Engineering Research.Institute University of Michigan Ann Arbor Progress Report No. 4 (through July 31, 1953) INVESTIGATION OF THE INFLUENCE OF TI-AL-B ON THE HIGHTEMPERATURE PROPERTIES OF CR-NI-MO-FE AUSTENITIC ALLOYS by E. B. Mikus C. L. Corey J. W. Freeman Project 2061 To AERONAUTICAL RESEARCH LABORATORY (W'CRRL) R ESEAR CH DIVISION WRIGHT AIR DEVELOPMENT CENTER WRIGHT-PATTERSON AIR FORCE BASE, OHIO Contract No. AF 33(616)-173 Expenditure Order No, R-463-8 BR-1 September, 1953

SUMMARY This is the fourth quarterly progress report under Contract No. AF 33(616)-173. This report concludes the work done on six experimental alloys containing varying amounts of boron and titanium, the object of the work on these six modifications being to determine trends of physical properties and behavior characteristics with composition. References to properties and characteristics of a large electric furnace heat and two small induction furnace heats, ma-de at another laboratory, are included. The effect of aging and of hot-cold working on the rupture strength at 1200~F is presented, data on solution treated specimens of the six alloys having been reported previously. Previous work indicated that aging did not improve the rupture strength of titanium-boron strengthened austenitic alloys and this was substantiated by the present work, except in that the low boron - zero titanium (heat 201) showed some improvement in rupture strength on aging. Hot-cold working 20%o at 1200~F greatly increased the rupture strength of all the alloys except the low boronzero titanium heat(201) which was only slightly increased. An alteration in either the direction or degree of change of both the rupture strength and the hardness vs. boron content occurred at an aimed content of 0. 03% boron. A study was made of the precipitation reactions which occurred in the alloys and other microstructural factors of interest. General background precipitation on aging for 24 hours at 15000F was more evident in the alloys containing titanium than in the straight boron alloys;

2 also a discontinuous grain boundary precipitate formed on aging. Some appreciable fraction of the added boron is tied up in a high melting point secondary phase since such a phase was present in the straight boron alloys, but not in the very low-boron zero-titanium heat (201). Lattice parameters did not change significantly on aging. Chemical analyses were obtained for the six alloys, but they indicated some boron contents to be higher than would have been possible with 100%o recovery of the added boron. The problems associated with the determination of chemical analyses are discussed and exemplified. Future work will center around the preparation and examination of vac-uum melted alloys. These materials should give more positive answers to such problems as tie composition of various secondary phases, the true direction of lattice parameter changes due to alloying, and the influence on strength of dissolved boron and titanium rather than that produced when part of the boron or titanium are tied up as carbides, nitrides, or oxides.

3 INTRODUCTION This report covers the progress made on the research work authorized under Contract No. AF 33(616)-173 (Expenditure Order No. R-463-8 BR-1) up to 31 July 1953. Six modifications of a lean austenitic alloy containing varying amounts of boron and titanium were previously made and a report has been submitted covering the properties of these modifications in two solution treated conditions. The present report covers the continuation of the work on these six heats in an aged condition, 24 hours at 1500~F subsequent to solution treatrnent, and as hot-cold worked 20%o at 1200 0F. Complete chemical analyses are reported for the six heats, however it will be shown that the obtained boron analyses are not consistent with the actual boron additions to the melts. The following table will serve to orient the reader with respect to the analysis of materials under study, past and present. Chemical Analysis Heat No. C Mn Si S P Cr Ni Mo W Ti B Fe A.- 0.069 1.43 0.58 0.011 0.014 12.5 16.2 2.42 0.60 0.58 0.027 Bal 5764* D41 0.045 1,33 0, 32 13.69 15.03 2.02 0.61 0.60 0 Bal D42 0. 60 1.25 0. 33 13.20 15.03 2.04 0.64 0.51 (0.03) Bal 2nd Anal - (0. 097) Aimed Analyses 201 0 0.01 202 0 0.10 203 0.60 0.005 204 0.60 0.10 205 0 0 03 206 1. 5 0. 03 * Alleats were mae in ala oratory induction urnace except heat -5764 which

4 Where it is pertinent and of value to a clearer and more complete understanding of the materials under investigation, references will be made to previously reported data on heats A-5764, D41 and D42. GENERAL PROCEDURE Two broad phases of the problem of the influence of boron and titanium on the rupture strength of a lean austenitic alloy will be considered in this report. On is concerned with the disposition of the boron and titanium in the alloy; this would include a study of the compounds or phases present in solution treated and solution treated plus aged specimens, their mode of occurrence and composition, and the general problem of chemical composition. The second general phase of the work consists of a study of the mechanical properties of the materials as they are affected by the disposition of the alloying elements, overall chemical composition, and by lattice strains produced by hot-cold working. Problems associated with the disposition of the alloying elements were approached from the standpoint of microstructures, variations in microstructures with heat treatment, lattice parameters, and chemical analyses. The mechanical properties which were measured to determine the effect of changirg the disposition of the alloying elements were rupture strengths at 1200~F and room temperature hardness. TEST MATERIALS The materials used in the present work were the six titanium-boron was a large electric furnace heat,

5 alloys whose preparation has been described previously. They were 15pound laboratory induction furnace heats. On the basis of experience obtained in the laboratory of a commercial producer, it was assumed that 30% of the added boron and 60% of the titanium would be retained in the poured ingot. The chemical analyses of these heats will be given in the results section. Rolled bar stock from these ingots was given either a full or an incomplete solution treatment, 1 hour at 2150~F or 4 hours at 1900~F, respectively. Specimens from each of these treatments were given a subsequent age of 24 hours at 1500~F. Since it had previously been determined that aging did not improve the rupture strengths at 1200'F, this aging treatment was chosen with the idea in mind of producing an overaged structure which might permit an identification of precipitating constituents and thus an insight into the disposition of alloying elements in the solution treated condition, rather than with the idea of producing a stronger condition. Another portion of stock was hot-cold worked 20%o at 1200~F to determine the effect of varying titanium and boron contents on the susceptibility of the alloy to be improved by such working. Perhaps higher rupture strengths would have been obtained by rolling at 10000F, but data previously presented on the electric furnace Heat A-5764 suggested that greater variability in strength and lower ductility might result from the lower rolling temperature.

RESULTS Disposition of Alloying Elements Chemical Analyses Chemical analyses have been obtained for the six alloys under study; the compositions are listed in Table I. The results are believed to have been carefully made by chemists who have had considerable experience with boron analyses. The presence of impossible results are evidence of the difficulties and uncertainties connected with the procedures for obtaining analyses for boron in the composition ranges of the six alloys. Factors which can be proposed to account for the failure of some of the chemical analyses to fall within possible ranges are at best unsatisfactory. There were considerable "fines" among the chips which were machined for the analyses. As there are considerable quantities of hard secondary phases, which have been assumed to contain boron, in most of the modifications it is possible that the quantity of the "fines" used in the analyses could have varied widely and thus accounted for the wide range of per cent recoveries: 2.7% to 400%. Another factor to be considered is the carry-over of boron or boron compounds, on the inside of the melting crucible," from one heat to the next. This might explain the high recovery obtained for heat 203, since it was a low-boron heat following a high-boron heat. Similarly, heat 201 may have contained less boron than the aimed because of boron left behind in the crucible after melting, there being no counterbalancing of this effect by the previous heat since it contained no boron,

7 Metallog raphy Microstructures of the six heats in the aged condition are presented in Figures 1 through 6. The significance of the results obtained from them cannot be completely evaluated. A large part of the material which formed the excess phase stringers in alloys is a boron containing compound, since approximately the same amount and type of excess phase stringers appeared in both the titanium bearing and titanium free heats (Figures 2 and 4), except 201 which contains very little boron and was quite clean (Figure 1), Boron contents of over 0. 03% resulted in a sharply increased amount of stringers. The titanium heats showed, in addition, scattered Ti N cubes (Figure 3). The Ti N cubes often exhibited a duplex structure, either by a division irregularly through the cubes or by the formation of a symmetrical outside darker shell (Figures 4 and 6). Aging produced the formation of a relatively massive grain boundary precipitate which somewhat resembled the boron compound phase. This precipitate formed in all heats including the low boron.- zero titanium heat 201 (:Figures 1 and 6). The precipitate could be a boron carbide or nitride or an M23C6 type of carbide. Aging also produced a general background precipitate (Figures 3, 4 and 6) which appeared to be more prevalent in the titanium bearing heats, It was stated in the last progress report, Progress Report No. 3, that no change in grain size, of more than one A. S. T. M. number, occurred by raising the solution treating temperature from 19000 to 2150~F. Since, as usually happens, the aging process sharpened the observable grain size, an exception should be made to the above statement. Heat number 203 showed a gain size change from A. S. To M. No. 5-6 to A. S. To M. No. 3-4 due to the raising of the solution temperature. This is quite in accord

8 ance with the general cleanliness of the structure. The previous induction furnace heat D-42, containing 0. 03%oB (0. 09%oB) and 0. 60%o Ti, exhibited a microstructure quite similar to heats 202 or 204 (Figures 2 and 4). The electric furnace heat number A-5764, containing 0. 027% B and 0. 60%Jo Ti was much cleaner than any of the other heats except 2.01; it did not show massive grain boundary precipitates on aging. It is undoubtedly true that cleaner heats and higher recoveries of reactirve additions, such as boron and titanium, are obtainable in large electric furnace heats than is possible with small induction furnace melts. Lattice parameter measurements were made on the aged materials and the values determined are given in TableII. Another determination of the precision of the computed lattice parameter values on these alloys was obtained. The results substantiated the previous reported precision of + 0. 0006 kx for lattice parameter measurements reported in the Third Progress Report. This method consisted of analyzing the x-ray films by statistical means in the manner proposed by Jette and Foote. The precision obtained resulted in a probable error of 0. 0002 kx and 95% fiduciary limits of t 0. 0006 kx. The lattice parameters indicated generally that the removal from the matrix of the atoms precipitating out on aging either did not appreciably alter the lattice or that equivalent amounts of atoms, some of which would increase and some decrease thelattice spacing, were removed from solution. It is difficult to imagine how the dformer case could exist; the latter case, however, could be represented by the removal of substitutional boron and substitutional titanium on aging (Figure 7), 1 Jette, E.R. and Fote, F. J. Chem. Phys. 3, 605 (1935).

Mechanical Properties Rupture properties of the six modifications were determined at 1200'F on specimens which had been aged 24 hours at 15004F and on others which had been hot-cold worked 20% at 1200~F; the results are given in Table IEI. Brinell hardness measurements were also made on these conditions of the six heats (Figure 8), The variations in the 100-hour rupture strength with boron content for the (1) solution treated, (2) aged and (3) hot-cold worked conditions are represented in Figure 9, This latter figure shows quite clearly that: 1. Aging generally reduced the rupture strength. 2, Aging slightly increased the strength only of the low boron - zero titanium heat 201D 3, Aging reduced the strength of the titanium heats more than for the straight boron heats. 4. Hot-cold working greatly increased the rupture strength of most of the modifications. 5. Hot-cold working increased the rupture strength of the low boron heats very little unless they contained titanium, and then the increase was very pronounced. 6. The rupture strengths of the titanium bearing heats tended to reach a maximum at O, 03% boron, while the straight boron heats tended to increase in strength quite rapidly up to 0. 03%Jo boron and to keep on increasing in strength, but at a lower rate for higher boron contents. This trend was also apparent for the hardness variations, The following table presents a comparison of selected 100hour rupture strengths at 1200~F.

10 Heat No. Condition R upture Elongation Grain Strength (%) Size A-5764 2150~F - 1 hr 40, 000 38 3 204 2150~F - 1 hr 42, 000 38 5 206 2.150~F - 1 hr 44,000 52 5 D-42 2150QF - 1 hr 44,000 33 5 A-5764 2150~F - 1 hr + 20%o HCW 56, 000 3 at 1200~F 204 2150~F - 1 hr + 20%o HCW 56,000 15 at 1.2000F 206 2150~F - 1 hr + 20%o HCW 63,000 12 at 1200~F 204 2150~F - 1 hr + 24 hrs at 32, 500 46 1500~F Z06 2150~F - 1 hr + 24 hrs at 44,500 40 1500~F Figures 10 and 11 are log-log plots of the rupture data of the six alloys as (1) solution treated, (2) aged and (3) hot-cold woxked, and Figure 12 is a summary plot which presents very graphically the effect of the various treatments on the 100-hour rupture strength Hardness of the different materials, as a function of boron content, is plotted in Figure 8. Three conditions are represented: solution treated, aged and hot-cold worked. Aging produced only a minor increase in hardness while hot-cold working raised the Brinell hardness values from about 140 BHN to in the vicinity of 240 BHN.

11 FUTURE WORK Vacuum melted heats will be fabricated and examined to determine individually the influence of carbon, nitrogen and oxygen on the effect of boron. Precipitation reactions, effect of working on the rupture strength, and lattice parameters will be followed. Work will also be completed on the effect of rolling temperature on the rupture strength and ductility of the electric furnace heat A-5764, CONC LUSIONS The disposition of the boron and titanium, i. eo, presence in solution or in precipitates and in different kinds of precipitates, has been difficult to follow. It has been indicated that much of the boron in excess of approximately 0. 03%o, or less, is probably tied up in inert secondary phases. Aging produced a background precipitate and a grain boundary precipitate, the former being perhaps more evident in the titanium bearing alloys. Aging did not appreciably change the lattice parameters. The value of chemical analyses for boron on materials containing appreciable quantities of the boron in compounds which are effectively inert to solution treatments is questionable. This conclusion resulted from the high recoveries of boron indicated by chemical analyses on materials containing considerable quantities of boron in metallurgically inert compounds.

12 The presence of titanium in the alloy was effective in producing higher 100-hour rupture strengths, either as solution treated or hotcold worked, than the straight boron modifications. The 1. 5%o Ti alloy possessed the highest hot-cold worked rupture strength. The 100-hour rupture strength of hot-cold worked titanium bearing alloys was much less affected by boron content than was the strength of the straight boron materials. Thus the response to hot-cold work, as measured by rupture strengths, of the straight boron alloys was very marked. This is particularly noteworthy when one considers the small changes in hardness with boron content of the hot-cold worked condition. It might be concluded that the working is responsible for a precipitation reaction similar to strain aging. The conclusions previously reached, that aging was not beneficial to the rupture strength, has been substantiated, except in that the strength of the low boron - zero titanium alloy was slightly improved.

TABLE I Chemical Analyses of Six Modifications of a Boron-Titanium Strengthened Austenitic Steel Heat B% B% l /0 B/oRec B% BNoRecTi% Ti% No. C Mn Si Cr Ni Mo W A1 N2 Aim Add Anal l Anal l Anal 2 Aal2 Aim Anal 201T* 0.065 0.036 0.01 0.033 0.0008 2.7 0 202T 0.057 0.029 0.10 0.33 0. 163 49.0 0.162 49,0 0 202B* 0.062 0.028 0.10 0.33 0.160 49.0 0.162 49.0 0 203T 0.045 0.024 0. 005 0o 017 0. 068 400, 0.60 0.70 204T 0.044 1.57 0.63 13.41 15o20 1.90 0o49 0.03 0.026 0.10 0.33 0,267 81.0 0, 238 72.00.60 0.58 204B 0.036 0.024 0.10 0.33 0. 341 102,o0 0. 238 72.00.60 0.56 205T 0.055 0.040 0,03 0. 10 0.224 224.0 0 0 206T 0. 046 0. 034 0.03 0. 10 0. 236 236.0 1.5 1.73 *T - top of ingot and sample materials had been slaction treated at 21500~F. *B - bottom of ingot and sample material had been solution treated at 1900~F. Blank spaces indicate analyses not made. NOTE: B% Rec Anal 1, represents the per cent recovery of boron based on the first analyses, likewise for the second analysis.

TABLE II Lattice Parameters of Boron-Titanium Austenitic Alloys Heat Aimed Analyses Heat Treatment Lattice No. Bo Ti%1o B Ti N C Parameter (kx) 201 0,01 0 0,.0008 0 0.036 0.065 S.T. 2150~F I hr W.Q. 3.5871 201 S. T, 2150~F 1 hr W.Q. + Age 24 hrs at 1500~F 3. 5869 201 S, T. 1900~F 4 hrs W.Q. 3.5857 201 S.T. 1900~F 4 hrs W.Q. + Age 24 hrs at 1500~F 3. 5848 202 0. 1 0 0.,163 0 0, 029 0.057 S.T. 2150~F 1 hr W. Q. 3.5836 202 0.3412 ST. 21500F 1 hr W.Q. + Age 24 hrs at 1500~F 3,5841 202 S. T. I900~F 4 hrs W.Q. 3. 5840 202 S. T. 1900~F 4 hrs W.Q. + Age 24 hrs at 1500~F 3. 5833 203 0, 005 0.6 0.068 0,70 0.024 0.045 S.T. 2150~F 1 hr W.Q. 3.5838 203 ST, 2150~F 1 hr W.Q. + Age 24 hrs at 1500 F 3,5850 203 S,T. 1900~F 4 hrs W.Q. 3. 5863 S.T. 1900~F 4 hrs W.Q. + Age 24 hrs at 1500~F 3 5851 204 0. 10 0.6 0. 1602 0.58 0.026 0,044 S. T. 2150~F 1 hr W.Q. 3, 5833 204 ST. 2150~F 1 hr W.Q. + Age 24 hrs at 1500~F 3, 5822 204 S.T. 1900~F 4 hrs W.Q. 3. 5817 204 S.T. 1900~F 4 hrs W.Q, + Age 24 hrs at 1500 F 3. 5824

TABLE II, Continued Heat Aimed Analyses Heat Treatment Lattice No. B%07 Ti,70 B Ti N C Parameter(kx) 205 0. 03 0 0,224 0 0, 040 0. 055 S. T. 2150'F 1 hr W.Q 3Q.5861 205 S,.T, 2150'F 1 hr W. Q. + Age 24 hrs at 1500'F 3, 5856 205 S. T, 19000F 4 hrsW.Q. 3. 5849 205 S, T. 19000F 4 hrs W. Q. + Age 24 hrs at 1500'F 3.5848 206 0. 03 1. 5 0.236 1. 73 0. 034 0. 046 S, T. 2150OF 1 hr W.Q. 3.5898 206 S. T.. 2150'F 1 hr W.Q. + Age 24 hrs at 1500'F 3.5890 206 S. T, 1900'F 4 hrs W.Q 3Q.5890 206 S. T. 19000F W. Q. + Age 24 hrs at 1500'F 3.5897 Top part of ingot 2 Bottom part of ingot

TABLE III Rupture Test Data from Tests at 1200'F for Six Induction Heats 201 - 206 with Varying Boron and Titanium Contents Heat Number and Stress Rupture Elongation Reduction Estimated 100-Hour Estimated 100-Hour Heat Treatment Time of Area Rupture Strength Rupture Elongation (psi) (hours) 6o in 1 in.) (%0) (psi) (%) 201 - S4 24,000 13.0.4 20. 8 15 25, 000 20 27, 000 54. 8 20 20 201 - S4A 25, 000 127. 3 47.6 45 26, 000 50 28,000 60.1 62 47 201 - 54R 32, 000 53. 6 3. 85 8 26, 000 9 40, 000 16 10 201 - S1 21, 000 227. 4 19 18. 5 23,000 19 25,000 49.5 19 12 201 - SIA 22, 000 390. 9 46 41 26, 000 50 30,000 28. 3 55 44 201 - SiR 251 000 334. 8 6. 8 6. 5 28, 500 6 38,000 7. 0 3. 8 8 202 - S4 35,000 341 43 65 38, 000 41 41,000 18. 1 40 38 202 - S4A 27,000 1129. 7 33,000 45 35,000 49.8 53 56 202 - S4R 48,000 257, 7 15,4 55 49, 500 21 5 3, 000 3. 7 33 45 202 - SI 33,000 427 42 67 38, 000 37 40, 000 56,4 36 46 * See code at end of table,

TABLE III, Continued Heat Number and Stress Rupture Elongation Reduction Estimated 100-Hour Estimated 100-Hour Heat Treatment Time of Area Rupture Strength Rupture Elongation -(psi) (hour s) (% in 1 in. ) (%) (psi) (%) 202 - SA. 29,000 1021 -.. 33,500 40 35,000 56.0 45 57 202 - S1R 50, 000 487.3 14 49 203 - S4 31,500 139.7 49 65 33,000 50 35,000 65.0 51 67 203 - S4A 25, 000 388. 1 62 61.5 28,000 68 33,000 14 80 72 203 - S4R 46,000 86. 2 15 57 45,000 13 50,000 29.4 30.4 64 203 - SI 30,000 769 40 45 36,000 60 40,000 33.4 65 68 203 - S1A 26, 000 257. 5 73. 8 68 29, 000 60 35, 000 16, 9 46. 6 57 203 - SIR 49,000 349.2 25 5 37 53,000 19 55, 000 66. 3 17 54 204 - S4 35, 000 227 __ _. 39,000 40,000 69.8 43.6 50 204 - S4A 30, 000 326 51.5 63 33,000 44 36,000 38,. 5 38 59 204 - S4R 52, 000 241.1 16 49 54,000 15 55,000 92.3 14,5 50 204- S1 40,000 139.9 33 64 42,000 38 45,000 68. 0 42 51

TABLE III, Continued Heat Number and Stress Rupture Elongation Reduction Estimated 100-Hour Estimated 100-Hour Heat Treatment Time of Area Rupture Strength Rupture Elongation (psi) (hours) (%o in 1 in.) (%) (psi) (%) 204 - S1A. 30,000 343.4 45.6 64 32,500 46 40, 000 4. 1 46, 6 57 204 -S1R 55,000 222 12. 8 48 56,000 15 60,000 6.1 15.7 49 205 - S4 28,000 233 49 45 30,000 38 32,000 54. 9 32 37 205 - S4A 26, 000 434. 8 58 63 38, 500 59 30,000 48. 1 59 59 205 -S4R 36,000 391.7 34.5 34 39,000 20 45,000 12.9 18 28 205 -S1 35,000 58.2 33 32 33,000 31 40,000 13.5 35 29 205 - SIA 26, 000 260. 1 54 53 28, 500 53 33,000 22 52.4 55 205 - S1R 44, 000 69 5. 6 14 42,500 3 50,000 17. 6 12. 6 12 206 - S4 37, 000 330 35 36 39, 000 47 45,000 3.4 52 61 206 - S4A 48, 000 892. 5.- - 33,000 40,000 10. 1 59 60 206 - S4R 58, 000 319.7 7. 9 15 59,500 10 62, 000 12. 3 21. 6 44

TABLE III, Concluded Heat Number and Stress Rupture Elongation Reduction Estimated 100.-Hour Estimated 100-Hour Heat Treatment Time of Area Rupture Strength Rupture Elongation (psi) (hours) (%/o in 1 in.) (%) (psi) (%) 206 - SI 40,000 862. 5 23. 6 23 44, 000 52 50,000 6. 3 56. 7 55 206 - SlA 43, 000 278.2 21 25 44,500 40 47, 000 9. 5 70 57 206. SIR 60,000 656.2 6.9' 9 63,9000 12 68,000 4,2 21.5 53 Code for Heat Treatments: S4 - S. T. 19000F 4 hrs aW.Q. S4A - S. T. 1900GOF 4 hr- s W -W.Q. +24,hrs at.1.500 0F 54R - S. T. 1900'F 4 hrs W.,Q. + ZO"o Red, atI12000F 51 - S. T. 2150'F 1 hr W. Q. SlA - S.T, 21500F 1 hr W. Q. + 24 hrs at 1500'F SIR - S. T, 2150'F 1 hr W.Q. + 20%o Red. at 12000F

"'"..,./....: ~ "".;-i'...,' / r~~~~~~~~ B.Q,...,: ~..-.,,,,,-: _'. I -( ~~~~~~~~\ r~~~~~~~~.' I ~ ~ ~~~~~~~~~~~,'..`i ~ r i";i ~:. &"..~~ /:."~.'..~''.''> /~~~~~~:'' ~ ~ " i~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~'.....:\....,;I,.,... ~~~~~~~~~~~~ / /'' t,,A~..' i': /~~~~~~~~.":i,,'.,. r: -f I;(I~~~~~~r,~.' ~ I~~~~~~~~~~~~~~~~~~~~~~~~.' i;~ I~~~~~~~~~~~~~~~~~~~~~ X100D XI000D Figure 1 - Microstructure of Heat Z01 Solution Treated 4 Hours at 1900~F Plus Aged Z4 Hours at 1500~F, Aim Composition 0.01%oB Oo i i~~~~~~~~~~~~~~~~~~. ~~~~~~~~~~~~~~~~~~~~~~~~......'LP~ si, r~~~~~~~~~~~~~~~~~~~~~~~~~, ~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~.........,:,-....'-:, tCrL ~t'; iI ~,'..'~: -.~',r-' —'-..'~~-"- r-Lq~- o o ~~~~~o. Oo~,~: rQL'. 4 1:.. [.;-? "',:''':,,':-'..~~...~..:..'"..,"-. ~:,:,~-,.,,.,.'~ ~.:.,;,.....: —._- i,:~.?.~ +.....,.....,-.....*,., r ~ ~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~' t?,'e,-i~~~~~~~~~~~~~~.._...,.~ r~~~~~~~~~~~r~~~~~~~~~~~i~~~~' ~- ~ XC100D XZ000D (a) Solution treated 4 hours at 1900 ~F, water quenched. ~..:,:>,-,.:.,'.. Z \I ~~~~~~~~~~~~' I':?~k ~;~~~~~~ 8,.~~~~-.....):J~."-~."...,,'"',, ~~~~~_,,....-.... ", -~~~~~C~~~~~ —ft5 ~ ~ ~ ~~~~~~~...,.~:.da -'J'.T.,.. c i~~~~~~~~~~~~~~~. 7 ~ r..,r-..,,.o.,.; t ~/-. ~.'.,.:. -.,.1,'~..,..,.,-.. ~-'-.......:-~'' ~~'":~"-:""....:..'... ~~~~.~'C"~~~~~"~~J~\ ~. —: ~ ~ Iz~-. -.<:_-.: —-'...., "". ~~'.-.:2....,.~'-... ~,..".~~~~~~~~~~~~-., X100D X1000D (b) Solution treated 1hour at Z150~F, water quenched. Figure Z Microstructures of Heat Z0Z Aged Z4 Hours at 1500~F, Aim Composition 0. 10%~ B, 0%o Ti.

:.,;' r Q. 6~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ / f,.. "-:)":' /- -....-.:~../J'. C -~~~, r-. I 2~ -'... i-" t~~~~~~~~~~~'- *t'i<?,I~i_ ~~r.?I~ 9:..', ~ ~ ~ ~ ~ ~ ~ ~ f", " j-~~~'~ / ~4 4''".,~,. *.'0.. ~:. ~.-.~~'\. -F,,.. -... _,'4'../;.. *. ~ — ~~~~~~~~~~-.. a~ _ ~ ~ ~.~-~-. -- ~~~~~~~~~~~~~~~~~~~~~~~~~~~.0 /~~~~~~~~~~~~~~~~> XlOOD XIOOOD Fig ure 4 Microstructures of Heat 204 Agedio 24atd Hours at 21500F, i Comosiio 0,e 10% Bur 0. 650%0 Ti. opsto,05/,a~l ~.:....~l, ~ ~ _~~~~~~~c~~~~~~~- ~ ~:.'-,.: ~' f c s~~~. ~, T~;'- -.-" -'" -.~-'~-,. --—..'.-,': -",:,.(,'"-.-' J~~~~- L~ vbffi~-~~~~C~r*"' "~':~-..,~...~,"d-1Iq'5 -:...'~'.. ~ t p-.' " -----: e''''-'....r:~ _:-,,..?~/:.-,,..-.j~ w~~~~~~-~~-:-r::' ~J'- ~ ~'r'~...'.5;~~~~~~~~~~~~~~~~~~~~~~~~~~'k~C.,, — ~~~~~~~~....,.~,.~:-: -...... -~....,, ~..-.:;r~~~~~~~~~~~~~~~~'. ~,: "~ ~ ~~~~~~~~~~~~~~~.,',,.)::.'.'. ",.o ~2~~-,,.~-,, ~1~i~L~ii~B~*~L~ r:,. -~ i ~". ~'i ~:~. \, I - i. P~~~~~~~~~~..,.. -' -,.,.,.~:,- ~..?.~.' —C~',..,, ~,~~..'~~:,. X100D X1000D (a) Solution treated 4 hours at 1900'F, water quenched..._ ~ ~~~~~;,,.'h~~~~~~~ c\~~~~~~~~~~~~~~~~~~~~~~,',:...-, ~,.,~< o.''.~'o,~.~,~~.-~:,~,.:.... o..' t ~ ~~~~~~.'r"c..:ic..? —( I....~ "'',4,,..... ~~~~~~~~~~~u~~~~~~~~~~ "~t.' ~ o ~~-.....,:.:.~,.,,......- -. —.,.....,.,: i~~~~~~~~~~~~~~~~~~~~~~~~~:,:-k!~-...?-""~...'-?-L'~a" ~''-7',~....::t','.. ~~~~~ —.._-?:<.,~,,~~~~~~~~Fc.. ":*-: f~~~~~~~~~~~~~~~~~~~~~~~~~~r~~~~~~~~~~~~'1L: 0,. ~ s ~ —~~~~~~~~~~~~~' Oo ~, ~ ~',.,. -`C~-..... D... ~..;.,. L'," ~~~~~:.:: i' ~,,~'"'....~'".'b~.._ ~- i~-yy.~.'"'m —. -~'. -~::. -'::'-'?.7:~'...' ~~~~~~~~~~~~~~~Y~~~~~~~~~~~~~BC ~ ~ ~ ~ ~ ~ ~ ~ ~~ C:.,,.- /~' ~~~~~-~~~~~~ ~....~.- _.L ~..~: ~-" -.....-,~ ~5Y. )'i..-f~ i,.......I~,';.i,,..'p.~ ~.. ~- k...I.., ~: -~,g.:,' "'.......'.( " ~~~~~~~~'""'...,.'..'. ~ -,,.:,;I. XlOOD XlOOOD (b) Solution treated 1 hour at Z150~iF, water unhd Figure 4 -Microstructures of Heat 204 Aged 24 Hours at 1500~~F, Aim Composition 0, 10%b Bt, 060% Ti.

-A r~~~~~~~ 0,.. ~ ~ ~..,:_..,._,.,. —,... - ~~ -"~~~~'.(, ~ x.,- < --.,. 1 -~~~~~~~~~~~~~~- c ~ ~ ~~~,.,...K.,...-,,'.. ~ X100D Xl OQD (a) Solution treated 4 hours at 1900~F, water quenched. i -~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~a Y~ ~ ~ I ~~~G tj~~~~~~~~~~,,..// ~~~~ ~ - - - --, - Co, _ o 0. 03 B 0% T,,~~~~~~~~... -t ~..,-::_~. II ~~~~~~~~~~~~~~~~~~~J~~~ i ~~~~~~~~~~~3~.~'..~il ~~~~~~~~~~~~~ I~~~~~~~~~~~~~~~~~~~~~~~ ~ i — ~ ~:. —'-~~.....-,'.-'J - - - Xl OOD XI000D Fiue6-Mirsrcue fHa 0 Solution Treated 1 Hours at 2150Fwae qechd Plus Aged 24 Hours at 1500 F, Aim Composition 0. 03% B, 1. a, ~ ~ ~t~~t~.~~bdlp ~, ~ ~...... C'?CF.~:..:..,:~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~ Comosiio 0.03 B, 0 Ti.:.:~,: >._ i'~~~~~ ~ ~~~~~~~'''- ~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ /r~~~~~~~~~~~~~~~~~,,'..~,-/. -"',,:'u(~~~~~~~~~~~ - ~,".' c...~'XlO XlOOOD~e —-7 Figure~ 6 - Mi crotrutur o f Hea 20 6 SouionTetd1Hu tZ5 -- ~ Pu Age 24Husa 50FAmCmoiin.3,15 i

t - T 1, 1 t i;.,, s Ti 4b i._ __ A j! __L - -— i ~ -- ~ — i: tvR --— 9 —-t —-----— l 1 - t 1 —1- i I~~~~~~~~~~~~~~~~~~~~~~AI i _ F t t+''; —t —-- I —- — ~ — -$ — - +, s~ $;-l-l —bt -Ct3 efl -+ sg e 24 --- r I~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~-1 — 0-l —' i - t t a - - c 0 ~ * 1- j- ji T —l-; t h~ t.qdd -j t + t- q~~~~~~~~~~~~~~~~~~~~~~~~F +s _g Ld tZrati4Ot+A t:6-b!~ ii ___ _4Ze- - a'tT id~~~~~~~~~~~~~ I, —.ee 7. — - --- ---- pI;; R $:8 1 t <2. _ /, 60% TiS r 7 I-0 Ti ~~~~~-~~. 2/S Fi —l tti R >t I I+ \ I,4_, e 4 — 1-t — ------- I < 1 —: —1 — l —1 i \ 1:l — 1 i D A:4 - --— l- -* I - -,: ^>583 1~~-<i'1 \ __ --- i- 1 -2 -t ——' -:1 —---- -; 1' -l i..-1.-.. i:~ - I F i: - I' i I - 1: -+''' TO —'Q1' 0, 10 - — a4 J to-45#4 --— + ---!- - — t —-l: | d 0 0 - t r 1 r --; - - — 4- - --,, ~.- Pi. 215..E` 1 + it ei ( -, r- 1 - -i r -----— t —~ —8 —C -+jtIa'' ~Al~ 1- T + i..l t S., t-.*..... +XEL.+. — *. t \ i* % t —-s-F-tDS~~~~~ ~ |' - t 7 f-: —':t'l:I 1 t:', At 1^'-' — ~ —-i —-F- -—'' I~ ~ -:! — +, __ _I X t — 1 --—; TF t I I i +~~~~~~~~~~~~~..: _.It.l.- t. i l | SI - ii 1: I I-:1,,'I:1- 1,'!, i 2 t, ~ ~.;'l-e 7.',. S4-.1 74 7-: i.8 i'. - j t~~~~ -...- V. -- -+-~t-l- - - 1 _}.,.. W t, 4| t —- -^ —- — t ~ —- - 1-!, —~t~~ ~*x-,~nltto~ibtdl6A- 11 t: 1:DI i:lui,

. I r "soiuon:Treated itg~ dc iilZ0' i __,. t~~~~~~~~~~~~~eit:"il......:+-fi - -. — - -------- --- — 77----— 1-24f L-t — 7i h 0 0 1 i Z i o f f: 1 - I 1 t -i I i I t- 87 --: —-t~ i-' -K.-:.7Il...... --— t-2- t _-f _____ <4- ~ — 1-;-I ---- --....' —----- 1 — i- -_L., -—'t --.- 4-'-T''',:oto.ri-f f- - - -:- ---— t-~- --.t-,-~ —-! —-1 —l t- -r t-~ t —-- t lX> r~~~t+ —;-= 1 x Lw. L!i 277 |.1 I i- I 1717771 a.t1{ t -t-*-e ~~ -~~ i- -5 CC -r-i- — t- --- r [, -.-....1 1*'-......... -'' 1 t.-. 4 —.,.:j i t: i!:'' -!i: i...!.i -~ I......,. i::~ __.u, ~-?m-f 4...4 F- ~... i'' Le-':::i ----—:-r:+- i:-,trt — r 1: — -......I... —+ - — t..-..i:......... - -,, l' 1 i1li';'' X X -. l M..... t-'',-.!:':-' -/,4 i -' f r.f- -d —4-f —... II *1 t4; --------—.. ~~............: I~:................!....j-. L I'"~~~~~~~~~~~~~~~'-: I~teik I Ti^Vd, Aged ar 4 Hi~~~r~' "_.1 —tt' _ _ i I —~~ -..... __x~':,.._",, __,._._ 1.:_t ------'i i........'~ wi~ b0o~~I i~ ~ ~ ~~~~~~~~~~~~~~:;;].' -''..'i t'.... -':'-:I.... i...'':'::i I r~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Ci~~~~~~~~~~~~~~~~~~~~~~'.... 4___.i.!~~i --'3t~~~~~~~~~~~~3; ~~~...:~~_~. ~~~~~P~~~~~~~~~ctt-I~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~~~~~'t': IfJ~'r-i'.: Q) i~~~.I,'.~.r

~77:: i;:':. 1 I T ~ rrr'F i' ~i....'.......'~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~................... -~' I..... 4: -4.~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~-''-.. ~~~~~~- ~ ~., 4, 2. };I 7II,7 44 ~ ~ ~ ~ ~ ~ ~ 14 t V_ IV~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~II --.I-_~.~. —:..'.'.,.! ~. _ _.-:J-V I'......i =__ IF ~'_'... z-t~:... ~~~~~~~~~~~~........:.... 4[ ILI-'' -.-~ —.....:_~ -'~ ~ L2....... ___~~~ 77 4j \J iq j=~~~~i. +~' ~ ~...... ITJ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ I~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ I......

1 2 3' 5 6'7'3 4 5 6 7 8.36 10 ~ L'....... [..,. ].[ [ ];...;.[_.,[. t':-....._ __ __ __ _ t" __ _ _ _ _.; 2:;....'......;..:~.' 7 —,. r {t7 -7 j- 7t t -4 1 T~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ t ~f~ 6~~~~~~~ --- -.~+,.-,,.A-i ~~~~~~~~:.........~';....:.10' 7- 1 10 i0 Figure -—.. —---- ~Rupture Time (hours) 10 Treated. Aged and Hot-~Cold Worked Conditions. -4~Ir 34R~~~~~~~~~~~~~j: W7 ni~~~~ ~1 a ~ ~ ~ ~ ~ ~ ~ ~ ~~+~~ - C- -- t: +? -~~~ t; * 7 r 4,~~~~u~r~ — t 4- ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ - L~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ IL~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ 41. L~~-~ ~ ~-r1~r - 9 T I -Z~~~~~~~~~~~~~~~~ 1~1JD 4,~~~~~~~~~~~~~ —— c —-— i — — i0. IF! zt ~~ - CHO ~~ ~ ~ ~ ( —

1 2 4 ~ 5 6'7 e S 1 2 3 4 5 C a e 1 4 ~ "'~~~~~~~~~~~~~~~~~~~~~~~~~~~~~!-............. 7,- -!:':;'.::T> V....... 3~~~~~~~~~~~~.......:-:: —-': —:;-~':-:;: 4~~~~~~~~~..L 6c..... ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~_ _ _ _ _ _ _:__L 0:.b' Q. -~~ ~ ~ ~~~~~.....'- J.... ~~~~~~~4A.i ~I --------—........ z~~~~~~~~~~~~~~~~~~~~a~~~~~~~~~ tM' A~lA 10 100 10000 Z' 4:.00 IF Treated, Aged and Hot-Cold W4rked Conditioiis' 200 F r";'[,,:,:~i/0 irMimi Ti~~~~~~~~~~~~~~~~~~~~~~~~~~!tt~ ~ ~ ~ ~~~ ~Rutr Time (hours t~ihr'-'~!"~'r~:~:' 4R -: — ~-'~:i ~t-R:'~"'.... Figure~ ~ ~ ~ ~ I.I. C maaieSralRpaePoete t1.....or utin' ".04.0: 206 Trete. Age an Ho-CldWoke"'dtins

___. _, > t t -'- 1 — ~ - X -- t __*__t____ _i;* I t O-O -____ ___ j11U~ - - *i P' ". i' 7' ~ 4' ~ "'' ii'?' --.= t:::. 4.:' 3 01 10 0 f wi 1 t 1 -1 12 F: -t':l).'!: t 1 _ _j -; 1 - - f g f -. - T 0 0- I t — - r _ r - * - i - - _ _ _ _ _ _ _ _ _ _ I l - - >: t~~~~~~~~l~ ____! k- 4|ttt - - - t-t;1rttt-t t,-|:mt-1 I "10 0t 0 0t W X X |~~~~~~ ~..1 —~....-<-..........-..... —.-1 ---— +-1 1~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~.- _,. - -,~ t t..1 t-1 ---— <- —, t 4 t t t ~ ~ ~ ~~~~~~~~~~~~4............; 1 - ----— 1............1 —-:.-. "-.'-...'t...,.".'"..',,'.,, I_ 1- _1,...~.i~:.~~ ~.~....... i...........................................s --- i -,,,._...................................t__:;.:>~~~~~~1 - -.*-1:i,' i,:-:l.fL,- Zl i J! i_.1:i!:.,!:~:if:::, i)Nstt ^1Ej;1 t 1-ta:,- l 0 nl —t: -t + + X ) X t 1 [.- f t.! - fT l X X i- i~~~~~~~~~~~~~~~~~~~~~~~~~-t — t~1 ---- I I ItoX:l 0-[ 1 ~< I k 5 Yl;| —-- -- -— X 1,1,.tel l- l..0:l::i:-::lf -t 1-:-i..:l -':-'..:!X —-1 —1.-;4;-0 —0l w:.'i A:004f4L, WE-T:;;', — 0'.'1-'..:'::-1 0 1 —- - I r rn- l.1-!- * w -[ -. 1 - - -'1wI — ^-,-w1 - ---'F~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ __ —tt —TT __ __ -— K —1!228 4 X VX <it —->- --— < —-— 1 —-^ —— r-+ —--— 0-,_ t~~ = _ - -4- - sz.,- - ---- I:i'i:''::J,:~!: [. ~;1'';''' J~''I i''' J'' |'- |- -t __ _ -_, A ___ _ j_ —*T- -r t "J' -': -........ —.' -j'!'-''..... ~''.~ ~~ ~-0L4 l --- ----- --—, — - -- -t- - --- - -- j............. i.. -.- I~~~~~~~~~~~~~~~~~,''' I i' __ i. ~ -' _______~~~~~~~~~~~~~~~~.....