the number graphs since the weighted average minimizes the effect of the small penetrations. Figures 7 and 8 are photomicrographs illustrating the effect of stress on intergranular penetration, A comparison of Figs. 7 and 8 shows that a stress of WADC TR 54-120 Pt 2 8

2480 psi increased the depth of the fissures. The points on the graphs showing the effect of stress on the mean depth and number of penetrations, with a vertical arrow extending through the point, indicate the lowest stress of those used, at which the sample contained fissures throughout the matrix. The 1900~F, 1750-psi sample showed some of these fissures throughout as shown in Fig. 9. In general, samples which exhibited this phenomenon were not counted because these fissures are the beginning of a stress rupture failure, and would therefore be misleading in a count of intergranular oxidation penetrations. However, it was noticed that the intergraular oxidation in specimens which showed these fissures throughout had occurred to a greater depth than was the case at stress levels where fissuring throughout did not occur. An interesting characteristic of the type 310 material, which exhibited these fissures throughout, is the appearance of an excess phase as shown in Figs. 10 and 11. Microhardness impressions shown in Fig. 10 indicate that the excess phase is much harder than the matrix. Although it has not been positively established, it is thought that this phase is a high nitrogen-chromium compound. A chemical analysis on a similar-phase found in creep-rupture specimens of 18-8 stainless steel by Smith (5) indicated that it was high nitrogen phase. Since this phase was only found in quantity in specimens which were fissured throughout, and therefore beyond the range of practical stresses, it was not deemed advisable to investigate the nature of this phase at the present time. Vacuum-Melted Type 310 Alloy; Heats Vt-5, Vt-7, and J10 This material contained a considerable quantity of inclusions as can be seen from Fig. 12. All three heats have the same grain size as typified by the above figure. All the vacuum-melted stock was tested in the unstressed condition and heats Vt-5 and Vt-7 were also tested in the stressed condition. It is to be emphasized that these heats differ markedly from the commercial type 310 material, with respect to the amounts of the minor elements present, as can be seen from Table 1. This alloy is essentially an iron, chromium, nickel alloy, and it is known that the minor elements such as carbon, silicon, and nitrogen have a pronounced effect on the properties of the commercial type 310 alloy. Figures 50 through 52 indicate the effect of temperature on the penetration frequency at various depths in the unstressed condition. Figures 53 through 58 show the effect of temperature on the number and mean depth of penetrations. It can be seen that the number of penetrations per inch and the mean depth of penetrations are extremely small. The number of fissures is relatively independent of temperature, and the mean depth increases only slightly with increasing temperature. This apparently good, intergranular penetration resistance may be the result of the relatively high-volume oxidation rates in the case of heats Vt-5 and Vt-7 as indicated in Fig. 38. The J10 alloy, however, has relatively good intergranular and volume oxidation resistance, Heats Vt.5 and Vt-7 have relatively poor properties under stress as revealed by the frequency vs. depth, and number and mean depth vs. stress graphs shown in Figs. 59 through 66. This is probably due in part to lower creep resistance caused by the extremely low-carbon contents of these alloys (Table 1). The effect of stress on the intergranular penetration is similar to that observed in heat X4)6572 of type 310 stainless alloy previously discussed, except that the increase in peneWADC TR 541-120 Pt 2 9

tration depth and number due to stress appears at a lower value. The sample of heat Vt.-5 which -was run at 1900~F and 750-psi stress was counted for intergranular penetration even though it showed a few fissures throughout the matrix. This sample showed a marked increase in the mean depth of intergranular oxidation. Figure 13 shows the edge of a sample which contained fissures throughout. Note the completely encircled grain, a phenomenon which was occasionally observed. The,photomicrograph also shows a considerable amount of thickening of the oxide at the boundary Figure 14 illustrates a similar case, as well as some islands of metal in the oxide phase.'presumed to be nickel-rich as found by other investigations (6). Chromel Alloys D, ASM^, and ARM (Heats A and B) All these alloys were first tested in the unstressed condition. Figure 67 through 70 illustrate the variation in penetration frequency and Figs. 71 and 72 show the effect of stress on the number and mean depth of penetrations;. Chromel alloys ARM (heats A and B), ASM, and D, showed a general increase in intergranular penetration resistance at 2000~F in the above order, D being the best, considering the mean depth to be the more significant measure. The number of fissures vs. temperature graphs show all alloys to have a comparatively large number of penetrations, the ASM material showing the largest number encountered in this investigation. Figure 15 shows a surface layer of small grains which could account for this large number of fissures, Although the other Chromel alloys showed a similar abnormality at the surface it is thought that the higher-volume oxidation in these alloys eliminated the affected surface region. The increased intergranular penetration resistance of the Chromel D and ASM alloys is apparently the result of a decrease in intergranular oxidation and not merely an increase in volume oxidation. This is shown by the volume-oxidation-rate constant (Fig. 58) which is low in the case of Chromel DJ and extremely low in the case of the ASM alloy. Chromel D, ARM (heat A), and ASM alloys were also tested in the stressed condition. Figures 73 through 81 show the effect of stress on the penetration frequency, and Figs. 82 through 99 show the effect of stress on the number of penetrations and mean depths In general the penetration-frequency curves show an increase in fissure frequency at the greater depths as the stress is increased. The ARM (heat A) material was tested at more frequent stress intervals than the other Chromel alloys and therefore more completely illustrates the effect of low stresses. The mean depth graphs (Figs. 853 85, and 87) show a decrease in depth in the slightly stressed samples over the unstressed values in every instance. This phenomenon was also noticed in type 310 alloy, heat X27258. As mentioned previously no explanation for this decrease has been found. When the elongation becomes appreciable the mean depth increases, and as the point at which fissures are observed throughout the matrix is approached, the depth increases greatly. This increase in depth is due in part to the appearance of some deep fissures which occur in the highly stressed samples, Figure 16 shows one of these fissures which occurred in the 1900~F, 500-psi Chromel ARM (heat A) material, and Fig. 17 shows the normal penetrations which occurred in the 1900~F 250-psi sample of the same material. The latter penetrations are typical of the unstressed material. Samples which exhibited these fissures throughout also contain an excess: phase, although not in the quantities or form encountered in the type 310 material. Figure 18 shows this phase in the Chromel material. It can be seen by comparing Fig. 18 with Figs. 10 and 11 of type 310 alloy that the phase WADC TR 54-120 Pt 2 10

is more agglomerated and widely dispersed in the Chromel material than in the type 310 alloys. Unstressed Studies In addition to the runs used for electron diffraction, weight gain, and stress studies previously discussed, unstressed runs were made to obtain unstressed data on type 310 alloy (heat J10) and Inconel, and to test the effect of increased humidity, extended time, and preferred orientation on intergranular penetration. The J10 material was discussed in connection with the other vacuum-melted alloys in the stressed section of the results. Inconel.-Enconel was subjected to unstressed oxidation for times of 10, 30, and 100 hours at temperatures of 1600~ through 2000~F at 100~ increments, using dried air having a velocity of 30 ft/sec. The number of penetrationsincreases at the higher emper as can be seen from pe temperatures as can be seen from penetraton-frequency vsperature graphs shown in Figs. 100 through 102. These penetrations are shallow, however, as shown by Figs. 105 and 104. Increasing the oxidation times from 10 to 100 hours has little effect on the mean depth. This small dependency of depth on oxidation time from 10 to 100 hours was also found in studies on type 510 alloys in work done during the previous year (1)* Effect of Time.-Since little variation in intergranular penetration was encountered with variation in oxidation time from 10 to 100 hours, a 500-hour test was performed on type 310 alloy (heat X27258), (heat X2728) Chromel ARM material (heat A), and Inconel to determine the effect of a fivefold increase in time over the longest previous run. The temperature used was 1900~F and the air velocity was 0 ft/min. Figure 105 shows the frequency vs. depth curves for the 500-hour run.. Since some of the number of small penetrations were off the scale in Fig. 105, the number of penetrations at various depths, the mean depth, and the total number of penetrations in the above materials for the 100- and 500-hour runs are given in Table 5. As can be seen from this table the 500-hour treatment on the type 310 alloy, heat X27258, resulted in a much greater number of penetrations and a greater mean depth than a 100-hour exposure. Figures 19 and 20 show the microstructure of the intergranular penetration in the 100- and 500-hour test for the type 310 material. In general the 500-hour treatment resulted in a much thicker scale layer and in wider penetrations than those observed for the 100-hour test. This increased thickness of the fissures is probably due to lateral volume oxidation from existing intergranular penetrations. The 500-hour treatment also forms a deeper and more continuous penetration. The greater number of fissures in the 500-hour-test is due in part to the fact that in the 100-hour run some very small entries may be considered surface imperfections and therefore not counted. However, after a 500-hour exposure these slight penetrations were deep enough to remove any doubt that they are real. Table 5 also shows a fewer number of very small penetrations in the 500-hour run. This is probably a result of initial entries progressing to the medium depths. The Chromel alloy acts similarly to the type 510 alloy just described. The Inconel alloy acts differently as can be seen from Fig. 105 and Table 5. The mean depth of the penetrations is not altered appreciably by increasing the time of exposure to 500 hours, although the number has increased. WADC TR 54-120 Pt 2 11

Effect of Humidityo.-The great majority of the unstressed oxidation runs made during this investigation were done'in air with the dewpoint close to minus 60~Fo To check the effect of a higher humidity on intergranular oxidation, type 310 alloyy heats X46572 and J10, and Chromel alloy ASM were tested in air having a dewpoint of plus 60~Fo The temperatures used during the 100-hour test were 17000, 1800~, 19000, and 20000F,and the air velocity was the standard 50 ft/min. Figures 106 through 110 show penetration frequency vs. depth graphs and the mean depth and number vs. temperature graphs. By comparing these curves with those obtained in the dry air test shown in Figs. 50, 53, and 54, and Table 6, it can be seen that the general effect of a high dewpoint is to increase the number and depths of penetrations. This increase in number is considerable, being of the order of 25%, while the increase in mean depth is very small in the Chromel ASM and J10 alloy, and of the order of 15% in the type 310 alloy, heat X46572. Texture Studies —From theoretical considerations it seems likely that if it were possible to introduce a very strong preferred orientation into the stainless steel, a profound decrease in intergranular oxidation should result. The line of reasoning behind this argument is as follows: intergranular oxidation is apparently a manifestation of preferential diffusion of 0 ions along grain boundaries. From recent studies of grain-boundary diffusion, it is known that the ratio of the grainboundary diffusion coefficient to the volume diffusion coefficient is strongly dependent on the relative orientation of the grains on either side of the boundary in question, this ratio decreasing to approximately unity for small angular misalignments between grains. The criterion of a strong preferred orientation is the existence of just such small angular misalignments among a majority of the grains of the metal. If, therefore, a thermally stable, strong preferred orientation could be introduced, intergranular oxidation should be significantly decreased in amount. The requirement of thermal stability of the preferred orientation rules out the consideration of rolling textures, leaving only the possibility of recrystallization textures. Of the possible recrystallization textures which can occur, the wellknown "cube" texture, which is formed in face-centered-cubic metals under suitable conditions, is outstanding for its high degree of orientation. The cube, or (100) [100], texture, in those metals in which it can be caused to form, results from a high-temperature anneal following an extremely heavy cold-working operation. It is also known that in some cases the presence of small amounts of impurities, such as As in Cu, will prevent the formation of a cube textureo An attempt was made to produce an annealing texture in. the type 310 alloy, heat 31372, as described in the procedure section- Forward-reflection Debye x-ray patterns were made of the material in the as-rolled and the rolled and annealed conditions. These patterns appear in Figs. 21 and 22. A strong rolling texture was developed, but this texture failed to transform to a strong recrystallization texture on annealing. Recrystallization did take place during the anneal, however, as is evidenced by the discrete spots; some degree of preferred orientation resulted. Runs were made at temperatures of 16000, 17000, 1800~, 1900~, and 2000~F for 100 hours, in which each furnace was at a different temperature and contained a 97% cold-worked and annealed reference specimen and a 10% reduced and annealed reference specimen. Following the run, the specimens were quenched, mounted, polished, and examined in the usual mannero The penetration vso depth curves resulting from this examination are presented in Figs. 111 and 112, and the penetration-frequency WADC TR 54-120 Pt 2 12

and depth-parameter curves appear in Figs. 113 and 114. As the latter pair of figures shows, there was not a great deal of difference in penetration characteristics resulting from the two treatments. It does appear that at the higher-temperatures the 97% cold-worked and annealed material was superior. It was noted that the 97% cold-worked and annealed material possessed an extremely adherent, reddish-brown oxide, which appeared to be considerably thicker than the oxides usually encountered, while the oxide produced on the reference specimens was black and very loosely adherent. This difference may have resulted in part from the difference in cooling rate encountered due to the variation in size of the two materials. Figures 23 and 24 show the microstructures after the oxidation treatment in the 97% cold-worked and annealed material and in the 10o reduced and annealed material. The intergranular penetrations in the 10% reduced material are different from any observed in the other type 310 alloys, being considerably thicker throughout. The structure observed in the texture specimen is more typical of the other type 310 alloys. A more extensive program to attempt to produce a more pronounced texture was not undertaken because the other phases of this investigation utilized all the available time on the project. Electron Diffraction One of the objectives of this investigation was an attempt to determine the nature of the intergranular material extending into the metal from the scale layer. It was desired to find the composition of this material and whether there were any significant differences between its composition and that of the external scale material. Just how this was to be done experimentally was a problem, since the intergranular material was well dispersed and extremely thin. The method ultimately adopted was described in the procedure section of this report and utilized reflection electron diffraction following successive etching treatments. Using this technique, it was possible to obtain data on the composition of the intergranular material as a function of depth below the metal-oxide interface. The results obtained by this method are presented in Table 6. Six heats of material were selected for examination: type 309 plus Nb; and type 510, heats 64177, 64270, X11306, X11338, and X27258. Specimens from the latter three heats were examined at all temperatures of oxidation, while the first three heats were examined only at the four lower temperatures. The program was restricted to an oxidation time of 100 hours. As was noted previously, the accuracy obtainable with the reflection electron diffraction technique is of the order of 1 or 2% error in interplanar spacing, the same order as the changes in lattice parameters between CrOs3 and Fe2O3 and between spinels having the highest and lowest possible lattice parameters. Therefore, the phases shown to be present in the electron diffraction patterns could be identified only as "rhombohedralj' or "spinel". Examples of these two patterns are presented in Figs. 25 and 26. Identification was made on the basis of the (220) spinel, line and several rhombohedral lines, notably the (100), (110), (120), and (200) lines. The appearance of the (100) line in the electron diffraction patterns, could be due either to oriented oxide growth or to the fact that the low-angle structure factor for elecWADC TR 54-120 Pt 2 153

trons is greater than for x-rays. The latter reason is the more likely, considering the probable randomness of the surface-metal grain orientations, The electron diffraction results showed that the same phases exist in the grainboundary fissures as were found in the external scales. In. heats 64177 and 64270 the spinel phase was rarely observed. In the other four heats both phases appeared, the spinel phase being especially prominent in the type 309 plus Nb alloy with its high Mn content (see Table 1)o The relative proportions of the phases in a given specimen seemed to vary slightly with depth but the two patterns taken on each -specimen at the same depth often showed similar variations. As nearly as can be determined, the intergranular material is identical to the material found in the external-scale and is in general simply an inward extension of the external scale. In order to be absolutely certain that the electron diffraction patterns obtained were not from reaction products between the metal and the etchant, a specimen was etched and allowed to dry without rinsing. The resulting electron diffraction pattern could be easily differentiated from those associated with the two oxide phases obtained by the routine process. Figures 27 through 30 show the metallographic appearance of the specimen surfaces following successive etching treatments, The photomicrographs were taken using oblique-light in order to show the oxides in relief more clearly. These photomicrographs show that electrolytic etching with 10% perchloric acid and 90% glacial acetic acid left the intergranular oxide films intact and exposed. Figures 27 through 30 also illustrate something which was observed at the time etching was carried out, namely- that the first etching usually attacked the metal only at certain points where the path through the surface scale to the metal was relatively open. Further etching undercut the scale layer adjacent to these points, and in the subsequent brushing process new metal surface was exposed. Ultimately, the scale layer could be completely removed by this process, but at the same time much of the deeper intergranular material in the areas which etched initially was probably lost. Furthermore, patterns taken while appreciable amounts of scale remained on the surface probably are not representative of intergranular material at all, since the scale would serve to block the intergranular material from t;he electron beam. In some specimens no difficulty was encountered with adhering scales and even the first patterns obtained are representative of intergranular material. It will be noted from Table 6, when compared with appropriate penetration vs. depth curves, that the measured depths below which no oxide patterns were obtained were sometimes very much less than the maximum fissure depths observed metallographically. In a few cases apparent increases in thickness of the metal were observed on etching. There are two alternative conclusions that can be drawn from these facts: either the thickness measurements as made on the supermicrometer were not as reliablas s they were believed to be, or the number of intergranular oxide areas in relief at the deeper levels was not sufficient to give an electron diffraction pattern. Considering the apparent thickness increases on some specimens and the sensitivity of the electron diffraction technique, the probability is that the measurements were not representative. Since the surfaces often became.rather rough as a result of the etching treatments it was difficult to devise a suitable means of making thickness measurements which would be accurate to o.0001 inch and at the same time would be representative of the surface as a wholeo WADC TR 54-120 Pt 2 14

X-ray Analysis The composition of high-alloy steels as determined by x-ray analysis has been extensively studied by a research group at Purdue University (7, 8, 9, 10). After oxidizing types 509 and 510 stainless steels for'100 hours at 1600~ through 22000F, this group found oxides consisting of Cr203 rhombohedral solid solutions of Cr203 and Fe203 having complete solid solubility, and a spinel of lattice parameter 8.310 to 8.330 KX in type 309 steel and 8.523 to 8.429 KX in the type 310 steel. The lowparameter spinel was identified as Fe-Cr oxide, and the high-parameter spinel as an Mh-Cr oxide. The individual alloys always contained a spinel except the type 309 alloy at 2200~F. The majority of the scales contained one solid solution, and a few contained two solid solutions of differing composition. Most of the scales contained either CraOs or a solid solution high CrCr03s. In alloys having a high nickel content, nickel compounds were also present in the scale. The x-ray results obtained in the present investigation are given as part of Table 4 with a key to the symbols being given in Table 3. There did not seem to be any trends in the oxide compositions with respect to time or temperature. All the oxide contained Cr203 or a Cr203-rich solid solution, and all the oxides analyzed were of a protective nature considering Randall and Robb's criteria of the presence of CrOs3, or high-parameter spinels. It is interesting to note that nickel compounds were found in the the high-nickel alloys. This is consistent with the results of the Purdue group mentioned above. It is to be emphasized here that the interplaner spacings of NiCr204 and NiFe204, as well as FeCr2O4 and NiMn204, are very close, differing only in the third decimal. SUMMARY AND CONCLUSIONS 1. The weight gained at various time intervals during oxidation was determined for Chromel alloys ASM, ARM, and DI and type 510 stainless steels^ in the temperature range of 1600~ through 2000~F. The parabolic rate constant was determined for each specimen investigated. 2. Chromel'alloys ASM, ARM, and' D type 310 stainless steels, and Inconel were subjected to oxidation in the unstressed condition in moving dry air, having a dewpoint less than minus 40F, at temperatures of 1600~ 17000 1800~ 1900, and 2000~F. The duration of the tests was 100 hours for the majority of the tests although oxidation times of 10, 30, and 500 hours were used. The oxidized samples were mounted, polished metallographically, and measured for intergranular penetration, recording the numbers of fissures and their depths. These data are presented as follows: (1) penetration frequency vs. depth, (2) penetration number [N] vs. temperature, and (3) the mean depth of penetration vs. temperature. In general, the intergranular oxidation increased with time and temperature. Increasing the testing time from 100 to 500 hours caused a marked increase in intergranular penetration in some alloys. 5. Chromel alloy ASM and type 310 stainless steels were oxidized for 100 hours at temperatures of 1700~, 1800%0 1900~, and 2000~F using'. moving air with a dewpoint of plus 60~F. It was found that the increased humidity of the ambient air had in general a small effect on the intergranular penetrations although it did increase WADC TR 54-120 Pt 2 15

the number of penetrations somewhat and also the mean depth to a slight extent 4. One heat of type 310 stainless steel, having some degree of preferred orientation, was studied for intergranular penetration characteristics. A slight improvement in resistance to intergranular oxidation was noted in the texture material. 5. Chromel alloys ASM, ARM, and D, and type 310 stainless steels were oxidized at various stress levels for 100-hour periods, using a temperature range of 1600~ through 2000~F. Intergranular penetration measurements were made and the data presented as follows: (1) penetration frequency vs. depth, (2) penetration number [N] vs. stress, and (3) the mean depth [X] vs. stress. There appears to be a minimum stress level for each material, above which a noticeable increase in intergranular oxidation is observed. 6. Visual examination and magnetic tests were performed on the oxidized specimens and the oxide itself. No correlation between these observations and oxidation characteristics could be found. 7. X-ray diffraction studies were performed on a few of the oxides resulting from the oxidation procedures. All the oxides. tested were of the adherent type using Randall and Robb's criteria of the presence of Cr203 or high-parameter spinel. 8. Electron diffraction examination of the subsurface structure was performed on type 310 stainless steels oxidized in the unstressed condition. -It was found that the oxidation products in the subsurface region were substantially the same as the surface oxides as determined by x-ray diffraction techniques. BIBLIOGRAPHY 1. Siebert, C. A., Sinnott, M. J., and Keith, R. E., An Investigation of Inter — granular Oxidation in Stainless Steels, WADC TR 54-120, January 1954. 2. Brockway, L. 0. and Bigelow, W. C., Development of Procedure for the Identification of Minor Phases in Heat-Resistant Alloys by Electron Diffraction, Annual Summary-Report on Project 2020, Eng. Res. Inst., Univ. of Mich., to Flight Research Laboratory (WCRRL), WADC, 15 January 1955. 5. Gulbransen, E. A. and Andrew, K. F.^ J. of Electrochemic Soc., 98, 241 (1951). 4. Simmons, W. F. and Cross, H. C., Report on the High-Temperature Properties of Stainless Steels, ASTM Spec. Tech. Pub. No. 124 (1952). 5. Smith, G. V., Dulis, E. J., and Houston, G. E., Trans. Amer. Soc. Metals, 42, 955 (1950). 6. Preece A., Richardson, G. T., and Cobb, J. W., Second Report of the Alloy Steels Research Committee, Iron and Steel Inst. Spec. Rept. No. 24, 9 (1939). 7. Yearian, H. J. and Radavich, J. F., Dept. of Physics, Purdue University, Unpublished Data. WADC TR 54-L20 Pt 2 16

BIBLIOGRAPHY (continued) 8. Boren, H. E., Jr., M.S:..Thesis, Dept. of Physics, Purdue University, August, 1950. 9. Warr, R. E., M.S. Thesis, Dept. of Physics, Purdue University, August, 1951. 10. Radavich, J. F., Ph.D. Thesis, Dept. of Physics, Purdue University, May, 1953. WADC TR 54-120 Pt 2 17

TABLE 1 CHEMICAL ANALYSIS OF MATERIALS, WEIGHT PERCENT o Alloy and Fe N2 Mn S i Cr Co Cu Ta P Ni C S Mo W Nb Heat No. Type 310, Bal. 0.1 0.42 0.55 24.03 0.01 0.15 0.01 0.018 16.93 0.13 0.008 0,053 <0.01 64177 Type 310. Bal. 0.06 0.50 0.43 22.30 0.01 0.10 -. 0.025 19.14 0.12 0.008 0.042 <0.01 64270 Type 309 Bal. 2.31 0.46 22.64 - -- 0.012 15.539 0.080 0.008 -- 0.82 plus Nb Type 510, Bal.. 1.53 0.83 24.48 - 0.25 0.029 20.08 0.085 0.029 0.14 x11338 Type 310, Bal. -- 1.58 0.75 24.80 -- 0.30 0.025 20.81 0.070 0.008 0.15 co X27258 Type 510, Bal, 0.18 0o. 25.25 0.,024 0001 0.08 - 01.63 0.08 o 0.04<0.017 J10* 0.01 Type 310, 55.20 -- 0.10 0.054 24.65 0.058 0.003 <0.085 - 20.39 0.014 0.019 <0.0015 0.042 <0.017 Vt -5* Type 310, 55.00 - 0.07 0.003 24.56 - <0.00004 <0.002 - 20.30 0.008 0.008 <0.001 0.025 <0.006 Vt-7* Inconel 8.25 -. 0.19 15.72 - - -.- 75.18 0.05 Chromel, 0.37 -- 0.30 1.43 19.81 --' - 77.65 0.05 ASM Chromel 0.39 -- 1.60 1.00 19.86 -- -- 77.01 0.04 ARM, heat A Chromel 0.42 -- 1.5 1.06 19.83 -8. - 77.36 0.1 ARM, heat B Chromel D 39.76 -- 0.67 1.61 21.69 - - 5592 0.09 -- *Vacuum-melted heat.

TABLE 2 SPECIFIC WEIGHT GAINED IN MILLIGRAMS PER SQUARE INCH Oxidizing Alloy and Heat No. Temperature, Time, Minutes OF 1000 2000 3000 4000 5000 6000 Type 510, X46572 1800 2.60 4.10 4.90 5.70 6.50 7.50 1900 2.90 7.30 8.90.10.10 11oo0 11.80 2000 8.oo.10.50 11.80 12.20 14.20 15.10 Type 510, Vt-5 1800 1.80 2.80 3.50 4.20 4.70 5.30 1900 3.80 5.50 6.80 7.70 8.70 9.60 2000 8.10 9.70 14.40 16.40 18.20.19.40 Type 310, Vt-7 1800 1.00 1.70 2.50 5.20 3.80 4.60 1900 4.10 6.10 7.40 8.60 9.60 10.70 2000 - -- - Type 510, Ht J10 1600 0.60 0.90 1.00 1.20 1.50 1.40 1700 0.70 1.00 1.20 1.40 1.50 1.70 1800 1.50 2.20 2.60 5.10 5.50 5390 1900 2.50 3.90 5.10 6.30 7.20 8.20 2000 5.50 7.90 9.60 11.00 12.20 15.00 Chromel ARM, heat A 1800 1.10 1.80 2.50 5.10 3.60 4.10 1900 3.60 5.10 6.50 7.20 8.10 8.70 2000 520 7.70 9.80 12.00 14.00 15.50 Chromel D 800 35.20 4.00 4.40 4.80 5.20 5.40 1900 4.00 4.60 5.10 5.60 6.20 6.80 2000 6.00 8.20 10.40 12.20 13.60 15.00 Chromel ASM 1800 1.00 1.40 1.50 1.70 1.80 2.00 1900 1.80 1.40 2.80 5.10 5.40 3570 2000 3.30 4.80 5.80 6.50 7.00 7.20 WADC TR 54-120 Pt 2 19

TABLE 5 EXPLANATION OF SYMBOLS USED IN OXIDATION DATA TABULATIONS SPECIMEN Appearance PGB - Powdery gray black PGB w/OS - Powdery gray black with orange substrate SGB - Shiny gray black B and S - Black and scoriated BP w/LG - Black pits with light gray-surface (mostly pits) LG - Light gray surface LG w/BP - Light gray with black pits (mostly light gray) LG w/IC -Light gray with interference colors Gr - Green Br - Brown Magnetism ND - Not detectable W - Weak M - Medium S - Strong No. of Fissures FT - Fissures throughout OXIDE SCALE Amount N - None S - Small M - Medium L - Large Color G - Gray B - Black GB - Gray-black Gr - Green Flake Size P - Powder SF - Small (<1/32 in.) MF - Medium (1/52 - 1/8 in.) LF - Large (>1/8 in.) Compbsition (X-ray) "SS XQ - Cr203 - Fe203 solid solution with Q t 10 atomic percent Cra03 HPS - High-parameter spinel Insuf.- Insufficient oxide for x-ray pattern W - Weak pattern M - Medium pattern S - Strong pattern WADC TR 54-120 Pt 2 20

TABLE 4 RESULTS OF OXIDATION TESTS SPECIMEN OXIDE SCALE Run Devpoint, Duration, Temperature, Stress, Elongation So. of Mean Depth Flake Composition No. F hr'F psi Appearance Magnetism in 2 in. Fissures/in in. x 103 Amount m Color ze Magnetism (X-ry) Type 310 Alloy, Heat 46572 17 <-40 100 1800 0 BP w/LG W - 90 0.493 M B P M LG w/BP PGB 14S - 100 1800 1500 LG w/IC W 0.8 907 0.393 L GB P S 14S - 100 1800 2000 PGB W 2.4 1132 0.519 S GB P W PGB 15S - 100 1800 2250 LG w/IC W 4.7 1128 0.4907 M GB P M 12S - 100 1800 2480 PGB M 13.5 1730 0.774 M GB P S 13S - 100 1800 3038 PGB S j26.6 Ruptured M GB P S LG 17 <-40 100 1900 0 LG w/BP M - 943 0.455 M B P S B and S LG 17S - 100 1900 1000 PGB M 1.6 1171 0.675 M GB P M 16S - 100 1900 1250 PGB M 2.0 1480 0.557 M GB P M 16S - 100 1900 1500 PGB M 3.2 812 0.667 M GB P S 23S - 100 1900 1650 PGB M 6.0 681 0.789 L GB P S 17S - 100 1900 1750 PGB M 22.7 1261* 1.429* L GB SF S 15S - 100 1900 2000 PGB ND 39.1 FT FT L GB P S ype 310 Alloy, Heat Vt-5 38 <-50 100 1600 0 PGB S - 358 0.340 N - - 38 <-50 100 1700 0 LG w/BP S - 422 0.354 S GB P M PGB 38 <-50 100 1800 0 PGB LG w/BP M - 452 0.373 M GB P S SS X75 (S) 18S - 100 1800 750 PGB M 1.6 386 0.502 S GB P M 19S - 100 1800 1000 PGB S 3.9 388 0.624 S GB P W 20S - 100 1800 1150 PGB S 4.5 397 0.672 S GB P M 39 <-50 100 1900 0 PGB M - 309 0.372 M GB MF M SS X75 (S) LG HPS (W) LG w/IC 28S - 100 1900 650 PGB - 4.0 753 0.476 L GB P S 18S - 100 1900 750 PGB M 4.7 544* 0.820e S GB P M 19S - 100 1900 1000 B and S S 16.4 FT FT L GB MF S 17S - 100 1900 1250 PGB S =532.8 Ruptured L GB MF S 39 <-50 100 2000 0 PGB M - 396 0.370 M GB MF M LG w/IC LG ype 310 Alloy, Heat Vt-7 <-50 100 1600 0 PGB S - 379 0.328 N - - 38 <-50 100 1700 0 PGB S 448 0.347 S GB P W 38 <-50 100 1800 0 LG w/BP M - 458 0.367 M GB P M SS X75(M) LG w/IC Cr203 (M) LG 18S - 100 1800 750 PGB M 1.9 386 0.522 M GB P S 20S - 100 1800 1000 PGB ND 3.5 435 0.679 S GB P M 23S - 100 1800 1150 PGB W 32.0 FT FT M GB P S 21S - 100 1800 1250 PGB W 32.0 FT FT S GB P S 39 <-50 100 1900 0 PGB M - *392 0.368 M GB LF M SS X75 (S) LG LG w/IC 28S - 100 1900 500 PGB - 1.5 792* 0.520* M GB P M LG 19S - 100 1900 750 PGB PGB w/OS W 6.3 FT FT M GB P W 20S - 100 1900 901 B and S ND 15.5 FT FT L GB P S PGB PGB w/OS 39 <-50 100 2000 0 PGB M - 404 0.373 M GB MF M LG LG w/IC Type 310 Alloy, Heat J10 33 <-50 100 1600 0 PGB M - 249 0.320 S GB P S SS X75 (S) Fe203 (W) NiFe204 (W) 33 <-50 100 1700 0 B and S W - 246 0.322 S GB P S SS X75 (S) Fe203 (W) 33 <-50 100 1800 0 B and S W 492 0.328 S GB P M F 33 <-50 100 1900 0 B and S LG w/IC M - 250 0.322 M GB P S SS X75 (S) NiCrO04 (W) 33 <-50 100 2000 0 PGB S - 425 0.382 M GB MF S SS X75 (S) Fe203 (M) NiFe204 (W) Chromel ARM Alloy, Heat B <-40 100 1600 0 Br ND - 328 0.338 N - - EPS (S) LG SS X75 (M) PGB v/06 34 <-40 100 1700 o Br W 929 0.344 N - - 34 <-60 100 1800 0 LG ND 920 0.392 M G MF W SS X75 (s) LG w/BP HPS (S) BP w/LG 34 <-40 100 1900 0 PB S 782 0.377 SS X75 (M) LG w/IC HPS (M) LG w/BP 34 <-60 100 2000 o Br W - 1342 0.581 S GB P W SS X75 (M) NIFe204 (S) *Some small fissures throughout. WADC TR 54-120 Pt 2 21

TABLE 4 (continued) SPECIMEN OXIDE SCALE Run Dewpoint, Duration, Temperature, Stress, Elongation No of Mean Depth Composition ~No.'F hr'F ~ psi Appearance Magnetism in2 in. Fissures/in. in. x Amout Color Size Magnetism (X-ray) Type 310 Alloy, Heat X27258 16 <-40 100 1600 0 BP w/LG - 1457 0.551 M B P W Cr205 (S) LG w/IC HPS (W) lOS - 100 1600 1850 PGB ND ND 1578 0.323 S GB MF ND 10S - 100 1600 5040 PGB W ND 1567 0.521 S GB MF W 16 <-40 100 1700 0 LG w/BP W - 808 0.399 L B MF ND Cr203 (S) PGB EPS (W) 6B - 100 1700 500 PGB W ND 1448 0.325 S GB P W 6S - 100 1700 960 PGB W ND 1346 0.325 S GB P W SS X75 (S) BP w/LG EPS (W) LG w/IC 7S - 100 1700 1425 PGB W ND 1105 0.322 S GB SF W PGB w/OC 8S - 100 1700 1880 -LG w/BP M ND 1073 0.322 M GB MF W HPS (M) PGB SS X75 (S) 16 <-40 100 1800 0 Lg w/IC - - 1409 0.526 L B MF ND SS x75 (S) BPS (S) 7S - 100 1800 520 PGB W ND 981 0.408 L GB P S BPS (M) Fe205 (M) 7S - 100 1800 940 PGB W ND 1158 0.392 M GB P M BPS (M) 8S - 100 1800 1440 PGB W ND 970 0.345 L GB P S SS X75 (S) BPS (M) 10S - 100 1800 2460 PGB W 2.0 1089 0.457 S GB P W 12S - 100 1800 2460 PGB W 2.5 1074 0.419 M GB P S LG 16 <-40 100 1900 0 LG w/BP W - 1015 0.615 M GB P ND SS X75 (S) B and S HPS (W) LG v/IC 36 <-60 500 1900 0 B and S M - 2047 0.948 L GB P S PGB w/OS 16 <-40 100 2000 0 LG w/BP W - - - M GB P ND LG w/IC Type 510 Alloy, Heat 31372, Annealed 33 <-60 100 1600 - PGB - - 1263.4 0.550 M GB P M SS X75 (S) HPS (M) 33 <-60 100 1700 - PGB - - 1715 0.351 S GB P M SS X75 (S) FeO20 (W) HPS (S) 33 <-40 100 1800 - PGB - - 1510 0.421 S GB P S 55 <-60 100 1900 - PGB - - 1256 0.888 L GB P S ss X50 (S) FeCr204 (W) HPS (s) 33 <-40 100 2000 - PGB, LG - - 1698 0.842 S GB P M Type 310 Alloy, Heat 31372, 97% Reduced, Annealed 33 <-60 100 1600 PGB ND - 1758 0.320 N - - - Insuf. 33 <-60 100 1700 - PGB M - 2003 0.3266 N - - - Insuf. 33 <-40 100 1800 - LG M - 1658 0.540 N - - - Insuf. 33 <-60 100 1900 - PGB W - 1680 0.492 N - - - Insuf. 33 <-40 100 2000 - PGB W - 1488 0.651 N - - - SS X50 (S), FeCr204(M) Chromel Alloy ARM, Heat A 54 <-60 i00 1600 0 BP w/LG W - 263 0.348 N - - - ss X75 (S) LG w/BP HPS (M) 34 <-60 100 1700 0 Br ND - 1362 0.335 N - - - X75 (M) BP W/LG HPS (M) 34 <-60 100 1800 0 Br W - 1238 0.464 N - - - BPS (S), Cr203(M) 1S - 100 1800 240 PGB W ND 1292 0.357 N - - - - IS - 100 1800 500 PGB W ND 1222 0.384 N - - iS - 100 1800 940 PGB W 0.5 1409 0.379 N - - 2S - 100 1800 1500 PGB W 4.0 1402 0.448 S GB P WPGB w/6O 2S - 100 1800 2000 PGB ND 34.0 FT FT N - - 34 <-60 100 1900 0 Br - 1510 o.524 N - - SS X75 (W) HPS (S) 3S - 100 1900 240 PGB ND ND 1744 O.430 S GB P W PGB w/OS 35S - 100 1900 535 PGB W 2.0 1732 0.431 N - 13s - 100 1900 880 PGB W 8.4 - - S GB P ND Br 3S - 100 1900 990 PGB w 19.0 1897 O. 604 N - 9S - 100 1900 1264 PGB w/O6 ND 39.0 FT FT S GB P W PGB 8S - 100 1900 1500 PGB ND 50.0 FT FT S GB P M HPS (MnCr2O4) (M) 36 <-60 500 1900 0 PGB W - 2440 1.078 L GB P W Fe30 (S) B and S Cr203 (M), Ni0 (M) 34 <-60 100 2000 0 Br W 1417 0.495 S GB P ND Cr2O0 (M) PS?M) NiFe20O4 ot FeCr2Ol, (M) 4S - 100 2000 235 Br W 1.0 1478 0.429 M GB P W Cr20 (M) HP2?S) (MnCr2O4) 4s - 100 2000 535 PGB W 4.1 1639 0.552 S GB P W SS X75 (M) PGB /06S HPS (S) 6S - 100 2000 655 PGB ND 8.5 1731 O. 694 L Gr P ND HPS (S) PGB w/oS (MnCr2O4) Gr 15S - 100 2000 690 PGB ND 8.6 2080 0.669 S GB P ND Br 5S - 100 2000 745 PGB ND 15.0 FT FT M GB P ND - PGB w/06 5S - 100 2000 985 PGB ND 55.0 FT FT S GB P ND HPS (S) Gr (MnCr204) WADC TR 54-120 Pt 2 22

TABLE 4 (c o n c luded) SPECIMEN OXIDE SCALE Run Dewpoint, Duration, Temperature, Stress, Elongatio No. ofT Mean Depth Flake Compositi No.'F hr F psi Appearance Magnetism inin. Fissures/ in. mount olor Manetm Chromel D Alloy 34 <-40 100 1600 0 PGB w/OS W - 274 0.32 N - - - BP w/LG 34 <-40 100 1700 0 LG w/BP M - 603 0.32 N - - - SS X75 BP w/LG HPS 34 <-60 100 1800 0 LG w/BP M - 914 0.396 M GB P W SS X75 (M) LG HPS (M) 22S - 100 1800 501 LG W 3.5 2315 0.395 L GB P M PGB 23S - 100 1800 750 LG w/BP W 11.0 1021 0.342 L GB P M LG 24S - 100 1800 850 LG w/BP W 13.0 916 0.426 L GB P W LG 25S - 100 1800 925 PGB ND 26.0 1726 0.520 M GB P W LG Br 21S - 100 1800 1000 PGB ND 40.0 FT FT S GB P M 34 <-40 100 1900 0 Br W - 1275 0.397 N - - - SS X75 (M) HPS (M) FeCr204 (M) 22S - 100 1900 500 PGB W 4.0 3127 0.689 S GB P W 24S - 100 1900 650 PGB W 9.0 3557 0.472 S GB P W 25S - 100 1900 700 PGB W 14.0 2114 0.568 M GB P W LG Br 21S - 100 1900 750 PGB S 32.0 FT FT S GB P M 9S - 100 1900 975 PGB S 40.0 FT FT S GB P ND 34 <-60 100 2000 0 LG w/PB S - 544 0.351 M GB P W Cr203 (S) LG w/IC HPS (S) 22S - 100 2000 500 PGB S 4.0 3652 0.560 M GB P M Br 25S - 100 2000 650 PGB ND 13.5 FT FT M GB P W Br 9S - 100 2000 730 PGB ND 13.5 FT FT S GB P S PGB w/OS 11S - 100 2000 982 PGB - 36.0 FT FT N - - - Br Inconel Alloy 29A <-45 10 1600 - SGB M - 250 0.335 N - - PGB 29A <-45 10 1700 - SGB S - 399 0.344 N - - 29A <-45 10 1800 - SGB S - 445 0.409 S B P ND 30A <-40 10 1900 - PGB w/OS S - 408 0.393 S B P ND 30A <-40 10 2000 - PGB w/OS S - 493 0.446 S B P S 29B <-45 30 1600 - SGB M - 269 0.324 S B P ND PGB LG 29B <-45 30 1700 - PGB M - 868 0.321 N - - SGB 29B <-45 30 1800 - PGB S - 991 0.320 N - - 30B <-40 30 1900 - PGB w/S S - 840 0.324 S B P S SS X75 (S) SGB NiFe504 (S) 30B <-40 30 2000 - SGB S - 887 0.325 S B P S SS X75 (S) NiFe204? (S) 29C <-45 100 1600 - LG w/BP M - 256 0.323 S B P ND SGB 29C <-45 100 1700 - PGB M - 557 0.323 N - - 29C <-45 100 1800 - PGB M - 427 0.326 S B P W 30C <-40 100 1900 - PGB w/OS S - 1150 0.463 M B P S Cr203 (S) SGB NiCr20O4 (S) 36 <-60 500 1900 - PGB w/OS S - 2046 0.464 S B P S B and S 30C <-40 100 2000 - PGB w/0S S - 969 0.408 M B P S Cr203 (S) SGB FeCr204 (S) Chromel Alloy, ASM 40 <-60 100 1600 0 Gr W - 482 0.32 N - 40 <-60 100 1700 0 Gr W - 1590 0.322 N - LG 40 <-60 100 1800 0 Gr W - 2396 0.344 S Gr P ND 28S - 100 1800 1250 Gr ND 1.5 3078 0.321 S Gr P ND 26S - 100 1800 1500 Gr ND 1.5 1620 0.320 S Gr P W 29S - 100 1800 1750 Gr ND 19.0 FT FT N 27S - 100 1800 2000 Gr ND 28.0 FT FT S Gr P W 40 <-60 100 1900 0 Gr W - 2037 0.384 S Gr P ND LG 26S - 100 1900 750 Gr ND 1.0 1240 0.402 S Gr P W 29S - 100 1900 1000 Gr W 6.0 1645 0.504 S Gr P ND 30S - 100 1900 1100 Gr ND 6.0 1407 0.455 S Gr P W 27S - 100 1900 1250 Gr ND 29.0 FT FT N - - 40 <-60 100 2000 0 LG W - 1648 0.472 N - - - ~~~~~- ~~OGr 29S - 100 2000 500 Gr ND 2.5 1897 0.469 L Gr P W 26S - 100 2000 650 Gr ND 6.0 1350 0.635 M Gr P W 30S - 100 2000 750 Gr ND 34.0 FT FT M Gr P W 27S - 100 2000 1000 Gr ND 55.0 FT FT S Gr P M WADC TR 54-120 Pt 2 23

TABLE 5 PENETRATION DISTRIBUTION Penetration Depth in 0.001" l Alloy and Time, Run 0 0.64 1.28 1.92 2.56 5.20 3.74 Total Mean Depth Heat No. hr No. to to to to to to up No. in 0.001"........0 o.64 1.-28 1.92 2.56 3.20 3.74 Chromel ARM, 100 34 1049* 434 24.8 1.8 1510 0.524 heat A Chromel ARM, 500 36 438 1342 473 127 41 16 5.5 2440 1.078 heat A Type 310, 100 16 510 418 27 1015 0.623 X27258 Type 310 500 36 673 951 261 99 45 18 2047 0.948 X27258 Inconel 100 30C 896 247 7.1 7 1150 0.463 Inconel 500 36 1642 348 49 2046 0.464 *The numbers in these columns represent number of penetrations per inch. WADC TR 54-120 Pt 2 24

TABLE 6 ANALYSES OF INTERGRANULAR OXIDES OF STAINLESS STEELS OBTAINED BY ELECTRON DIFFRACTION Oxidizing Temperature, ~F 1600 1700 1800 1900 2000 Etch Measured Measured Measured Measured Measured Depth, Analysis Depth, Analysis Depth, Analysis Depth, Analysis Depth, Analysis in. in. in. in. in. TYPE 309 PLUS Nb ALLOY, Run 20 Scale Cr2O3(S) CraO3(S) Cr2O3(S) Cr203(S) (x-ray) HPS (S) FeaO3(S) FeOs3(M) Fe2a3(M) HPS (W) BPS (M) HPS (M) Surface 0 Sp (S) 0 Sp (S) 0 Sp (S) 0 Sp (S) Rh (S) Rh (S) Rh (M) I - Sp (S) - Sp (S) 0.0002 Sp (S) 0.0004 Sp (S) Rh (S) Rh (S) Rh (M) Rh (VW)? II - M23C6e - Sp (S) 0.0002 Sp (S) 0.0006 Rh (S) Rh (M) III - - - Sp (M) 0.0001 Sp (W) 0.0007 Sp (VW) Rh (M) Rh (W) Rh (VW) IV - - - - 0.0004 Sp (W) 0.0007 Sp (vWW) Rh (W) Rh (VW) TYPE 510 ALLOY, HEAT 64177, Run 20 Scale Cr2O3 Insuf. X 50 X 50 (x-ray) Surface 0 Rh (S) 0 Rh (S) 0 Rh (S) 0 Rh (S) I - Rh (S) - Rh (S) -0.0003 Rh (S) 0.0000 Rh (S) Sp (Vvw)? II - Rh (S) - Rh (S) 0.0000 Rh (S) -0.0003 Rh (S) Sp (VVW)? III - - - - -0.0001 Rh (W) -0.0006 Rh (S) IV - - - - -0.0005 No Pattern -0.0007 Metal TYPE 310 ALLOY, HEAT 64270, Run 20 Scale X 50 Fe2O3(S) X 50 (S) X 50 (S) (x-ray) LPS (M) LPS (W) Fea03(W)? Surface 0 Rh (S) 0 Rh (S) 0 Rh (S) 0 Rh (S) Sp (VW)? Sp (vvW) I - - -0.0002 Rh (S) 0.0000 Rh (S) 0.0000 Rh (S) Sp (VVW) II - - 0.0000 Rh (W) 0.0004 Rh (S) 0.0001 Rh (S) Sp (VVW)? III - - -0.0001 No Pattern 0.0006 Rh (M) 0.0005 Rh (M) Sp (VVW)? IV - - - - 0.0007 Metal 0.0001 Metal TYPE 310 ALLOY, HEAT X11306 Scale FeaO3(S) Fea03(S) Cr203(S) CraO3(S) X 75 (S) (x-ray) HPS (M) LPS (M) EPS (S) HPS (S) LPS (S) LPS (W) HPS (M) Surface 0 Sp (S) 0 Sp (S) 0 Sp (S) 0 Sp (S) 0 Sp (S) Rh (M) Rh (M) Rh (W) Rh (VW)? I 0.0002 Sp (S) 0.0000 Sp (S) 0.0000 Contam. 0.0005 Sp (S) 0.0002 Sp (S) Rh (VW)? Rh (M) Rh (VW)? II 0.0001 Sp (S) 0.0000 Sp (S) 0.0000 Sp (M) 0.0003 Sp (S) -0.0001 Sp (W) Rh (M) Rh (VW)? Rh (S) Rh(VVW)? III 0.0001 Sp (S) 0.0001 Sp (M) 0.0002 Sp (S) 0.0004 Sp (M) -0.0002 Sp(VVW)? Rh (M) Rh (M) Rh (M) Rh (VW) IV 0.0002 Metal 0.0001 Sp (M) 0.0000 - 0.0004 Sp (W) -0.0005 Sp(VVVW) Rh (M) Rh (W) Rh (VVW) V - - 0.0001 Sp (Vvw) 0.0000 Sp (M) 0.0002 Sp (M) - Rh (VVW) Rh (W) Rh (M) VI - - - - 0.0001 Sp (W) 0.0000 Sp (M) - Rh (VW)? Rh (W) VII - - - - 0.0001 Sp (W) 0.0005 Sp (W) - Rh (VW)? Rh (W) VIII - - - - 0.0001 Sp (VW) 0.0007 Sp (VVW) - - Rh (VVW)? Rh (VVW)? TYPE 510 ALLOY, HEAT X11558 Scale Cra03(S) Cr203(S) Cra03(S) X 25 (S) X 25 (S) (x-ray) HPS (S) HPS (S) HPS (S) LPS (M) LPS (M) LPS (W) LPS (W) Surface 0 Sp (S) 0 Sp (S) 0 Sp (S) 0 Sp (S) 0 Sp (S) Rh (S) Rh (S) Rh (W) Rh (VW) I 0.0001 Sp (S) 0.0002 Sp (S) 0.0001 Contam. 0.0002 Sp (S) 0.005 Sp (S) Rh (S) Rh (S) Rh (W) II 0.0001 Sp (S) 0.0002 Sp (S) 0.0001 No Pattern 0.0002 Sp (S) 0.0005 Rh (M) Rh (S) Rh (S) Rh (S) III 0.0001 Sp (W) 0.0005 Sp (M) 0.0004 No Pattern 0.0002 Sp (M) 0.0005 Sp (M) Rh (M) Rh (VW)? Rh (M) Rh (M) IV 0.0001 No Pattern 0.0002 Sp (W) - -.0004 Sp (S) 0.0004 Sp (M) Rh (VVW)? Rh (S) Rh (M) V - - - - - - 0.0002 Sp (M) 0.0004 Sp (VW) Rh (M) Rh (VW) VI - - - - - - 0.0002 Sp (M) 0.0004 Sp (vW) Rh (W) Rh(VVW)? VII - - - - - - 0.0002 Sp (M) Rh (W) VIII - - - - - - 0.0002 Sp (VVW) Rh (VVW)? TYPE 510 ALLOY, HEAT X27258 Scale Cr2O3(S) X 75 (S) Cra03(S) X 50 (S) Cr03(S) (x-ray) HPS (S) HPS (S) HPS (S) HPS (S) HPS (S) LPS (W) LPS (W)? Surface 0 Sp (S) 0 Sp (S) 0 Sp (S) 0 Sp (S) 0 Sp (S) Rh (S) Rh (M) Rh (W) Rh (W)? Rh (W) I 0.0000 Sp (S) 0.0002 Sp (S) -0.0001 Sp (S) 0.0001 Sp (S) -0.0001 Sp (S) Rh (M) Rh (M) Rh (W)? Rh (W) II 0.0000 Sp (S) 0.0005 Sp (S) 0.0002 Sp (M) 0.0005 Sp (S) 0.0001 Sp (M) Rh (S) Rh (M) Rh (W) Rh (W) Rh (M) III 0.0001 No Pattern 0.0006 Sp (S) 0.0005 Sp (S) 0.0006 Sp (S) 0.0000 Sp (VW) Rh (M) Rh (M) Rh (S) Rh (W) IV 0.0002 No Pattern 0.0008 No Pattern 0.005 Sp (S) 0.0005 Contam. 0.0001 Sp (VW) Rh (M) Rh (VW) V - - 0.0007 No Pattern 0.0005 Sp (M) 0.0005 Sp (S) 0.0000 Sp (VW) Rh (W) Rh (S) Rh (VW) VI - - - - 0.0004 Sp (W) 0.0007 No Pattern -0.0001 Sp (VW) Rh (VW)? Rh(VVW)? VII - - - 0.0005 No Pattern - - - - HPS - High-parameter spinel LPS - Low-parameter spinel Sp - Spinel phase Rh - Rhombohedral phase WADC TR 54-120 Pt 2 25

(4) (5) 0 0 I I ___ XI___ ~ L__ _ — LEGEND | }I z |I - ALUMINUM SHELL l I.o0 I l l 2- VERMICILITE z 3- TRANSITE wI I 4- ALUNDUM CEMENT einl 5- CHROMEL COILS | I | 1 6- LOAD' 1uL I I 1 7- DIAL GUARD 20" 1 8- INDICATOR DIAL (6) E 0 0'(7) LL - - =;' [_ _ _ _(8 - -- ( 8 ) Fig. 1. Schematic Drawing of Stress Oxidation Unit. WADC TR 541 —120 Pt 2 26

1~~~~~~~~~~~~~5. ~ ~: ~ ~ ~:~'!~ ~ ~ ~ ~~~~~~~~~........ ~:: ii: iiiii:iiiiii!iii/iiiiiiiiiii i:i:.4:.........;::: ~'t: ~~~;:~:00:0:0000 WADC Th 5)K1.20 Pt 2 27

1.- = HUMID AIR LEGEND (7) (I) ENTRAINMENT (2) SEPARATOR (2) BERL SADDLES (3) TEMPERATURE CONTROLLER (4) HEATING ELEMENT (5) PUMP (6) LEVEL CONTROL (7) SPRAY (6) REFILL WATER (4) (5)' LINE AIR 1220V SCALE I" ~ 3/4' Fig. 35. Schematic Drawing of Humidifier Unit. WADC TR 54-120 Pt 2 28

(2) LEGEND I- CHAINOMATIC BALANCE 1__l____ - 1(3) 2-PLATINUM WIRE /( //3-PYREX GLASS II —, r /(4) 4-TRANSITE BAFFLE 5- COOLING COILS (5) 6- SILIMANITE TUBE (15) \1 _ __ - F __ (6) 7-FURNACE 8- SPECIMEN (16) 9- PORCELAIN BEADS 10(7 -BROKEN CERAMIC AIR I( 1I-INDICATING THERMO(14)...~; COUPLE I 2-ROTAMETER I I-; V~ | ( 13-VALVE (13)| | 1'I D*'^ 14-DEW PT. INDICATOR', ^^~~~-^ - (10) ______ —- ---- I-15-CHROMEL COILS L,^~(12) | |;~'.. EMBEDDED IN ALUNDUM,.l *'''||16-VERMICULITE it Fig. 4. Schematic Drawing of Weight-Gain Unit. ~;ADC TR 54-120 Pt 2 29

;SAMPLES -AFTER; CUTTING FROM { ~~2"l GAGE LENGT PORTION OF _r: /- STRESS SPECIMEN E /0010 - -BENT SAMPLE 11 5! <P~lPRIOR TO 00 I { / ~MOUNTING Fi.5.:_cine:ehen. Afte Montng WAI)C1111~1111111111~11~........................................................................................ 4 P i??iiiiiiiiiiiii~ ~ ~ ~ ~ ~ ~ ~ ~~~~~~~~~~~~~~~~~~~~~~~~iSSS-:::SSt::SStS:000::g::S:0000i0000g200iii000000000-: -. i-iiiiSSSSSSSSSSS:::::::::g::::::_:::!!!i 0000002i022i000i!!!!!i!!!!!!!!!!!!!!!!iiEEEE~EEEEEEES~EEEEEEEEEEEEEzl i ~ ii ~;4~~;~~4~~;;;;;~44;;;~~4;;;~~~~~;;~I........................................................................................................................................ Fig. 5. Specimen000000000000000000000000000000000000000fore and After Mounting.0000000000000000000000000000000000000000000000000000 WADC TR~~~~~~~~~~~~~~~~~~~~~~~~~00000000 000000004-120 Pt 2 300000000000000000000000000000000000000000000000000000000000000000000-000000000-00 -0 ll0

111"', ~ ~ ~ ~ ~ ~ ~ ~ Scio,~etha I _ _...,. -. 11-.. I::..-. — w 11-.1-1,..;, I ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~-. -~~~~~~~~~~~~~~~~~~~~~~~~~, - -~:-: —T -:~:-:::-:i::O:_: I I~~~~~~.,.. "I~ ~~~~~~~~: —..,7,i!- - I::'','. —-..... -.-..:: ii-i~-: I ilil:I:.11 ""~~~~~~~~~~~~~~~~~~::::::::::::::::::::.I:::-::-:::~ ~ ~~~~~~~:I I _ - _:_:: -:::: -:::::::::: I.,..::.::,:::::::::::::::::~:::::::::::-::- -,,lil~i:::::':: ",: ~~~~~~~~~~~:.. -..I-:. " I11 7.ac ~ ~::::::.-..:: —i-il: —-:::::-:'k,~ ~~~~~~~ - 1~~~~~~~1, i ~~~~~~~~~~, ~~~~~~~~ ~~~~ -, ~~~~~~~~~~~1.,., 4~~~~~~~~~~~~!!~~~~~~:::, ~ ~ ~ ~ ~ ~ ~:_::.:::::-.::::..::~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~. I - ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~I ~~~~~~~~~~~~~~~~~~~~~ "I. ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~::::::i. ~ ~..,~~~.. - ~ ~ ~~~~-".._,... ep~~~~::, -.!. -::-:. -.::..., -,., ~ ~ ~~~ ~~~~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~r::::::::::::::::yc:I:::-:_..-. -:-:-:. _,,:~ —l_:i-.. - -.-._::::::::::::::.... —:::::-:''::::::ii:::: -:: -:': —-'::::ill~~lili-~~~ljjjjjl i il ~~ ~~~~~~~~~~~~~~~~~~~~~~~~::::::::, -::: —::-i:::-::-:i,,.~~~~~~~~~~~~::-:::::::::::::::::::. —..:::::::::::: "4K w...,. ~::-:'::::::.:.._: —:-:'-:''i'''::~-'-::'~ii~: —~lI-~::::... 1....f:_ 1 - 11 -.A,,., - _..... _ _ wa~~~~e TR 54-120 9~~~~~~~~~~~~~~~t 2 ~~~~~~ s

I.... I...... :K*I.; -.: I -.4. I-,I.w../.,:: I - %... I,. 1..I..., 0 p.I I-. 1. ......:..... -I - 0 0 Di :.:p . I ,.. I.1, I. II r-4 r-q 00% -H., - - r I... 11: I 11 tlI.: .; W 4 r-q. II. II I I II I.I I I I I I I,. I,N. I. I I..1 -::....'r -,,..i: 04, 0 ro, I -,.... I I...., ; - I111,11O.... I II..-11111,I:: .-,.-:O —,- :', ;-, ——,.-. -.`-. —- 11!., 0. > 1 I I I.. I ... I. I. I. I i;j —:-:-:-:111-,.,.:. , I ::.J:, : ,:x:: : I.. 4-) C ) P i n 0 I.. I., I1:::: I... .." I I - - l -..11''I"..'..''11 1.1 11-. - I., #11 11.- 11 I''. I I 1 I'll 11 1 I . I''..''... 11 -.","." I - I I - "I'l.'.."'.", ".., Cl. I, ,:. I I I I I I.1. I...,I I - Z t__ x,, _, I I I., -'.., 1, I " I I 11 11 I',*. , ::: !. !: : , I , X x:::X: :;;:,... I,., -, I... 1.111,11, ". k I:i:;:, 1.,, "''I'', - , I I,, I —- --- — _:- —:::;:.::!:xx:! w 0O I:.-;.A. 4.'%-, I'llI11 —''I'll - 1..1.. -.1;''I 11'' I'1 1, 11..:, p - I.-,.",,,...." II.1..11,11.1. I I.: 111.11, 1,.. \1.I'.,.1 I. r; :,11,.- I 1"..'', -I.I'll, 11 -%,I.,:::,.:: 1.,..,',,!!,. I..,,..'', : V %. ,,,,;, :id.........,..,.'',.,''''''",""'ll''''....""""..""..",".,..'',l".,. I ,:!X :::, :: r,:::.- ',j:1.1' :.."..", - I A -1, -. X::x::X: ".::::::::::::,:::::::''"".."'I I I 1, 11 11..... "', ".. 1. 11. r i..... I -.- 4 - I..-I"'..'."11,- 1..11.-X::::X:,...... 11 11 ::.......1 I I, _ 1;:''I''....... 1.11,11.1111,-...:... .::::::.,,',:::''.''".",.,. 1,-.: 1 111.11.1- 1111 1.1. 1111.1. 1111''. I. "'..111.1.11. I 1,,, %'..."'., "...:..".,:4_ ,`,,:i:, -,'! ,-'i':: +: iiii7;;;;.....1.1. -'I'll".,,", 1 1.."'.'..., "'.''- I :::i. II ",. - 1..,.. - I'.;1;1.'"'Il".",..'';",:!,,i,'I., .,.:,1.11, 0% r_4 M 10,,,X'':'..::::.",.,".ii:",.,.,.,: I..%,",",'' I'll" I. 11, -— %%-%,. I -111- -::X:: X: ::.... I-: 1: ,..-':: I../.,..:,::,:,:,:.::,:,:,,:,::.,:,:::''::,:.:,:,:..............11... I...,... i -.-.,,.,,,'',''....'. "..''..."',.1 "...''." ".,.,..' """':,:,:'::,',:,;.lr:::.:.:...::::: I::1. 1. I :, !:. I..::::::: xx.,. I - -...:/. -:1, — r. -.11,.: ::::,-'. "'.'.1,1_1111... —.::x::::x: I I., X::, I..:::::i:x x x: - - -,::.,.- ::* I 11..p._....:1-ppX..''r...:,:,:,..0,.i ;.,,.,.....,.,..,.."..."..,.......I...... "..1.1'...., "I'%%%"% 1"'.,,, 1,.......... P'..... : - II V,"I"...,'._ II...'. I.-P..,.,...".......,..,..."..."",.,.,,..,. I.% ".,.''..'%%, I 1".."" 1, I,.'%,. -', I.."'%%..%%%%,:.". I.. ".,. t o p q C )...".1.111.::::: 111,111.11,1 II...I............. p:: 1: 1. I I I I I.. %%%, 1 I 1,.,.:..".I.."'I"'..."... "'.:;-::.: -,." 1, 11. %%'....,.;1q_...;... I /,.,,... 1. I I....,,, p,:,:.:.:,:.:,x, I.",.....I,,,, :: ,;i;i..I....I................ :4 1:-,:,if ... - :,:X,x::::;:...I...-... I.1.1.; "I'_::_ -:...... b.11 ;v,e.-.,, :::::::::';,:'11, - -,.",_ — I 7::..'1,-,-,-.%.....:.:: I.......... ... I I.. 1.. 1..,.,1,1_.1.1,1.r,,.,1..,1.4 1. I I 11'..''...,::: I....".".....,.,....,..".....:0 1. -) 11''I'll'' -I::::X::.`.::::X:X 1_11'1'1,1.,,. 1.::,:x jx 1''..'',II.''...."".""..,.,."....",,..,., 1....:: I1. to 4) 4 I.,,.'....,._ %%.,.",-::,.,::k. : I''. ". :;!. ;i!!l...I__ —.-.-..-...,..1........... 1111-:.: z::IN:,.-!,:-: __ 0 0 II: 1:1 1-1*.,:,;-1..........11I".::111.:::: AX 7................,.... 1. 1. I. I.. I.. I.. 1., I%, ::-:..,-..................... ".,....."....,.........""",...,., I...'...1.1....... I......... I-, I r I.'',.....'',.... I 1....."..,...'',''.''..."r".,.,-... I I,. I.1.1. -. 0 II.................. 1,." ".. ". 1. I I,.,-,.......'..%...,. r,.,','.:::::: :::::::::::X:.;,:, .... X.,, _-,..................... "".... I I I.... I....", I.I.-''..-',.",, I -'r"".., o... ..-::,. I. - "".",.,...., 1;... 1:.:::::..::::::::.::,.:.......,....... 11 i::.....''...11... 11...... I.,.....''''.,''. 0.1 11... 1.,. 11II.II II,.11.1II 1_11......... _- 1.::::::............. 1..1 I I..... I......: 7S..r ". "." I -'.."I",:::::::::::::::::::::::::::::::.I I I :iiO i:::::::.:,:.:.:,:.:.:,:,::.:.:.. I'll, 11, -'' ..,, .,:::::0 to n O::D ""I'll"...",.,",.,",......"..,.... i: !!::::::'.,:,:,::::::::::::::::, I..I1". I I I-:j::,:j:...''...""",..1'::::::::X:X:.11.1- 1... I...''. ) i::::;:.!:::,:,:,:,:.:,:,::::::.., .i. II......%. I, - "'I'_...'',... I I "......iI —----....., I _q - I...,,r...I'.,-.. r...'%, -::::::...,..... % -.1.1.1. I r.... r:::.....1. I I I X: ::::.4-.:. I I I 1. I I................I....:;:..... ___.-. —... 11. ij:::.:..,.i!li to \10r.j::,_'. I... I....:::::::::,.,.,,.r - 1- 1 11,.. .;:!7:::::::::;::::::::::;::::::::::::: I,. .:.111.1'....''. 1- 1... X.:,..,,,.1,.,r,.,...... I.1- 1.""...l."..'.."'. I. I I'..,."""",,....".,.'....: X X X X I I. I I...,..1.1.._ _...,.,. I.... 1.1.111..:. - -''I'll"*.111 *:-.,....... I 1"... I....,., I I I 1..1...-........... Irl."'..''.1 1.- 1'...,..1.1'.".::.::;,;.,:, :::::..... 4 1% I I,:1,-_ -;. I 1.::::::::::::::...::._, - -.1111 - I.1'1..F .Ph.......I... -1.... "". -,_..-:.?.I-...................I... I.......'.'......".....,, ".".,...1,.,r-.'.', "'..".....", :: X X X X::X.x.r.:.:,:,:::p::::::::::::::':`... I.''.. J; —-,I. I-......,....... 1.1"'I".1. 11 11.11 1.11 "I"..'' —...,I.......I -1.:..''.1. _-.. II.I.1 I.....'r,". -,."....,......... I.....".."', 1, 1.11.1 - I....,-::: X........ 1"'......'.......,..................'',., _..::::::::::...,,,...,..".,..,.....,.,..,..", I r I I..... 111.111..............'I'l.", I 1. I I I I.,., -I r,:,:,::,:,:,::,i,:,:,,,::::iiiiii............................. 1. I.. 1. I.....:i "...,....,.,.,....,., "., r.... I'll,.....,..,,:,........ 1.1.11.1111,........ I 11..... 11.11.1'.......''....... 1-.1".1'.111................'i !,..........,.........."'. ""., : I I.r.11.... 11.1..........,..."-...,,, -1 XXI''."..,, I... I!......''.......''...'''11111.11..... I ::. I 4'."'."',........"...,.",.",."..,..'", -,...,.,..,,,.,,,.,I.r.',','.,',,'.....m.x./::: p.-...,,.-111... m 0 1 1,,r I -':!:..',,:!.......::..,,.1,1,.r..,.'.,1.1'1,1.- I I, I.I1-1.1::X.::::::::::::::::::.to rk,.., xp....... ".. I.. 1........................... "....... I:-:::, ",.,,...,,.,,,.,.,,..r....,:::::::...,.,."....",.",........'',,.,,.,..- I...I...,.11.1... 1- 1......, I 1.11''. I I..",.......... 1.:,........:p::p::.FF,:,:.x.F.. I I-. I'll....;.,: -:.,.';,"_,""...'..%....... I'.,................,::.i!...i-1"...iiiiiiiii! a...:.,:.:::::::::::::::;::::::::::::::.. I... I.. I I I''...'.'..".".,''I:: I::..,...."......."."....,.,."... 1.11,11'......................,". r,,,''.......... 1.,..'.','.',- _...-..:,._... t o -,.." x:F:p;x;',.'... "....... I I -,4'"., ::::,: "..".., -7::::::::::::::,,:..............:-:. -,:::.:::::::::::X:I...'. I'll.......... a), 11.."..."'................. Ii i I... " I" I.1-x _,.....-... 1.1111.111111.1.1,.,.,.,..........."........","'..-11",..',:j;::::::::::,,-..N"................."..::1.::: . -..i::::::::: () ID 7.. ,.: ". 1x ::::::..,..:::.:,:,:,:,:.:.:,::::::::,:.:.:,:',, :::::::::::::iiiiiiiiiii xxxx. I.I.....;i:i,ii:I X. _P a ) -H k. -:::-.., " xxxxxxx -: "I.:it 7!i, 4-. — - .:,::::!:: ::: ::::::::::::::::::::::::::::!::::!:::::::::::::::. "..,.,.,. II II I,.;:..::::::::.::::::::::::;:: :;::iii::::i:jijj,..'..,::,% ::...." I.,:.1.111... I:rx:::/: i::::iiiiiiiiii....!i..; -..:!''.."11". .,.,.,.";ii..II.....,II. II'll._.'.1.",:,::::::,....1 "... 1: Z.,..'..-`.."..",.,....""::i..::::.,......:;::::::,:.:,:.:.:.::. 1........... I IIII,.1.:::::::::::':::iii::i:iii:l,i: Fii ":........:-1-..:?'., I.....,1....... 1 1,. 1.. -.. i?'-.ii J........... 1..1.1:I I.......-,,,:XXX.-!:,,4.. -..., r.. r..,.,.:."." .1.FF...,;...''.....:..i:ii::.,...,...,.".....,:11, ,,,,-....., I.::,..... 11"'....'..", - :..,.:: 1".................... "..I.I.,...''....''.1 11... 1.1"'......"...",............. I........1.1.1".1... I —- ---... I'll", 1..i::,:,:::::::::::::iiiiiiii!iiiiij I.... I..11... -.,... I 1.,....1.1'."'....'.."'"...,.... I....."................... I...,., -I. -1.........:::::, ::..:.::::.:.":,:,:,:,:,:.:.::::::::::::;::::::::::.:.:.:.:.:.:,:.::p I -. I,......:;......,,i,,,,,,,,,,,,,,,,'',,'.:,I.r.l.'.'''..., i iI..1.11.111... I I I -''......'.'....".....".....................''I,.,...,.,.,...... I." 11.1''.: ......I......'....1.1 -ri 11 1. 1. 1.1111,.......,:-,::`:,:`:`;,,, I I..1 I - _ -...........;1::':..:::....... r...-.......... I I- _. I I,.. I..............I I.......,, II III,11I III IIIIII I...... - . -' (V I,.......... I,... 11II I.,.- I..,, 1. 1. 1: ! ;::XIII'll...I.I......''I 1.11::::::::::::: I.......I.....I........... 1.. 11.1: :i:ii!'.,iiiiiiiiii: I.- -.,,,.....,-,-.,._ -.,............,I..".....,.,..:::::::::::::::::::::i,..4WCO ". I - _..''....I...... 111. 1.............:'' -.1.1... r. -...I........ ",.,,.,..%r,. I I..... I.. I I I.::::.........'i. -i i''.........I.,.".:;...",': .,,..:;7;,...:;:;:;::,::::::::,.-...,.,.1r1,1.'.1.:::: "... I.. I I...:;. I.....,:: -..::-:X,:.: IIIII,,I,,I I..i:-:-:-::*::: ,::.,i!.i.i....". ii:'I.:::::X;X::: 11 ...1., r.,:.:,:ii::::i:::::i::::i:::::.::::::i::::::::i:I::i..,,,,, I.","....",... ""...''.:;::,,.;aided t o;..".1""'. 111.2 1:v!jj!...:::;:i::::.."..","..."."""",..''..,.... I., X:.4,:::::::-., I,.II'llII II III IIIIIII.II.." i;;O:;!;- rPFF.,.....1...;I..... I I...:..::,;:::: ":i:,.. O'.. *-. - -...,......-.,.... I... I............ i I I, I.K.,'f.....1111'.1..... I... 111''.:. 11.1'...''. I-,'',,.,..............1.1.1'1'...:., -1. I_............ 1.1,, x. ,.,."... I II IIII II I x :i, ii , !::; -......::::: X, :: 1.,.1.......".....'. ".",:FF..........,,-....'r ,.-:.-.,'::.,...,.,.,...,..,.::..".:.::.:,::,iii:iiiiii.'-.-..-'-..........:;,:...........::.:'.'. --:X;,::;-, ",.. 11.11,11,..................,... p::::::,.:.-........."......"".".",.,...""", I III III-I IIII-I'll, I II I'll ---''..''..I.,... I.....''....,.r..........,......1,-,-.. I I I I..''........'... I..,....",''.,............ I...''..,,,'',::::::::::::::::::::::::::::::::::::::::::::::::::::!;::::::::::::::!i: - 4 - P......F......,......,...,..,.,.,...,..",.......,..,.'''',..".....,........,....., "'..,.,.,. 1.11 11 ". I 1...........,,-,-.-.,.,.,.,.,.. 1: *...,.,..1.1.1.,. _.._ r 1. 1. - "I "....:: I'::::::. -.......'.... r I,,, "I'llII-,'''',I III II III II II.1 I11 11,I11 11

'I~i~,,~ ~!~!~!~i~i~i~i~i~i~~................ *:L.:!:i >,'^y...........:.:......''......... I........:...Y tt v...... ^ ^.;":,,.' Fig. 14. Edge of Sample Containing Fig. 15. Surface Grains of Chromel Pre-rupture Fissures; Type 510 Alloy ASM, 250X; Cross Section, Alloy, Heat Vt-7 1900~F, 100 Etched Electrolytically in 1-1-5 Hours, Stress 900 Psi, 750X; HCl, HN03, H20 Solution. Cross Section,, Unetched. 0...'.. ~.I~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~- i Chromel Alloy ARM, Heat A, 1900:F, Chromel ARM Alloy, Heat A, 1900~F 100 Hours, Stress 500 Psi, 750X; 100 Hours, Stress 250 Psi, 750X; WADC T 5t4- 20 Pt 2 5 wae) TR 541~20 P$ 2 3

pture Fissures Chromel Alloy ARM Type 510 Alloy, Heat X27258, 1900;F, Heat A 1800~F, 100 Hours, Stress 100 Hours, Unstressed, 750X; Cross 2000 Psi, 750X; Cross Section, Un- Section, Unetched. etched, Oblique Light., WAD w.'Z0't 4 Sec%%on,,'.: 6 Fig. 20. tergr etration Fig. 21. X-ray Transmission Pat Te 510 Alloy, Heat X27258, 19000F, ternj Tpe 510 Alloy, Heat 51572; 500 Hofurs, Unstressed,- 750X; Cross Cold-reduced 97% in Thickness. WADC TR 5k.120 Pt 2 54

........I.......... - - 1.1- 1- 1- 1-......................I............I..... 11...... I'll-.............. 11.... 111.1111, 1- - l- 11-... - - -.. I I I. 1 O, - ",!!:::::::..,. ------ -........ I I I 1. ........ -...-..........., _.......... .........:.......::........ si:::..:.....::.::::::::::::: -:I..., - X..,I...-...........................,....I.... I......I,...................,...............-................... I........................... - ...............................................................................................,...........,...................,......................I.1..............::::A.,..........................,.......,...,......... I.. I.....I...I.......I.....................I....... I... :]xx::, xx: ................'..................... 1.I... I..................................:,:.:.... -. ........... I................................::::::::::.,.I..... ....................... - -........ - ..........,.................................. "......... I.....-........:J4 ,........,.......,....."............,.,........ —....................... —.:::::::::::::::::.,:.:.:,:.:.:::::::::::::::;;0!7:::::::::..................:::::::::::::::::::::............,.....,...,...........,...,.'....................................... --.......-.................................................................................................... 1.................................................................................I........................................................................... ".....,.......................,.......................,.......,..........,.. I.::::::::::::::::::::::::::...'f... -...............................-I.............. I.........................-........................................................ I..................................................................... -........................................................... I-..........I...I -..............................................-.................................................................... —-.....I................'...'...'...'.....'. I............................................................................................................................,'.......,.'...................,...,.....,.....,.......,.,.............................,............................'............." ".......,...................................................... I.................................................................................................................................................................I.................................................................. ..............................................................................I................,.........................,...................,.....,.....,.....,.,...,...'.,...,...,................I....I..... I..,... I —..%...............,...,.......,...,.,.,...,., -................................................I.............................................................................................................I......... -—,....... I.. ..................................................................................................................................................................I................ I-,.......,.....,.......,...,.........................,.,.....,...,.....,...,...,.....,.'...,.,.......,.........,.,.....,...,.........,.,...,.,.......,...................,....................................................................................................................................................................................................................................................................................................................................................,.........,.....,...........,...,.,.........,.....,.......,...,...,.......,.,.....,.......,.,.,.....'...,...,.,...,.............,.................,.....,.............,.....,.....'...,.....,...............................................................................................................................................,...,...,...,...............................,.....,.............,.......,.,...,.,.......,.,.,.....,...,.....,.,................."..,...,...........,...'....".......,.,...,.,.,...,.,.....::................................................................................................................................................................................. I..........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................I.......................................................................................................... ................................................................................................................................................................................................. ......................................................I.................................I........................................................................................................................................................................................................................................................................................................ .......................................................................................I......................................................................................................... ....................................................................................I.......................................................................................................... .................................................................................................I.................................................................................................. ........................................................................................I.................................................................................................... ................................................................................................................................................................................................... ................................................................................................................................................................................................. ................................................................................................................................................................................................. ................................................................................................................................................................................................. ................................................................................................................................................................................................ ................................................................................................................................................................................................... ...............................................................................I........I........................................................................................................ ................................................................................. I I.....I..................................................................................................... ............................................................................................I..................................................................................................................................:::::::::::::::::::::: *.::::::.,.,.,.,.,.,.,"...,.,.,.,.,.,.,.,.,.,.,.,.,.,.,.,.,.,.,.,,..,.,.,.,.,.,.,.,.,.,.,.,.,.,.,., -...............................................................................I........I......................................................................................................... -.................................................................................................................................................................................................... -.....................................................................-............................................................................................................................ -...................................................................... I..''.......I....I........................................................................................................ -............................................I.......................................I............................................................................................................. -.................................................................................................................................................................................................... -.................................................I...........................I.................................................................................................................... I.........................................I....I.....................................I............................................................................................................. -.................................................................................................................................................................................................... I..................................................................................................................................................................................................... -.................................................................................................................................................................................................. -..........................................................................I........................................................................................................................ I.....................................I........I..................................................................................................................................................... I........................................I......I..................................................................................................................................................... -...............................I................................................I................................................................................................................. -.......................................I.....I..................................................................................................................................................... -.................................................................................................................................................................................................. I................................................................................................................................................................................................... I.................................I......I......................................................................................................................................................................................................................................... 11....I...................................................................................................................................................................................................I........................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................I...................................................................................................... I........................................................................................................................................................................................................................................................................................................................................................................................................... I.............................................................I......................................................................................................................................................................I............................................................................................................................................................................................I.......I...................................................................................................................................................................................... 11.......................................................................................................................................................................... -............................................................................................. .......................................................................................................................................................-............................................................................................................................................................................................................................................................................................................................................... I......................................................................................................................................................................................... I............................................................................................................................................................................................................................................................................I.........................................................................................................................................................................................................................................................................................................................................................................I...................................................................................................................................................................................................................-............................................................................................................................................................................I..........................................I..........................................................................................................................................................I....................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................I........................ 11...................I.....................................................................................................................................................................................................................................................................................................................................................I...........................................................................................................................................................................................I..............................................................................................................................................................................,.,.,.,.,.,.,.,.,...,.,.........'.,.,.,.,.,.,...,.,.,.,.,.,...,.,...,.,.,.,.,.,.,...,.....,.,.....,.,.,.,...,.,...,.,...,.,.,.,.,.,...,.,...,.,.,.,.,.,.,.,.,.,.,.,...,.,.,.,.,.,.,.,.,.,.,.,.,.,.,.,.,.,.,.,.,...,.,.,...",.,.,.,.,.,.,...,.,.,.,.,.....,.,.,.,.,.....,.,.,.,.,.....'.....,.,...,...,.,.,.,.,.,.,.,...,.,................................................,...,.,.,.,.,.,.,...,.,.,.,.........,.,.,.,...,.,...,.,.,.,.,.,.,.,...,.,.,.,.,.,...,.,.,...,.,.,...,.,.,.,...,...,.,...,.....,...,.,.......,.,...,.,...,.....,.,.,.,...,.,.,.,.,.,.,.,..........................................................................................I.............................................................................................................................................................................................................,.,.,.,.,.,.,.,.,.,.,.,...,...,.,...,...,.,...,.,...'.,.,.,.,.,.,.,...,.......,...,.....,.,...,.,.,.,.,.,...,.,...,.....,.,.,.,...'.....,...,.,.,...,.,.,.,.,.,.,.,.,.,.,.........................................................................................................................................................................................................................................................................................................................................................................................................................................:,:,:,::::,:,::::::::::::::::::::::::........,.,.,.,.,.,.,.,.,.,.,.,.,.,.,.,.,.,.,.,.,.,.,.,...,.,.,.,.,.,.,.,...,.,.,.,.,.,.,...,.,.,.,.,.,.,.,.,.,.,.,.,.,.,.,.,.,.,.,...,.,.,.,::::::::::...:::::::::::::::::::::::::::::::::::::::::::::::,...,...,.,.,.,.,.,.,.,.,.,.,.,.,.,.,.,.,.,.,.,".,.,............................................... I..,............................................................. -.''..,................................................................................................................................-............................................... I —.... 11.1.111,... I-,................................................................................................................I........I..................................................................................................................................................................................................................................................................................................................I....................I......................................................I..........................................................................................................................................................................................................................................................................................................................1.....................................................................................................................................................................................................................I...............................................................I...................................................................................................................1..................................................................................I..............................................................................................................................................................................................................................................................................................................................................I........................................................................................................................................................................1.................................................................................................................................................................................................................................................................................................................................................................................................................I.......I....................................................................................................................................................................................................I............................................................................................................................................................................................I...........................................................................................................................................................................................1.........................I..........................................I........................................................................................................................................I................I.................................................................................................................................................................................................................I..........................................................................................................:,:.......I.......................................................................................................................................I...............................................................................I......................................................................................................I.....I..........................................................................................................................................................................................1...............................................................................................................................................................................................................................................................I................I.................I.........................................................................................................................................................................I..............I..................................................................................................................1.......I..............................................................................I...........................................................................................................1.1..................................................................................................................................................................................................1.....................I..............................................................................................................................................................................1.1.................................................................................................................................................................................................1....................................................................-..................I......................................................................................................... -...........................................................................................................................................................................................1..............................................................I................................................................................................. I..,................I...I.......................................................................................................................................................1................I...............................I................................I........-....................................................................................................... 1.11................I.....''..,....I...........I....I.............................. I..,.... I..'................................................................................................... 11.11,......-.... 11...-...I..........I....I.................I......I..........I... 11.....I.................................................................................................... I... —.-...-.... I.''..,...... I-,.... 1.111-1-1... 11.................. I-,........................................................................................................1.1...... 1.11.1.1-1.1-1-1-1-1.1.1..... 1.1.11,11.1111.1.1..................... 11........................................................................................... I..,... 1''..,.... —..''......-... I-,... 11... 1.1111.1111.11.1-1-1....I... ---... I..,................................................................................................11-1.1.11-1111.1-111... I.''..''.''.'''',''''.'''''ll'.1.1.11.1.1.... -—.-,...I.. _.''.'',... I..''.,..,.''..,.,..''.,..,.'',.,'',.,,.,''.,.1.1111I.I.I.I..'.'I..... 1-1.11.111............................................................................................. I..,.,.,'',.,.,.,,.,,.,1.1.1'..,..''.''.,.'''',.,..''..''.'..,.,.,''.''''.''''1.11.11.11I... 11.11............................................................................................................................................................................... __ —-—. —....I....''Ill-,...''..''.'',.''''..,..,.''''.''.,..I...I... I..,...I......I.............................................................................................-,-. —-----....... I.''..''.,.'',.,..''..'','''',.''.,.,,.,.,.'I... 1.11.1.11.1....I.....I........................................................................................._. —-..-.-... I..''..,.,.,.'''''''''',.,,1.1.1.111,11.11.1.111..I.....''..-..,... 11....I..............................................................................................,..,.''.''.,.,,.,''''.,.I.I.I..I... 1.111,11.111,111.1.1111.11,111,11.11.111.11.111.1.1111.111.1.11......................................................................................... I..'',,.'',.,,..'',''.,.'',.,.,.,.I... —. —.-.-... 11.11,11111.1'..'',.''..''.''''.'''',I...I __ —...''..'',,.''.,.,'''',.,,.11,1111.1.11.11I... 1.1111I.I..'',,.''''.''''''''''.1.11.11.11.............................................................................................................................................................................. 1.11.1..''..,.,..,.''.''.''.''.''''.,1.11.11.111,11.11.11.1'll''''I'll'.11,ll,.I.I..'',.,.,,.,,.,''.................................................................................. 1.1.11.111.1111.111.1..'',''.''''.'',..''.''.''''..'',''''.,.'',.'ll''''II.I.I111.11.1111.11.1...........................................................................................''I'l''''I'll''''I'll'll''''II.1111.1.111.11,11,111,111,11,Ill''''I'll'',.'',,'ll''''I'll''''I' 11 Type 310 A110Yo Heat 31372; Cold. h nealed In Argon at 200.0'F for 5-1/e Hours. Section) I..''..........I.... 1.11,11,'' -,''''I'll,''I'l''''I'll'''' I............... -------- I''I'l''''I'll''''I'll'll1l.111,1111.11I..............................I.... II I I I II''I'l''''I'll''''I'll'll''''I'll''''I'll'','ll'.11,111,11,''''''................................. II I I II II''I'l''''I'll''''I'll'll''''I'll''''I'll'','ll'.11,111,1........................................... II I I I. I 11 -----—.''I'l''''I'll''''I'll'll''''I'll''''I'l.................................................. II - II''I'l''''I'll''''I'll'll''''I'll''''I'll'','ll''''I'll'''.................................................. II - I''I'l''''I'll''''I'll'll''''I'll''''I'll'',.1111.11,111,111 I................................................. -I I I 1 11 11 I''I'l''''I'll''''I'll'll''''I'll''''I'll'','ll1l.111,1,............................................. II I I - I I''I'll,''I'll'Il.11,11,1111,'ll''''I'll''''I'll'.1'll'.1.................................................. II 11 - ll'I'll''''I'll'll''''I''..'',''.'''','''''''','ll1l.1111...................................................... -I I I I'll, I''I'll'I'll''''I'll.,'ll''''I'll''''I'll'','ll''''I'll''...................................................... 11 I'll,''I'l''''I'll''''I''.11,111,111,11111.111,'ll''''I'll'''....................................................... 11 I 11 --''I'l''''I'll''''I'll'll''''I'll''''II.111,'ll''''I'll''''I',..................................................... II I 11 -''I'l''''I'll''''I'll'll''''I'll''''II.111,'ll''''I'll1l.111,,'''','''',...................................... II I I -''I'l''''I'll''''I'll'll''''I'll''''II.111,'ll'.11,111,111,11................................................... I11 11 11''I'l''''I'll''''I'll'll''''I'll''''I'll'','ll''''I'll''''I'l...................................................... II -''I'l''''I'll''''I'll'll''''I'll''''I'll'','ll''''I'll''''I'll'','..................................................... II II --''I'l''''I'll''''I'll'll''''I'll''''I'll'','ll1l.111,11111.11,,, -.............................................. III I -''I'l''''I'll''''I'll1.11,11,11111.11,111.1'll''''I'll''''I'll','''''',.......................................... II I ---''I'l''''I'll''''I'll'll''''I'll''''I'll'','ll''''I'll''''I'l........................................................... 1 I I''I'l''''I'll''''I'll'll''''I'll''''I'll'','ll''''I.Ill''''I'........................................................... II-''I'l''''I'll''''I'll'll''''I'll''''I'll'','ll''''I'll''''I.Ill''1..........................................................''I'l''''I'll''''I'll'll''''I'll''''I'll'.1.11,111,111,11111.111,111.......................................................... II''I'l''''I'll''''I'llIll''''I'll''''Ill.,,.11,111,111,111.111.11.'............................................................... III I I'll, -------—.''I'll'I'll''''I.111,.11.11.11,11.11,11,11,'ll........................................................... II II-''I'l''''I'll''''I'll'll''''I'll''''I'll'',11.11,111,1111.111,11.1............................................................... I- I I - 1.11,11,111,1111.111,'ll''''I'll''''I'll'',111.1111.11.11,11,111,' I........................................................ II I 1 I -,''''I'll'',''I'l''''I'll''''I'll'll''''I.I.111.11,111,.1.11.......................................................... II I I I I I 11''I'l''''I'll''''I'll'll''''II.11,11,111,11l''..'',''''.'''',.............................................................''I'l''''I'll''''I'll'll''''I'll''''I'll'',1.1.11,111.11.11,1111............................................................. II II I''I'l''''I'll''''I'l'll''''I'll''''I'll'','ll''''I.I.I.Ill.1111,.1............................................................... III - 11 -''I'l''''I'll''''I'll'll''''I'll''''II.111.11,111,111,111.111.11........................................................... II I I I 1 I I I I -''I'l''''I'll''''I'llIll''''I'll''''Ill.,''.1.111.1111.11'........................................................... 11 I I I I I I I I -''I'l''''I'll''''I'll'll1l.11.111,11111.11,.11.11.11.1111,........................................................ 11''I'l''''I'll''''I'll'll''''I.Ill'.11.1.11I... 1.111.111'',........................................................ II II I I I 11''I'l''''I'll''''I'llIll''''.''''''.,.''.,.1.111,111.11.11,1............................................................ II II''I'l''''I'll''''I'll111.111,111.111.11111.11.1.1.111.111,111,........................................................ 1 I I I I I''I'l''''I'll''''I'll'll1l.111,111.11.11,11.11,11.11.1111........................................................... -11 -------------''Ill.l.,''.'',.,.,.,'ll''''I'll'.111.1111........................................................... III I'll, I I''I'll,''I'l''''I'll''''I'll'll''''I'll'..''.,.''''''''.,.,.......................................................... I-I I''I'l''''I'll''''I'llll,'',.'',''''''''''.,1.11,11.11,1111.111,11ll......................................................... 1 I I 11 11 11''I'l''''I'll''''I'll'll''''I'll''''I'll.11'll''''Ill.l I...................................................... I-I --''I'l''''I'll''''I'll'll'.11,111,111,1111.1'll1l.111,1111.111,11,........................................................''I'll''I'l''''I'll''''I'll'll''''I'll''''I'll'',.11,111,111,11........................................................ 11 I I I 1 I I 1 11 —.''I'l''''I'll''''I''.11,111,111,1111''..''.'''',''''''.................................................. 11 1 I''I'll ---------—. — ------------- ---—.........................................................''I'll I I 1 - --------—,''I'll'I'll''''II.I.I'll''''I'll''''I'll''......................................................... II I I I I 1 1 I''I'll ---—., —-—,''I'll'I'll''..'','''',''''''''...................................................... II II I I I I I I I 11''I'l''''I'll''''I'll'll''''I'll''''I'll'','ll''''I'll''...................................................... III I I 1 11 11''I'll, -''I'l''''I'll''''I'll'll''''I'll''''I'll'','ll''''I''........................................................ III I I 11 11''I'll, - -----------''I'll'I'll.11,11,11,'ll''''I'll'..................................................... I- I I'll, 11 -''I'l''''I'll''''I'll'll''''I'll''''I'll'','ll''''I'll''''I'll'............................................................ II I I I —,,-''I'l''''I'll''''I'll'll''''I'll''''I'll'','ll''''I'll''''I'll'

Fig. 26 Typical Electron Diffraction Pattern of Spinel Phase (Same Rhombohedral Phase Also Present). WADC TR 54-120 Pt 2 36

0 0r:#.::.... 1:x. 111, I. $ 1..,. e,.::,. ".!:!::-: ~li -I I I'll, C-~ I II I.1.. eli r;:::::::::::: I. 1:,...... C) 0 r-4 ITZ;~~~~~~~~~~~~~~~~~~~~~~~~~~~C~.1-11 ~ t~..",I: "Ill a qF fF;;..'*;. i~~~i~~~8 ~~/ i~~~~~.:.:::::::::::::::::::~11 1 ~,.:::..;., -::x l.. I.F4;~C~4 11.1.. I -.1. p~~~~~~~~~~~~~~~~~~~~~~l Z Cd Q I~~~~~~~f ~: I ~~~~ k ~~~~~~~~3~~~ 11=1: rrri~~~~~~~11 I I:~~~~~i~~~~~'~~~~9 o o, P~~~~~~~~~.1 I1 I'll C 1 rq C d - c 4,. - I1"...........::::ii~i~:::ii::::n~i;;~;: ~li~li- -— i-~b ~'ii~-iii;/;~1j. - I... 11. 11,i ~ ~ ~~~~~~~~~,. I...''. 1.~~~~~~~~~~~~~~~~~~~.:iirI:::::.1 ii: f;C ~5> 1~5~~~~~ X ~~~~~IJ... I ~ ~:~:::;..::::,::: t7. k O: i...., 1, 1. I'll...... I I. I, I......-I I~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~:-:ii:- - -i ~ i,. -.y~: I II."'I"',..., 5 f~ - r H I'll,. - w o,:4e w1".. ~ A.6. iiiiii i I 1 - -, i~~i~ ~ ~i,~~j~~::i::: -:::i-:i;:;::ii~~~iiii~~ii:::i.iiiI - I... - -l-.111-1 ~~~I d8 d cr~~~~~~~~~~~~l kC~~~~~~~ (3r~~~~~~~t I. $3.:. tl 1:0) W I Of-.-) - o II - I.1, I:: s I ~3;iiiiiiiiiiiiiiiiiiiiiiij:QS 5iit O ~-.. ip~,-I'll, I........... - I.. 11,., I "... I.. I.. I... ".:.i.1, tl -H IO~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~iiiiiiiiiiijii~cr I......... -::aj::.i i iiiii-i:I 3.I:~:':x:: i ~ii:ji:X r~iiix:"'48- - i;::::::~::~;~iiiijB~~:~i: -. P4;~ ~l.:~~i.. i ~ fO ~ c II...,."... I 1.1 iiii'::: "I'll.,-I,-.. ""I'll, I::::~ ii~ ---: II I I......'."I'l-::-~ -----— l i ~cV I:,;Z C. i 0 = I..., -.iS;-''. ~~~: "'I'll-11-11- -..; ~a~i iiIA.,a I,..I I I iiiii1ii 1: 0 ~ ~~ ~~-:! ~ ~ ~ ~;:::'',, I.I0.'i........''I'l, I i~~~~~~~~~~i ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ a c~~~~~~~~~~~~~~~~~-..I~,r-.. -, I,j~~~~~:.~P_ Ca iiii ~~~ Aiii~~,.~: l...p ".. I I I.;l I,..1,11' —-I' l l -..;.ii.4 - I.ji: I P -*.~F, x X::: I'l:b::::::::.~:rd:::r.."..:i7 O - --- I,^..;;-. I'%%, "I'%%,5 Q n if ~ ~~~~~ rO PSNV ~. 4 z H..,.. ~:.,11111 -- - ~ ~... - ~:~ ~~~~,~~,~ ~~~::!!:~..,,~~ I.,"I'l,"'l "I "I I I I I I I I I I -: ~~11........~ ~ ~~ ~ ~~~~~:~::i:~~,~~~:; ~ %%,""I'll- - -— l- I i:r1r2 -,. ~ ~ - I ~ Il*!!;:I I'll t,, 1 1111-11,i:..!,.~:iii;:i* itir ~.'i rcQ. 11 I. -.,'.., 4 -..'.~~~~~~~~~~~~~~~~~~~~. 4~O k ) F-..~~Q'iii ~::i~ii:aiii~-iii ~:Sf ~ C 5 ~~: %% I'%xx xx ZF~~~W'::~s::3 o; ~~ ~ ~ ~, 1, I.. ~,- " I',, %%,Ow,; - - -l. w ~~~~~' j ~~-..11-111-., —---- -.. %I% %%.....- I ii, ii.1 11 11 1 1, 11 1,I l''' I ( H......... -- - -''I'll. 11. —-%::,:,:,:.~ -- --. I II Ill, IJWVOi.-p 0 1 - -— %,,- ~~~::::::,::,:~~~l*'"',''''''''I 1111'1,1~~~::~ xx~: ~~~ ~ ~. ~ ~ ~'' I'll - - - - - - -- -, 11 - -H 0 0 ~~~~~~~~~~~~~~~r —~~~~~~~ I I-I -— l- -— ~~~~~~~~~~~~~~~~~~~~~~~

98 Z ^-d OZT-5 dLL H3CVA *OTr CaGH'OTTV OI T ad0cL jR'iBC UcTeD- T 4GM o; d:TqsuoT-ETGH O.TToq-IecJ jo uoT OTT-Tddv'- FT- T. NIW - 31W11 0009 009 00Ot 000~ OOO 0001 0.3 0 — - 0 1-s -00 9 11o 0081 1* doOOOO9 1o 0061.o 0002 r 1'I- I II - -------------........ —0 - O L ------------------------------------------. OQ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ------------------------------------------ 02.~~~~~~~~~~~~~~~~~~~~~~~~~~~ ----------------------------------------— ~ ~~~~~~~~~~~~~~~~~ 08 -------------------------- 06

*V q-eaH'X-ITTV WNV TGaurojq fe-.eCa UT'eO-q-cIaM o0 dcTqsuoTqeTa a OToq.L'Ceacd jo uoFT'eTTddV *'' T, NIW - 3W1 0009 OOOg OOOf00 OOO OOOZ 0001 0.4_ 0081 ^ ----------------— I - I -- I —, 08 do 0000O -------— I —--------------------— 0 9 1': l CTI 00Z 08z ~/ I IIc./

ot g'-d OFT- ^l aIi OC[V *L-i-A -'eH "'OTTV OTQ aGdi fuwqa UT'eo-q;-JqTG oe dTqsuoT;BTaI oTfoqqed6 jo uoT;.OTEdd~V'' T, NIW - 3WUll 0009 0009 000 000~ O 0001 0 do0081,, 08............. OZI m z i _0... IV 082............... ------------- 091 - - - -- - -"- __ -- - ---. ----— I Q9~

Tt-T c-d OFT-t HI DG[VM'KOTJTV WV[ TSrojauLoD Ifoqae UTDD-cvitLTMI oq diTSuoTq-eTGa aOTTOqc'eXe Jo Uo-.OTIddv *'I *' T I NIW - 3WI1 0009 0009 OOO ~ ooo 000z 0001 0 S I0061 0 A___ 01 0_~ *9 N~ /o m o, 091 0/ G) ________ —- 0008 _~~~~~~~~~~~~~1'~~~~~~~~~~~~~~~~~~~~~~~~~~O9Z

360 - 32o 20. 320 ________ ___ —--- 280.... — 0000F 240 E 200 _ _ z 160 ~ I60 _____ —---— Te30 ------ - -- SC 80 / o1900-'0.__._... --'1800~F- " 0 1000 2000 3000 4000 5000 6000 TIME - MIN Fig. 55. Application of Parabolic Relationship to Weight-Gain Data; Type 310 Alloy, Heat Vt-5. WADC TR 54-120 Pt 2 42

~'h' E3 acId 0 T-ti' &L OCVM' OTTV aC TsuoJqo f'e.'eCQ UT.iS~-pqT M o;. dTT4suoT0BTG oTToq. t dl: jo uoT,-DOTTddIY 9c *.TJ NIW - 3VWll 0009 OO0009 Ov0 000 000 0001 0. I I I I I.I L —-— /,, 08 — |~.OI m 091 z OZG) o08 - --' —---- I I 09 ~

360:360 |',,, l 320...... 280 240 C... CM E 200 z 160 0 1000 2000 3000 4000 5000 6000 l/' TIME- MIN Fig. 37. Application of Parabolic Relationship to Weight-Gain Data; Type 310 Alloy, Heat X46572. WADC TR 54-120 Pt 2 44 WADC TR 54-120 Pt 2 44

HIGH OXIDATION RATE 1 800 OF 1900~F 2000~F -i —.07 w - VT-5(.0632) z,06 I: 0 w.05 -. ARM- A (.0456) c.04 S j I F L)^~~~~~~~~D (.0364) - X46572(.0316).f 1.o25 _ J-i o02(27) NE.024 CM 6N -X 46572 (.02272) E 1r o.02 z I^- VT-7(.0184) C) z 0.016- VT-5(.01564) 0 g I I LARM-A(.01236).012- J-10(.01216) -X- 46572(.00904).008 ASM (.00732) D(.00616) VT-5 (.00452).00 VT-7(.004) D(.0036) AR Aj0668) -ASM(.002) NOT LINEAR 0 ASM (.000532) LOW OXIDATION RATE Fig. 58. Ratings of Alloys Tested on the Basis of Parabolic Rate Constant. WADC TR 54-120 Pt 2 45

9T F, d OT-+^ aH O[VM'sanoH OT'do009T'8GiLSX VaH'XoTTV OT~ adX, faosjangS AoTag qi-daG' sA uoI^T;Pua *6~'BTi. S3HONI'NOIVlJ3N3d JO Hld3a 9000 SOO'O Ooo'0 OO'00o 100'0 0 SS3U1S ON ISdOtOQ2 _______ ______ I Isdog I ------ - -- 001 t I oo II 33. 00 I (/) I 7C 009 m IS rn I, 33 009 I Ii O.____....____ —----—..-.-....... 006

900 - NO STRES I zl I __ __ __ __ __ 600. oWAC I 500. w500' ocnI U) CO I i300 1430 Ek I k960ps1 1880 psi 5p 0 0.001 0.002 0.003 0.004 0.005 0.006 DEPTH OF PENETRATION, INCHES Fig. 40. Penetration vs. Depth Below Surface; Type 510 Alloy, Heat X27258, 1700~F, 100 Hours. WADC TR 54-120 Pt 2 47

8+F; id OFT- ^ ai DOWA *sanoH OOT 4o080T'98LXX TeaH'OTTV OT adGi(L fG'sEsjng AoTg9 qT-te da SA uo;-pjqaausd Tt -o. S3HONI'NOIV011 3N3d JO Hld30 900'0 O00'O ~*00'O ~00'0 Z0'0 1000 0 IsdOv6' sd0o6g l l!sd~ OZC. 001...1.. 003 SS38U1S ON I 6 Isd09Z I t — I00~ I ~ I l....................... 00 __________________ —----- I — ------ 009 0 0 i Cz............ —-----— 1 ~OOS ____1A _009

60 -— K 1600~F o —-o 1700~F r — 1800~F ------------ 50 z I 13 2: -- ge,. —.-..... —- 40 eN 0. z cn1200 Fig.. 2._S aryPenetatioFreenc -Cu z -J 0 / 6 / w a. 1000 2000 3000 4000 5000 STRESS psi - -- 1600F o~ —-o 1700OF 0r,,50 x z I z Z 0 N W2. o4 0 I 1.5 _0 __ I I g 1.0 -------------------------------------------------- 20 0 ~' S ^ - --------- 10 elongation 1000 2000 3000 4000 5000 STRESS psi Fig. 42. Summary Penetration Depth Curves; Type 310 Alloy, Heat X27258, 16000, 17000, and 1800~F, 100 Hours. WADC TR 54-120 Pt 2 49

0o c;d OSIT-1 Hi OCDM[ *jsnoH OOT Lo009T'o26l9tX THaH'OTTV OT adSil fGJO'eJnS XOT9a Lfd J' sA uoT;'qaCUIa d'tlt('*TjI S3HONI'NOllV8J3N3d JO HLd3G 900'0 00'O t 000' ~000 OO0' 00'0 00 W m I.001 i i 00?,l z00~: lIII i:: 0' i-00g.MC — S3W-S ON m M -— d —--— IsdO- \ 0 09 II o 00 006

900 i! 800 V _ \700-I1000 psi 600 | Zm L. \| I I I I 500 _ _ n3 \! — 12500psl ll|etX65psl 500 1500psi 400 Alloy, Heat X46572, 1900 Hours. 20WADC T 54-120 Pt 2 51 WADC TR 54-120 Pt 2 51

60 2000 50 0 5Zo z z cr 1600 - 40 CM wd ou number SAMPLES SHOWED FISSURES z -5^ 710, THROUGHOUT AT THIS w 0 - /I STRESS AND ABOVE.. wl/ z co I / z / 400o -o -3 10 elongotlon 1000 0Oo 3000 460b STRESS, psi Fig. 46. Summary Penetration-Frequency Curves; Type 310 Alloy, Heat X46572, 1800~F, 100 Hours. 60 50 0 x I w z z ____ __________ __40 N =z z I - 0 o Z "' SAMPLES SHOWED FISSURES 3 I-4r THROUGHOUT AT THIS ~ I?~ ^1(~.~~I STRESS AND ABOVE. w 204 0. /. z c.________ depth I1L ielongation 1000 2000 3000 4000 STRESS, psi Fig. 47. Summary Penetration Depth Curves; Type 310 Alloy, Heat X46572, 1800~F, 100 Hours. WADC TR 54-120 Pt 2 52

2000 1 1 50 SAMPLES SHOWED FISSURES u THROUGHOUT AT THIS STRESS AND ABOVE. 5 1600 ~0 40 CI 3U 0 1200'-30 p 8oo, / 1~ ///. Fig.z~~~~~~~ 48.Sumar Pnet n/ — elongeatiyl 31 Alloy, Heat X46572, 1900~F, 100 Hours. 04. II' I60 0 <0 x 4 ----------------------— 0040 C N - -- SAMPLES SHOWED FISSURES.. 30 T | THROUGHOUT AT THIS --- // 5 500 1000 1500 2000 2500 STRESS pAND ABOVE. Alloy, Heat X46572, 900~F 10 Ho10urs. 00 1000 1500 2000 2500 STRESS, psi kFig. 49 Summ AMPLES SHOWED FISSURES Curves; Type 10 THROUGHOUT AT THIS STRESS AND ABOVE. a. $~ 0 0 I 000 1500 2_000 2500 STRESS, psi Fig. 49. Summary Penetration Depth Curves; Type 310 Alloy, Heat X46572, 19000F, 100 Hours. WADC TR 54-120 Pt 2 53

j Z~ Ct~d OoiT-d tQ L I 3 CVM ~passGazsufn'T01 qetH'ROTTV OT('(1,T fooaJ~anS oTa q cdaaG * sA uoA T X uaTL'qGU *' 0 *!,Tj S3HONI'NOI.LV13N3d JO Hld3a 900'0 SOO'O t00'O ~00'0 Z00'0 100'0 0 I II II I I i o. J10061 I -0091 ------ 10 0 1'OO' 009::10061 9 1 m 00LoOOZ I - do00091 0 \ 00/) C) i' II pq Im 009 I -— 00-8 008 I.: — I —006

-d OI-I-5 HI DT3CVM passa:Ssufn'slnoH 001 OT -A eaH ~'OTTV OTK adGii, facsojng AOTg lq;cdac SA uoFx;IeauaG *T1 -S[J S3HONI'NOI.LV8.L3N3d JO Hld3a 900'0 g00o0 OO'O ~00'0 Z00' 0 00' 0 ^o0Z 0091.' oOOO I 0 I'o0061'I 001 -40008110...............oo,' O 11 1o0069l 0 c) m 009008i ____ —-- --— NOI XO 03SS____n __000ozL ~~ ~~ 030

NUMBER OF FISSURES PER INCH 0 0 0 0 0 0 0 0 0 0 0 0 0 o 0o o o II O - o 0 n 0 d VP 0 00 c-l 0D 00 s- o ~' "1rl (I 1N c+ 00, ~ 0 8 r o OH 0 0 _ _ _ _ -._ _ _ o 0 c3 c+ 00 ~ m 0 0 ~3' o.ox CO 0 0 0) 0 03

a. (O w C 120 LL 0 Ir w 800 m z Cn 400 1600 1700 1800 1900 2000 TEMPERATURE, F Fig. 53. Summary Penetration-Frequency Curve; Type 510 Alloy, Heat J10. 0 x CL W o 15 - z O w 1.0 0.5 w 1.0 ------------------------------ I i1 1 I1a1 1600 1700 1800 1900 2000 TEMPERATURE, OF Fig. 54. Summary Penetration Depth Curve; Type 310 Alloy, Heat J10. WADC TR 54-120 Pt 2 57

z W. 0,: 800 w aD 4 00 ------------....... — v) LL L00 1600 1700 1800 1900 2000 TEMPERATURE, F Fig. 55. Summary Penetration-Frequency Curve; C,) 2 I (L w o 1.5 z 0,,, 1.0 z w a. z: 0.5 -417-0010 — - -— 0 —------- -a00 1600 1700 1800 1900 2000 TEMPERATURE, F Fig. 56. Summary Penetration Depth Curve; Type 510 Alloy, Heat Vt-5, 100 Hours. WADC TR 54-120 Pt 2 58

I z I QC 1200 V) L. 0 w 800 A, H t -- 10 z 400.. I.....ERTURE__~7 1600 1700 1800 1900 2000 TEMPERATURE, ~F Fig. 57. Summary Penetration-Frequency Curve; Type 310 Alloy, Heat Vt-7, 100 Hours. 0 O X z,) W 0. z Ia hI~ 1.0.... —------ z 0.5 5 0.5 ---------- 1600 1700 1800 1900 2000 TEMPERATURE, OF Fig. 58. Summary Penetration Depth Curve; Type 310 Alloy, Heat Vt-7, 100 Hours. WADC TR 54-120 Pt 2 59

900....... ------ 900 800 " 800 \j1 0 700, 700 c+ pe i 0NO STRE;S: \ 600 600 a:\- ---- — 650 psi a. \ I I i a0. ------ 750 psi- SOME FISS!JRES THROUGHOUT (/) \/3 _ w 500 - 500 I LL.- -750 psi - 400 400 IL. I..L 0 0 0 n- cZ ^ o: I tt: 1,1 w W 3| 300 - 300 z z I 200 -- 200 1000oopsi.o 150ps \ NO STRESS 0 0.001 0.002 0.003 0.004 0.005 0.006 0 0.001 0.002 0.003 0.004 0.005 0.006 DEPTH OF PENETRATION, INCHES DEPTH OF PENETRATION, INCHES Fig. 59. Penetration vs. Depth Below Surface; Fig. 60. Penetration vs. Depth Below Surface; Type 310 Alloy, Heat Vt-5, 1800~F, 100 Hours. Type 310 Alloy, Heat Vt-5, 1900~F, 100 Hours.

900 800..... 700. I \ z 600 - a INO ST ESS I a. 400.. ii U) o I w co 300 uz - 200,750 psi 100 lOOOpsi 0 0.001 0.002 0.003 0.004 0.005 0.006 DEPTH OF PENETRATION, INCHES Fig. 61. Penetration vs. Depth Below Surface; Type 310 Alloy, Heat Vt-7, 1800~F, 100 Hours. WADC TR 54-120 Pt 2 61

900 8- o 700 - I-! z 0. w 500 400 - I 0 _ _ _ _ _ _ _ j 300 200 - 500psi 100 NO STRESS 0 0.001 0.002 0.003 0.004 0.005 0.006 DEPTH OF PENETRATION, INCHES Fig. 62. Penetration vs. Depth Below Surface; Type 310 Alloy, Heat Vt-7, 1900~F, 100 Hours. WADC TR 54-120 Pt 2 62

HEAT o —— o VT-5 o_ —-- VT-7 2.000 so-0 I I Cr 1600 1 4. 40 N w a. z l z 400&r t —0 ao _n___,mb _ _ 1_04_.,noo I I, 30, u) I I 500SAMPLES SHOWED FISSURES 20 _oo THROUGHOUT AT THIS number /. 400 -------— 4- -- -- -THI- t0 elongation _- _ - _ __ _._____ 5'00 000 1'500 2000 2500 STRESS, psi Fig. 63. Summary Penetration-Frequency Curves; Type 310 Alloys, Heats Vt-5 and Vt-7, 18000F, 100 Hours. HEAT o —-o VT-5 o C.) x 0 z _________ 4 N Z b. z i.5 __ _ _e 30 a Io o~ I 0., depth -npd~ ^STRESS AND ABOVE. w 1.00.ooo 00 2000 250 STRESS, AND ABOVEs / a. 2 0.5 T 10 elongation 500 romo 1500 2000 2500 STRESS, psI Fig. 64. Summary Penetration Depth Curves; Type 310 Alloys, Heats Vt-5 and Vt-7, 1800~F, 100 Hours. 4ADC TR ~4-120 Pt 2 63

2000 50 Cl, z z,: 1600. 40 c I. z w o z p / cn 1200 7_ _ 30 / 3 U/ w we~~~ /. _ number W /z;/ / I SAMPLES SHOWED FISSURES a. 400.t S.t - -— / /- ---— a THROUGHOUT AT THIS 10 0 -' - ^I-elongation STRESS AND ABOVE. I1. ~ -" —- i!If I 500 1000 1500 2000 2500 STRESS, psi Fig. 65. Summary Penetration-Frequency Curves; Type 310 Alloys, Heats Vt-5 and Vt-7, 1900~F, 100 Hours. WD T 5-2 I 2 6460 HEAT o —— o VT-5 j0~~~~ ~~ ~ S~~~~~~~~50 x x z z _______ 40 N w 1 / IU I - 0. z r: - - /I STRESS AND ABOVE. _I' STRESS. psi Fig. 66. Summary Penetration Depth Curves; Type 310 Alloys, Heats Vt-5 and Vt-7, 1900~F, 100 Hours. WADC TR 54-120 Pt 2 64

59 e;d OT1-T5 HIO 3OVM slnoH 00T'V;T-H'OlTV IWHV TiauoJIOD faGojenS T OTa L4;dsa SA UOT;e;TGUsd *Lg 9TdJ S3HONI'NOllVU13N3d JO Hld30 900' 0 OO'O f00' 0 ~00'0 Z0000 1000' 0 ~'q ~., ULINOO 001,~40 9,, 009 109:l.008 I z l ooo z X03itl\ I' i I]'4,,l~~~00 I -doOO6 I C D I I* 0019 m I, i 009 NOVOIXO 03SS38lSNn 1 OOg r 1> 1

=IC NUMBER OF FISSURES PER INCH 0 0 0 0 0 0 0 0 0 n=- O do - Z- - - O — C+. —-— 0HA - W0 0 0~ ~' -- / -- -, O 00 0.0 f N oD 0o c ^0 o 0 r;D 0 0C o0 o o 0 D rrl / 0 o r C+ 0::d - IT- C __ o 0 <4 O0 /0 0>~~~~~cJ) ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~() o-, ~n)'0 C w -D 0 / P rn O 0 r0 0 M 0

900 - 800 700 "00'\ D UNSTRESSED OXIDATION z 600 w 1700OF a. L) 500 - ~0 1800~F 400.11 U. I,oo 20000F ~200 100 IL.... 1600~F 0 0.001 0.002 0.003 0.004 0.005 0.006 DEPTH OF PENETRATION, INCHES Fig. 69. Penetration vs. Depth Below Surface; Chromel ASM Alloy, 100 Hours. WADC TR 54-120 Pt 2 67

900 800 --- I 700 III UNSTRESSED OXIDATION z w l 500..._ n I- -17000F w I 7I U. 400 Ua\. "-'- 20000F ~.- 1-1600F M. I'l m 300 -' —--- 1z 1800OF 200 1900OF 100 0 0.002 0.002 0.003.004 0.005 0.006 DEPTH OF PENETRATION, INCHES Fig. 70. Penetration vs. Depth Below Surface; Chromel D Alloy, 100 Hours. WADC TR 54-120 Pt 2 68

cALLOY D —--- CHROMEL ARM [ (HEAT A) | X —-— 4( CHROMEL D UNSTRESSED OXIDATIO O.. —-- CHROMEL ARM sz I(HEAT B) COT 10 —- 10 CHROMEL ASM __ U) 1200 \o" <UL / / ~< 800OD 0 - 400 CONTROL 1600 1700 1800 1900 2000 TEMPERATURE ~F Fig. 71. Summary Penetration-Frequency Curves; Chromel Alloys, 100 Hours.

C' IM^ g ALLOY 0- ---— O CHROMEL ARM F- | (HEAT A) ro 0o X ) —— X CHROMEL D UNSTRESSED OXIDATION -d 0 r X x ----— a CHROMEL ARM w (HEAT B) z - 0 CHROMEL ASM a. o r _ 1.5 - Q. 2I 0.5 LU L CONTROL 1600 1700 1800 1900 2000 TEMPERATURE ~F Fig. 72. Summary Penetration Depth Curves; Chromel Alloys, 100 Hours.

rVu I I' 5IU~i I 600 11- 240 psi a_ 1 NO STRESS w 500 cn ml III ~gi l 300 ii z 500 psi 940 psi 200 \1500 psi 0CONTROL \ 100 \ \ 0 0.001 0.002 0.003 0.004 0.005 0.006 DEPTH OF PENETRATION, INCHES Fig. 75. Penetration vs. Depth Below Surface; Chromel ARM Alloy, Heat A, 1800~F, 100 Hours. WADC TR 54-120 Pt 2 71

900 800 - I —-------- 800 700 z 600 Lc,, 500' U 5 400 0 _cr ~880 psi. 0I 200 2990psi 240 &I 540 psi NO STRE S I00'CONTROL 0 0.001 0.002 0.003 0.004 0.005 0.006 DEPTH OF PENETRATION, INCHES Fig. 74) Penetration vs. Depth Below Surface; Chromel ARM Alloy, Heat A, 1900F, 100 Hours. WADC TR 54-120 Pt 2 72

900 - 800 700 z_ a.OI 500 i1 ~cn ~DE NO STRES U-~~I 240opsi -O.500psi 660 psi - 69 ps 0 0.001 0.002 0.003 0.004 0.005 0.006 DEPTH OF PENETRATION, INCHES Fig. 75. Penetration vs. Depth Below Surface; Chromel ARM Alloy, Heat A, 20000F, 100 Hours. WADC TR 54-120 Pt 2 75 4b~~~~9._~._,

+[L 3;d O0T-i^ HI DffVM ~ sanoH OOT o00OO1T'XOTT~V 14-V TauVoaq3 faJo jzJng`oTag qdc{J ~s OA uoTqoaGuaGJ 9J'9 ST S3HONI'NOILVW.L3N3d JO Hld30 900'0 OOO trOO'O ~000 zO'0 100'0 0 ___________________________d 00, 1sd - 001 z -- -- 00~ CD II -u oopo OOg m I 009 L 006 OO Z

900 l 800 - ---------- 700 600 cS w 0. 1 _ _ _ _ _ _ _ _ cZI QCR. _500 U) 400 I 200.... 1000 psi 100... NO STRESS 0,^^*IIOOpsi 0 0.001 0.002 0.003 0.004 0.005 0.006 DEPTH OF PENETRATION, INCHES Fig. 77. Penetration vs. Depth Below Surface; Chromel ASM Alloy, 1900~F, 100 Hours. WADC TR 54-120 Pt 2 75

900 i i cc I 800 -. - ll.U( 200 1U 400 300 650 psi 500 01O 3 50150000 s 100 --— Chrome- ASM Alloy, 2000-F, 100 Hours. NO STRETR 0 0.001 0.002 0.003 0.004 0.005 0.006 DEPTH OF PENETRATION, INCHES Fig. 78. Penetration vs. Depth Below Surface; Chromel ASM Alloy, 2000~F, 100 Hours. WADC TR 54-120 Pt 2 76

800 - --------- 700 - 700 500psi 60 a:: 79 P 750psi I. I 40 -I oS i w I i 300.... z I I' — 850 psi'I I NO STRES 200-j.. V 100 0 0.001 0.001 0.02 0.003 0.004 0.005 0.006 DEPTH OF PENETRATION, INCHES Fig. 79. Penetration vs. Depth Below Surface; Chromel D Alloy, 1800~F, 100 Hours. WADC TR 54-120 Pt 2 77

'sjnoH OOT 0',OO6T Z'oTTV C Tai uot3O f GoojnJg _OTGa t~dCIC ~SA u0oTqh'q9UGcj -'0 STJ S3HONI'NOllV1.3N3d JO Hld30 900'0 900'0 V00'0 ~00'0 300'0 100'0 0' \!?S3t1LS ON _______ _______-001 00? ___ __ __ OO D,~oo'\ Ui\l m.sd 009 OOL II r 006

900 - 800 - 700 - \ - z 600 i.: w 500 Co D Al,500psi 400 -.. U. r300 1 0 I - 300 -- -........ —z I 200........... 100 " —---- \ NO STRES 0 0.001 0.002 0.003 0.004 0.005 0.006 DEPTH OF PENETRATION, INCHES Fig. 81. Penetration vs. Depth Below Surface; Chromel D Alloy, 2000~F, 100 Hours. WADC TR 54-120 Pt 2 79

50 r o SAMPLES SHOWED FISSURES z Cn THROUGHOUT AT THIS: w STRESS AND ABOVE.40 z a. number I z = 1200 |/ 530 cn z z3 / 0 - z /s / 0 / "' Chromel ARM Alloy, Heat, 800~F, 100 Hours. z z 1 - 00a. 500 1000 1500 2000 2500 STRESS / si J Z/ Fig. 83. Summary Penetration-Frequency Curves; Chrol ARM Alloy, Heat 1000 100 Ho0 ur IC7 5-2 Pt2850 Fig. 82. Summary P e netraion-ren ICurnes.5.~STRES AND AOTE...... 4. 30 o I 50 a. w wz ~~~~~~~~~~~~ LZ 0 2 z 1. 0 2 L-. / / z. —.=Z::::,elon ion

60 50 -x w~/ / z number / zI runnb"..-|.. I / a |c/ SAMPLES SHOWED FISSURES 40 N K /I- THROUGHOUT AT THIS Z,.|3m / I STRESS AND ABOVE. z S w~~~~~~/ 0 ~ / 0. / o i 800 20 w / z ~z | /elong tion a0 400 10 / 500 1000 1500 2000 2500 STRESS, psi Fig. 84. Summary Penetration-Frequency Curves; Chromel ARM Alloy, Heat A, 1900~F, 100 Hours. J 30 60 o ----------- } - - - - - - 50 0 o) ( SAMPLES SHOWED FISSURES / z THROUGHOUT AT THIS z _: " STRESS AND ABOVE.. z/' / o 1.5. z z o / o /I 0::w 54-120 Pt 2 81 z 1.0 d/ pthD2 - elongt Fig. 8. Summary Penetration Depth Curves; Chromel ARM Alloy, Heat A, 1900~F, 100. Hours.

------?, — - SAMPLES SHOWED FISSURES -- - 50 I.. -- - THROUGHOUT AT THIS w z STRESS AND ABOVE. z L z mr umb z a / o 1200. U. z, elonga / o0 /, LL / -/ / 9w r 800 20I.: cooS, / psi 500, Heat 1000 100 2500 m / 4001 / I I 1 1 I0 I.' elongation 0 o0 500 1000 1500 20 0 2500 I ________,____ 60 o C / w / THROUGHOUT AT THIS 0 0. STRESS AND ABOVE-.- - 10 on ation z 40 N z,,, / 0,.5..... o I~ z z o / 0j,, / w n" ~/'z --- ____depth ____ _ 500 1000 1500 2000 2500 STRESS, psi Fig. 87. Summary Penetration Depth Curves; Chromel ARM Alloy, Heat A, 2000~F, 100 Hours. WADC TR 54-120 Pt 2 82

60 50 zo^~~~~~ ~~~SAMPLES SHOWED FISSURES THROUGHOUT AT THIS WQ 4000 40 ca ffi g~~~~4000 r. ~\, | STRESS AND ABOVE. 0. a II I I ~ 3o000oo - --- r- - I30.._... numbr' \longaItion,,500 2000 10 2500 STRESS psi Fig. 88. Summary Penetration-Frequency Curves; Chromel ASM Alloy, 1800~F, 100 Hours. _.. 1000 ------------------ --------— I60 LI r -~ 1. I Z 50, l SAMPLES SHOWED FISSURES | z - THROUGHOUT AT THIS ~~~z ~~~~~~~~~~/ 500 1000 1500 2000 2500 -STRESS, psi Fig. 88. Summary Penetration-Frequency Curves; x a ~C 1__Alloy,_1800~F,- 10THROUGHOUT AT THISo WADC.TR z 1.5 3 a / S 0.5 - _______ 10 --- -- _-.. dehtJ-. JI|~~~ 4~~/engotlongto 500 1000 1500 2000 2500 STRESS, psi Fig. 89. Summary Penetration Depth Curves; Chromel ASM Alloy, 18000F, 100 Hours. WADC TR 5.4-120 Pt 2 85

60 2000 1 I \ 6 C | | o z z a' 1600 40 c4 w a. z Chrome ASM A/ \ z )',number / \ z 60 ~ / SAMPLES SHOWED FISSURES - 0 31200:0 1c 1200 ---- - - = THROUGHOUT AT THIS 30 LL n z [U.,0 STRESS AND ABOVE. CD 0 / W lAJ / Z / Co z / 0 / 400 I10 elongation 500 1000 1500 2000 2500 STRESS, psi Fig. 90. Summary Penetration-Frequency Curves; Chromel ASM Alloy, 1900~F, 100 Hours. 60 0 5C cO I z 0 - z w SAMPLES SHOWED FISSURES 0 1.,5 --------------- \ - -LL THROUGHOUT AT THIS 30 z 0 c3 STRESS AND ABOVE. o w / 0. / z w 0' I — / w w I / a5 10 I depth 500 1000 150O 2000 2500 STRESS, psi Fig. 91. Summary Penetration Depth Curves; Chromel ASM Alloy, 1900~F, 100 Hours. WADC TPR 54-120 Pt 2 84

60 2000. 50 CD =I~~~~~~~~~~~~~~~ w~~~~~~~~~~I..-'number / cc 1600 40 0C - \ / SAMPLES SHOWED FISSURES c ) _ THROUGHOUT AT THIS M I STRESS AND ABOVE. g c01200 30........ 30 Lg 2400L3 ~~~I elongation I z. 00... I I I 500 1 000 1500 2000 2500 STRESS, psi Fig. 92. Summary Penetration-Frequency Curves; Chromel ASM Alloy, 2000~F, 100 Hours. 60 "x Iw! elongation I w z z 40- 400 _ 10 / SAMPLES SHOWED FISSURES I: I, z THROUGHOUT AT THIS W.5 TRESS AND ABOVE. 0 1.5 -t — - 30, z I I I e L C P 20 500 1000 1500 2(000 2500 STRESSj psi w I Fig. 9. Summary Penetration-Frequency Curves; 0.5 10 I ---—. —-—....... 50 longation.0 /10 2000 2STRESS psi Chromel ASM Alloy, 2000~F, 100 Hours. WADC TR 54iS-120 Pt 2 85 WADC TR 54-120 Pt 2 85~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~.

60 50 C.) 6I z _ x ~ ~ ~ ~ ~ ~Iz S |SAMPLES SHOWED FISSURES z 4000 THROUGHOUT AT THIS 40 N I. | i STRESS AND ABOVE. z C) / z w 0 3000 30 Cl z 4 el ngation 3j LL. 2000 20 w Z 1000 ____. 10 Tm~~ 3 w~60 0X ~ ~ / 0 x i ii Cn) 0 SAMPLES SHOWED FISSURES 2000 2500 -S STRESS AND ABOVE.psi Fig. 9 Summary Penetration-Frequency Curves; Chromel D Alloy, 800~F, 100 Hours. z 30 I-0 z6 O4 I Z I i — / u Z. I elor zC.) ~0.5,- -7 ig. 95. Summary Penetration Depth Curves; Chromel D Alloy, 1800~F, 100 Hours. WAIDC TR 54-120 Pt 2 86

60 50 CO 5i0 looo l50 2000 2500w 4000 10 40 w / X L / z c/ A / SAMPLES SHOWED FISSURES ~S i \ 4 |TH —- OGTHROUGHOUT AT THIS o 3,5 _. STRESS AND ABOVE. 30. / un ber elongation | 000 00 2000 200 STRESS, pi 1000lChromel D Alloy, 1900F, 100 Hours. 500 1000 1500 2000 2500 STRESS, psi Fig. 96. Summary Penetration-Frequency Curves; Chromel D Alloy, 19000F, 100 Hours. 60.50 0 x 5z~~~~~~~~ /<. ~~~~z II 2 ------- —, - - 40 I *i ~/2 I/ SAMPLES SHOWED FISSURES 1 o THROUGHOUT AT THIS 3 1z.5 J' STRESS AND ABOVE. - S/hoelongatiors J ~J ---- ( x w z 1.0 20 -L /. I 0 500 1000 1500 2000 2500 STRESS, psi Fig. 97. Summary Penetration Depth Curves; Chromel D Alloy, 19000F, 100 Hours. WADC TR 54-120 Pt 2 87

....illl~~~~~~~ l 5060 50 w IC-)~ ~ ~ ~ ~ ~ ~ ~ ~ ~~~~~I c 4000 1 40 N w a- z',' / o h LL W =' z / 7 SAMPLES SHOWED FISSURES w 1000 | /i - | ___ THROUGHOUT AT THIS 10 3000 / 30 / STRESS AND ABOVE. STRESS, psi Fig. 98. Summary Penetration-Frequency Curves; Chromel D Alloy 000~F, 100 Hours. x II zWT T 54-12__0 40 TH Fig. 98 SummaryPenetration-Frequency Curves;/ COO w z^~~~~ w z I4 (2 0 z / ~~~~~~w A~~~~THROUGHOUT AT THIS 0.5 10 STRESS AND ABOVE. -,depth 500 1000 1500 2000 2500 STRESS, psi Fig. 99. Summary Penetration Depth Curves; Chromel D Alloy, 2000~F, 100 Hours. WADC TR 54-120 Pt 2 88

900 800 700 600.. I, 500..8 400IL. I o 0 1600OF?300 200 --------- i 1002 _1700F____ 0 0.001 0.002 0.003 0.004 0.005 0.006 DEPTH OF PENETRATION, INCHES Fig. 100. Penetration vs. Depth Below Surface; Inconel Alloy, Run 50A, 10 Hours. WADC TR 54-120 Pt 2 89

900 800 I17000F19000F 700........... Q: UJ w 500 QL 0 I cn) LLn I 400 0 I)I I 300 200 ----— 1'S0 —-16000F * -CONTROL 0 0.001 0.002 0.003 0.004 0.005 0.006 DEPTH OF PENETRATION, INCHES Fig. 101. Penetration vs. Depth Below Surface; Inconel Alloy, Run 50B, 50 Hours. WADC TR 54-120 Pt 2 90

T6 36;d 0ET-+[^ ai OCEVM's.lnH OOT' 30 un'O-OTTV TeUOOuI f!a ojnS OT-e'q cIsa ~ SA uoT;.';q.suad'OT *ST, S3HONI'NOIVN13N3d JO Hld3O 9' 1 00'0 0 l.\..10NoiNOO l I111 I -— I —I —----------— ^- ooz 001' I'S I 00 AO01 I --------— i i \ omi m, d.0091 S 0 JOOOOZ — H.1 J...0091. \I\..0061 ----—.... ------— L00009,006

RUN NO. DURATION,HR.. ----— X 30A 10' — ----- 30B 3 0 I aZ o 0 — --- 30C 100 Q: 4200, _-; h: / ~ 800 CONTROL 1600 1700 1800 1900 2000 TEMPERATURE, /F x / -— 30A 10.- * \ - x -------- Y -.30B 30 I |O —-— J 30C 100 0 -___ —-__,_____,______ aONTROL 1 6.00 700 180 1900 2000 TEMPERATURE, ~F Fig. 103. Summary Penetration-Fre Duency Curves; Inconel Alloy, Effect of Time. RUN NO. DURATION,HR. x —-—.X 30A I0. a —---— a 30B 30 - 0 X ~o 0. — — 0 30C 100 0 (r, 1.0 CONTROL 1600 1700 1800 1900 2000 TEMPERATURE, OF Fig. 104. Summary Penetration Depth Curves; Inconel Alloy, Effect of Time. WADC TR 54-120 Pt 2 92

900'l i ALLOY TOTAL NO. MEAN DEPTHin 80 I INCONEL 2046 0.464 X10-3 800 " l b: | CHROMEL ARM 2440 1.078 XI0-3 l*,(HEAT A) | l I1 I TYPE 310(X27258)2047 0.948X 10-3 700 -—! I I I soo I' 6 500.... Fig. 1.ettnsDt-eCHROMEL ARM V) I(HEAT A) 400 Wt 5 I' l I I I 100 Fi. 105 Penetration vs. Depth Below Surface; Inconel, Chromel ARMand Type 510 (Heat X27258) Alloys, 19000F, 500 Hours. WA2DC TB 5-120 Pt 2 95 -.TYPE 310 [X27258) i Il WADC TR 54-120 Pt 2 95

900 800 _ _ —--- 700 600 a. 600,, 1800OF B i [1900OF CL 1 c oo0 IU 400 U U l. co 200~- 00 100,. 0 0.001 0.002 0.003 0.004 0.005 0.006 DEPTH OF PENETRATION, INCHES Fig. 106. Penetration vs. Depth Below Surface; Type 510 Alhoy, Heat X46572, Dewpoint = +60~F, 100 Hours. WADC TR 54-120 Pt 2 94.

900 i I I I I z I 700 --— OF I u. 4000~ f z. I - I 00 - u. I 400 I 100 I 18000F 19000F 0 0.001 0.002 0.003 0.004 0.005 0.006 DEPTH OF PENETRATION, INCHES Fig. 107. Penetration vs. Depth Below Surface; Type 310 Alloy, Heat J10, Dewpoint = +60~F, 100 Hours. WADC TR 54-120 Pt 2 95

96 d O~ oT-1 HI[ OD[T ~sxoH OOT oJ09+ = WuTodG[aa'OTTV NSV TG-uiojqD f!o.ejanc Ao-[TG qq-dca'SA uoTq.e:RGau@a'90T'OT$ S3HONI'NOIJ.lV13N3d.O Hld30 9000 9OOt'O ~00'0 0OO'O 0'0 100'0 0 002 [! t' ~~~~~I ZC) 0080 c III'1" -e0061-,i:: \i ~ 009 4.000 00I 009

-— o OHROI EL ASM Co | -|| —-- 310, H AT X46572 z a. 4000 ---- hU (0 Z 3000 2000 (0 00 ------ _-_- -.1.__ 1_ _ 1700 1800 1900 2000 TEMPERATURE OF Fig. 109. Summary Penetration-Frequency Curves; Chromel and Type 310 Alloys, Dewpoint = +60~F, 100 Hours. o-o CHROM L ASM' ------ ----- ----- -u —, 310 HE AT JlO x co ---- 310, HEAT X46572 LU z 0 z I ILU z 0 Q. 1700 1800 1900 2000 TEMPERATURE F Fig. 110. Summary Penetration Depth Curves; Chromel and Type 310 Alloys, Dewpoint-= +60~F, 100 Hours. WADC TR 54-120 Pt 2 97

900 I I 800 700 z 600 UJDw \ 20000F L 500. 400 0 I %"t-l 700\F 200 o 600F 18000F \ 1900F 0 0 001 0. 002 0.003 o.o'"O6'5- o)s DEPTH OF PENETRATION,INCHES Fig. 111. Penetration vs. Depth Below Surface; Type 310 Alloy, Heat 31372, As-Received, Run 5533. WADC TR 54-120 Pt 2 98

66,'-d OT L-'- HI DtVlM *Cn uCn'parauu) V pus %bL6 pasonpa~ {ZlTu ^eaH'XOTTV OT1 adl fa!o'ejng OTa qWdaa' *sA uollTaua U9d -TI *' TF S3HONI'NOIJY.13N3d dO Hld3a 9(000 goo0o,OOO,00'0 - 100,0 0 I I I1" 0001 ll| | loOOL\11 | 0 \I1 or.. 09 _:___oOO0 I0061 I.;o 009 I ~00~ IIII.. 006

RUN NO. CONDITION X -----— X 33 AS-RECEIVED I |. —---- 33 REDUCED 97%o Z AND ANNEALED oL ___________ ___________I1-__, aLL. 0 160/ ri12000.800. IT' ^ ^ — ^ ---- ----- ---- -.." 1600 1700 1800 1900 2000 TEMPERATURE, OF Fig. 113. Summary Penetration-Frequency Curves; Type 310 Alloy, Heat 31372, 100 Hours, Effect of Preferred Orientation. RUN NO. CONDITION X ----— X — 33 AS-RECEIVED....')' 0 X --------- | 33 REDUCED 97 I AND ANNEALE 1600 1700 1800 1900 2000 TEMPERATURE, ~F Fig. 114. Summary Penetration-Frequency Curves; Type 310 Alloy, Heat 31372, 100 Hours, Effect of Preferred Orientation. X X AS-RECEIVED __________ 0 I z w 1. Qw 1.0 z I 0z:0 1.0.. ------—. —--------. —---------------— ~ —- ----- g ~ —-^ —X 1600 1700 1800 1900 2000 TEMPERATURE, ~F Fig. 114. Summary Penetration Depth Curves; Type 310 Alloy, Heat 31372, 100 Hours, Effect of Preferred Orientation WADC TR 54-120 Pt 2 100

UNIVERSITY OF MICHIGAN 3 910 1 3524 4211111 3 9015 03524 4253