ENGINEERING RESEARCH INSTITUTE THE UNIVERSITY OF MICHIGAN ANN ARBOR. MICH. SEVENTH PROGRESS REPORT TO MATERIALS LABORATORY WRIGHT AIR DEVELOPMENT CENTER ON EFFECT OF PRIOR CREEP ON MECHANICAL PROPERTIES OF AIRCRAFT STRUCTURAL METALS by J. V, Gluck H, R, Voorhees J. WD Freeman Project 2498 Air Force Contract No, AF33(616)-3368 Supplement 1(57-850) Task No, 73605 August 25, 1957

SUMMARY This report covers progress made under Contract AF33(616)-3368, Task No. 73605, for the period from May 26, 1957 to August 25, 1957 on a study of the effect of prior creep on the short-time mechanical properties of several aircraft structural sheet metals. The materials under study include 2024-T86 aluminum alloy, C110M titanium alloy and 17-7PH (TH 1050 condition) precipitation-hardening stainless steel, During the period covered by this report an improved furnace for elevated temperature tension-impact tests was constructed and placed in operation, In addition, an anvil and set of dies for conducting cold bend tests were constructed, Tension-impact tests at 350'and 400'F were conducted on samples of 2024-T86 subjected to prior creep at these temperatures, The results indicate that total deformations above 1 percent had an adverse effect on tension-impact strength, Tensile tests of C1 OM at room temperature following prior creep at 650-, 700~, and 800'F showed increases in strength with increased total deformation with a maximum effect for 700~F exposure, The effects of unstressed exposure on elevated-temperature tensile properties and room temperature and elevated-temperature compression properties were determined for 17-7PH, In general, changes in these properties were moderate, although the room-temperature compression test data showed a number of inconsistencies The effects of prior creep on the tensile and compression properties of 17-7PH at both room temperature and the temperature of exposure were determined for a number of prior deformations, Deformations above 1 percent adversely affected the ductility of samples exposed at 600 and 800 F and subsequently tested at these temperatures or room temperature, Prior creep tended to raise both the tensile and yield strengths, Compression yield strengths were generally lowered by prior creep with the greatest effects found for 600 F exposure,

INTRODUCTION This report is the seventh progress report to be issued under Air Force Contract No, AF33(616)}3368, Task No. 73605 and the second report to be issued under Supplement No, 1(57-850), The period covered is from May 26, 1957 to August 25, 1957, The purpose of the investigation is to study the effects of elevated temperature prior creep exposure on the subsequent mechanical properties of three aircraft structural sheet metals, The materials and temperatures at which each are being investigated include: 1, Aluminum Alloy 2 2024-T86 at 350', 400' and 500@F 2, Titanium Alloy C1 10M at 650', 7000 and 800'F 3. Stainless Steel - 1777PH (TH 1050 condition) at 600', 800' and 900'F The work accomplished during the first year of the contract was reported in WADC Technical Report 57-150, This work included a fairly complete study of the aluminum alloy and some survey work on the stainless steel, The present phase of the investigation is concerned with the titanium alloy and the continuation of the investigation of the stainless steel, Stressed and unstressed exposure tests are being conducted for times of 10, 50 or 100 hours, The stressed exposures are carried out at the nominal stresses to yield 0 5, 1, 0, 2, 0, and 3, 0 percent total deformation in the specified time interval, The total deformation is defined as all deformation, elastic and plastic, that occurs during the application of the load and during the creep of the specimen at the testing stress and temperature, By fixing stress, temperature, and time, it is necessary to accept whatever total deformation is obtained, Time elongation data are recorded for each test and all correlations of subsequent properties are made in terms of the actual deformation,

2, After the specified exposure the following properties are evaluated at either room temperature or the temperature of prior exposure; short-time tensile properties; short-time compression properties; tension-impact strength; and also hardness determinations at room temperature, Cold bend tests are to be conducted on selected conditions, Where significant effects are noted, metallurgical studies will be employed to explain their cause, The stresses for the nominal exposure conditions are determined from curves of stress versus time for the specified total deformation, established for each material at each temperature of interest, The properties of the exposed material are compared with the properties of unexposed material which have been established by 7 to 10 tests of samples chosen at random from the various sheets of test material, Replicate exposure tests are run in many cases in order to ensure generality of the results, The contract specified that the test materials be obtained in the form of 0, 064~ inch thick sheets. The test specimens are cut so that each material is tested in its nominally weaker direction, Thus, the aluminum and stainless steel are tested crosswise to the sheet rolling direction, while the titanium is tested parallel to the sheet rolling direction, Test Materials and Specimen Preparation The aluminum and titanium alloys are tested as furnished by the manufacturer while the stainless steel was heat treated to the TH 1050 condition at the University, All materials as received conformed to their nominal composition limits, Complete details of composition and specimen preparation are contained in the First Summary Report, WADC TR 57-150, The aluminum alloy 2024-T86 contains 3, 8 - 4, 9 percent copper 0, 3 0, 9 percent manganese, and 1,2 1, 8 percent magnesium, As furnished by the producer, it is cold worked and artificially aged,

3. The titanium alloy, C1 10M, is a binary alloy containing 7 - 9 percent manganese, It was furnished in the hot-rolled and annealed condition, The 17-7PH alloy is a precipitation hardening stainless steel containing 16 - 18 percent chromium, 6, 5 - 7, 75 percent nickel, 0, 75 - 1, 5 percent aluminum, and 1 percent manganese,, It is received in the annealed condition and then given the TH 1050 heat treatment, This heat treatment consists of double aging, first at 1400.F and then at 1050Fo. Sheet sampling procedures were developed for each material in order to ensure generality of the test results, A modular, repeating sampling system was designed for each sheet. The module system allows randomization of specimen selection with respect to both the length and width of the original sheet, A code number stamped on each specimen identifies the sheet number, module number, and position within the module. The exposure specimens were so designed that the specimens for the subsequent tension, compresssion and tension-impact tests could be machined from them with minimum difficulty, The shoulder radii and gage sections are ground after the specimens have been milled to rough dimensions. Test Equipment and Procedures Testing equipment and procedures developed in the first year of the contract were discussed in the First Summary Report, WADC TR 57-150, and will. not be repeated here. In the period covered by this report two new items of equipment were completed, These consisted of an improved furnace for tension-impact testing at elevated temperatures and equipment for conducting cold bend tests. As discussed in previous reports, elevated temperature tension-impact tests had been run by heating the specimen assembly in a separate furnace and then attaching it to the pendulum head while it was hot,

4. Originally it had been planned to heat the specimen while it was attached to the pendulum head, A standard creep testing furnace was adapted to allow heating the specimen, its gripping assembly and the impact striker while all were in the vertical position prior to the release of the pendulum latch. It was intended that the entire assembly would then fall from the furnace, Unfortunately, a combination of circumstances caused a large temperature difference over the specimen gage length, These included the high thermal conductivity of the aluminum specimens, the relatively large unheated mass of the pendulum head, and the clearances necessary in the furnace core in order to accommodate the impact striker, The heating elements of a standard furnace did not permit compensation for the large temperature difference that ensued, Consequently, the elevated temperature tension-impact tests reported in the First Summary Report, WADC TR 57-150, were run by first heating the specimen assembly in a separate furnace and then attaching it to the pendulum, This procedure was time-consuming and clumsy, necessitating compensation for the time delays involved, However, fairly consistent values of impact energy could be obtained in this way, Nevertheless, it was felt that improvement of this procedure was highly desirable and this was accomplished by the construction of a small split furnace that just fits around the specimen grips, When the test temperature is attained, the furnace is opened like a book and removed from the specimen assembly, and the pendulum latch released, The time required for this operation is about 3 seconds and the total time between removal of the furnace and the fracture of the specimen is less than 5 seconds,, The furnace itself consists of a split-transite box about 4 inches square by 6 inches long, the halves of which are hinged, The heating elements are contained in a pair of drilled-out fire bricks which form the core of the furnace. The inner furnace liner was fabricated from sheet stainless steel. The heating elements consist of four 285 watt and four 90 watt cartridge heaters inserted in the furnace annulus parallel to the core, A provision is made for varying the longitudinal position of the heating elements

5. in order to ensure proper temperature distribution. The 90 watt heaters are wired through a controller to provide on-off control, while the 285 watt heaters are on continuously. The power input to both sets of heaters is controlled by a Variac, This allows close control to be obtained at any desired temperature level. At temperatures up to 900~F it has been possible to obtain specimen temperature variations of less than 3~F over the gage length. Thus, the new tension-impact furnace allows a two-fold improvement in procedure over the previous method. First, temperature distribution problems are minimized, and second, the time to conduct a test has been greatly reduced. The other equipment completed during this report period consists of a set of dies for conducting cold bend tests on sheet samples. The test consists of bending the samples to a 75-"V" over successively smaller radii. A set of nine 75"'V" indenters whose point radii vary in graduated steps from 1/4-inch to a sharp point are used to press the sample into a 75'"V"-shaped cavity in a test anvil. The specimen dimensions are 0, 5 inches wide by 2-3/4 inches long, The test is conducted in a tensile machine utilizing the compression head, The procedure is simple and consists of bending the samples over the smaller and smaller radii until visible cracking is noted. In preliminary tests it was found that the aluminum alloy, 2024-T86, and the stainless steel, 17-7PH (TH 1050 condition), cracked at the largest radii and,consequently, one or two additional indenters with even larger radii are being constructed. Samples of C 10M in preliminary tests did not evidence cracking until at least four or five of the indenters had been used, Some additional preliminary tests are to be conducted following completion of the test indenters with larger radii. It is then anticipated that bend testing will be conducted on samples given stressed or unstressed exposure at the intermediate testing temperature selected for each material,

6, Efforts continue on the development of procedures for recording room-temperature stress-strain curves in tension-impact testing, Consideration has been given to the instrumentation of the system, Experimental work on this phase has been delayed while the tension-impact equipment was tied up during tests of the elevated temperature impact furnace. RESULTS AND DISCUSSION Elevated Temperature Tension-Impact Tests of 2024-T86 During the first phase of the contract a series of specimens of 2024-T86 were given prior creep exposures at 350' or 400~F with the intention that they be tested in tension-impact at the same temperature. The actual tests of these specimens were delayed until planned improvements were made in the test equipment, Following the completion of the new impact test furnace (see page 4 ) these tests have now been run, The data are reported in Table 1 and plotted in Figure 1, Data previously reported showed the effects of prior creep on the room temperature tension-impact properties of this material (page 32 of WADC TR 57-150) to be quite variable, The room temperature tension-impact strength was not much affected by moderate changes in the conditions of prior creep exposure, although a point for 1, 6 percent prior total deformation at 350'F showed a possible significant drop in room temperature tension-impact strength. The effects of prior unstressed exposure on the elevated temperature tension-impact strength were small and indicated little or no effect on strength for exposures up to 100 hours at 350~ or 400'F, The present test results indicate that the elevated temperature tension-impact strength of this material was affected by prior creep, With the exception of the two points for 10 hours exposure at 350F it appears that the tension-impact strength was generally reduced by larger amounts of prior creep, while the effect of exposure time is questionable,

7, Table I indicates that the samples showing a drop in tension-impact strength also showed a severe loss of ductility, A variance analysis is to be made of the results in an effort to establish the amount of change that can be considered significant, Qualitatively, it appears that prior total deformations above 1 percent might be necessary before a significant change can be said to occur, The ductility data seem to bear this out, Effect of Prior Creep on Room Temperature Tensile Properties of C 1 OM The results presently available on the effects of prior creep on the room temperature tensile properties of C I IOM are presented in Table 2 and plotted in Figure 2, Most of the desired nominal exposure conditions have been covered for exposures at 700' and 800'F while the larger amounts of total deformation have yet to be studied for prior creep at 650'F, Replicate tests are planned for several conditions. The data for 650~F exposure show a divergence of effect and no particular trend appears to be evident, At 700'F, however, increased amounts of prior creep resulted in an increase in both the tensile and yield strengths, For 800F prior creep, the subsequent tensile strengths appeared to be little affected and the yield strengths depended more on the time of exposure rather than the amount of prior creep. Increased amounts of prior creep at 8000F tended to raise the room temperature yield strength slightly, For all three temperatures of prior creep exposure the tensile elongation was lowered slightly as the amount of prior creep was increased, No particular effect of time was evident and the loss of ductility was not at all severe,,

8, Effect of Unstressed Exposure on Elevated Temperature Tensile Properties of 17-7PH The results of tensile tests conducted at the exposure temperature of samples of 17-7PH (TH 1050 condition) given 10, 50, or 100 hours unstressed exposure at 600, 800, or 900'F are presented in Table 3, A plot of the tensile and yield strengths and elongation versus exposure time is presented in Figure 3, The results indicate a moderate loss of strength with exposure time for samples exposed at 600'F and slight increases in strength for the samples exposed at 800and 900F, The data for 10 and 50 hours exposure at 600FF show considerably more scatter than do the other times and temperatures, The ductility of the samples exposed at 600~F was virtually unaffected while the 800' and 900'F samples showed only moderate losses in ductility, Effect of Unstressed Exposure on Compression Properties of 17-7PH Duplicate compression tests at either room temperature or the temperature of prior exposure have been conducted on samples of 17-7PH (TH 1050 condition) given 10, 50, or 100 hours unstressed exposure at 600', 800~, or 900'F, The data for the subsequent room-temperature tests are presented in Table 4 and plotted in Figure 4, while the data for the tests conducted at the temperatures of prior exposure are presented in Table 5 and plotted in Figure 5, A comparison of Figures 4 and 5 indicates that considerably more scatter was encountered in the room-temperature tests than was found in the elevatedtemperature tests, Consequently, additional samples are being exposed at most conditions for eventual testing at room temperature, In the case of the elevated= temperature tests, excessive variation was encountered between the first two tests for samples exposed 10 hours at 600' or 900~F and subsequently tested at the same temperatures, One additional test was then run for each of these conditions,

9, Figure 5 indicates that the 600' and 800'F compression yield strengths were little affected by the time of prior exposure beyond a slight drop for 10 hours exposure,, The 900~F strength was increased somewhat by prior exposure, The change in the elevated-temperature strength was in no case more than 15 percent of the base value at the given temperature, At the present time no comments can be offered on the room-temperature test results presented in Figure 4, The data are inconsistent and it is hoped that the additional tests planned will clarify the situation, Effect of Prior Creep on Tensile Properties of 17-7PH Tensile tests at either room temperature or the temperature of prior creep exposure have been conducted for samples of 17-7PH (TH 1050 condition) subjected to prior creep for 10, 50, or 100 hours at 600', 800, or 900'F at stresses selected to produce total deformations between 0, 5 and 3, 0 percent, The results of subsequent room temperature tensile tests are summarized in Table 6 and plotted in Figure 6, while the tests conducted at the temperature of prior exposure are similarly presented in Table 7 and Figure 7, Additional testing is still in progress for a number of exposure conditions, Examination of Figure 6 indicates that a fair degree of scatter exists in the room temperature tensile and yield strength results following prior creep, As yet no attempt has been made to delineate the effect of exposure time for the specimens tested after prior creep at 600' and 800~F, while the relationships presented for the 900~F data are considered very tentative, For all temperatures of prior creep there is a tendency for larger amounts of total deformation to increase both the tensile and yield strength relative to the unexposed condition. The 600~ and 800F data suggest that this effect may level off after about 1 percent total deformation while the 900~F data indicate the possible presence of maximum effects at intermediate deformations,

10, Prior creep at 600 and 800~F also has an adverse effect on the room temperature tensile ductility, This is brought out in Figure 69 with the greatest effect occurring for 600~F exposures, After about 141/2 percent total deformation at 600 F the room temperature tensile test elongation leveled out at about 2 percent, Similar amounts of prior creep at 800~F caused a reduction in ductility to about 3 1/2 to 4 percent, A mixed effect was noted for the 900~F data, Figure 7 shows that the effects of prior creep on the tensile properties at the exposure temperature are most noticeable at 600~ and 800F,, The general effect of increased total deformation is increased tensile and yield strength with some decrease in elongation, Maximum effects appear to be present at intermediate deformations, Additional testing still in progress should aid in defining these possible effects,, The tensile test ductility does not appear to be as severely affected as were the previously discussed room-temperature results, Only for the tests at 600~F was the elongation seriously reduced, It should be emphasized that the curves presented in Figures 6 and 7 are tentative and subject to revision as additional data are obtained, The data will also be analyzed in terms of the creep deformation rather than total deformation and the variance of normal properties will be taken into account in determining just what effects are significant at each testing temperature,, Preliminary studies indicated that changes in room-temperature strengths of about 12 - 15 000 psi would be required to fall outside of the 95ppercent confidence limits established from replicate tests of the unexposed material, Effect of Prior Creep on Compression Properties of 17-7PH The results obtained to date on compression tests of 17~7PH (TH 1050 condition) following prior creep for 10, 50, or 100 hours at 600~, 800~, or 900~F are presented in Tables 8 and 9 and plotted in Figures 8 and 9, The data of Table 8 and Figure 8 are concerned with subsequent tests at room temperature, while the data of Table 9 and Figure 9 are for tests conducted at the temperature of prior creep exposure,

11. Figure 8 indicates that the room temperature compression yield strength of 17-7PH can be variously affected by prior creep depending on the time and temperature of exposure. Increased amounts of prior creep at 600'F greatly reduce the yield strength, while 900'F exposure shows first an increase and then a slight decrease in strength. The 800'F exposure resulted in divergent effects with increased total deformation, As shown by Figure 9, compression testing at the temperature of prior creep generally resulted in a decrease in yield strength with increased total deformation, This was most striking for tests conducted at 600 F and was quite similar to the roomtemperature results. The 800' and 900'F data show moderate changes in yield strength -- not more than 10 percent with respect to the base condition, Further comment on these results will be deferred until the results of additional tests in progress are available, Again, it is emphasized that the curves presented are tentative,

12, FUTURE WORK Work planned for the near future includes the following: 1. The development of stress-strain recording equipment for tensionimpact testing will be continued. 2. The effects of unstressed exposure on compression and tension-impact properties will be determined for C 1 10M, 3. Cold bend tests will be conducted on samples of all three materials given exposure at the Inter mediate testing temperature designated for each material,, 4, Smooth bar and notch bar tension-impact tests will be conducted at room temperature and the exposure temperature for samples of 17-7PH subjected to prior creep, Base properties in tension-impact will be determined at elevated temperatures for 17-7PH and C1lOM, 5,, The study of the effects of prior creep on room temperature and elevated temperature tensile and compression properties will be continued for 17-7PH and C1L OM, Primary emphasis will be placed on completing the work on 17-7PH,

TABLE 1 EFFECT OF PRIOR CREEP EXPOSURE ON ELEVATED TEMPERATURE TENSION-IMPACT PROPERTIES OF 2024-T86 Tension-Impact Properties Nominal Exposure After Exposure Conditions Actual Exposure Conditions Tension-Impact Temp Time Total Def. Time Temp Stress Loading Def. Loading Def. Creep Def. Total Def. Test Temp Strength Elongation Reduction of ('F) (hrs) (%) Spec. No. (hrs) ('F) (psi) (Total) (%) (Plastic)(%) (%) (%) (F) (ft. -Ibs) (%/2 inches) Area (%) 350 10 0.5 5B-T4 10.0 350 36,000 0.37 0.01 0.14 0.51 350 19.5 6.0 17.6 10 1.0 5H-T2 9.9 350 44,500 0.49 0.03 0.54 1.03 350 26. 5.0 15.3 50 0.5 5K-TI 50.0 350 29,000 0.32 0 0. 15 0.47 350 15. 6.5 17.5 100 0.5 5B-T11 100.0 350 28,000 0.28 0 0.18 0.56 350 14 6.0 14. 100 1.0 5K-T4 100.1 350 37,000 0.40 0.01 0.61 1.01 350. 6.0 11. 100 2.0 5P-T2 100.1 350 39,000 0.43 0.02 1.50 1.83 350 7. 3.0 3.9 400 10 0.5 5G-T11 10.1 400 28,000 0.31 0.01 0.17 0.48 400 9. 3.0 8.5 10 1.0 5C-T55 10.1 400 36,000 0.41 0.04 0.65 1.06 400 14. 7.0 16.8 10 2.0 5K-T3 10.0 400 37,000 0.50 0.04 0.76 1.26 400 12. 4.5 11.5 50 0.5 5H-T4 50.0 400 23, 00 0.23 0 0.28 0.51 400 14. 7.0 16.0 50 1.0 5P-TI 50.0 400 29,000 0.33 0.01 0.49 0.82 400 12. 4.0 16.2 50 2.0 5H-T11 50.0 400 31,500 0.36 0.02 1. 15 1.51 400 6. 1,5 4.6 100 0.5 5B-T2 100.0 400 21,000 0.22 0 0.26 0.48 400 10. 5.0 9.2 100 1.0 5K-T55 100.0 400 27,000 0.29 0.01 0,81 1.10 400 14. 6.2 8.5 100 2.0 5P-T4 100.0 400 29,000 0.35 0.01 1.43 1.78 400 7. 1.2 4.7

TABLE 2 EFFECT OF PRIOR CREEP-EXPOSURE ON ROOM TEMPERATURE TENSILE PROPERTIES AND HARDNESS OF C11 OM Nominal Exposure Room Temperature Tensile Properties After Exposure C onditions Actual Exposure Conditions Ult. Tensile 0.2%7 Offset Reduction Modulus, E Temp Time Total Def. Time Temp Stress Loading Def. Loading Def. Creep Def. Total Def. Strength Yield Strength Elongation of Area 10 Hardness (CF) (hrs) (%) Spec. No. (hrs) ('F) (psi) (Total) (%) (Plastic )(%lo) (%). (%) (psi) (psi) (%/2 inchep) (9) j R"C" Not exposed 146,211 142,889 22.4 31.3 16.5 650 10 0.5 2CD3 10.0 650 59,000 0.42 0 0.06 0.48 145,500 141,000 21.0 29.4 15.9 36.6 1.0 1AB11 10.0 650 95,200 1.610.2 0.22 1.83 145,000 145,000 20.5 31.4 16.2 36.1 2.0 3A29 10. 650 97.500 1.30 0.6 0.30 1.60 148,000 148, 000 20.0 27.5 15.7 36.8 50 0.5 3CD8 50.0 650 56,000 0.32 0 0,08 0.40 147,000 144,000 19.5 32.0 16.9 37.9 1.0 1C4 50.0 650 86,000 0.89 0 0. 19 1.08 141,000 139,000 22.5 33.2 14.9 36.8 100 0.5 1A30 100.0 650 54,000 0.41 0 0.10 0.51 145,000 130,500 22.0 32.0 15.0 37.0 1.0 3A8 100.0 650 82,000 0.74 0 0.26 1.00 151,000 147,000 21.0 28.3 15.4 37.5 2.0' 2C3 100.0 650 95,200 0.80 0.2 0.47 1.27 152,000 148,000 18.8 28.2 16.0 37.9 700 10 0.5 1A4 10.0 700 56,000 0.43 0 0,.12 0.55 138,000 135,000 21,0 30.0 14.7 38.5 1,0 3AB8 10.0 700 79,000 O. 62 0.1 0. 17 0.79 149,000 144,000 23.2 31.4 15.5 36.6 2,0 2A16 10.0 700 93,000 1.77 1.1 0.96 2.73 150,500 149,500 21,0 31.2 15.2 37.9 3,0 3CD14 10.0 700 100,000 3.76 3.0 5.44 8.80 177,000 175,000 7.8 18.2 15,6 34,2 50 0.5 1CD30 50.1 700 43,000 0.34 0 0,.21 0.55 146,000 141,000 22.0 32.1 17,0 37.7 1,0 3AB14 50.0 700 62,000 0.46 0 0.38 0,.84 152,000 145,000 20.5 28.8 15,7 37,5 100 0.5 3A33A 100.0 700 36,000 0.25 0 0.26 0.51 148,000 136,500 20.5 28.8 16,5 38.0 1.0 2A7A 100.1 700 51,000 0.36 0 0.32 0.68 149,000 138,000 21,7 32.9 15,2 34.7 2.0 1A26A 100,.0 700 63,000 0.50 0 1.78 2.28 162,000 149,000 17.3 26.2 16,1 39.4 3,0 3AB11 117.7 700 69,000 0.51 0.05 1.89 2.40 162,000 152,000 15.0 23.8 15.2 38,3 800 10 0.5 1CD11 10.0 800 21,000 0.18 0 0.33 0.51 144,000 134,000 22.5 33.2 15.2 36,0 2,0 2CD16 10.0 800 34,000 0.29 0 1.76 2.05 147,000 135,000 20.5 30.6 15.3 35.8 3,0 1AB4 10.0 800 37,000 0.29 0,.02 2.08 2.37 146,000 137,500 22.7 30.8 15.5 37,2 50 0.5 2CD21 50.0 800 11,000 0.08 0 0,.40 0.48 142,000 125,000 23.5 31.1 16,0 36.7 1,0 1CD4 50.0 800 17,000 0.14 0 0.92 1.06 143,500 128,000 21.0 31,4 15.4 36,7 2,0 3CD18 50.1 800 22,500 0,16 0 2.16 2.32 149,000 130,500 20.0 25.5 15.8 35,1 3,0 1AB15 50.0 800 25,000 0.20 0 2.44 2.64 146,000 131,000 21.3 30.3 15,7 36,1 100 0.5 IAB3 100.0 800 9,500 0.11 0 0.45 0.,56 142,000 121,000 22,3 30. 3 15.9 33 7 1,0 3AB18 100.0 800 14,000 0,.13 0 1.11 1,24 145,000 129,000 21.8 29.6 16,1 36,5 2,0 2C7C 100.1 800 19,500 0.17 0 2,.04 2.21 146,000 130,000 20.5 25.8 16.5 34,3 3,0 IC3C 100.0 800 22,000 0,.17'0 2.67 2.84 145,000 -- 19.5 28.7 16,3 33,1

TABLE 3 EFFECT OF UNSTRESSED EXPOSURE ON SUBSEQUENT TENSILE PROPERTIES OF 17-7PH (TH 1050 CONDITION) AT EXPOSURE TEMPERATURE Exposure Exposure Ult, Tensile 0,2% Offset Reduction Temp Time Test Temp Strength Yield Strength Elongation of Area Modulus,E Hardness (yF) (hr) (F) Spec, No, (psi) (psi) (%/2inches) (%)10 (psi) R"C" * Not exposed 600 Average 171,989 163,233 4,8 15.1 28,2 43,7 600 10 600 1D-T3 159,000 151,000 5,5 15.2 25,4 42,0 10 600 3U-Tl 180,000 1779,000 4,8 13.9 26,0 43,7 Average 169,500 164,000 5,2 14,0 25,7 42,8 50 600 2U-T3 148,000 139,500 6.5 19,.6 26.0 39,4 50 600 3E-T2 187,000 177,000 4,5 16.5 25,4 46,5 50 600 5P-T1 160,000 152,000 5.0 15,1 25.5 401 Average 165,000 156,167 5,3 17,1 25,6 42,0 100 600 1J-T3 159,000 148,000 1,8 19,.7 26,4 40,9 100 600 2U-T616 61,000 153,000 5,0 18.3 25,8 42,1 Average 160,000 150,500 3,4 19,0 26,1 41.5 Not exposed 800 Average 148,233 137,444 12,2 27.6 25,1 43,7 800 10 800 1A-T5 147,000 136,000 10,5 27,1 24,4 44,9 10 800 2C-T4 153,000 75,700 (a) 15,0 28.7 25,0 47,6 Average 150,00 136,000 12,8 27.924,7 46,2 50 800 1N-T5 151,000 144,000 11,0 24,5 23,4 45,9 50 800 3N-T2 158, 000 149,000 7,5 18,7 24,0 45,7 Average 154,500 146,500 9,2 21.6 23,7 45 8 100 800 1T-T6 150,000 140,000 7, 5 21,0 24,5 43,5 100 800 2C-T5 154,000 141,000 8,0 21,8 25,2 45,5 Average 152,000 140,500 7, 8 21,4 24,844,5

T1ABLEi jB conUcl. Exposure Exposure Ult, Tensile 0, 2% Offset Reduction Temp Time Test Temp Strength Yield Strength Elongation of Area ModulusE Hardness (FF) (hr) (OF) Spec. No. (psi) (psi) (%/2 inches) (%) 106 (psi) R"C" * Not exposed 900 Average 122,800 112, 133 19.3 39.1 21,6 43 7 900 900 900 1F-T5 127 000 116 000 25.0 41.0 224 8 46 9 10 900 3K-T3 126,000 1179 000 17. 3 35.2 22,2 45 9 Average 126,500 116, 500 21 2 38, 1 22 5 46 4 50 900 2C-T3 130 000 119,000 15, 0 27, 8 22 2 44 0 50 900 3U-T5 122,000 115,000 18,5 37 3 23, 1 479 Average 126,000 117,000 16 8 32 6 22,6 45 9 100 900 1T-T1 133,000 125 000 11, 3 25.2 21.5 44 4 100 900 3T-T2 132,500 122 000 10,3 27 2 22.4 44 7 Average 132,750 1239500 10, 8 26,2 22 0 44 6 (a) omitted from average * Rockwell "C" hardness at room temperature

TABLE 4 EFFECT OF UNSTRESSED EXPOSURE ON SUBSEQUENT COMPRESSION PROPERTIES OF 17-7PH (TH 1050 CONDITION) AT ROOM TEMPERATURE Exposure Exposure 0, 2% Offset Compression Temp Time Test Temp Yield Strength Modulus, E (F) (hrs) ('F) Spec, No, (psi) 10 (psi) Not exposed Average 220,777 29. 8 600 10 room 1D-X33 183,000 29 5 10 room 2T=X44 2319 000 30. 3 Average 2079000 29, 9 50 room 2G-X44 2189000 30, 0 50 room 3K-X3 224 000 29, 4 Average 221, 000 29, 7 100 room 1N-M71 1779 000 28 9 100 room 2G X33 176 000 30. 0 Average 1769 500 29,4 800 10 room 2U-M74 2269000 28, 8 10 room 3R X33 227 000 28. 6 Average 226,500 28, 7 50 room 1T-X33 2029 000 30. 3 50 room 2L=X33 219 000 300 0 Average 210,500 30. 2 100 room 3A-X33 1959000 29 4 100 room 3K-X33 2289000 30Q 0 Average 211500 29,,7 900 10 room 1N-M72 1949000 28, 8 10 room 2L-X3 223,000 29, 3 Average 2089500 29,0 50 room 2G X3 212 000 30 0 50 room 3T-X33 2339000 302 2 Average 2229500 30, 1 100 room 1N-X3 235,000 29 6 100 room 2T-X33 2109000 30.8 Average 2229500 30.2

TABLE 5 EFFECT OF UNSTRESSED EXPOSURE ON SUBSEQUENT COMPRESSION PROPERTIES OF 17-7PH (TH 1050 CONDITION) AT EXPOSURE TEMPERATURE Exposure- Exposure 0,2% Offset Compression Temp Time Test Temp Yield Strength Modulus, E ('F) (h rs) (*F) Spec, No, (psi) 106 (psi) Not exposed 600 Average 1859723 26, 0 600 10 600 1N-M76 1479000 25, 3 10 600 2U-M73 1839000 27,2 10 600 3D-X33 149,000 26.5 Average 1599667 26, 3 50 600 1J-X3 184, 000 26, 5 50 600 2U-M72 174,000 26,5 Average 1799000 26 5 100 600 2A-X3 1739000 26, 9 100 600 3T-X3 1769000 26,5 Average 174 500 26, 7 Not exposed 800 Average 1469 800 24, 6 800 10 800 1N-M75 133 000 24, 4 10 800 2U=M75 1429000 26 8 Average 1379500 25, 6 50 800 2U-M76 1529000 24 4 50 800 3R-X3 150 000 24, 3 Average 15 1000 24 4 100 800 1N-M7 148 000 24, 2 1 00 800 2C-X33 1499000 24, 4 Average 1489500 24, 3 Not exposed 900 Average 113 877 23, 1 10 900 1N-X33 121,000 22, 6 10 900 2U-X33 95 500 22, 7 10 900 2L-X44 136,000 22 8 Average 1179 500 22 7 50 900 1J-X33 1309 000 22, 7 50 900 2C-X3 128 000 Z 1. 2 Average 1299,000 22,0 100 900 1N-M74 1179000 21,2 100 900 92UM71 1279000 22.0 Average 122 000 21, 6

TABLE 6 EFFECTOF ELEVATED TEMPERATURE STRESSED EXPOSURE ON SUBSEQUENT TENSILE PROPERTIES OF 17-7PH (TH 1050 CONDITION) Subsequent Room Temperature Properties Nominal Exposure Conditions _____ Actual Exposure Conditions Ult. Tensile 0.2% offset Temp Time Total Def. Time Stress Load Def. Creep Del. Total Dec. Strength Yield Strength Elongation Reduction of Area Modulus, E Hardness ('F) (hr) (%) Spec. No. (hr) (psi) (%) (%) (%) (psi) (psi) (%/2 inches) (%) 10~ (psi) R"C" 600 10 0.5 2U-T5 10.0 118,000 0.43 0.02 0.45 186,500 179,000 5.5 20.5 29.'6 41.1 2K-TI 10.1 118,000 0.43 0.02 0.45 198,000 190,000 6.8 19.5 27.9 42.1 10 1.0 3D-T6 10.0 159,000 0.69 0.35 1.04 210,000 210,000 4.0 16.3 29.7 45.0 10 2.0 ID-T6 10.0 167,000 0.77 0.99 1.76 211,000 211,000 2.3 13.3 28.0 43.3 2T-T5 -- 167,000 rupture on load. -- -- -- -- -- -- -- 10 3.0 G20-T4 10.2 173,000 0.98 1.53 2.51 227,000 227,000 2.0 11.2 28.5 44.7 3R-T6 173,000 rupture at 6.5 hours -- -- -- -- -- -- -- 50 0.5 ID-T5 50.1 116,000 0.43 0.06 0.49 205,000 195,000 7.0 16.7 30.0 45.1 50 1.0 3K-T2 50.0 150,000 0.54 0.32 0.86 205,000 205,000 3.2 13.8 29.2 44.2 50 2.0 2A-T3 -- 160,000 rupture on load -- -- -- -.- - -- 2B-T4 50. 0 160,000 0.66 0.84 1.50 220,000 220,000 2.0 10.3 29.0 46.1 50 3.0 3T-T5 50.0 164,000 0.63 1.18 1.81 216,000 216,000 2.2 10.5 29.9 44.0 100 0.5 3D-TI 100.0 114,500 0.39 0.05 0.44 191,500 186,000 9.8 17.2 29.6 45.0 2B-T5 100.0 114,500 0.41 0.04 0.45 210,000 202,000 6.5 15.630.4 45.6 100 1.0 1D-T4 99.9 146,000 0.55 0.31 0.86 218,000 218,000 3.0 10.7 29.2 42.9 100 2.0 2N-T1 100.5 157,000 0.60 1.28 1.88 223,000 223,000 1.5 13.7 29.4 -- 3Q-T7 104.9 157,000 ---- 3.84 209,000 -- 2.0 8.6 30.3 41.1 3H-T4 -- 157,000 rupture at 17.8 hours -- -- -- -- -- -- -- 1IP-T24 99.9 157,000 -- -- 5.30 217,500 188,500 2.0 5.8 28.9 42.8 100 3.0 2C-TI 100.0 161,000 0.74 3.68 4.42 218,000 218,000 1.8 6.3 29.0 43.9 800 10 0.5 3K-T6 10.2 70,000 0.29 0.13 0.52 212,000 206,500 4.3 13.1 29.8 42.6 2M-T2 10.0 70,000 0.28 0. 12 0.50 216,000 208,000 4.3 13.4 29.8 45.6 10 1.0 2G-T5 10.2 88,000 0.36 0.68 1.04 191,500 188,000 6.5 16.6 30.2 41.1 3J-T2 11.6 98,000 0.35 0.65 1.00 229,000 226,000 3.513.3 8.2 46.9 10 2.0 1J-T6 10.0 98,000 0.35 1.86 2.21 208,000 207,000 3.5 16.528.4 45.5 2K-T2 11.6 98,000 0.41 1.58 1.99 217,000 214,000 3.5 13.3 29.6 44.4 10 3.0 3R-TS 10.0 101,000 0.42 2.08 2.55 234,000 222,000 3.0 14.2 30.2 48.7 50 0.5 IN-TI 50.0 62,000 0.23 0.15 0.48 187,090 174,000 9.5 17.0 29.4 42.3 4G-TI 49.9 62,000 0.24 0.28 0.52 218,000 212,000 5.0 16.728.0 45.7 50 1.0 2A-TI 50.0 75,000 0.32 0.64 0.96 221,000 207,000 9.5 16.6 29.5 47.4 50 2.0 3R-T2 50.0 86,000 0.35 1.43 1.78 172,000 171,000 3.0 16.4 29.2 45.0 2K-T6 50.0 86,000 0.35 1.81 2.16 227,000 224,000 3.514.730.0 45.0 50 3.0 1J-T4 50.1 91,000 0.33 2.77 3.10 216,000 212,000 3.5 17.0 29.6 46.9 100 0.5 3P-T5 100.0 59,000 0.23 0.15 0.48 208,000 204,000 3.8 17.6 30.3 2B-T3 100.0 59,000 0.22 0.34 0.56 233,000 230,000 4.512.730.3 47.5 100 1.0 3H.-T5 100.0 70,000 0.27 0.62 0.89 220,000 215,000 3.5 14.0 32.1 -- 1F-T6 99.9 70,000 0.26 0.65 0.91 236,000 231,000 4.013.830.0 46.8 100 2.0 3P-TI 102.6 81,000 0.31 1.81 2.12 223,000 229,000 3.5 12.1 29.9 46.7 25-T6 102.1 81,000 0.32 1;56 1.88 227,000 222,000 4.2 15.8 30.2 46.7 100 3.0 3L-T2 100.0 85,000 0.32 2.13 2.45 218,000 214,000 2.2 20.2 30.1 -- 900 10 0.5 2L-T6 10.1 46,000 0.21 0.36 0.57 228,000 218,000 2.23.630.3 46.3 IM-T2 10.0 46,000 0.19 0.38 0.57 204,0.00 198,000 8.219.230.0 45.0 10 1.0 IJ-T2 10. 1 55,000 0.24 0.89 1.13 215,000 207,000 4.015.229.9 44.0 10 2.0 3K-TI 10.0 62,000 0.28 2.03 2.31 221,500 219,000 3.512.729.4 47.0 10 3.0 1N-T6 10.1 68,000 0.27 3.09 3.36 201,000 195,000 4.817.6 29.2 43.1 50 0.5 2UL-T4 50.0 40,000 0.17 0.45 0.62 235,000 228,000 7.0 9.8 30.0 48.4 3J-T3 50.0 40,000 0.15 0.54 0.69 240,000 237,000 5.511.329.3 48.0 50 1.0 2A-T2 50.0 48,500 0.20 0.91 1.11 200,000 191,500 9.8 18.029.4 44.3 50 2.0 ID-T2 49.9 54,000 0.29 1.48 1.77 205,000 197,000 6.8 170 292 47 5 3S-T4 50.4 52,000 0.23 1.41 1.64 224,000 222,000 4.5148 30.2 46,0 50 3.0 3R-TI 50.0 56,000 0.25 2.15 2.40 195,000 189,000 8.0 19.630.0 43.0 100 0.5 3G-T5 100.0 37,000 0.14 0.33 0.47 204,000 196 000 4.5 17.6 29 2 100 1.0 2M-TI 100.0 46,000 0.19 1.51 1.70 227,000 222,000 3.517.230.0 45.6 3A-T4 100.0 46,000 -- -- 0.94 228,000 220,000 4.514.430.1 46.0 2R-TI 100.0 49 000 0.19 1 36 1.55 214,000 209,000 6.516.729.9 45.3 2K-T5 100.0 46,000 0.19 1.63 1.82 238,000 218,000 3.3102 30.4 47.8 100 2.0 3G-T2 100.1 50,000 0.22 1.82 2.04 224,000 219,000 4.015.229.7 46.8 IQ-T22 100.0 50,000 0.20 2.13 2.33 235,000 230,000 4.013.130.0 48.1 100 3.0 1H-T1 100.1 52,000 026 3.30 3.56 223,000 0.2622,000 3.5 14.5 29.0 46.2 3Q-T4 100.0 52,000 0.23 2.07 2.30 221;000 219,000 5.0 14.9 31.0 --

TABLE 7 EFFECT OF ELEVATED TEMPERATURE STRESSED EXPOSURE ON SUBSEQUENT TENSILE PROPERTIES OF 17-7PH (TH 1050 CONDITION) AT EXPOSURE TEMPERATURE Nominal Exposure Tensile Properties After Exposure Conditions Actual Exposure Conditions Ult Tensile 0. 2% Offset Temp Time Total Def. Time Stress Loading Def. Creep Def. Total Def. Test Temp Strength Yield Strength Elongation Reduction of Modulus, E Hardness* (,F) (hrs) (%) Spec. No. (hrs) (psi) %) (%) (%) (~F) (psi) (psi) (%/2 inches) Area (%) 106 (psi) R"C" 600 10 0.5 1T-T3 10.0 118,000 0.44 0.03 0.47 600 172,000 159,000 4.314.926.1 42.2 1.0 2L-T3 9,9 159,000 0.78 1.09 1.87 600 169,000 138,000 2.517.5252 42.3 6G-T6 10.0 159,000 0.68 0.41 1.09 600 178,000 177,000 2.5 11.824.0 44.3 2.0 2M-T3 10.5 167,000 0.72 0.75 1.47 600 179,000 178,000 3.014.3 27.7 46 0 3.0 IA-T6 10.3 173,000 0.82 2.23 3.05 600 185,000 182,000 2.7 11.826.0 47.1 50 0.5 2L-T4 51.0 116,000 0.43 0.03 0.46 600 177,000 171,000 3.5 14.8 25.2 43.0 6R-T2 50.0 116,000 0.39 0.03 0.42 600 184,000 173,000 5.0 10.4 27.3 46.2 1.0 IT-T4 50.0 150,000 0.54 0.28 0.82 600 192,000 180,000 6.8 13.6 26.0 43.9 2.0 3T-T4 50.0 160,000 0.69 1.09 1.78 600 180,000 — 2.3 10.3 26.2 43.4 3.0 2T-T3 50.0 164,000 0.68 1.57 2.25 600 185,000 185,000 2.0 10.5 25.4 42.6 100 0.5 2L-TI 100.2 114,500 0.42 0.06 0.48 600 167,600 155,000 3.8 15.0 24.4 41.9 1.0 3R-T4 100.-0 146,000 0.65 0.78 1.43 600 169,500 169,500 2.3 13.4 28.6 41.2 2.0 1T-T2 100.4 157,000 0.76 3.29 4.05 600 176,000 171,000 1.8 7.8 26.0 41.4 4T-TI 100.0 157,000 0.67 1.49 2.16 600 176,000 176,000 1.0 12.4 25.6 42.4 3.0 3D-T5 100.0 161,000 0.68 2.02 2.70 600 185,000 185,000 1.5 9.8 25.6 42.7 800 10 0.5 IT-T5 10. 1 70,000 0.27 0.20 0.47 800 148,000 136,000 9.3 24.0 23.4 43.7 1.0 3T-T3 10.2 88,000 0.33 0.54 0.87 800 143,000 133,000 13.0 24.8 23.0 43.2 IS-TI 10.0 88,000 0.35 0.62 0.97 800 152,000 144,000 14.0 26.0 24.5 45.6 2.0 2A-T5 10.2 98,000 0.37 1.51 1.88 800 151,000 143,000 9.5 24.4 24.4 46.0 3.0 1N-T3 10. 101,000 0.38 2.04 2.42 800 141,000 141,000 6.5 19.9 25.0 42.0 5L-T6 10.0 102,000 0.40 2.32 2.72 800 145,000 139,000 7.5 20.0 25.6 41.7 50 0.5 3D-T3 50.0 62,000 0.25 0.28 0.53 800 144,500 135,000 11.0 24.5 24.1 43.5 1.0 2A-T4 51.4 75,000 0.29 0.71 1.00 800 155,000 145,000 8.8 20.3 23.3 47.8 5K-T6 50.0 81,000 0.29 1.10 1.39 800 152,000 144,000 10.0 23.3 27.9 44.1 2.0 2L-T5 50.0 86,000 0.33 1.57 1.90 800 152,000 143,000 15.0 25.8 23.4 43.5 3.0 3T-T6 50.0 91,000 0.36 2.44 2.80 800 159,000 137,000 12.0 23.3 23.6 47.7 100 0.5 1N-T2 100.0 59,000 0.24 0.29 0.53 800 156,000 136,000 8.3 22.2 23.8 45.9 1.0 3E-T4 100.0 70,000 0.32 0.25 0.57 800 172,000 154,000 15.0 27. 1 24.3 47.6 2T-T6 99.9 70,000 0.26 0.47 0.83 800 149,000 140,000 16.8 27.7 22.6 47.6 2.0 3T-T1 100.0 81,000 0.32 1.76 2.08 800 144,000 137,000 14.8 28.8 23.3 46.5 6Q-T6 100.0 81,000 0.30 1.54 1.84 800 165,000 147,000 12.0 22.3 25.4 47.1 3.0.2G-TI 100.1 85,000 0.35 2. 12 2.47 800 147,000 139,500 7.8 14.6 24.2 42.8 900 10 0.5 1N-T4 10.1 46,000 0.18 0.30 0.48 900 118,000 104,000 21.5 39.0 22.4 42.6 1.0 6K-T6 10.0 55,000 0.20 0.45 0.65 900 128,000 120,000 21.3 36.4 25.2 46.4 2T-T2 10.0 55,000 0.24 0.75 0.99 900 121,000 111,000 20.0 34.6 21.0 41.0 2.0 3R-T3 10.9 62,000 0.27 1.43 1.70 900 122,000 115,000 16.5 25.2 22.0 42.8 3.0 2G-T6 10. 1 68,000 0.31 2.41 2.80 900 125,000 117,000 14.5 31.3 21.3 43.9 50 0.5 2L-T2 50.0 40,000 0.16 0.54 0.70 900 131,000 117,000 12.5 22.422.8 45.3 1.0 3K-T5 50.1 48,500 0.22 1.00 1.22 900 132,000 121,000 25.1 35.6 21.9 44.9 2.0 2C-T2 50.0 52,000 0.25 1.50 1.75 900 132,000 120,000 22.6 34.4 21.9 45.9 1R-T6 50.0 52,000 0.22 1.59 1. 81 900 135,000 128,000 11.824.423.2 46.0 3.0 3D-T2 51.4 56,000 0.26 2.41 2.67 900 134,000 107,000 15.0 28.0 22.0 43.6 100 0.5 ID-TI 100.2 37,000 0.16 0.43 0.59 900 132,000 119,000 17.828.423.0 45.6 1.0 2G-T3 100.0 46,000 0.20 1.13 1.33 900 129,000 118,000 14.3 20.822.2 45.4 2.0 3K-T4 100.0 50,000 0.22 1.72 1.94 900 126,000 113,000 17.5 33.621.8 44.0 1R-T2 100.1 50,000 0.21 1.88 2.09 900 132,000 119,000 15.0 30.624.4 44.1 3.0 IJ-TI 100.0 52,000 0.24 2.73 2.97 900 129,000 115,000 15.0 29.822.1 43.2 * Rockwell "C" hardness at room temperature.

TABLE 8 EFFECT OF PRIOR CREEP EXPOSURE ON SUBSEQUENT COMPRESSION PROPERTIES OF 17-7PH (TH 1050 CONDITION) AT ROOM TEMPERATURE Compression Properties Nominal Exposure After Exposure Conditions Actual Exposure Conditions 0.2% Offset Compression Temp Time Total Def -Time Temp Stress Loading Def. Creep Def, Total Def. Test Temp Yield Strength Modulus, E (F) (hrs) (%) Spec. No. (hrs) ('F) (psi) (%) (%) (%) (F) (psi) j06 (p 600 10 0.5 IH-T6 10.0 600 118,000 0.43 0.02 0.45 room 218,000 30,3 1.,0 3J-T5 10.0 600 159,000 0.79 0.20 0.99 room 197,000 29,9 2.0 1F-T3 10.0 600 167,000 0.64 0.72 1.36 room 165, 000 29.9 50 0.5 1H-T2 50.0 600 116,000 0.44 0.04 0.48 room 210,000 29.0 1.0 3N-T3 50. 0 600 150,000 0.58 0.27 0. 85 room 200,000 29.4 2.0 2F-T7 51.0 600 160,000 0.63 1.26 1. 89 room 152, 000 29.5 100 0.5 2T-T4 100.0 600 114,500 0.41 0.04 0.45 room 224,000 29. 9 1.0 2U-TI 100.0 600 146,000 0.56 0.64 1.20 room 157,000 28,9 2.0 3H-T7 100.0 600 157,000 0.66 1.22 1.88 room 163,000 30.1 3.0 1S-T1 100. 1 600 161,000. 68 1.,80 2.48 room 176,000 28.6 800 10 0.5 IF-Ti 10,0 800 70,000 0.27 0.18 0.45 room 238,000 29.9 1. 0 3N-T4 10, 0 800 88, 000 0, 37 0, 62 0.99 room 226,000 29, 0 2.0 1S-T2 10.1 800 98,000 0.37 1.12 1.49 room 202,000 30.0 3.0 2F-T3 10,0 800 101,000 0.41 1.69 2.10 room 202,000 30, 0 50 0.5 2B-T6 50.0 800 62,000 0,.22 0.30.0.52 room 237,000 30,1 IF-T4 50.4 800 62,000 0,.22 0.26 0.48 room 250,000 29.4 1.0 IA-T4 50.7 800 75,000 0.30 0.65 0.95 room 226,000 30.0 2. 0 3J-T6 50. 5 800 86, 000 0.32 1.32 1. 64 room *238, 000 29.9 3.0 3U-T2 50.6 800 91, 000 0.36 2,64 3.00 room 240, 000 28.6 100 0.5 2G-T2 99.9 800 59,000 0.23 0.31 0.54 room 214,000 29.9 1. 0 2U-T2 100. 0 800 70, 000 0.27 0.55 0. 82 room 202, 000 30.1 2.0 3L-TI 100.0 800 81,000 0.37 1,45 1.82 room 218,000 30.0 3.0 IA-T2 100. 0 800 85, 000 0.35 2. 0 2.55 room 237, 000 29.6 900 10 0.5 lA-T1 10.1 900 46,000 0.18 0.37 0.55 room 240,000 29.4 1.0 2F-T5 10.0 900 55,000 0.23 1.01 1.24 room 236,000 29.5 2.0 3N-T6 10. 0 900 62, 000 0.26 2.00 2.26 room 232, 000 30.0 3.0 1S-T4 10. 1 900 68,000 0.31 4.74 5.05 room 230,000 29.0 50 0.5 1A-T3 50.0 900 40,000 0.17 0.44 0.61 room 242,000 29.4 1,0 3U-T4 S0.0 900 48,500 0.22 1.35 1.57 room 241,000' 30.0 2.0 I1H-T5 50.0 900 52,000 0.22 1.,64 1.86 room 232,000 29.3 3.0 2F-T6 50.0 900 56.000 0.22 1.93 3.15 room 228,000 28.6 100 0,.5 2A-T6 100.0 90Q 37,000 0.16 0,52 0.68 room 243,000 30.0 1.0 3D-T4 100.0 900 46,000 0.19 1.06 1.25 room 245,000 30.2 2.0 IJ-T5 100. 1 900 50,000 0.23 1.83 2.06 room 217,000 29.8 3.0 2T-T1 100.0 900 52,000 0.24 1.58 1.82 room 200,000 29.4 Note: Replicate tests in progress for a number of exposure conditions.

TABLE 9 EFFECT OF PRIOR CREEP EXPOSURE ON SUBSEQUENT COMPRESSION PROPERTIES OF 17-7PH (TH 1050 CONDITION) AT EXPOSURE TEMPERATURE Compression Properties Nominal Expos ure After Exposure Conditions, Actual Exposure Conditions 0.2% Offset Compression Temp Time Total Def. Time Temp Stress Loading Def. Creep Def. Total Def. Test Temp Yield Strength Modulus E (*F) (hrs) (%) Spec. No. (hrs) ('F) (psi) (%) (%) (%) (F) (psi) 10 (psi 600 50 1.0 6M-T6 50.0 600 150; 000 0.56 0.33 0.89 600 157,000 25.9 100 0.5 3E-T1 100.0 600 114,500 0.40.044600 88500 265 2.0 3J-T1 119.0 600 157,000 0.62 0.97 1.59 600 12, 000 25 9 3.0 IS-T6 100.0 600 161,000 0.68 2.48 3.16 600 123,000 25.8 800 50 2.0 6K-T2 50.1 800 86,000 0.37 1.85 2.22 800 137,000 24.0 100 0.5 3N-T5 105.6 800 59, 000 0.22 032 0.54 800 146 000 24 8 1.0 IF-T2 105.2 800 70,000 0.27 0.68 0.95 800 154,000 23.5 2.0 2F-T1 100.0 800 81,000 0.31 1.35 1.66 800 139, 000 25.4 3.0 3U-T6 100.0 800 85,000 0.34 2.02 2.34 800 138,500 24.3 900 10 0.5 3J-T4 10.0 900 46, 000 0.22 0.52 0.74 900 1 17,000 22. 9 IH-T4 10. 1 900 46,000 0. 19 0.25 0.54 900 112,000 23. 4. 0 IB-T2 10.0 900 55,000 0.25 1.76 1.01 900 123,000 21.6 2BT 10.0 900 50, 000 0.24 0.66 0.90 900 102, 000 23.4 3E-T6 10.0 900 52,000 0.21 0.64 0.85 900 114,000 21.5 2.0 6A-T6 10.0 900 62,000 0.27 1.68 1.95 900 117,000 23.0 3.0 5B-T6 10.0 900 68,000 0.29 2.77 3.06 900 116,000 22.6 50 0.5 4L-TI 49.9 900 40,000 0.21 0.41 0.62 900 134,500 22. 1 1.0 1B-T1 50.0 900 48,500 0.20 0.95 1.15 900 133,000 23.1 2.0 3M-T3 50.1 900 52,000 0.24 1.26 1.50 900 135,000 22.6 3.0' 6R-T6 50.4 900 56,000 0.26 3.47 3.73 900 128,000 23.5 100 0.5 3E-T3 100.0 900 37, 000 0. 14 0.56 0.70 900 120, 500 22,9 1.0 1S-T5 100.0 900 46,000 0.26 6.09 6.35 900 108,000 22.4 2.0 2F-T2 100. 1 900 50, 000 0.22 2.05 2.27 900 115,000 23.4 3.0 IH-T3 100.0 900 52,000 0.22 3.57 3.79 900 114,000 21.9 Note: Replicate tests in progress for a number of exposure conditions.

Prior Creep at 350*F 30 _ Tested at 350'F -4 o ^10 hrs ~0 w f H,, I 0 1.0 2.0 Total Deformation - Percent 30 - Prior Creep at 400F.1 ITested at 400-F o - Code -'o~~ ~~~~~.0' Unexposed 0) 0 1.0 2. ) Prior0 Total Deformation - Percent 30 A Prior Creep E s at 30 4 0 O 0 100 hrs) Time 0 -, I P C

Prior Creep at 700~F 165 165 100 hrs 165 160 Prior Creep at 650F 160 /160 Prior Creep at 800F - 60177,00 oQ | | / at 8. 8% o 155 155 50 hrs 155 0 0 100 hrs /' 150 - / 150 --- ~ l0 hrs 150 A 145.C.-1 0 10 hrs 145 145 o 3 ~ ^ 140 - 50 hrs 140 \ / 140 - 0C~~~~~~~~~~ 0 135 10-, — - -- - 135 I-, — - - - - 130. 130 0 1.0 2.0 3.0 0 1.0 2.0 3. 0. 0 1.0 2.0 3.0 155 r00h5s 175, 000 155 ~155~~~~~~~~ / 155 100 hrs at ~o 140 ~ /~ / 140|~ /~ /A 50t Unexporsed 150 150 100 hrs 150 o lohrs 10hr s 13535A|-350 10 19hrs 35'?! |~ \|/ 1 0 50 hrs g 140 14.0 a 50 hrs 140^ 1235 - 135 25 19 h^ 1 I00 Y' "' -t' ~. ed ~n A ~ s 50 hrs 125 125 125 N. 2 / 10 I 1 1 20 s. 0 30 1.0 2.0 3.0 4.0 0 1.0 2.0 3.0 Figure 2. - Effect of Prior Creep Exposure on Room Temperature Tensile Properties of C1 OM. Totl efomaion- ercntToal efrmaio Pecet ota Dforaton Pr~ Figre2 Efec o Pio CeepExosreonRoo Tmpraur Tesie roeriesofC IOM

190 Code o - 0 600*F Exposure Temperature o t A 800 TF and O 170 0 900go J Test Temperature 1160 - o r~ ~~ -' —~600*F' 160 O 2'soL ^ -____ --- — ~ —-------------— ^'IF 15 0 A 4-) < 140 - a ~ 900*F 130 _ o 0 10 20 30 40 50 60 70 80 90 100 180 - o o0 170 _. o0 o- 600 *F, 130 - " 800 F.-r4 900-F * * 11 900 T 120 _ o _1101 -. I I, Ial. oO O 10 20 30 40 50 60 70 80 90 100 U, 30 20D -_ —- - __ __ _ __ _ _ 10 __ _ __ __ _ __ _ __ _ _- _ _ _ ~ 900'F 0 i —' —-- --- —' —' 800 F 0 0 0 600'F 0 10 20 30 40 50 60 70 80 90 100 Exposure Time - Hours Figure 3. - Effect of Unstressed Exposure of 17-7PH (TH 1050 Condition) on Subsequent Tensile Properties at Exposure Temperature.

24 o 9,/\ ~.. 900'F X 210 0 h A \ 0" 200 \ X0 | _.___ _ Code 0 > 190- LUnexposed \ ~^' a 800'F ) Exposure, 180 0 ~ 900*F ) Temperature 600 F o 170 160 II I 0 10 20 30 40 50 60 70 80 90 100 Exposure Time - Hours Figure 4. Effect of Unstressed Exposure on Subsequent Compression Yield Strength of 17-7PH (TH 1050 Condition) at Room Temperature.

Exposure Temperature and Test Temperature o 600*F A 800*F 200 o 900*F 190 180\~~~~~~ ~ 600~F 0 \ o0 0 180 O & 170 \ |1 150 L o H i- - ---- 800'F *r4 " a40 ~ _ O c 130' 900'F X 120 a o u 110 100 I 0 0 10 20 30 40 50 60 70 80 90 100 Exposure Time - Hours Figure 5. - Effect of Unstressed Exposure on Compression lield Strength of 17-7PH (TH 1050 Condition) at Exposure Temperature.

240 240 Prior Creep at 8000F 240 A ___________________ A ~~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~a Prior Cree t90 Prior Creep at 600 0230 230'230 2 o a030 0 \d /a 22a A A / 0~~ ~ ~ ~ A r~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 2210 180n 2 180 s230 230 a 0a 230 ~ /\ a 1-10000 -' 2201.-. ~20 0 — n 220 0 / a aa.10 aI// p' ^ 00 0 > 200 / 1200 200 0 A 50 hrs ) Prior Creep a N~~~~ 50h 5~~~~~~~~00 hr.)^ Timeh n 190 a190 0 190 A l hrs 180 -180 180 170 ---- * ----' ---- ^ ---- ^ ------------- ^ ---- ^ -------- ^ ----. 170 ------------ l-A-l ----. ---- I ----. ---- I 170..... ________1 0 1.0 20 3.0 4.0 5.00 1 0 1.0 2. 0 3.0 4.0 230 1230 1 0 A 0 A a \1" 0 o aI * \^. o 220~~~~~~~~~~~~~~~~ 210 - O/ ~ Cod, 2 10. 21A~l0 - I S!1 ~ ^/ ^Un.,po~e. \. C U~expos ed a 200 0 203hr0 4.2000 200i 1 2. 3 4.0 i. A & 0hs)Pir re ^~<^ 19. / 0 00 Hrs) Time \^: ^^ ^^^ 10 1lo010 a co 13'; A _- 50 hrs. 0 0 1. 0 2. 0 3. 0 4. 0 5. 0 0 1 0 2. 0 3.0 4. 0 "0 1.0 2. 0 3.0 4 Total Deformation - PercentTotal Deformation - PercentTotal Deformation - Percent Figure 6. - Effect of Prior Creep Exposure at 600*, 800*, or 900*F on Room Temperature Tensile Properties of 17-7PH (TH 1050 Condition).

'5 " Prior Creep at 900~F'm ~~~~~~~~~Prior Creeo at 800~F -4 - o. Prior Creep at 600' Pro ee o ose a 0t_0t_ o 200 Tested at 600o 180 Tested 1at 900 40 o L - A- 50 hrs - ~ ~o fA a 0 A —-- ~ -~-' 190 / - 50/r 1 A90 - A A50hr.- -' 170 100 hrs 130'' -0 a - 100 hrs 1 9 0. a 10 hrs J.: 4|- A/ A-' A 0I- / - --— t j —- - 1 1580- / 0-~ ^ ^^ ^ i6o - 50hrs 1 0 1 1^^^^~~~.!.o 3.-0 hs 0i 10. 0 0.0 0 190 50 0hrs16 156 00 0 17'^''~~ "' — ^/'~0~~ — 10 lhrs l r 140f 0 HQo 160 w 4 - 0 o'^p~/Io^0 —Ma'0 130F 0 o ~/- o~p' 0 150 ~ 10,. 4.0 0 1. 0 2. 0 3. 0 (7' 0 1. 0 2 0 3.0'; 190 50 hrs^ ^ 100 hrs 160 - 140 - ^ ^ ^^' ~P o lO~~hrs'50hrs ^ jr ^-00 ^ —— 0 —100shr3 g160 / ^J~~~~~~~~~~~~~~~~~~130 -. 130lO180040 o 0 10 ~7o ~- 1 ^ — o ---- -'-hrs 1750 -- 1a 0 A0 hrs ) -ror I0 o 01 10 > hrs 0 A 50 hrsO a Areep 100 hrs100 hs Timer b 14 -. 110 -(x 90 00 -0 0 150 10 120 0 10 hr~~~~~~~~~~~nxpsePio 10050hr a)'0a) ~~~~~~~~~~~~~~~~~~~~~~~~~~~A 50 hrs )Creep El 100 hrs) Time 140 ~~~~ ~ ~~110 90 90 Zo 0 0~~~~~~~,-~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~C;~.S ^- a~~~~~~~~~~~~~~~~~~~~~~~~~~~~oo0 o^ A, 10 II I c100 a,'C* 0 1.- 0 2.0 3.0 4.0 0 1.0 2.0 3.0 0 1.0 2.0 3.0 13 30 A A N ~~~~~~ ~ ~~~~~~~N A9A 5~~~~~~~~ ~~~~~~~~~~~~~~~~~~~~ 115 —] o0 AOh en~0 * A ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~140 13~~~~~~~~~~~~~~~~~0' ___________ 0~~~~~~~~~~~~ o 1 10 0 3.I 0 ____________________________________________________________ ~ ~ ~,'_______________80___________________ 1. 0 2.0 3.0 4.0.0 1ot0l2 3.0 De0o1m0 t2o0 3e 0 Total Deformation - Percent Total Deformation - PercentTotal Deformation - Percent Figure 7. - Effect of Elevated Temperature Stressed Exposure on Subsequent Tensile Properties of 17-7PH (TH 1050 Condition) at Exposure Temperature.

230 Prior Creep at 600'F 220 \ 2 -0-J'!>\ Code 2 10 PI ^\ Unexpos ed < / \\ 0 10 hrs ) / \ A.50 hrs ) Prior Creep Time 200 / 0 0 100 hrs 190 \ \Points for zero deformation are / \ \ 10 and 50 hrs average values. 180 160 *\ \ o^ ~a \ o 150 4.00 1.0 2.0 3.0 4.0 Total Deformation - Percent 4.a J 250 A Prior Creep at 800-F * 240 A _ 50 hrs 24 2 30 - — A —/ 230 [//i/ *E230 L t >\ / 100 hrs Sl 220 / \ / l,2o \ / o 210 i _ \ 7 200 TO 10 hrs h 0 1.0 2.0 3.0 4.0 c~ Total Deformation - Percent 5 250 240 E~y- -13 Prior Creep at 900*F o 240 - X. // O\'23, A^OA — / - 10 and- 50 hrs 230'20 / \?J \ O \ 100 hrs 210 " i, _ I \ [, 200 0 1. 0 02,,0 3.0 4.0 5.0 Total Deformation - Percent Figure 8. - Effect of Prior Creep on Room Temperature Compression Yield Strength of 17-7PH (TH 1050 Condition).

0) o 190- LPrior Creep at 600F 0 / f. ~ Tested at 600F _I / \' 184 / \ Code \ Unexposed 170 _0 10 hrs qo. \ A 50 hrs 0 100 hrs 1601> 60 a\ 1 19 hrs 0 o \ 150 E 140 U. \ ~ 130 =1 o' - - -0 v 120... I.I, I - t - - - 0 1.0 2. 0 3,0 4.0 Total Deformation - Percent ( hs Prior Creep at 800'F p (105 hrs) Tested at 800-F ),< 150 r —---- Op^ o-140 - j —0_ * _,oCD 130 I a I co:~ 0 1.0 2.0 3.0 4.0 Total Deformation - Percent 140 Prior Creep at 900*F A^ --- 2S _ Tested at 900-F 133 1 -A- 50 hrs 0 c 12 --- 0 10 and 100 hrs ~ ~ O ~ ~0 0 S ^~0 O -6.35% 100o 9G,-9I o- 0 1.0 2.0 3.0 4.0 Total Deformation - Percent Figure 9,. - Effect of Prior Creep Exposure on Compression Yield Strength of 17-7PH (TH 1050 Condition) at Exposure Temperature.