FINAL REPORT TO WRIGHT AIR DEVELOPMENT CENTER., MATERIALS LABORATORY ON PROPERTIES AT 10000, 1100~, AND 12000F FOR TURBINE WHEELS OF FOUR LOW-ALLOY STEELS By A. Zonder A. I. Rush J. W. Freeman Engineering Research Institute, University of Michigan Project Number: M903 AIR FORCE CONTRACT NUMBER: AF33(038)-13496 EXPENDITURE ORDER NUMBER: 605-227 SR-7 July 1, 1953

FOREWORD This report was prepared by the Engineering Research Institute of the University of Michigan under Contract Number: AF33(038)-13496. The work authorized under this contract involved the determination of the properties of eleven turbine wheels, as covered by this report, together with a study of the relationships between structures of the alloys as controlled by heat treatment and properties at high temperatures. The latter study was carried out using bar stock and was planned to help explain the influence of heat treatment on the turbine wheels. This report covers the properties of the turbine wheels. Another report is being prepared which covers the results of structural studies on the wheels and bar stock and correlates the two studies

PROPERTIES AT 1000~, 1100~, AND 1200~F FOR TURBINE WHEELS OF FOUR LOW-ALLOY STEELS SUMMARY Properties at 1000~, 1100", and 1200~F are reported for jetengine turbine wheels made from four low-alloy hardenable steels. The steels were SAE 4340, 1.25 Cr..Mo-Si-V ("17-22A"S), 3 Cr-Mo-W-V (H-40), and 12 Cr-Mo.-W-V (C-422). The wheels were contour forged from commercial heats. Wheels of each alloy were heat treated by normalizing, oil quenching, and by an interrupted quench. All were tempered to an aim hardness of 280 to 320 Brinell. All wheels were surveyed for hardness and tensile properties at room temperature and rupture properties at 1100~F, The wheel of each alloy having the best properties in these tests was used for more extensive surveys of properties. These included tensile and rupture tests at 1000~, 1100~, and 1200~F, and determination of curves of stress - time for total deformation of 0. 1, 0. 2, 0. 5 and 1. 0 per cent at 1100~F. Less extensive total deformation data were obtained at 1000~ and 1200~F, The objective of the investigation was to define the range of high temperature properties available in turbine wheels made from commercially available low-alloy creep resistant steels. The low-alloy steels would have the very important advantages of low requirements in strategic and costly alloying elements, together with relatively simple production characteristics. The data reported are sufficient to define quite closely the service conditions under which the alloys could be operated as turbine wheels for jet engines. There was very little difference in strength between the alloys for the wheels with the best heat treatment at short time periods. The 4340 steel fell off rapidly in strength with time. The "17-22A"S steel had the highest strength at 1000~F, but fell off with time at 1100~ and 1200~F, The H-40 and C-422 steels maintained their strength better with time and temperature. Heat treatments which produced intermediate transformation products in the structures of the steels resulted in highest strength, except for C-422 alloy. The latter 12 Cr alloy could not be heat treated to such structures. The treatments producing the best properties were normalizing for 4340 steel, oil quenching for "17-22A"S steel, oil quenching for H-40, and oil quenching for C-422 alloy.

2 INTRODUCTION Tensile, rupture and total-deformation data at 1000~, 1100~, and 1200~F are reported for forged and heat treated turbine wheels of four low-alloy "ferritic" steels. The four steels are SAE 4340, 0. 3C1.25Cr-0, 5Mo0 60Si-0. 25V ("17-22A"S), 0. 3C-3Cr-0, 5Mo-0. 5W-0. 8V (H-40), and 0. 2C-13Cr-lMo-0. 8W-0. 25V (C-422). The influence of heat treatment was first surveyed by rupture tests at 1100~F on normalized and tempered, oil-quenched and tempered, and interrupted quench and tempered wheels. The wheel of each alloy appearing to have the best properties was used to obtain tensile, rupture, total-deformation and creep data at 1000~, 1100~, and 1200~F. The investigation was undertaken to supply information which could be used to evaluate low-alloy hardenable steels for service as turbine wheels for jet engines. Suitable properties for the low temperature - high stress service at the center of the wheels can easily be developed with such alloys. Their ability to withstand the high stresses and temperatures at the rims of the wheels is limited by the decrease in creep and rupture strength of the type of alloy with increasing temperature. Therefore, the main value of this report is to indicate the relationships between temperature and stress as a function of service life for typical commercially available low-alloyed steels in the form of commercially produced and heat treated turbine wheels. Low-alloyed hardenable ferritic steels would have two important advantages for turbine wheel service. They require relatively small amounts of such scarce elements as nickel, chromium and molybdenumo Secondly, their production and fabrication characteristics are far superior to the highalloy austenitic steels commonly used. Both of these characteristics would be of considerable strategic importance, provided properties were adequate for turbine wheel service or if service life and temperatures were limited to the capabilities of the low-alloy steels. DESCRIPTION OF TURBINE WHEELS The turbine wheels were made from commercial heats of steel having the reported compositions in Table I. The wheels were contour forged in dies to the approximate dimensions shown in Figure 1 by an experienced forging company. Figure 1 does not show the stub shaft and boss which were cut off prior to cutting the wheels into test coupons. The forging company also heat treated the wheels as summarized in Table II. The forged and heat treated wheels were furnished to the University by the Materials Laboratory, Wright Air Development Center. The properties of low-alloy steels are dependent on the types of metal structure developed by heat treatment. These structures are dependent in part on temperatures at which transformation occurs on cooling, a factor controlled by the cooling rate. In addition, structural conditions established by processing prior to hardening probably influence the final structures. Such effects are difficult to predict for large size forgings with varying section size, For this reason, two common coolo

3 ing rates for hardening were used, oil. quenching and ai coolig. In addi1tion, a: attempt to develop a high strength structure was made by using an ineuterrupted quench selected to cause transformation to occur at intermediate temperatures. The interrupted quench was omitted for C-422 alloy because the available trans formation data indicated that necessary transformation times could not be obtained by the interrupted quench method. Temperatures of heat treatment used were those established by the manufacturers for the alloys. Tempering conditions after hardening were selected to established a hardness range of 280 to 320 Brinell in the wheels. This hardness range is representative of that usually required to provide adequate strength at the centers of turbine wheels to withstand hhe high stresses at low temperatures at that point; The hardness values in Table II were those reported by the heat treaters for surface measurements before the wheels were shipped to the University. There were certain unexpected responses to the originmal heat treatrrmts which required additional heat treatments, as indicated in Table II and discussed below: 1. The oil quenched and normalized forgings of 4340 steel were initially tempered at too high a temperatre to meet the hardness requirements. The second treatments used were usual commercial practice for the steel for the desired hardness. It should be recognized that the tempering temperature of the oil-quenched forging had to be restricted to 1050~F and no tempering could be used for the normalized forging. The retention of hardness of the interrupted quench wheel after tempering at 1200~F was unexpected. Either there are stable intermediate transformation products, or some unknown deviati:n from reported tempering conditions occurred. 2, The interrupted quench forging of "17-22A"S steel required a second temper to reduce the hardness to the desired range, 3, The initial tempering of the H-40 forg.:ngs was inadequate. Additional tempering at 1200~F reduced the surface hardness to the upper limit of the desired range. Subsequently, it was determined that the internal hardness of the forgings was too high for useful properties, and additional tempering at 1250 F was used on coupon:s cut from the fo rgiEngs to reduce the hardness to the specified range, 4. The surface hardness indicated that the C-422 forgings apparently responded properly to the initial heat treatmenlts However, hard spots were found during attempts to cut the forgings into test coupons. The Crucible Steel Company, producers of the steels, reheat treated the wheels to eliminate this difficulty. They used a full anneal at 1600~F before heating for hardening. A double temper of two hours at 1200~F was used to produce the proper hardness. 5. Due to tempering difficulties, it was necessary to accept the wheels from the producer with surface hardnesses higher than 320 B rine 11.

4 RESULTS Three general types of results are presented: (1) quality tests, (2) survey tests of the influence of type of heat treatment, and (3) extensive properties for the wheel of each alloy with the best heat treatment, Check tests were made to study the variation in properties with location in the wheels. The location of each test specimen can be determined by eceking the code numbers with Figure 1. Quality Tests The central slice (1-2-3 of Figure 1) from all wheels was magnafluxed and macroetched. All of the forgings, except the normalized and tempered C-422, were free from indications of defects. The slice from the C-422 forging gave two small magnaflux indications and showed inhomogeneity on macroetching near the center, Photographs of the macroetched surfaces are shown in Figures 2a, 3a, 4a, and 5ao Each center slice was surveyed for hardness variatio:ns with the results shown in Figures 2b, 3b, 4b, and 5b. The location of principle ranges in hardness are indicated by codng of the locationS of the hardness impressions. The following tabulation summarizes the hardhess surveys: Steel 4340Wl1 Treatment Principle Ranges in Brinell Hardness 4340 4340 4340 Normalized Oil Quenched Interrupted Quench 300-320 near center; 321-345 at rim 260-280 at center; 281-300 at flange; 301-320 at rim 280-300 except at rim; 301-320 in center of of rim and 321-340 at rim surface 235-260 except at rim; rim center 260-290; rim surface 321-330 280-300 at center, mainly 290-320 except 321-340 at rim 301-320 at central portion; 321-345 in flange and rim "17-22A"S Normalized "17-22A"S Oil Quenched " 17-22A"S Interrupted Quench H-40 H-40 H-40 C -422 C-422 Normalized Oil Quenched Interrupted Quench Normalized Oil Quenched Mixed 315 to 380 Mixed 315 to 390 Mixed 327 to 393 283-290 at center; 290 to 323 in flange and rim 275^290 at center; remainder 290-310 except for one location on flange of 321352 It will be noted that: lo The normalized "17-22A"S wheel was softer than specified over a considerable portion of the cross sectiono

5 2, A major portion of all the H-40 wheels was harder than 340 Brinell. 3. The centers of the 4340 and "17-22A-1S wheels tended to be the softest, while the hardness of the wheels of the other two steels varied over the entire cross section. 4. The surface hardness measurements made by the forging company did not show the high hardness of the H-40 wheels. In general, the ranges in hardness were about those to be expected in large forgings with the section size variation involved. The more uniform values for C-422 wheels was probably due, at least in part, to the conditioning involved in the prior heat treatments and annealing applied before hardening. The tensile properties at room temperature of specimens taken from the forgings are included in Tables Ilia, IVa, Va, Vb, and Via. Emphasis was placed on specimens from the centers of the wheels becagse poor center properties, particularly low ductility, are a common problem in turbine wheel forgings. It will be noted that: I1 The tensile and yield strengths generally reflect the hardness. Those steels and treatments which resulted in high hardness generally gave the highest strengths and lowest ductility. The specimens from the normalized 4340 steel wheel had unusually low proportional limits, due to the lack of tempering. 2, Specimens taken from the center of wheels in general had adequate ductility, except for H-40 wheels. 3. All of the H-40 wheels had very high tensile and yield strengths in accordance with their high hardness. Those specimens taken from the center of the wheels had very low elongation. Retempering coupons at 1250~F to reduce hardness of the oil-quenched wheel reduced strengths and improved ductility. Test material was not available to determine if the additional tempering improved the low center ductility. 4. The C-422 wheels also tended to have somewhat low center ductility. It is uncertain whether the lower values from the normalized than from the oil-quenched wheel reflects heat treatment or variation of individual specimens. Survey of Effect of Heat Treatment on Elevated Temperature Properties of Wheel Forgings Rupture tests at 1100~F were used to evaluate the influence of heat treatment on the turbine wheels and to select the best wheel for extensive testing. 4340 Wheel Forgings The stress - rupture time curves obtained are shown in Figure 2c, and the test data are included in Table IIIb. Testing was stopped at 100 hours at 1100~F, due to low strength, and the major evaluatio:n

6 carried out at 1000~F. The were as follows: rupture strengths and interpolated ductilities Treatment Temp 10 -Hour Strength Elong..(~ F) (psi) (%) C 0IU~~~ 100-Hour Strength Elong. (psi) (%).a-.e - 1000-Hour Strength Elong. (psi) (%) N. 1750~F OQ. 1550~F + T. 1050*F Interrupted Quench + T. 1200~F N 1750~F O Q 1550~F + T. 1050~F Interrupted Quench + T. 1200~F 1000 1000 58,000 28 48,000 38, 000 3 16 24,000 3 15,000 12 22,000 - 1000 48,000 2 1100 36,000 6 1100 28,000 20 18,000 5 16,000 40 19,000 5 1100 33,000 3 There was little difference between the normalized and the interrupted-quench wheels. The oil-quenched wheel was weaker and had higher elongation in the rupture tests, The normalized wheel was selected for more extensive testing on the basis that its strength and ductility were equal to the interruptedquench wheel with a much simpler heat treatment. The low eIongation of the normalized wheel was edmittedly an undesirable characteristic, The oil-quenched wheel was judged, however, tp have too low strength to be of interest. "17-22A"S Wheel Forgings The stress - rupture time curves at 1100~F for the three heat treatments are shown in Figure 3c, and the test data are included in Table IVb. The rupture strengths and interpolated'ductilities were as follows: Heat Treatment 10-Hour Strength Elongo si) (%) 100-Hour Strength Elong. (psi) (%) 1000 -Hour Strength Elongo (psi ) (%) __ _. w*. N. 1750~F+T. 1200~F O. Q 1750~F + T. 1200~F Interrupted Quench + T. 1200~F (64,000) -- (68, 000) -- _0 a o 35, 000 41, 000 41,000 3 3 3 15, 000 19, 000 22,000 (2) 3 The interrupted-quench wheel had slightly higher strength than the oilquenched. The normalized wheel was the weakesto All three treatments resulted in low elongation in the tests. The oil-quenched wheel was selected for more extensive testing. The higher strength of the interrupted-quench wheel was not sufficient to offset the problems of the more difficult heat treatment, The normalized wheel was too soft, as well as being too weak in the rupture tests.

7 H-40 Wheel Forgiongs The stress - rupture time curves at 1100~F for the three heat treatments are shown in Figure 4c, and the test data are included in Tables Vc and Vdo The rupture strengths and interpolated ductilities were as follows: Heat Treatment 10-Hour Strength Elong. (psi) (%o) 100-Hour Strength Elong. (psi) 00) 1000-Hour Strength Elong, (psi) (%) Wheels Tempered at 1200~F No 1950~F O.Q. 1750~F Interrupted Quench Coupons Re-Tempered for 4 (64,000) (<1) 48,( (72,000) (2) 52, (74,000) (<1) 50, ( Hours More at 1250~F )00 )00 )00 (<1) (1-2) (2) (36, 000) (37, 000) 34,000 Normalized Oil Quenched Interrupted Quench 56, 000 59, 000 56, 000 7 44,000 17 47,000 7 48,000 3 7 4 32,000 31, 000 31,500 (2) CD G All of the wheels, as supplied, gave very erratic rupture-test data and low ductility. Reduced diameter specimens with enlarged fillets were required to avoid fracture in the threads and fillets. None of the forgings, as furnished, were judged suitable for further testing. Because the hardness surveys had shown all the wheels to be excessively hard, tests were made to determine the additional tempering required to reduce the hardness to the proper rangge Four hours at 1250~F produced the proper hardness and alleviated the brittleness in the rupture tests. There was very little difference in rupture properties at 1100~F (Figure 4c and Table Vc) between the various initial treatments. Coupons cut from the oil-quenched wheel retempered at 1250~F were selected as having the best combination of properties and heat treatment procedure for more extensive testing. C-422 Wheel Forgings The stress - rupture time curves at 1100~F for the two heat treatments are shown in Figure 5c, and the test data are included in Table VIb. The rupture strengths and interpolated elongations were as folows: Heat Treatment I -Hour Strength al'ongo (psi) (_%) ~Li~t~h~-E~, _ oi 100 —Hour Strength Elong. (Esi) (%) 1000-Hour Strength Elong. (psi) (%0) N. 1900~F + T. 1200~F O.. 1900~F + T. 1200~F 48,000 25 51,000 36 39,000 18 43,000 31 32,000 9 36,000 14

8 The oil-quenched wheel was selected for further testing on the basis of higher strength and ductility. Tensile, Rupture, Total - Deformation and Creep Properties of Selected Turbine Wheels at 1000~, 1100~, and 1200~F SpecimeMe fromthose wheels,selected on thb basis of the survey rupture tests, is described in the previous section, were subjected to more extensive testing. The rupture strengths were established out to 1000 hours for 1000~ and 1100~F and to 100 hours at 1200~F, except for the 4340 wheel, where the testing time was limited to 190 hours at 1100~F. Curves of stress versus time for total deformations" ) of 0. 1, 0. 2, 0.5 and 1. 0 per cent were established fairly completely for time periods of 1000 hours at 1100~F for the "17-22A"S, H-40 and C-422 wheels. The testing of the 4340 wheel was most extensive at 1000~F. Lower stress creep tests, which were discontinued at about 1000 hours, were used to established some of the lower deformation valuesO The total deformation valuesa at 1000' and 1200~F were limited to those available from the time - elongation curves for the rupture ts. Simila dta he stests have been included in the tables for all the wheels. Tensile tests were carried out at 1000~, 1100~, and 1200~F on the selected wheels. The minimum creep rates were measured for all rupture and creep tests. The creep rates were generally sufficiently slow for the lower stress creep tests at 1100~F, so that the creep strength for a creep rate of 0. 0001-per cent per hour could be established. Specimens having a 0. 505 inch diameter and a 2 inch gage length taken radially near the rim were used for the majority of the tests. Single specimens taken from three other locations, as indicated below, were used to indicate the variability of properties: 1. A specimen taken tangentially at the rim. 2. A small specimen (02250 inch diameter by 1 inch gage length) taken radially as near the rim as possible. This test was run because the gage lengths of the larger specimens were further ftrom the rim than the normal depth of blade root fastenings. 3. A small specimen taken at the center of the wheels to indicate center properties. These variable location specimens were limited to the wheels selected for extensive testing, and to rupture tests at 1100~F for the "17-22A"S, H-40, and C-422 wheels and to 1000~F for the 4340 wheel. (1) Total deformation as used in this report includes both the deformation on loading and the creep deformation.

9 The results of the tests are presented as follows: 4340 Wheels lo Tensile data - Table Ilao 2. Rupture data - Table IIHb and Figure 2d, 3. Total-deformation data - Table IIIb and Figures 2e and 2f, The stress - time for total-deformation curves were shown for all three heat treatments. 4, Available stresses for rupture and total deformations of 1 0, 0.5, 0. 2 and 0. 1 per cent in 1, 10, 100, 500 and 1000 hours are summarized in Table IIIc for all three wheels. 5, Figure 2g summarizes tensile, rupture and total-deformation strengths at 1000~, 1100~, and 1200~F for the normalized wheel. 6. Minimum creep rates - Table IIIb and Figure 2ho No tests were made at sufficiently low stresses to define the 0. 0001-per cent per hour creep strength. " 17-22AS Wheels 1o Tensile data - Table IVa. 2. Rupture data - Table IVb and Figure 3do 3. Total - deformation data - Table IVb and Figure 3e, Graphical presentation of the total-deformation data was limited to the oil-quenched wheel. Table IVb, however, contains the available data from the rupture tests on the other two wheels, 4. Available stresses for rupture and total deformations of 1.0, 0.5, 0, 2 and 0. 1 per cent in 1, 10, 100, 500 and 1000 hours for the oil-quenched wheel are summarized M Table IVco 5. The tensile, rupture and 1. 0-per cent total-deformation strengths at 1000~, 1100~, and 1200~F for the oil-quenched wheel are summarized graphically in Figure 3f 6, Minimum creep rates for all rupture and creep tests are included in Table IVb. The stress - creep rate curves for the oil-quenched wheel are shown as Figure 3g. The indicated stress for a rate of 0 0001 -per cent per hour at 1100~F is included in Table IVc. H-40 Wheels 1. Tensile data - Table Vb. 2. Rupture data - Table Vd and Figure 4d, 3. Total-deformation data - Table Vd axn.d Figure 4e, The data for all tests are included in Tables Vc and Vd, while the stress - time for total-deformation curves of Figure 4e are limited to the retempered

10 oil-quen:ched wheel selected for extensive testing. 4. Available stresses for rupture and for total deformation of 1.0, 0 5, 0. 2 and 0. 1 per cent in 1, 10, 100, 500 and 1000 hours for the oil-quenched and retempered wheel are summarized in Table Ve. 5. Figure 4f summarizes the tensile, rupture and 1. 0-per cent total-deformation strengths for the retempered oil quenched wheel. 6. Minimum creep rates for all tests are included in Tables Vc and Vd. The stress - creep rate curves for the retempered oilquenched wheel are shown in Figure 4g. The stress for a creep rate of 0. 0001-per cent per hour at 1100~F indicated by Figure 4g is included in Table Ve. C-422 Wheels 1o Tensile data - Table VIa. 2. Rupture data - Table VIb and Figure 5d. 3. Total-deformation data - Table VIb and Figure 5e. 4. Available rupture and total-deformation strengths for 1, 10, 100, 500 and 1000 hours for the oil-quenched wheel are summarized in Table VIc. 5. Tensile, rupture and 1. O-per cent total-deformation strengths at 10000, 1100~, and 12000F for the oil-quenched wheel are summarized in Figure 5f. 6. Creep data are included in Table VIb. Figure 5g shows the stress - creep rate curves for the retempered oil-quenched wheel and the indicated stress for a creep rate of 0. 0001-per cent per hour at 1100~F is included in Table VIc. As would be expected, there was some scatter in. the data for the tests on each wheel, The scatter was due to specimens being taken from fairly large forgings with variable response to heat treatment at different points in the forging, as evidenced by the hardness variations, Specimens taken radially at the rim, tangential to the rim, and at the center of the wheels in general gave about the same rupture test properties as the radial 0. 505 inch diameter specimens used for establishing properties. The points did not deviate from the stress - rupture time curves appreciably more than the specimens used ot establish the curves. In only one case, the H-40 wheel, did the elongation of the specimen taken at the center fall appreciably below that of the rim specimens. It will be recalled (Table Va) that this was also true for room temperature tensile tests for this alloy. Tangential specimens had about the same properties as the radial specimens. Thus, the majority of tests indicate that there was no great variation in rupture properties at 1100~F throughout the wheels, More tests would possibly show small consistent differences.

11 DISCUSSION Data are presented in this report which define the rupture properties of turbine wheels made from four low-alloy steels at 1000~, 1100, and 1200~F. This is supplemented by the relationships between stress and time for total deformations of 0. 1, 0. 2, 0. 5 and' 1. 0 per cent at 1100Fo Less extensive total-deformation data are reported at 1000~ and 1200~F. In addition, information is supplied regarding the response of the four alloys in the form of turbine wheels to three types of heat treatment. The data also present the opportunity to compare the properties of the four alloys. The comparisons of properties can be relied upon with certain reservations. As will be discussed in a forthcoming report, and as was demonstrated in this report, the properties of the alloys vary with heat treatment. Essentially; this means that the properties are depe rnd~ ent on the hardening temperatures and on cooling rates as they control temperatures of transformation. Since cooling rate is a function of the size of the wheel and the particular cooling conditions, the data are limited to the particular heat treatment conditions and should be applied to other sizes and treatment conditions with the fundamentals of heat treatment clearly in mind. Recognitions should be further given to the well known tendency for response to heat treatment to vary between heats of such alloys, As is well known in the metallurgy of such materials, the necessary restriction of tests to one wheel for each condition is perhaps the most severe limitation. Almost invariably it is necessary to develop forging procedures and heat treatments by experience to obtain optimum properties for a particular alloyo Thus, a small lot of wheels made experimentally is always subject to uncertainty. Such effects were evident in this investigation in that treatments had to be repeated and modified. These limitations should not be allowed to obscure the value of the data in this report. All, experimental applications of alloys are subject to similar limitations. The data do indicate the level of properties obtainable in the form of actual turbine wheels and are sufficient to make a choice of material and to proportion parts with the usual safety factors of enrgineering design. In actual use of the alloys, tbhe metallurgists would develop suitable practices and checks to insure uniform and as nearly optimum properties as possible for any particular alloy through experience, Influence of Heat Treatment The metallurgical principles controlling properties of lowalloy hardenable steels at high temperatures have not been well established in the literature. It has been recognized in work on bar stock that normalizing and tempering of bar stock generally gives higher strength above some limiting temperature, but lower ductility, thban liquid quenchit:g and tempering. This essentially means that tempered martensite has lnferior strength to intermediate temperature tran nsformation products, but superior hot ductility.

12 The test temperatures considered in this investigation were a1 in the range in which the normalized structure in bar stock develops superior propertieso It should further be recognized that 12 Cr steel (C-422) is considered to transform to martensite on either liquid quenching or normalizing. A strong possibility also exists for vanadium bearing steels that cooling rate affects a secondary hardening reaction which is also important to properties at high temperatures. Varying treatments were used for the wheels to establish the influence of the heat treatment conditions in the large size wheels. The interrupted quench was used to develop intermediate transformation products to determine if superior properties would be obtainedo The latter type of treatment, in theory, offers considerable promise if structures with better properties could be obtained than those usually resulting from liquid quenching or normalizingo With this background, the results obtained are considered,for the individual alloys. 4340 Turbine Wheels The oil-quenlched wheel had the lowest rupture strength and highest ductility because the structure was largely tempered martensite. Both normalizing and the interrupted quench developed the higher strength intermediate transformation products in the structure. The hardening characteristics of 4340 steel are marginal for normalizing the size of wheel used in this investigation. The hardenability of 4340 steel varies widely with normal composition variation within the specification. The composition of the heat used for this investigation indicates that it represents the higher hardenability heats of 4340 steel. Apparently. it barely hardened to the specified hardness range on normalizing. The tempering characteristics of 4340 steel are also marginal for service at 1000~ to 12000F. In general, it is considered desirable to temper considerably above the service temperature to reduce. structural instability during service. Such instability generally is reflected in the strength values falling off rapidly wih increasing time of testing or service. To maintain the necessary hardness, the tempering temperature of the oil quenched wheel had to be limited to 1050'F and the normalized wheel could not be tempered at all. The omission of a temper for the normalized wheel probably contributed to the rapid decrease in rapture and total-deformation strength with time, The interrupted quench wheel was reported to have been tempered at 1200~F while maintaining proper hardness. This appeared to be so questionable that, when no great difference in rupture properties was observed at 1000' and 1100~F, it was a contributing factor for selecting the normalized wheel for extensive testing. If subsequent experience substantiates that controlled isothermal types of tra.nsformation treatments do result in more stable structures for 4340 steel, its utility for high temperatures may be considerably improved. The oil quenched and normalized wheels had to be rehardened due to overtempering after the first heat treatment. The double treat

13 ments may have resulted in different characteristics than would ha.ve re suited from a single treatment. "17 22A"S Turbine Wheels In the case of this steel, the normalized wheel did not harden adequately. Furthermore, it appeared as if the oil quenching produced a cooling rate which gave structures with properties very near those characteristic of normalized bar stock of this alloy. The interrupted-quench wheel developed structures and properties similar to the oil-quenched wheel. This behavior is difficult to understando Experience with the alloy indicated that it should have hardened satisfactorily by normalizing. Secondly, oil quenching should have developed martensite with inferior strength. There is no evident reason in the available information to explain this behavior. It seems necessary to conclude that: 1. The oil-quenched wheel had the structures and properties ordinarily considered characteristic of intermediate transformation structures and not of tempered martensite, The properties obtained were those normally expected for "normalized" material. 2. Care should be exercised to make certain that some unknown factor did not disturb the normal response to heat treatment before the properties reported are accepted as typical of oil-quenched wheels of the size tested. Even though the hardening characteristics of "17-22A"S appear to be marginal in the size considered, it could be tempered at 1200~ Fo This is a characteristic of vanadium bearing steels and probably is related to their secondary hardening characteristics, H-40 Turbine Wheels Apparently all three heat teatatments gave about the same initial structures and properties. The microstructures were mixed ma rt ensite, bainites and acicular ferrite. In a subsequent report, it will be shown that bar stock does respond differently to oil quenching and:normalizing. It appears, therefore, the size effect restricted cooling rates during oil quenching to the point where some high temperature transformation occurred, On the other hand, normalizing and inter.rupting the quench apparently caused only about the same amount of transformation,, in spite of longer times for transformation, The response of th he wheels to heat treatment probably reflects the restricted temperature range and sluggishness of transformation of this higher alloyed steel. These features greatly limit variation in response to heat treatment, It will be noted that it was doubtful if there was a real differe between the three wheels — certainly the choice of the oilgquenched wheel fo~r extensive testing was based on small differences insofar as properties are concerned, A good deal of difficulty was encountered in tempering the H-40 wheels. Limited available information at the time indicated that 1200~F should have reduced the hardness to the desired range.

14 C-422 Turbine Wheels In theory, the hardening power of this 12 Cr steel ought to be sufficient to remove differences between oil quenching and normalizing. In actual practice, the quenching treatment gave better properties. In spite of transformation to martensite in both cases some additional metallurgical variable involved in cooling rate influenced properties, This is also characteristic of bar stock. The properties obtained were practically identical with those established for the alloy by the manufacturer on bar stock, The exact cause of the hard spots observed after the initial heat treatment was not established, The manufacturer used an equalizing heat treatrrent prior to hardening. Apparently this alloy can ahow variable response to heat treatment as a result of variations in prior hot working conditions, unless such variations are eliminated by intermediate heat treatments. Comparative Properties of Turbine Wheels of the Four Alloys The stress rupture time and stress - time for 1. O-per cent total deformation curves for the wheels selected for extensive testing are compared in Figures 6 and 7. It will be noted that: 1. All four alloy wheels had similar rupture strengths up to about 20 hours at 1000~F and to one hour at 1100~F. The strength of the 4340 steel wheel fell below the other alloys for longer time periods at these temperatures and for all time periods considered at 1200~F. 2. The "17-22A"S wheel maintained ruptare strengths higher than or equal to the other alloys for time periods out to 1000 hours at 1000~F, to 100 hours at 1100~F, and to 10 hours at 1200~F. 3. There was little difference in rupture strength between the H-40 and C-422 wheels at 1000~ and O1100,F The H-40 wheel, however, gave substantially higher strengths at 1200~F. 4o The elongation in the rupture tests of all alloys except C-422 dropped to values in the range of 2 to 5 per cent with increasing time for rupture. There were two exceptions to this: (a) The elongation of the H-40 samples stayed up to values between 6 and 10 per cent at 1000~F. (b) The 4340 samples had high elongation at 1200~F. 5. The relative strengths for a total deformation of 1, 0per cent compared similarly to the rupture strengths. The C-422 steel in general had slightly lower total deformation strengths in comparison to the other steesthan indicated by the stress - rupture strengths. This was due to relatively fast creep rates during first-stage creep for the C-422 material, Consequently,, O-per cent total deformation was obtained in a rather small fraction of the time to rupture for the C-422 al loy, whereas the other materials were usually in third.stage creep, at least for the longer time tests, before 1. 0-per cent deformation was obtained,

15 The semilog stress i time for total deformation curves of Figure 7 suggest greater differences between steels than the log stress time for rupture curves of Figure 6. This, however, is mainly due to the condensing of the stress axis by the logarithmic scale for the rupture tests, The comparative total-deformation strengths for 0o 5-per cent were similar to those for 1. O-per cento However, at 0. Zper cent and 0o 1-per cent, the differences tended to disappear for all except the 4340 steel, which was still weak in comparison to the other steelso This is due to the deformation on loading largely controlling these low total deformations, The 4340 remained low due to lower yield strengths, as well as low creep strength, 6. The creep strengths for 0, 0001-per cent per hour given in Table IVc, Ve and VIc show a cnnsiderably higher strength for the C-422 wheel. Reference to the creep curves will, however, show that this difference only appears for the creep rates loewe.e than 0. 00 -per cent per houro Therefore, the creep resistance follows the pattern of other strengths in that the differences between the steels tended to disappear at high stresses. The 4340 steel became weaker than the others at relatively short time periods, probably mainly due to low creep resistance. "17-22A"S fell off with time before H-40 steel, and C-422 mai:ntained strength for long time periods, except at 1200~F, where H-40 seemed to maintain strength better. The relative strengths of the alloys suggests that: 1. At short time periods the strengths are mainly dependent on the hardness, Thus, there was little difference between the four alloys, and such differences as did exist were probibly mainly due to hard:ness variations o 2. The loss in strength with increasing time for 4340 steel in comparison to the other steels was probably due both to lower inherein.t creep resi.stance and to an unstable structure which tempered during testing. The same factors probably apply to the '"l7-22A"S steel, but to a lesser degree. 3. Apparently the main difference between H-40 and C-422 steels was inherent creep resistance. It may well be, however, that the maintainance of strength of the H-40 steel at 1200~F also reflects a greater resistance to loss of strength by tempering. 4. There does not appear to be a complete explanation of the loss in elongation with time for rupture for the three lower alloy steels. High ductility in the rupture test is characteristic of 12 Cr steels and was therefore to be expected for the C-422 steel. 5o Oxidation was extensive for 4340 steel in the longer tests at 1200~F. The same was true for 17-22A"S and H-40 steels to a lesser degree. This means that their use at temperat.ures above 1100~F would be limited to rather short time periods. Oxidation was also sufficiently advanced at 1100~F for these same three steels in the longer tests so that

16 their use for periods prolonged beyond the time periods used in these tests might.require pratection from oxidation, So far as could be determined, the comparative strengths of the alloys were reasonably typical. The superiority of H-40 to C-422 at 1200~F is a possible exception to this, Some adjustments in actual levels of properties could be obtained by improvement of heat treating conditions to develop more favorable structures. This would probably show up mainly in the prolonging of the time at which properties tend to fall off with time and in reducing the rate at which properties decrease with time~ It would also shift the relative strengths at the shorter time periods to a slight extent. For these reasons, the rupture and total deformation data should be considered as mainly showing how the strength tends to fall off more rapidly for the lower alloyed materials. The differences in elongation and reduction of area in the rupture tests mainly show the superiority of the 12 Cr type steels. Minor improvements in this characteristic probably could be achieved for the lower alloyed steels. This, however, apparently will be small so long as the higher sitrengths characteristic of intermediate transforrration products is developed by restriction of the cooling rate. The greater ductility possible by quenching to martensite and tempering would necessarily be accompanied by a considerable sacrifice in strength. CONCLUSIONS Commercially produced contour forged turbine wheels for a jet engine made from for low-alloy hardenable steels were examin.ed for properties at both room temperature and 1000~, 1100~ and 1200~F. The more important results were as follows: 1, With one possible exception, all of the forged wheels were solud and free from defects. o. The wheels were to be produced to a hardness range of 280 to 320 Brinello Some difficulty in obtaining this hardness range was encountered. This unquestionably could be corrected through experience in producing and heat treating the alloys in the section sizes considered, 3, Some evidence of low center ductility was encoutntered. Because this is probably mainly a function of manufacturing techniques, considerable improvement could be expected with production experience~ 4. Normalized, oil-quenched and an interrupted quench wheels were compared by rupture tests at 1100~Fo Except for the 12 Cr (C-422) alloy, the treatments which produced mixed transformation products had the highest strength at the elevated temperatures The oil-quenched 12 Cr wheel had better strength than the normalized wheel, although both had tempered martensitic structures. The interrupted quench produced properties in the three other steels as good as, but no better than, normal izing or oil quenching. The better of the latter two treatments appeared

17 to be -, function of both, composition and unidentified heat treatment condi5. The wheel of each alloy having the best rupture test properties at 1100F was also subjected to rupture tests at 1000~F and 1200'F. Curves of stress versus time for total deformations of 0. 1, 0 2, 0. 5 and 1. 0 per cent were developed at 1100~F. Less extensive total deformation data were established at 1000~ and 1200~ F, 6. The wheels all had similar strengths at short time periods, except that lower strength was obtained from the 4340 wheel at 1200~F for all time periods considered. The 4340 steel gave the lowest strengths for the longer time periods at 1000~, 1100~, and 1200~F. The strengthtime curves for the 1. 25Cr-Mo-Si-V (817-22A"S) steel increased in slope at 1100~ and 1200~F, so that it had lower strengths at these temperatures for the longer time periods. The 3Cr-Mo-W-V (H-40) steel wag strongest at 1200~F. Only the 12 Cr (C-422) steel gave high elongation in the rupture tests at all three temperatures. 7. The 4340 and the 1"17-22A"S steels had marginal hardenability for normalizing wheels of the size tested to a minimum Brinell of 280. The 4340 steel also has marginal tempering characteristics for service at 1000~ to 1200~F. All of the other steels, however, could be tempered at 1200~F or higher.

Type Steel 4340 "17-22A"S H-40 C -422 C (%) 0.40 0.30 0.29 0.23 Mn (%) 0.76 0.57 0.48 0.81 Chemical Si P (%) (%) 0.29 0.010 0.60 0.018 0.26 0.012 0.16 0.011 TABLE I Composition of Forged Turbine Wheels S Cr Ni Mo' V W (%) (%). (%) _ (%) (%) (%) 0.015 0.74 1.91 0.50 0.019 1.22 0.23 0.49 0.24 0.018 3.05 0.49 0.49 0.85 0.55 0.012 13.19 0.65 1.03 0.25 0.84 I I Cu Manufacturer's (%) Heat Number - 656601 0. 13 38516 0. 15 K-2509 -- W-3561

TABLE II Heat Treatments of Forged Turbine Wheels 4340 Steel All forgings were isothermally annealed for 15 hours at 1200~F directly from the forging operation, Surface Brinell Hardness Rim Hub Disk No, 1 - Normalized Forgiag Ist Treatment: Air cooled from 1750~F and tempered 2 hours at 1200~F 217 229 2nd Treatment: Renormalized from 1750~F (no tempering) 285 285 Disk No 3 - Oil Quenched Forging 1st Treatment: Oil quenched from 1750~F and tempered 8 hours at 1200~F 269 255 2nd Treatment: Oil quenched from 1550~F and tempered at 1050~F 302 285 Disk No, 4 - Interrupted Quench Forging Water quenched from 1750~F until black, then withdrawn until glow returned. This was repeated until glow did not return upon withdrawal from water. It was then transferred to a furnace at 700~F and held for 8 hours. It was then tempered for 2 hours at: 1200~F, 302 293 "17-22A"S Steel A.ll forgings were isothermally annealed for 8 hours at 1200~F directly from the forging operation, Surface Brinell Hardness Rim Hub Disk No, 1 - Normalized Forging (a) Air cooled from 1750~F and tempered 2 hours at 1200~F 302 285 Disk No, 3 - Oil Quenched Forging (a) Oil quenched from 1750~F and tempered 8 hours at 1200~F 302 302

FABLE II, Continued. "17-22A"S Steel Surface Brinell Hardness Rim Hub Disk No. 4 - Interrupted Quench Forging (a) Quenched in water until black, withdrawn until glow returned, requenched until black, and process repeated until glow did not return. The forging was then placed directly in a furnace at 700~F for 8 hours, then tempered at 1200~F for 2 hours 399 399 (b) Retempered for 2 more hours at 1200~F 341 331 H-40 Steel All forgings were isothermally annealed for 8 hours at 1200~F directly from forging. Surface Brinell Hardness Rim Hub Disk No, 1 - Normalized Forging (a) Air cooled from 1950~F and tempered 2 hours at 1200~F 429 444 (b) Retempered 3 more hours at 1200~F 341 341 Disk No. 3 - Oil Quenched Forging (a) Oil quenched from 1950'F and tempered 8 hours at 1200~F 415 415 (b) Tempered 3 more hours at 1200~F 341 352 Disk No 4 __Interrupted Quench Forging (a) Interrupted quench from 1950~F in water as previously described for other steels; then tempered at 1200~F for 2 hours 389 363 (b) Retempered for 3 more hours at Z100 F 341 331 Final T reartments for All Forgings Subsequently. bars cut from all three forgings were retempered for 4 more hours at 1250~F 287 to 322

TABLE II, Concluded. C-422 Steel All forgings were isothermally annealed for 8 hours at 1200~F directly from forging. Surface Brinell Hardness Rim Hub Disk No. 1 - Normalized Forging 1st Treatment: Air cooled from 1900~F and tempered for 2 hours at 1200~F 321 331 2nd Treatment: Full annealed for 6 hours at 1600~F and furnace cooled; then air cooled from 1900 F and double tempered 2 + 2 hours at 1200~F 285 293 Disk No. 4 - Oil Quenched Forging 1 st Treatment: 2nd Treatment: Oil quenched from 1900~F and tempered 8 hours at 1200'F Full annealed at 1600~F for 6 hours and furnace cooled; then oil quenched from 1900~F and double tempered 2 + 2 hours at 1200~F 285 302 285 311 Note: Second treatments required due to hard spots after first treatment.

TABLE IlIa Tensile Properties of 4340 Turbine Wheels Specimen Specimen Number Location W___e__ No( 1. Wheel No. 1. Brinell Test Tensile Of: Hardness Temp. Strength (~F) (psi) 0. 02% Heat Treatment: First Treatment - N. Second Treatment - N. fset Yield Strengths (psi) Proportional Elongation Reduction Limit in 2-in. of Area - 0.1% 7 0.2% (psi) (%) 1750~F + T. 2 hrs. at 1200~F. 1750~F. (%).> 1W 1X 2W 2X 2Y 2Z 1Y 3W 14Z 3X 1Z SRR CRR SRC CRC CRC SRC CRR SRR STR CRR SRR 328 331 316 316 308 304 325 334 331 313 75 163,500 75 163,500 75 156,500 75 155,000 75 155,250 75 151,000 1000 99,000 1000 1000 - 98 -750 100,000 69,500 72,000 62,000 58,500 70,500 65,250 56,500 65,500 57,250 46,750 34,000 31,000 11,750 15,500 15,500 97,000 102,500 92,000 87,000 96,500 92,500 77,250 80,250 77,500 57,000 51,000 47,250 23,750 24,500 22,750 112,000 119,000 106,500 101,500 110,000 105,500 86,500 87,500 85,750 64,000 57,750 58,000 29,000 31,000 27,500 46,000 43,000 37,000 40,000 46,000 44,000 46,000 48,000 37,500 25,000 18,500 19,500 10, 000 9,000 8,500 15.0 12.5 6.5 10.5 12.0 11.5 1100 71,500 1100 1100 1 64i 250 72.., 500 16.0 21.0 16.0 14. 0 24.5 14. 0 25.0 30.5 30.5 45. 5 40. 3 9. 3 25.5 32. 8 30. 2 48. 7 58. 5 44. 8 35. 0 56. 8 26.7 41. 3 37.0 28. 8 14Y CTR 3Z 3Y SRR CRR 320 328 1200 -- 38, 0-0 1200 3:38 5D0 1200 34,500 14X CTR (concluded on following page)

Table IIIa(concluded) Specimen Specimen Number Location Wheels No. 3. Brinell Test Tensile Offset Yield Strengths Proportional Elongation Reduction Hardness Temp. Strength (psi)_ Limit in 2-in. of Area ____ (OF) (psi). 02% 0.1% 0.2% (psi) (%) (%) Heat Treatment: First Treatment: O. Q. 1750~F + T. 8 hrs. at 1200~F. Second Treatment: O.Q. 1550~F + T. at 1050~F. 1W lx 2W 2X 2Y 2Z SRR CRR SRC CRC CRC SRC 75 136,500 75 129,000 75 125,500 75 123,750 75 122,750 75 123,750 112,500 107,000 96,750 91, 750 89, 750 92,500 115,750 109,250 98,750 94, 750 94,000 95, 750 116,000 110, 750 99, 250 95,250 94, 500 96,250 73,000 78, 000 79, 000 82,000 74,500 74,500 18.5 17.0 15.5 17.0 18.0 18.5 62. 2 58. 3 39. 2 44. 6 48. 6 47. 7 Wheet No. 4. Heat Treatment: Int. -quench from 1750~F + T. 2 hrs. at 1200~F. 1W IX 2W 2X 2Y 2Z SRR CRR SRC CRC CRC SRC 288 289 290 292 286 287 75 141,250 75 140,250 75 137,750 75 137,750 75 137,750 75 136,250 90,500 87,000 79,000 86,250 91,250 85,750 104,750 101,250 97,500 99,500 102,250 98,500 109,250 106,250 103,750 105,250 106,500 103,250 64,500 63,000 47,000 65,000 68,000 60,500 17.0 17.0 11.0 12.0 14.0 12.0 49.5 48. 8 23.4 29. 8 26. 1 31.7 (L) SRR - Surface plane radial specimen at rim of.wiheel CRR - Central plane radial specimen at rim of Wheel SRC - Surface plane radial specimen at center of w'heel CRC - Central plane radial specimen at center of Whiel STR - Surface plane tangential specimen at rim of wheel CTR - Central plane tangential specimen at rim of &wheel

TABLE IIb Rupture, Total Deformation, and Creep Data for 4340 Turbine Wheels Time at Start Specimen Specimen Test Stress Time to Elongation Reduction Time to Reach Specified Total Deformations of Third Stage Minimum Deformation Number Location Temp. Fracture in 2-in. of Area (hours) Creep Creep Rate on Loading () ('F) (psi) (hours) (%) (%) 0. 1o 0. 2% 0.5% 1. U0% (hours) (%/hr.) (In. /In.) Disk No. 1 Heat Treatment: (a) N. 1750'F + T. 2 hrs. at 1200~F. (b) N. 1750~F. I o1W SRR 1000 65,000 35 4Y CRR 1000 50000 88(e) 6W SRR 1000 45,000 163 4Z SRR 1000 39.000 146 6Y CRR 1000 34,000 292 9Z) SRR 1000 34,000 277( 7A(b) SRR 1000 34.000 165d) 5A(b) SRC 1000 34.000 200 6Z SRR 1000 24,000 957 14W STR 1000 24,000 635 9X CRR 1100 44,000 3, 6X CRR 1100 25,000 37 ) 4W SRR 1100 20 000 67 4X CRR 1100 17,000 130 9Y CRR 1200 20,000 2 l0Y CRR 1200 14.000 12 ) 10X CRR 1200 8 000 139 10Z SRR 1200 7. 000 157(g) 3.5 5.9 (c) (c) 2.2 1.2 (c) (c) 2.8 1.8 (c) 1 2.7 1.7 (c) 0.8 2.3 4. 0 () 11 2.2 2.8 (c) 4... -- (c) (c) 4.2 4.0 (c) 3 3.3 1.3 (c) 21 3.5 2.4 1 30 6.8 12.0 (c) (c) 5.5 7.8 (c) 0.4 6.2 7.0 0.2 1.6 5.3 3.9 (c) 1.6 1.4 13 22 68 35 118 40 122 108 250 88 213 68 180 339 683 220 470 0.1 0.8 2.8 12 9.2 22 14 41 (c) 0.25 1.3 3.3 5.5 14 20 63 95 98 185 170 170 390 320 5 17 64 4 0. 00310 0.0055 0 00200 0.005 0.00180 0.0045 0.00160 0.0025 0.00140 0.0033 0 00140 0.0045 0.0037 0.00163 0.00086 0.00097 0.0015 0.00094 -- 0. 00275 0.0365 0. 00129 0.035 0.00090 0.0186 0.00095 2.3 0.00290 0.26 0.00150 0.061 0.00066 I I 15.0 20.0 27. 5 30.0 19.1 (c) (c) 14.9 (c) 0.2 25.5 (c) 0.6.,. _,,..,. _, Disk No. 3. Heat Treatment: (a) O.. 1750'F + T. 8 hrs. at 1200*F. (b) O.Q. 1550'F + T. at 1050*F. 4Z SRR 1000 50,000 23 6W SRR 1000 40, "00 77 6X CRR 1000 32.500 247 6Y CRR 1000 27,500 372 6Z SRR 1000 20,000 604 4W SRR 1100 25,000 17 4X CRR 1100 20,000 31 4Y CRR 1100 13,000 212 28.0 16.5 11.5 11.5 14.0 20. 5 23.0 57.0 48.7 (c) (c) 30.8 (c) (c) 14.5 (c) 1.5 17.8 (c) 2 26.8 1 6 39.1 (c) (c) 34.4 (c) 0.2 41.0 0.2 1.2 0.5 2 2.5 8.5 11 40 18 68 42 124 0.2 2(h) 0.8 2.6h) 8.5 20 68 110 120 73 0. 00215 0. 00265 0.019 0.00130 0.0095 0.00120 0.0055 0.00079 -- 0.00190 -- O 0.00134 0.017 0.00085 Disk No. 4. Heat Treatment: Int. -quench 1750'F + T. 2 hrs. at 1200'F. 4Z SRR 1000 50,000 88 6W SRR 1000 40,000 185 6X CRR 1000 34,000 278 6Y CRR 1000 28,000 377 6Z SRR 1000 19 000 Off1150(j) 4X CRR 1100 30,000 17 4W SRR 1100 25,000 29 4Y CRR 1100 16,000 199 2.2 3.5 (c) 0.4 3.1 3.5 (c) 1 1.8 2.2 (c) 7 1.8 2.4 (c) 18 - -- 2 82 3.5 5.9 (c) 0.2 4.7 8.1 (c) 0.5 5.6 7.0 0.6 9 28 81 55 140 123 256 181 355 560 1228(h) 2 4 3.6 11.2 39 84 63 120 150 210 960 19 90 0.0076 0.00190 0.005 0.00160 0.0024 0.00135 0.0018 0.00118 0.00063 0.00090 - 0.00173 0.066 0.00137 0.011 0.00073 (a) SRR - Surface plane radial specimen at rim of disk CRR - Central plane radial specimen at rim of disk SRC - Surface plane radial specimen at center of disk STR - Surface plane tangential specimen at rim of disk (b) 0. 250-inch diameter specimens (c) Specimen reached this deformation on loading (d) Broke in threads (e) Broke in fillet ( f) Broke in gage mark (g) Very badly scaled (h) Extrapolated value ( i) Creep test ( j) Test discontinued at this time

TABLE ILIc Rupture and Time - Deformation Strengths of 4340 Turbine Wheels Total Deformation (%) Wheel No. 1. Stress to Cause Total Deformations at Indicated Times (psi) 1 hour 10 hours 100 hours 500 hours 1000 hours Heat Treatment: First Treatment - N. 1750~F + T. 2 hours at 12000F Second Treatment - N. 1750~F 1000~F 0.2 0.5 1.0 Rupture 42,000 67,000 _ _ 31,000 54,000 69,000 34,000 43,000 48,000(3%) 19,000 25,000 29,000 (3%) 17,000 24,000(3%) 1100~F 0.2 0.5 1.0 Rupture 20,000 31,000 42,000 19,000 27,000 36, 000 (6%) 11,000 18,000(5o%) 0.5 1.0 Rupture 15,000 17,000 25, 000 05%) 1200~F 6,000 9,000 14,000(22%) 7,800(27%) Wheel No. 3. Heat Treatment: First Treatment - O.Q. 1750~F + T. 8 hours at 1200~F Second Treatment - O.Q. 1550~F + T. at 1050~F 0. 2 0.5 1.0 Rupture 34,000 46,000 54,000 1000~F 16,000 32,000 40,000 58,000(28%),12,000 23,000 38,000 (16%) 22,500(12%) 15,000 (12%) 1100~F 0.2 0.5 1.0 Rupture 15,000 20,000 26,000 12,000 16,000 28, 000 (20%) 16, 000(40%) Wheel No. 4. Heat Treatment: Interrupted-quench from 1750~F + T. 2 hours at 1200~F 10000F 0.2 0.5 1.0 Rupture 44,000 31,000 _,, _ _ _ 19,000 35,000 46,000 48,000 (2%) 18,000 25,000 28,000 (2%) 17,000 22,000 ( -) 0.2 0.5 1.0 Rupture 24,000 _,_ 1100~F 16,000 22,000 26,000 33,000(3%) 15,000 19, 000 (5%) NOTE:.Estimated elongation at fracture given in parentheses with rupture strengths.

TABLE IV:a Tensile Properties of "17-22A"S 7Turbine Wheels Specimen Number Specimen Location ( ) Brinell Test Tensile Offset Hardness Temp. Strength __(F) (psi) 0. 02% Yield Strengths (psi) 0. 1% 0.2% Proportional Elongation Limit in 2-in. (psi) (%) Reduction of Area (%) 1W lx 2W 2X 2Y 2Z Wteel No. 1. Heat Treatment: N. 1750~F + T. 2 hrs. at 1200~F. SRR 314 75 142,750 98,500 109,500 CRR 282 75 137,000 98,000 107,000 SRC 242 75 117,000 72,000 79,500 CRC 238 75 116,000 73,500 78,500 CRC 238 75 117,000 73,500 77,000 SRC 241 75 119,000 74,000 79,500 114,500 111,500 81,000 80,000 79,000 81,500 76,500 89,000 47,000 66,000 62,500 61,500 15.0 14.5 9.0 15.5 20.5 19.0 50.3 47. 1 13.4 38.5 48.9 48.0 1W IX 2W 2X 2Y 2Z 14X 3W 3X Wheel No. 3. SRR CRR SRC CRC CRC SRC Heat Treatment: 326 75 313 75 313 75 311 75 295 75 294 75 O.Q. 1750~F 151,000 145,000 145,000 145., 000 145,000 146,000 97,500 96,250 96,500 + T. 8 hrs. 123,000 123,500 122,000 120,500 119,000 121,000 65,000 64,500 72,500 at 1200~F. 132,000 130,500 126,500 126,000 125,500 126, 500 83,000 83,250 84,750 134,000 133,000 128,500 128,000 128,000 129,000 90,000 89,000 90,000 93,000 94,000 109,500 103,000 99,500 106,000 38,000 45,500 50,000 18.0 16.5 11. 0 12.0 17.5 15.0 21.5 23.0 26.0 56.4 50.9 23.8 29. 2 46.6 40.7 71.0 73.0 72.5 CTR SRR CRR 1000 1000 1000 14Y 1Z 1Y STR SRR CRR 1100 1100 1100 83,500 90,500 83,250 49,500 48,500 46,000 68,250 76,000 24,500 65,250 72,000 29,000 67,000 74,250 25,000 27. 0 29. 5 23. 5 72.5 71. 6 73. 5 (concluded on following page)

Table IVa(concluded) Specimen Specimen Brinell Number Location Hardness __ () __ (continued)Whee-:lNo. 3. Test Tensile Offset Yield Strengths Proportional Elongation Reduction Temp. Strength...(psi) _ Limit in 2' in. of Area (~F) (psi) 0. 02% 0.1%.. 2% (psi) (%) (%) Heat Treatment: O.Q. 1750~F + T. 8 hrs. at 1200~F. 3Y 3Z 14W CRR SRR STR 1200 1200 1200 62,500 63,000 62,500 32,000 28,500 33,500 46,750 44,500 44,000 54,000 51,000 54,000 16,000 12,500 19,000 24. 0 22.5 22.0 44. 8 48.3 41. 6 Wheel No. 4. Heat Treatment: Interrupted-quench 1750~F + T. 2 hrs. at 1200~F + T. 2 hrs. at 1200~F. 1W 1X 2W 2X 2Y 2Z SRR CRR SRC CRC CRC SRC 332 321 320 317 318 312 75 158,500 75 155,500 75 148,500 75 149,000 75 149,000 75 149,500 137,500 125,500 121,000 124,000 119,500 124,000 142,500 135,500 131,000 130,500 128,000 131,000 143,500 138,000 134,000 133,000 131,500 133,000 126,000 93,000 98,000 104,000 101,000 108,000 16.0 16.5 5.0 8.0 15. 0 15.5 51. 1 49. 8 6.4 9. 3 41. 0 41.9 (i) SRR - Surface plane radial specimen at rim of wheel CRR - Central plane radial specimen at rim of w'heel CTR - Central plane tangential specimen at rim of wheel STR - Surface plane tangential specimen at rim of wi-heel SRC - Surface plane radial specimen at center of wheel CRC - Central plane radial specimen at center of Whe-el

TABLE IVb Rupture. Total Deformation, and Creep Data for "17-22A"S Turbine Wheels Time to Reach Specified Time at Start Specimen Specimen Test Stress Time to Elongation Reduction Total Deformations of Third Stage Minimum Number Location Temp. Fracture in 2-in. of Area (hrs. ) Creep Creep Rate (a) ('F) (psi) (hrs.) (%) (*) 0. 0. 2% 0.5% 1.0% (hr.) (%/ hr.) Disk No. 1. Heat Treatment: N. 1750-F + T. 2 hrs. at 1200'F Deformation on Loading (In. /n. ) 4W SRR 1100 50,000 4X CRR 1100 45,000 4Y CRR 1100 40,000 4Z SRR 1100 30,000 6W SRR 1100 20,000 26 12.3 36 5.7 60 5.6 175 1.7 519 2.6 7.0 (b) (b) 3.9 (b) (b) 7.0 (b) (b) 0.8 (b) 3 2.8 (b) 35 0.6 6 3.5 13 8 24 62 134 216 406 5.5 14 46 238 0.095 0.046 0. 025 0.0035 0.0016 0.0029 0. 0023 0.0021 0.00135 0.00113 Disk No. 3. Heat Treatment: O. Q. 1750'F + T. 8 hrs. at 1200'F. 7Z SRR 1000 90,000 1.8 15.0 9Z SRR 1000 80,000 66 13.1 7W SRR 1000 70,000 171(C) 5.6 7Y CRR 1000 60,000 487 2.5 9X CRR 1100 80,000 0.2 16.0 4Z SRR 1100 47,500 51 2.6 4X CRR 1100 42,500 94 3.5 4W SRR 1100 38.500 86(c) 3.0 4Y CRR 1100 32,500 219 3.0 9W SRR 1100 32,500 165 3.2 7A(d) SRR 1100 32,500 171 3.0 5A(d) SRC 1100 32,500 244 3.2 6W SRR 1100 25,000 489 2.6 6X CRR 1100 20,500 792 1.7 14Z STR 1100 19,500 1112 3.6 6Yje~ CRR 1100 15,500 Off 1120 6Z SRR 1100 12,500 Off 1120 9y(e) CRR 1100 7,000 Off 1085 10W SRR 1200 35.500 5.2 7.0 10Y CRR 1200 32, 000 6.2 5. 5 lox CRR 1200 22, 000 33 3.0 1OZ SRR 1200 16, 000 73 1.4 67.0 51.0 15.4 4.5 70. 3 5. 1 8.2 3.5 1.6 3. 1 3.2 4.7 3.2 2.8 2. 8 (b) (b) (b) (b) (b) 1 (b) (b) 6 (b) (b) 92 (b) (b) (b) (b) (b) 6 (b) (b) 10 (b) 1 19 (b) 2 49 (b) 2 44 (b) (b) 29 (b) (b) -- (b) 21 199 3 57 441 1.5 48 374 5 109 896 26 227 12i10( 630 1805(f) - 0.2 14.5 60 350 29 47 45 156 97 98 402 774 728 2460(f) 32 75 270 20 48 64 116 74 94 280 575 380 2 3 12 19 0.030 0.009 0. 0016 0.0172 0.0135 0.018 0. 0043 0.0065 0.0068 0.0057 0.0015 0. 0008 0.0009 0. 00032 0.00032 0.00009 0.33 0.24 0.054 0.016 0. 00470 0.00340 0. 00297 0. 00260 0. 00220 0.00200 0.00190 0.00147 0. 00138 0.00148 0.00108 0. 00082 0. 00095 0.00065 0. 00060 0.00031 0.0026 0. 0022 0. 0015 0. 0011 8. 5 (b) (b) 4.8 (b) (b) 6.2 (b) 2 4. 3 (b) 3 0.4 1.9 1 3 7 16 19 38 Disk No. 4. Heat Treatment: Interrupted-quench 1750'F + T. 2 hrs. at 1200F + T. 2 hrs. at 1200F. 4X CRR 1100 45,000 4W SRR 1100 37,500 4Y CRR 1100 32,500 4Z SRR 1100 26,000 6W SRR 1100 20,500 69 2.3 151 4.0 287(c) 3,0 479 3.9 1233 3.0 4.0 (b) (b) 1.6 (b) 1 2.0 (b) 2 1.6 (b) 9 3.6 2 55 7 36 44 20 79 91 77 186 77 156 337 167 490 964 677 0.018 0.0086 0.0033 0.0018 0.00071 0.0021 0.00176 0.00150 0.00117 0.00085 (a) SRR- Surface plane radial specimen at rim of disk CRR - Central plane radial specimen at rim of disk SRC - Surface plane radial specimen at center of disk STR - Surface plane tangential specimen at rim of disk (b) Specimen reached this deformation on loading (c) Broke in gage mark (d) 0. 250-inch diameter specimen (a) Creep test (f) Extrapolated value.

TABLE IVc Rupture, Time - Deformation, and Creep Strengths of the "17-22A"S Turbine Wheel (Heat Treatment: O. Q. 1750~F + T. 8 hours at 1200~F) Total Deformation (%) Stress to Cause Total 1 hour 10 hours Deformations at Indicated Times (psi) 100 hours 500 hours 1000 hours 0. 0001% per Hour Creep Strength (psi) 1000~F 0. 5 1.0 Rupture 80,000 86,000 90, 000(15%) 69, 000 81,000 84, 000(14%) 59,000 67,000 75, 000(10%) 56, 000 60, 000(2.5%) 51,000 54, 000( - ) 0. 1 0. 2 0. 5 1.0 Rupture 21,000 37, 000 67, 00010o%) 15, 000 27,000 43, 000 50, 000 53, 000(6%) 1100~F 10, 000 18,000 29,000 36,000 41, 000(3%) 7,000 10,000 19, 000 22,000 24,500(2.5%) 5, 000 8, 000 14,000 17, 000 19, 000(2%) 7,500 1200~F 0. 5 1.0 Rupture 32,000 39, 000 50, 000103%) 20,000 25,000 29, 000(5%) 10,000 14, 000(1.5%) NOTE: Estimated elongation at fracture given in parentheses with rupture strengths.

TABLE Va Room Temperature Tensile Properties of As-Received H-40 Turbine Wheels Specimen Specimen Number Location ( 1- ) Brinell Tensile Offset Yield Strengths Proportional Elongation Hardness Strength (psi) Limit in 2-in. (___ psi) 0 02%O 0.1% 0.2% (psi) (%) Reduction of Area (%) 1W iX 2W 2x 2Y 2Z Whee-l No. 1. SRR CRR SRC CRC CRC SRC Wxheel No. 3. SRR CRR SRC CRC CRC SRC 352 350 363 350 356 345 Heat Treatment: N. 1950~F + T. 2 hrs. at 1200~F + T. 3 hrs. at 1200~F 168,500 167,500 163,250 165,500 169,250 169, 000 129,250 128, 750 126,500 125, 000 130,500 129,000 147,000 145,500 145,500 144,000 148,000 145, 750 153,500 151,750 154,000 151,750 154,250 152,500 102,000 104,000 96, 000 104,000 105, 000 104,000 12.0 11.0 1. 0 1.5 5. 0 7. 0 40. 5 31.2 4. 3 3. 9 9. 6 13 4 Heat Treatment: O.Q. 1950~F + T. 8 hrs. at 1200~F + T. 3 hrs. at 1200~F 1W IX 2W 2X 2Y 2Z 364 364 362 365 346 341 182,000 183,500 175,250 172,500 177,000 178,750 139,250 137,000 131,000 124,000 125,500 127,750 160,750 158,500 155,750 150,250 150,750 150,500 166,000 164,250 163,750 159,750 159,500 159,750 113,000 108,000 104,000 95,000 96,000 99,000 9. 5 10.0 2. 2. 0 5. 0 8. 5 23. 5 23. 7 2. 8 2. 8 7. 8 16.0 1W lx 2W 2X 2Y 2Z Wheael No. 4. SRR CRR SRC CRC CRC SRC Heat Treatment Int. -quench 1950~F + T. 2 hrs. at 1200~F + T. 3 hrs. at 1200~F 351 361 357 367 357 355 173,000 176,000 169,250 171,500 174,750 175,000 133,500 130,000 137,000 129,750 131,000 129,250 150,000 149,250 157,750 150,250 150,750 149,000 156,500 157,750 164,000 158, 250 158, 750 156, 750 108,000 101,000 109, 500 102,000 101,000 102,000 10.5 10. 0 1. 5 2. 0 2. 5 9. 0 33. 7 23.4 1.2 4. 7 7.4 19.5 (4) SRR - Surface plane radial specimen at rim of wvheel CRR - Central plane radial specimen at rim of wheel SRC - Surface plane radial specimen at center of Whirel CRC - Central plane radial specimen at center of wiheel

TABLE Vb Tensile Properties of Retempered H-40.Turbine; Wheel Heat Treatment: O.Q. 1950~F + T. 8 hrs. at 1200~F + T. 3 hrs. at 1200~F + T. 4 hrs. at 1250~F Specimen Number 3W 3X 1Z 1Y 14W Specimen Loc ation (i) SRR CRR SRR CRR STR B:lMnell rTest Hardierss Temp. (~F);,'~- ~I, w., sI Tensile Strength (psi) Offset Yield Strengths (psi) Proportional Elongation Limit in 2-in. O. OZ/o U. 17o O. Z/o 295 to 320 305 - 320 75 146,500 75 145,250 75 155,000 113, 500 113, 000 120, 000 68,500 70,000 126,500 125,500 133,500 87, 000 86,500 130, 000 129, 000 139,000 94, 000 92,250 (psi) 90,000 98, 000 102,500 47,000 50, 000 (%) 15. 5 16.5 13.5 15.0 19.0 Reduction of Area (%) 50. 5 51.5 44. 0 50. 5 61.0 1000 1000 99,750 96, 750 3Y 14X 3Z 14Y CRR CTR SRR CTR 295 - 320 295 - 320 1100 1100 1200 1200 80, 250 80, 000 65,500 63, 750 54,500 54,000 39,000 39,750 68,500 68,500 50, 500 52,000 74, 500 74,.500 55, 500 58,000 37,000 34,000 26, 000 25,000 21.0 16. 5 15. 0 16.0 61.0 48. 8 53.5 47. 8 ( t) SRR- Surface plane radial specimen at rim of wheel CRR - Central plane radial specimen at rim of wheel STR - Surface plane tangential specimen at rim of Frheel CTR - Central plane tangential specimen at rim of Retbel

TABLE Vc Rupture, Total Deformation, and Creep Data for As-Received H-40 Turbine Wheels Speci NumI Disk 4W 4X 4Z 4Y 6W 6X Disk 6W 4Y 4W 4Z 6Y ~men Specimen Test ber Location Temp. (a) ('F) No. 1. Heat Treatment: N. 19 SRR 1100 CRR 1100 SRR 1100 CRR 1100 SRR 1100 CRR 1100 No. 3. Heat Treatment: O.Q. SRR 1100 CRR 1100 SRR 1100 SRR 1100 CRR 1100 Stress (psi) )50*F + T. 2 55,000 55,000 55,000 45,000 45. 000 37,000 1950'F + T 60,000 50,000 45,000 39,000 38.000 Time to Elongation Reduction Time to Reach Specified Total Deformations Fracture in 2-in. of Area (hours) (hours) (%) (%) 0. I% 0. Z70 0. 5% 1.0% Z hrs. at 1200~F + T. 3 hrs. at 1200'F. 28( -- (c) (c) 12 -- 48(b) - -(c) (c) 19 40 97 1.4 0.9 (c) (c) 14 93 64(g) - -(c) (c) 121 242 8.3 14. 1 (c) (c) 22 97 518 5.0 4.0 (c) 2 118 336 8 hrs. at 1200'F + T. 3 hrs. at 1200~F. Time at Start of Third Stage Creep (hrs) 30 90 100 300 21 96 218 400 180 Minimum Deformation Creep Rate on Loading (%/hr.) (In./In.) 0.011 0.011 0.0039 0. 0067 0.0022 0.011 0.00465 0.0019 0.0013 0.00084 0.00285 0.00342 0.00195 0.00215 0.00177 0.00270 0.00229 0.00213 0.00175 0.00178 35 136 298 189b 2.2 2.8 (c) (c) 1.8 3.9 (c) (c) 1.8 3.9 (c) (c) 2.2 4.3 (c) 1 1.0 0 (c) 2 13 26(e) 44 106(e) 76 262(e) 141 455(e) 185 188 Disk No. 4. 4X 6W 4W 4Y 4Z 6X 6Y Heat Treatment: Int. CRR 1100 SRR 1100 SRR 1100 CRR 1100 SRR 1100 CRR 1100 CRR 1100 -quench 1950'F + T. 2 hrs. at 1200'F + T. 3 hrs. at 1200~F. 60,000 34(g) -- (c) 55,000 67 1.9 5.8 (c) 50, 000 108 2. 6 8. 1 (c) 45,000 243(g) -- -- (c) 39,000 407( g) -- -- (c) 40,000 457(b) 1.4 3. 1 (c) 35, 000 697 2.3 7.0 (c) (c) 3 28 (c) 14 63(e) (c) 18 73 (c) 75 228 1 142 400(e) (c) 170 451 5 326 690 22 40 73 156 200 408 688 0. 014 0. 0065 0. 0088 0.0025 0. 0014 0. 0012 0.00084 0.00322 0.00291 0.00238 0.00214 0.00170 0.00197 0.00168 (a) SRR - Surface plane radial specimen at rim of disk CRR - Ce ntral plane radial specimen at rim of disk (b) Broke in fillet (c) Specimen reached this deformation on loading (d) Test discontinued at this time (e) Extrapolated value (f) Broke in gage mark (g) Broke in threads

TABLE Vd Rupture, Total Deformation, and Creep Data for Retempered i-40 Turbine Wheels Specimen Specimen Number Location _(a) Disk No. 1. 9W SRR 9X CRR 9Y CRR 9z SRR Disk No. 3. 8X CRR 8Y CRR 8W SRR 8Z SRR 10W SRR 9W SRR 9Y CRR 9X CRR 5AJe1 SRC 9Aet SRR 9Z SRR 6X CRR 14Z STR 1 o Yg) CRR 1ozWg) SRR 7Z(g) SRR 7Y CRR 7W SRR 7X CRR Disk No. 4. 9W SRR 9X CRR 9Y CRR 9Z SRR Test Stress Temp. ('F) (psi) Heat Treatment: N. Time to Fracture (hrs.) 1950'F + T. 2 Time to Reach Specified Elongation Reduction Total Deformations in 2-in. of Area (hrs.) (*) () 0.1% 0.2% 0.5% 1.0% hrs. at 1200-F + T. 3 hrs. at 1200'F + T. 4 hrs. at 1250'F. Time at Start Minimum Deformation of Third Stage Creep Rate on Loading Creep (in. /in.) (hrs.) (% /hr.)____ 1100 60,000 2 7 10.5 1100 50,000 43(b) 3.0 1100 45,000 81 2.7 1100 34,000 735(c) 2.3 Heat Treatment: O. Q. 1950'F + T. 8 hrs. at 120 1000 75,000 3.3 20.0 1000 70,000 8.7 19.3 1000 65,000 130 6.3 1000 60,500 256(b) 10.0 1000 57,000 443 9.0 1100 60,000 10 17.0 1100 50,000 80 8.0 1100 42.000 175(b) 5.0 1100 40,000 313 2.0 1100 39,350 354 5.1 1100 36,000 514 4.5 1100 36,000 566 4. 0 1100 33,000 1032 4.5 1100 28,000 Off 1120 1100 20,000 Off 1120 1100 12,000 Off 1100 1200 42,000 7.8 7.0 1200 35,000 36 5.5 1200 30,000 74 5.5 Heat Treatment: Interrupted-quench 1950'F + T. 1100 60,000 2.9 10.5 1100 50,000 70 4.5 1100 45,000 144 2.5 1100 39,000 273 6.5 37.4 7. 8 6.2 4. 3 O'F + T. 58. 3 60.0 14.7 29. 5 31.4 50. 0 22. 0 8. 8 7. 0 9.4 10. 0 9.0 9.2 23. 7 8. 1 12. 3 3 hre 2 (d) (d) 0.04 (d) (d) 0. 3 (d) (d) 5 (d) 1 219 i. at 1200'F + T. 4 hrs. at 1250F (d) (d) 0. 1 (d) (d) 0. 2 (d) (d) 1 (d) (d) 4 (d) (d) 10 (d) (d) 0. 1 (d) (d) 1.5 (d) (d) 13 (d) (d) 94 (d) (d) 2 (d) 2 71 (d) 1 156 (d) 2 248 (d) 16 810 1 256 2396(f).35 1725(f) (d) (d) 0:4 (d) (d) 5.5 (d) 0.1 12.2 0. 5 11 53 652 0. 7 2 26 43 116 1.4 23 84 304(f) 140 280 507 616 2477(f) 3. 1 18 37 rs. at 1250'F 0. 8 26 94 100 -0.66 25 0. 026 68 0. 0096 520 0.001 1.3 3. 5 68 146 222 30 100 282 120 280 285 400 3 22 28 0.67 0.24 0.01 0.0078 0. 0033 0.285 0.02 0.0066 0.0016 0. 0036 0.0024 0. 0011 0. 0011 0.0003 0.00014 0. 000064 0.16 0.039 0.019 0.00440 0. 00305 0.00265 0.00169 0.00383 0.00350 0.00300 0.00285 0. 00281 0. 00333 0.00262 0. 00254 0. 00254 0.00256 0.00199 0.00185 0.00157 0.00142 0. 00096 0.00057 0. 00267 0. 00236 0.00197 0.00323 0. 00285 0.00240 0. 00209 ~, 2 hrs. at 1200'F + T. 3 hrs. at 1200*F + T. 40.2 (d) (d) 0.03 8.2 (d) (d) 1.5 7.4 (d) (d) 13 12.6 (d) (d) 14 4 hz 1 0.38 55 0.02 44 0.0084 100 0. 0056 (a) SRR - Surface plane radial specimen at rim of disk CRR - Central plane radial specimen at rim of disk SRC - Surface plane radial specimen at center of disk STR - Surface plane tangential specimen at rim of disk (b) Broke in gage mark (c) Broke in fillet (d) Specimen reached this deformation on loading (e) 0. 250-inch diameter specimen (f) Extrapolated value (g) Creep test

TABLE Ve Rupture, Time - Deformation, and Creep Strengths of Retempered H-40 Turbine Wheel (Heat Treatment: O. Q. 1950~F + T. 8 hours at 1200~F + T. 3 hours at 1200~F + T. 4 hours at 12500F) Total Deformation (%) Stress to Cause Total Deformations at Indicated Times (psi) 0. 0001% per Hour Creep Strength (psi) 1 hour 1U hours 10U hours 50U hours 1000 hours 1000~F 0. 5 1.0 Rupture 65, 000 73,000 78, 000(20Y4 56,000 67,000 70, 000(19%) 57,000 64, 000(10%) 56, 000(9%) 52, 000( - ) 1100~F 0. 1 0.2 0. 5 1.0 Rupture 20, 000 37,000 51,000 61,000 _m_ 17,000 30,000 44,000 52,000 60, 000 (17%) 13,000 22, 000 36, 000 42,000 48, 000(77%), 11,000 17,000 29, 000 34,000 36, 000(4%) - 10,000 15,000 26, 000 31,000 32, 000 (4%) 16,000 1200~F 0. 5 1.0 Rupture 40,000 31,000 -- 37,000 ~ — 40,000(6%) 25,000 30, 000(5/%) NOTE: Estimated elongation at fracture given in parentheses with rupture strengths.

TABLE VIa Tensile Properties of C-422 Tuirbine Wheels: Specimen Specimen Number Location Wh___T No (1. W~heel No. 1. Brinell Test Tensile Offset Yield Strengths Proportional Elongation Reduction Hardness Temp. Strength (psi) Limit in 2-in. of Area (~F) (psi) 0.02% 0. 1% 0.2% (psi) (%) (% ) Heat Treatment: (a) N. 1900~F + T. 2 hrs. at 1200~F. (b) Full anneal 6 hrs. at 1600~F. N. 1900~F + T. 2 + 2 hrs. at 1200~F. 1W IX 2W 2X 2Y 2Z SRR CRR SRC CRC CRC SRC 301 308 300 295 288 294 75 145,500 75 145,500 75 133,500 75 133,250 75 135,250 75 134,000 105,500 95,000 88,500 92,250 93,250 94,000 117,250 112, 500 102,500 102,250 104,750 105,250 122,750 118,250 107,250 107,000 110,250 109,500 87,500 16.0 67,000 16.0 70,500 5.5 77,000 5.5 77,000 8.0 75,500 7.5 anneal 6 hrs. at 1600~F. 35. 0 33. 8 7.4 8. 1 12.2 22. 7 Wheel No. 4. Heat Treatment: (a) O.Q. 1900~F + T. 8 hrs. at 1200~F. (b) Full O.Q. 1900~F + T. 2 + 2 hrs. at 1200~F. 1W IX 2W 2X 2Y 2Z 14Y 1Y 3W SRR CRR SRC CRC CRC SRC CTR CRR SRR 291 299 294 287 285 282 298 299 75 141,500 75 141,000 75 135,500 75 133,000 75 132,500 75 130,750 98,500 96,500 94,250 89,750 91,000 86,000 54,500 55,500 52,500 1000 1000 1000 1Z 14W 3Y 3X 14X 3Z SRR STg CRR CRR CTR SRR 305 305 313 299 1100 1100 1100 1200 1200 1200 83,500 84,000 78,000 66, 250 64,500 67,000 49,500 48,500 50,000 108,500 107, 500 104,000 101, 000 101,500 100,000 70,250 69, 250 65,750 55,500 53,250 54,500 39,250 36,250 39,250 45,500 42,500 37,500 28,500 28,000 26,250 60,250 58,250 60,000 43,750 41,500 44,250 35,500 30,500 22,000 13,500 19,500 15,500 37. 0 39. 0 31.5 40. 5 39. 0 45. 5 113,000 112,500 108,750 106,000 105,500 104,500 75,500 74,000 70,750 83,000 82,500 80,000 69,000 71.000 66,000 38,500 36,000 38,000 16. 0 16. 5 7. 5 7. 5 12, 5 17.0 30. 0 29. 0 34. 5 40. 1 37.9 8. 9 13.0 30. 2 41.8 70. 0 66. 7 78. 8 79. 8 81.4 76. 8 86. 8 83. 8 87. 5 (i) SRR CRR SRC CRC CTR STR - Surface plane radial specimen at rim of vheel - Central plane radial specimen at rim of whe&el - Surface plane radial specimen at center of *heel - Central plane radial specimen at center of wrheel - Central plane tangential specimen at rim of wrh-el - Surface plane tangential specimen at rim of hrliel

TABLE VIb Rupture, Total Deformation, and Creep Data for C-422 Turbine Wheels Specimen Specimen Number Location Disk No. 1. 4W SRR 4X CRR 4Y CRR 4Z SRR Disk No. 4. 9W SRR 9X CRR 9Y CRR 10X CRR 4W SRR 4Z SRR 4X CRR 10Z SRR 7A(d) SRR 5A(d) SRC 4Y CRR 14Z STR 10W(e) SRR 6X(e) CRR 1OY(e) CRR 6Y CRR 6Z SRR 6W SRR 9z SRR Test Stress Time to Temp. Fracture ('F) (psi) (hr. ) Heat Treatment: (a) N. 1900'F + T. Time to Reach Specified Time at Start Elongation Reduction Total Deformations of Third Stage Minimum in 2-in. of Area (hrs.) Creep Creep Rate (%) (%) O. 1% 0.2% 0.5% 1.0% (hrs.) (%/hr.) 2 hr.. at 1200-F. (b) Full anneal 6 hrs. at 1600F. N. 1900-F + temper 2 + 2 hrs. at 1200-F. 1100 55,000 1100 45,000 1100 35,000 1100 32.000 Heat Treatment: (a) 0 1000 1000 1000 1000 1100 1100 1100 1100 1100 1100 1100 1100 1100 1100 1100 1200 1200 1200 1200 67,500 62,000 58,000 54,000 50,000 44,000 40,000 40,000 40,000 40,000 35,000 35,000 28.000 22,000 13,000 45,000 30,000 25,000 20,000 3 10! ).Q. 19C 1] 11 Off 11! 1] 1; 2r 10( 7: Off 112 Gff 11C Off 10E 1 5 13 2 26.5 15 23.5 18 15.0 55 9.5 O'F + T. 8 hra. at 12 26.0 72 15.0 16 21.5 50(c) 14 36.0 81 28. 0 99 29.5 19 33.8 75 27.0 58 20.2 D1 14.5 30 14.5 D4 - 34 35 - 0.2 31.5 i5 26.0 i3 28.5 )4 18.0 69.5 (b) 73.0 (b) 36. 3 (b) 20.4 (b) 1200'F. (b) Full anneal (b) (b) (b) 1 6 hrs. at 1600'] (b) (b) 1 4 26 45 225 F. O.Q. 1900'F + temper 2 216 550 + 2 hrs. 0.0069 0.0017 at 1200-F 70.4 64.0 68.5 80. 5 77. 0 69. 3 72. 8 69. 5 57. 0 56.9 57.9 81.0 74. 3 77. 0 65.8 (b) (b) (b) (b) (b) (b) (b) (b) (b) (b) (b) (b) (b) 1 40 (b) (b) (b) (b) (b) (b) (b) (b) (b) (b) (b) (b) (b) (b) 0.5 0.5 4 58 1090 (b) (b) 0. 3 0. 5 0.10 3.0 0.8 4.0 0.2 3 2 2. 5 5 5 16 17 318 2300(f) (b) 0.9 8.4 25 0.8 12.0 8. 5 184 1. 1 11 19 16 15 23 234 1991 IT90(' 4.2 19.6 50 0.35 38 0.041 40 0.0342 0. 00079 5 0.39 160 0. 0055 100 0.021 130 0.0097 394 0. 0015 448. 0024 - 0.00033 - 0. 0001 -, 00007 6 0.15 20 0.041 40 0.015 Deformation on Loading (In. /In.) 0.00555 0.00326 0.00220 0.00180 0.00415 0.00340 0.00310 0.00272 0.00312 0.00249 0.00207 0.00230 0.00190 0.00190 0.00150 0.00099 0.00070 0.0055 0.00183 0.00159 0.00121 (a) SRR - Surface plane radial specimen at rim of disk CRR - Central plane radial specimen at rim of disk SRC - Surface plane radial specimen at center of disk STR - Surface plane tangential specimen at rim of disk (b) Specimen reached this deformation on loading (c) Test discontinued at this time (d) 0. 250-inch diameter specimen (e) Creep test (f) Extrapolated value

TABLE VIc Rupture, Time - Deformation, and Creep Strengths of C-422 Turbine Wheel (Heat Treatment: (a) O.Q. 1900~F + T. 8 hours at 1200~F. (b) Full anneal 6 hours at 16000F O.Q. 1900~F + T. 2 + 2 hours at 1200~F) Total Deformation (%) Stress to Cause Total Deformation at Indicated Times (psi) 1 hour 10 hours 100 hours 500 hours 1s000 hours jl, _., I 0. 0001% per Hour Creep Strength (psi) 1000~F _ m 0. 5 1.0 Rupture 58, 000 67,000 50, 000 60,000 66, 000(26%) 55,000 ~ 52,000 60, 000(20%) 57,000 ( - ) 56, 000 ( - ) 0.1 0. 2 0.5 1. 0 Rupture 22,000 33,000 44,000 50,000 16,000 26,000 37,000 43,000 51,000(36%) I100~F 10,000 20,000 31,000 36,000 43,000 (31%) 15,000 26,000 31,000 38,000 (20%) 13,000 24, 000 29, 000 36, 000 (14%) 22,000 0.5 1.0 Rupture 31,000 37, 500(31%'4 23,000 27,000 30, 000(27%) 1200~F 15,000 17,000 21, 000(20%) NOTE: Estimated elongation at fracture given in parentheses with rupture strengths.

I I 1 W___ 2 - W 3 - W 1 -X __ 2 _ 3. - y _ _ _ _ _ _ __I _ _._ _y_ _ Tt co n, - ~ I V 1. Z 2 Z 1 -19~~12/2 I Figure 1. Method Used for Sectioning and Coding of Test Specimens from Forged Turbine Wheels

t: (a) NoM S.malize F. (b) No ormaliT iz 4340 X)i-,.:sk No., 3, Hieat Treatmrent: (a) Oil quentch 17.50~1 +4 t t)e.per 8 hrs., at IZOO'F,0 (b) Oi(l qutcnxch 15500VF + tem:per at 1050 oPF. BHiN.260/32 0. 4340 Ditsk No* 4, He at Treat mentent lnterru ptedq.uench IT50 ' + t emper t: h rso at 1200 X, IB Ni..80/ 2 A 8 40* Figure a ga Mtacroetched Center Sectrios of 4340 Dis8:ks Nos, 1, 3, and 4.

339 329 331 335 331 327 327 325 321 325 329 319 317 319 319 307 3210 331 327 343 33 345 335 3T7 333 327 337 323 333 341 331 329 335 317 343 333 335 329 325 317 331 329 331 331 331 341 329 327 311 325 315 311 305 3 313 339 327 341 329 333 327 329 333 329 329 329 333 3T3 337 337 331 327 323 325 325 327 325 319 315 299 300 311 321 309 311 317 304 309 311 327 319 317 323 325 335 327 325 327 327 329 341 304 339 313 321 333 317 309 39 1 321 3 11 307 321 315 315 319 319 317 309 302 3A5 * 297 300 33 37 37 317 39 317 321 321 327 317 319 315 I^. 3?7 307 33 ' —~^^ ^^3 302e * ^ 5 302 321 321 35 33 309 313 3*23 fis 5 327 25 f27 f39 25 327 317 3233 Wheel No. I First Heat Treatment: N. 1750'F + T. 2 hours 1200'F Second Heat Treatment: N. 1750'F 304 300 287 290 274 284 292 283 280 279 270 281 285 271 2844 24 80 e e e o. o..30 4 o 296 * * * * * * 314 310 302 303 299 292 292 289 292:69 283 291 296 302 298 303 313 301 309 o 29 310 273 2 o0 0 304 274 311 0 0 316* * * * L * * ~ ~ ~. * * ~ ~ 0 267.07 9, '. o e o 308 290 296 299 288 286 289 276 273 279 293 297 303 280 271 280 276 o 260 272 265 275 279 273 28Z 276 2 8 34 272 297 -90 385 305 280 3097 311 259 3 1 3?2 302 3 8 3?9 66 ~ 30- 309 304 316 314 o e 2S". 303 306 296 298 291 285 283 280 276 270 2'3 276 22 76 79 75 291 079 2 7 -I Brinell Hardness Range Wheel No. 3 0 260 - 280 First Heat Treatment: 0. Q. 175019 + 1. 8 hours 1200' Second Heat Treatment: 0.. 1550~F + T. 1050'5' ~ 281 - 300 o 301 - 320 * 321 - 345 298 287 287 291 295 297;8287 791 297 295 340 342 338 313 293 292 285 288 290 287 Z'97 303 290 287 302 313 286 24 2*9 * 297 287 285 299 288 f87 293 290 291 295 290 295 303 302 293 305 315 335 337 314 294 287 297 287 289 286, e. o ~ o o ~ ~ o a ~ ~ ~ ~. h N 4 315 303 297 291 290 A22 2*90 297 296 289 H92 288 2Tm7 285 300 294 280 284 zS4 F312 GURE0 2 - BRNL HADESSRE OF EN R SCINO 430 SE T B WH a12 287 290 289 293 290 285 283 290 Z79 287 L90 302 302 2191 305 297 309 314 o 0 0'.. * * * *. ~0~~~ ~ 0~~...0 ~,. 7 2/76 277 279.295 285 302 293 290 300 305 299 295 302 300 300 300 325 333 339 * e e I I * * *7. o * * o2 331 313 302 287 2*(, * ZR2 291 286 284 290 287 2 9 4 280 281 288 300 305 280 2 285 283 292 289 291 291 291 289 296 291 287 vVheel No. 4 Heat Treatment: Int.Q. 1750'F + T. 2 hours 1200'F FIGURE 2b. - BRINELL HARDNESS SURVEY OF CENTER SECTION OF 4340 STEEL TURBINE WHEELS

100, 000 80, 000 60, 000 40, 000 30, 000 100011F I N-q *.r4 a 0. '1 4) 20-000. I I — I- I 1 I...._ _ -- I _ I I _ _o Wheel No.1-Normalized _ Wheel No. 4-Interrupted Quenched and Tempered A Wheel No.3-Oil Quenched and Tempered 10. 000 - I ' I:,-,. I I - -- -- III I - i I - I- -- - I-I I I I I I _ 10,.000 _ 80,000 ____. 'oooc 60,000 - -. 40. ooo --- -- T I I 3n. onon - -I -i --- I — I - I -I I- I I I-. -— I I I. v wt vw 20,000 10,000 Z:za.,3 I I I I I I -- 1 0 100 1000 Rupture Time-hours Figure 2c. - Survey Stress-Rupture Tirrn Curves for the 4340 Turbine Wheels at 1000~ and 1100~F. (Wheel No. 1: First Heat Treatment, N. 1750~F + T. 2 hours at 1200~F; Second Heat Treatment, N. 1750'F. Wheel No. 3: First Heat Treatment, O.Q. 1750~F + T. 8 hours at 1200-F; Second Heat Treatment, O.Q. 1550'F + T. at 1050F. Wheel No. 4: First Heat Treatment, Int. Q. 1750~F + T. 2 hours at 1200~F.)

100,000 80, 000 O OCO - oo -l I I I I I I I I I I I- — I I I — --- 0, 000 _ _ 5 30, 000 - 20, 000 LU____ 4^^^,^^20% z 0 11o00 Normalized TT 7, 000 ------- - ----- -- -—.. ~O - 4 0 ~ z% zo 100,000___ - loo~ ",, ----- i --- ( -- i 1 1 1 1 -\ - -i0 - 0 1. 3(0, 000We Fr -No 17.50" di. radimal secen frm eter o0, 0001 Tangentil specimen from rim tOil-Que~he Oil-Qud ~enchp~ed an Tmpre Wee ad 100. ( W e Tae N. 7FT hr 1200 0F; Second Heat Treatment, o~'0,00~~N. 17500F. Oil-Qu OilQuenched heel: First Heat Treatmet, OQ. 1750F + T. 2 hours at 1200F; Second Heat Treat10m, 00FF.) 1 10 I coo r (Normalized Wheel: First iHeat Treatment, N. 1750F + T. 2 hours at 1200~F; Second Heat Treatment, N. 1750"F. Oil-Quenched Wheel: First Heat Treatmenti O.Q. 1750~F + T. 2 hours at 1200~F; Second Heat Treatment, O.Q. 15530F + T. at 1050F.)

0p l 410 CO 20, 10 00(1 _ _ _., Il I I I I I I I I I I I I I I1 0. 1 0 Time - hours Figure 2e. - Stress-Rupture and Total Deformation Curves Obtained for the Normalized 4340 Turbine Wheel at 1000~, 1100~, and 1200~F. (First Heat Treatment: N. 1750~F + T. 2 hours at 1200~F. Second Heat Treatment: N. 1750~F.)

Time - hours I... - Figure 2f. - 3tress-Rupture and Total Deformation Curves Obtained for the Oil-Quenched and Tempered and the Interrupted Quenched 4340 Turbine Wheels at 1000' and 1100'F. (Oil-Quenched Wheel: First Heat Treatment, O.Q. 1750~F + T. 8 hours at 1200~F; Second Heat Treatment, O.Q. 1550~F + T. at 1050~F. Interrupted Quenched Wheel: Int.Q. from 1750'F + T. 2 hours at 1200~F.)

*a 4) cn Temperature - ~F Figure 2g. - Summary of Short-Time Tensile Properties and Rupture and One-Per Cent Total Deformation Strengths of the Normalized 4340 Turbine Wheel. (First Heat Treatment- N. 1750'F + T. 2 hours at 1200~F. Second Heat Treatment: N. 1750'F.)

100, 00 80, 00. I I I 11 a 6 4 3, 2 o 0 1 4) 0, 00 — 0___, _00(^P 0- - ____ ______ _-100_ 0,00( 0. 25 " ra.ia,specimen at center L0,0 o - 00(1_ _# — ___ Sur ace-plane tangential specimen at rim 7,00 - O- ---- -- -- -- _ --- -- - - ------- - - -I f 5. OO L nnI I I n u. 00ol U. UU1 Creep Rate - per cent/hour Creep Rate - per cent/hour V. I -. V Figure 2h. - Stress-Creep Rate Curves for the Normalized 4340 Turbine Wheel at 1000~, 1100~, and 1200~F. (First Heat Treatment: N. 1750~F + T. 2 hours at 1200~F. Second Heat Treatment: N. 1750~F.)

" 17.22AtAS D)isk No. 3. Heat T ratmentt: t q uench 1750f + temper 8$ h rs* at 12iOO( o BH.N': 21 8 /1 340. "17 -ZA Al Dik No. 4. Heat T:reatmentt!.nter"; ruptekdquench 1 750o 71 + temper 2 hrs. at 1200* i + temper 2 hrs at 120OO 0 B Nz' 30013 0. igiure 3a. Macroetcled C (nter Section of '17 22.A," S Disks Nos,., 3, a::nd 4.

321 327 311 321 313 311 309 301 287 274 248 3?S 316 3T5 3?9 3T1 304 285 219 214 z28 214 2?9 2g0 3 249 23 2 46 9 237 245 33 319 311 A27 2 z8 2 216 29 29 z8 249 242 311 319 321 317 31l 319 217 z22 279 228 28 3 2%8 A28 2Z9 z2o 214 241 zi 315 315 295s Z 80 280 2%6 248 237 237 246 259 257 262 258 282 293 287 297 309 309 317 323 329 317 323 331 235 250 253 250 20 217 284 2a 3 317 323 329 240 0 0 0 5 0 0 2.35 20 2034 '52 244 249 2048 226 723 78 269 277 287 280 288 2097 309 3*29 321 3*27 2A8 323 240 A7 246 A28 25 290 282 315 309 * 319 325 325 323 0 5 321 239 * 327 321 yic. o oc ~o ~ e- 3~~0 307 255 256 265 265 256 265 284 218 282 305 22, Wheel No. 1 Heat Treatment: N. 1750'F + T. 2 hours 1200'F Is 32z 3T9 327 331 331 327 32? 3002 317 299 302 299 303 315 3?5 3?3 31l 311 329 3?5 317 319 1 313 315 329 31 323 315 300 327 307 323 321 311 311 309 302 317 321 325 309 313 305 325 307 317 302 305 3'1 327 313 317 321 305 300 321 300 303 313 303 311 302 299 290 295 297 300 295 315 305 309 299 305 305 299 315 311 307 337 321 p"- 215 27 321 323 321 337 335 335 335 315 305 303 311 307 300 300 307 300 303 292 288 285 309 311 317 311 3*7 39 343 313 325 302 * 335 302 300 303 309 309 353 31 317 325 3f7 3333S Brinell Hardness Range Wheel No. 3 o.UH~r^.R^,~ Wheel No. 3 0 235 - 260 _ '= — Heat Treatment: O. Q. 1750'F + T. 8 hours 1200'F 9 261 - 290 291 - 320 * 321 - 350 \ / 3 f0 A 331 331 340 329 3Z2 333 325 32A 319 P9 A3 336 337 338 336 340 332 335 329 333 31339 333 329 31 319 338 3213 317 31*I 32!3 3A 3*09 325 316 309 37 325 319 321 3A1 337 3 33 3 3 33 1 341 343 321 309 321 329 315 336 * * e e * * * * * e B o e IB 3 331 335 333 325 332 321 325 321 326 328 317 322 311 302 328 307 309 307 316 350 313 33% 329 315 321 315 311 329 327 323 329 317 313 AS3 321 3 324 3 30 311 3 09 311 313 31 37 34 35 39 3319 25 9 35 30 3 3 33 3 33 37 35 39 37 327 329 311 317 311 35 1 3 3 315 33 j3331 342 3*2 344 338 341 3*3 32'7 33*7 331 320 Wheel No. 4 Heat Treatment: Int. Q. 1750'F + T. 2 hours 1200*F + Ret. 2 hours 1200*F. FIGURE 3b. - BRINELL HARDNESS SURVEY OF CENTER SECTION OF "17-22A"S STEEL TURBINE WHEELS

100, 80, nnno. I I I I I I I I 1 1 111111 VVV I I i i I L i i i i i i i I i I i I i I I I I I 1 I 0001 - I I I t I - - 60, i I I I I I I I 1 1F Z -4 1,=-A I I 1 i i i i 1 I g | - -ol4 LL S. I to 14 0) (n 40, 30, 20, 0non-00 I II I — I —1 I I-I-f — if —I II i vv v 9 nnnl. -i --- -+- i i i --- I I I I -- vvv =fqc _ I 000 - -— 4 I -4- I 1 i 1 -" — -- --- O Wheel No.l-Norm. and Temp. A Wheel No.3-Oil Quench. and Temp. * Wheel No.4-Int. 9uench. and Temp. I I I I I111I I 10,( ---, U3001 I I I I I I I I I I. I I I - I I I I - A lv i~~~~~~~~~~~~~~~~~~u~~ -~.,,,,. 1 iU 100UU LUUU Figure 3c. - Survey Stress-Rupture Time (Heat Treatment: Wheel No. Wheel No. Wheel No. Rupture Time - hours Curves for the "17-22A"S Turbine Wheels at 1100~F. 1 - N. 1750~F + T. 2 hours at 1200~F. 3 - O.Q. 1750~F + T. 8 hours at 1200~F. 4 - Int.Q. 1750~F + T. 2 hours at 1200~F + Ret. 2 hours at 1200~F. )

0 ----------— 00 --- 1 *o^0 o u 3-I m m_-_ — _ ___ - * 40.000^ --- —-—, ----. — _ ---------— __ 80,0 00 1i I 1 I 60,000 - _____ 1000~F 3. Sa40, 000 1200C' 1d 1 (HatTraten:.Q 150 5 8 U3 20,000 b 20,000 |. P- ' o 0.505" dia. radial specimens 1 5 * 0. 250" dia. radial specimen from. cente O 0. 250" dia. radial specimen from rim * Tangential specimen from rim 10, 00 10. 000 I! I I ' ' i I I! I 1 _ I I *1 10 100 1000 Rupture Time - hours Figure 3d. -Stress-Rupture Time Curves for Oil-Quenched and Tempered "17-22A"S Turbine Wheel at 1000, 1100-, and 1200-F. (Heat Treatment: O.Q. 1750-F + T. 8 hours at 1200F.)

90. 80.000 70, 000 60, 000 50,000 40,000 0s h 30,000 20,000 10, 000 40,000 30, 00C z C, ',! C., 0. Time - hours Figure 3e. - Stress-Rupture and Total Deformation Curves Obtained from Oil-Quenched and Tempered "17-22A"S Turbine Wheel at 1000~, 1100', and 1200~F. (Heat Treatment: O0.. 1750~F + T. 8 hours at 1200~F.)

160.000 140, 000 \s \ 120, 000 100,000 \ VTensile Strength Turbine1 Hour ( 0T4 O Q Hour ' o. I Offse I 1 5 Ii Teld Strengt~i~_ 0 I I\-~ --- —~ ---potoaID Hu E\ l 0 0>10 Hours 0) N.N. ^S. ^. 0 ^ N. ^0 00 Hours 0, 000 0 00 ~40. 000 j --- —-4porl t nal 1 Lirnt u' X00 Hours -- 0 c 0500 Hours 20 000 -- -- 0 --- —------ J500 Hours I0 0^^^1~ ours5t o 01000 Hours I 0 ~7 101000 I(o 1200 1 I0 110- 110 Temperature - "F Figure 3f. - Summary of Short-Time Tensile Properties and Rupture and One-Per Cent: ital Deformati;n Strengths of the Oil-i. tenched and Tempered "17-22A"S Turbine avheel. (Heat Treatment: O.Q. 1750'F + T. 8 hours at 1200~F. )

20,00- --- 0 0. 505" radial specimen __r10 _, -== _000 - - O — - - -- ----- -- -- - ~~ _ _<D 0.250" radial specimen at rim () O. 250" radial specimen at center 7, -~~0 f ---- --- -------— __ __ ~ Tangential specimen at rim 7,000o.0ii_ 5. 0001-j I I. 000 0 001 0. 01 0. 01 Creep Rate - per cent/hour Figure 3. - Stress-Creep Rate Curves for the Oil-Quenched and Tempered "17-22A"S Turbine Wheel at 1000', 1100~, and 1200~F. (Heat Treatment: 0. Q. 1750~F + T. 8 hours at 12CG~F. )

* ' p jr o j ov mt x!: OSIi: a O.:of02 p^:o -:"* ~ - v /o 6s ig C,"00.xa p:aq ' '>tI Io w18aCod.o + o00:Z: *CS:.TI At z J odxE + J.S0-f61 6tuOanb.p }d,.sauJ::i.....-.r.t..J.. 1j.*OI o..4. ov *06~/CSfTNIjMHf '0l 'I00 * s-:tq:;'Wt..ti; + f.i,:00, () '( "r 8 7; * 9, Yadu. c +,ioO 6 Ut'utrfib ll io!:.iow o..H-, *oM Xn.(tt O t # ys 1-H; u '*08t.7./ST~i.:NHai *'. OOZ01. *g tj. xolt:dwa +,O t * 8too71 i x 2 -odmlo + i0 o06 t tm.X1stoiN:4u-X0m:;J, 3*LouH 'I * 0:J ( O >11f H " (t0T Y-s ' HC.,.

P 5 * ~ * 0 0 B 0 a O O B B B B 03 0.0 _B 5 75 0 03 ' 0 0-' 362 34?5 341 350 330 354 35 5 363 32 3I'.. 1 361 ' 75 ) 3-5 373 35-. '.75 370 352 "75 375 352 339 '39 -,5 350 00 0 0 9 0 0 0 * a 0 0 0 B 5 B a 0 0 0 3-8 327 327 343 339 345 354 345 345 354 341 352 360 371 348 36', 37 4; 7 50 380 36 31 361 366 352 331 339 655 S. 030 0 0 B00, 33 3 333 30 334?1 348 323 317 325 329 350 359 348 341 366 666 352 361 341 363 357 35.. 361 361 352 354 363 361 354 357 352 333 341 o ~ 34F 0 0 a 0 0 0343 o 345 339 348 333 354 327 329 3 — 345 345 333 352 329 341 331 354 357 3% 31 335 348 350 361 337 357 345 363 357 375 359 357 335 3 ~5375 345 0 0 341 0 361 3 _:-^ ^ 348 370 354 339 361 333 348 345 375 373 368 354 354 35t 359 Wheel No. I Heat Treatment N. 1950~F + T. 2 hours 1200~F + T. 3 hours 1200"F 341 350 357 361 359 352 359 361 370 378 376 374 374 393 383 350 363 357 374 366 350 368 357 368 359 355 352 361 357 348 350 318 * * a * * * * * a * * 35 2 * * * * a * o o * o, * 0 o * 0 337 348 366 3259 35- 361 385 370 375 361 359 61 388 352 337 383 354 343 341 368 325 341 339 354 341 335 331 343 339 333 3 9 33 37 990999009990 90 0 0S0 T 0 0 0 0 0 0 0 0 0 337 373 3'54 366 368 335 3-37 338 352 331 331 341 337 354 354 345 331 350 343 339 357 339 335 335 327 325 327 335 345 337 343 327 0 0 -50 343: 1 3 36 366 348 348 335 323 335 359 341 345 337 321 348 325 354 339 329 352 370 348 356 357 339 337 357 354 37C 361 348 380 352 315 361 348 339 368 12 341 34O1 35340 o 36 - 3 355 0 356 - 375 376 - 393 31' 339 337 350 348 356 352 354 352 348 34, 6 356 3 7 66 5 578 i68 386 188 j83 390 368 363 -370 50 3-ic 52 341 378 359 oo 343 337 1 a a34 a 6.. 9 9 9. 9 9 9 6 B 37 335 31 2 376 31 957 5352 37 363 341 373 360 360 350 ',;2 7 3;7 38 390 7 3Sa 3il 3bU. La3 341 337 330 0-;i 0 T B B 0 B B a0 B 9 B B * 0 329 327 348 357 368 3'52 359 32 34, 36"I.2 j A41 ) 183) 345 363,6 6 363 357 361 354 373 39 I3 0 '5-i.36.7 7.0 385 390 3 1 39 3 0 ^333 343 346 352 348 346 367 357 343 361 357 366 355 350 34 346 346 6', 1 157 148 357 373 161 357 352 359 3 -4 18.41 335 33 -Ar:57 4 3, ^^*^^~^^ 341 3 ~ 350 343 348 3VA C 6h 34;. 370 368 366 370 366 354 370 368 370 354 Wheel No. 4 Ileat Treatment Int. Q 1950F + T. 2 hours 1200~F + T.. 3 hours 1200'F FIGURE 4b. - k3IN3EL. FfARPUDE4.': SURVEY OF CENTER SECT''ION OF H-40 STEEL T'URINE WHEELS

100, 000 80. 000 60, 000 40. 000 30,000 20, 000.o4 a I 10.000 Oo S 100,000 U) 80,000 60, 000 40. 000 30. 000 As-R ceivec O Norm. 1950F+T. Zhr 1200F+T. 3hrl200F -- & Int. Q. " + Oil Q. i" +T. I a a a I II 8hr #I I I.. + sl + *' I 20, 000 10,000] R etem pered 4 Hobrs at 12M5G I I I I I I 1 1 UU 1000 Rupture Time - hours - Survey Stress-Rupture Time Curves for the As Received and Retempered H-40 Turbine Wheels at 1100~F Figure 4c.

. 40, oo- - 00 -- ____g,03. _ 0 4 5 - - - 30,00 *T-~ —M.5 1200OF 1.00 <lO 30,00 — O --- 0 --- _ __ 50, o 0. 505" dia. radial specimens. 250" dia. radial specimen from center 0. 250" dia. radial specimen from rim Tangential specimen from rim 10., I 1 0' ~~OOOU~17 6 r~ 10 10 lUUURupture Time - hours Figure 4d. - Stress-Rupture Time Curves for Oil-Quenched and Tempered H-40 Turbine Wheel at 1000~, 1100~, and 1200~F. (Heat Treatment: O.Q. 1950~F + T. 8 hours at 1200~F + 3 hours at 1200~F + Ret. 4 hours at 1250~F.)

m, P. to 40 4) Time - hours Figure 4e. - Stress-Rupture and Total Deformation Curves Obtained from the Oil-Quenched and Tempered H-40 Turbine Wheel at 1000~, 1100~, and 1200'F. (Heat Treatment: 0. Q. 1950~F + T. 8 hours at 1200~F + Ret. 3 hours at 1200~F + T. 4 hours at 1250'F.)

7'5 1000 1100 12002 1000 1100 1200 1000 1100 Temperature - F Figure 4f. - Summary of Short-Time Tensile Properties and Rupture and One-Per Cent Total Deformation Strengths of the Oil-Quenched and Tempered H-40 Turbine Wheel. (Heat Treatment: 0. Q. 1950~F + T. 8 hours at 1200~F + T. 3 hours at 1200~F and Ret. 4 hours at 1250~F. )

100, 80, ( 60, C 40,( 30. ( 0 0. 505" radial specimens 20, 000_- 0.250" radial specimen v~~ko~~~~~~~ c^^ ~o 0. 250" radial specimen 10, 000 7,000 5, 000 — oo. 1 Fi~~nn0.u0001 0. -001 t CCreep Rate - per cn ur Creep Rate - per cent/hour Figure 4g. - Stress-Creep Rate Curves for the Oil-Quenched and Tempered H-40 Turbine Wheel at 1000~, 1100~, and 1200~F. (Heat Treatment: O.Q. 1950~F + T. 8 hours at 1200~F + 3 hours at 1200~F + Ret. 4 hours at 1250~F. ) at center at rim rim

C-422Z Di;sk No.1 1 Heat Treatment: (a) Normalize 1900 + temp er 2 hr se at 1i00z F (b) Full anneal 6 hrrs. at 1600~F. Normalize 19000F + temper 2 + Z hrs. at 1200~F. BHN2Z83/323 C-.o4ZZ Disk No* 4. Heat Treatment: (a) Oilquench 19QOO F + temper 8 hrs. at 12OOF. (b) Full anneal 6 hrs, at l6000 F Oil quench 1900*F + tempoer 2 + Z hrs. at 12 00F. BHN=2 75/35 Z Figure!5a. Macroetched Center Sections of C422 Disks Nos. I and 4.

299 300 299 299 299 306 300 299 * B B. B 0 0 * * * 299 300 306 300 304 302 306 310 308 308 * B * * 0 0 * * 293 295 297 300 304 311 310 304 302 308 302 302 306 304 308 309 313 311 313 304 * 310 316 Brinell Hardness Range 0 266 - 290 * 291 - 310 Seco * 311 - 330 * 331 - 352 * 0 0 *0 300 315 306 295 295 * * 0 G 0 B. a B 311 308 310 313 315 302 297 310 293 30o 382 31% 28s 2805 317 310 304 299 29 29o0 293 2?7 26% 317 323 306 297 B0 a a B B B 311315 304 304 a313 388 36 300 3~ 0 3~2 297 304 311 321 308 319 310 30 31 1 31 3 34 304 308 3B3 308 36 300 3A0 302 0o 290 0 27 A25 306 308 299 302 306 310 299 304 306 308 310 287 2g3 298 2?7 2?3 2?1 302 300 304 3P7 311 308 3&2 308 3&2 398 342 300 304 27 0'6 3 311 3a 4 2~7 287 382 388 3? 1 3q7 3?0 303 302 289 ~~5 330 311.9 308 290 21 7 32 30 38 317 Wheel No. 1 First Heat Treatment: N. 1900~F + T. 2 hours 1200~F nd Heat Treatment: Full anneal 1600~F 6 hours; N. 1900~F + T. 2 + 2 hours 1200~F * 0 0 B 0 0 295 290 292 295 293 290 292 287 0 B ~. B a * B * 290 304 293 297 300 299 300 295 302 300 302 * ~ * o 0 0 * * 292 295 302 300 285 304 304 299 293 295 293 295 295 295 306 302 313 299 302 2%8 o 290 0 290 285 295 295 30? 2A2 2m3 292 2 09 302 32 5 30?5 302 3A0 2?5 2'8 2'17 298 2'90 298 3A2 329 39 7 37 3 3 3 3 3 -0 279 * * * B B B B 0 305 302 304 308 304 302 295 285 235 20 306 297 292 23 29 331 35 33 36 35 3R7 285 317 304 293 28~728 2 80 280 2 285 2?9 304 3?)6 3?1 3f 382 3P 3 397 2?. 366 2A9 2'9 3A 2 219 2A9 3 -0 288 Q 0 B m n n 0 0 0 0 282 230023 7 302. 299 2o7 302 300 293 1 2 25 25 277 20 2877 2 288 30 0 2887 29 29 300 302 30 2 300 30 23 7 280 279 295 2 3 B 291 293 350 299 297 21 30 297 32 30 30 297 215 23 2g8 299 Wheel No. 4 First Heat Treatment: 0. Q. 1900~F + T. 8 hours 1200~F Second Heat Treatment: Full anneal 1600~F 6 hours; O.Q. 1900~F + T. 2 + 2 hours 1200~F FIGURE 5b. - BRINELL HARDNESS SURVEY OF CENTER SECTION OF C-422 STEEL TURBINE WHEELS

100,000 80,000 60. 000 I I f- I —~-f-I-+-I-+ I I-II ---I f,4 I OL k 4.1 ^.*I 40,000 ItA f% n ru JU, 20, U000 000 O-Wheel No. 1-Normalized and Terrered A Wheel No. 4-Oil-Quenched and Temp iered nnn- I --, -...., — 10, 1 10 UU 1 J{(!U Rupture Time - hours Figure 5c. - Survey Stress-Rupture Time Curves for the C-422 Turbine Wheels at 1100~F. (Wheel No. 1 - Heat Treatment: N. 1900~F + T. 2 hours at 1200~F. Second Heat Treatment- Full anneal at 1600~F for 6 hours. N. 1900~F + T. 4 hours at 1200 F. Wheel No. 4 - First Heat Treatment: O.Q. 1900~F + T. 8 hours at 1200~F. Second Heat Treatment: Full anneal at 1600~F for 6 hours. O.Q. 1900~F + T. 4 hours at 1200~F.)

40, 000 X 20.00 --- —' -' --- —---- - -_ ---- -- - -_ _18.. 0 0 0. 505" dia. rad. specimens 12 0I - 0. Z50'dia. rad. spec. from center ~ 0.250" dia. rad. spec. from rim 0. 1 1.0 10 100I Rupture Time - hours Figure 5d. - Stress-Rupture Time Curves for Oil-Quenched and Tempered C-422 Turbine Wheel at 1000~, 1100~, and 1200F. (First Heat Treatment- O.Q. 1900'F + T. 8 hours at 12000F. Second Heat Treatment Full anneal 6 hours at 1600~F. O. Q. 1900~F + T. 4 hours at 1200~F. ) 1000

70. 000 60,000 50.0000- --- - J —_ ^|JiLL_ L.D__= _ ----_iLrTLL --- — - _ v --- 10.0 30, 1'"OG~, e 50( 000Heat T O 1 + T 8 hrs 1 E lngat~F Ocn 0. 505 da ra s n0 40. 0000 ) 7 — -- - - - 2^_e o 0 d. a e ls c nfo ~ 1 100toF I* 0. 1 Tt Dfngatio n 40,000 ------ --- -- -- ^- -- -- - - ---- -- -- - ---- -- -- - _ __ --- — -- 0 00.0i0 rai — sp000 20,000 - 3 1 % E long 1tin 1 0 300 000 2604 A..OO - 80. 250" dim. radial specimen from center Time. radial specimen s Figure 5e. - Stress-Rupture and Total Deformation Curves Obtained from the Oil-Quenched and Tempered C-422 Turbine Wheel at 1000 1100 and 1200 (First Heat Treatment: O.~Q. 1900 F +O Total. 8 hours at 1200ioF. Second Heat Treatment: Full anneal 6 hours at 1600~F, O.Q. 1900~F + T. 2 hours at 1200~F.)

160, 000 Tensile Properties 140. 00( _ R upture Strengths 120, 00 \ ' 100, 0. * 80, vc 60, AnI UUU '% \ % \ \ Tensile Str ngth \ 02% Offset ~000 __ _ Yield Strength 0 " 000 1 40 000 - -. ---.__-20 o~~~~~~~~~ 0 10 Hours 100 j\ | Hour \ 10 0 Hours ~ 40, 20,( o u 41 C) 0 (d 3. Figure 5f. 1000 1100 1200 1000 1100 1200 1000 1100 Temperature - ~F - Summary of Short-Time Tensile Properties and Rupture and One-Per Cent Total Deformation Strengths of the Oil-Quenched and Tempered C-422 Turbine Wheel. (First Heat Treatment O.Q. 1900~F + T. 8 hours at 1200~F. Second Heat Treatment- Full anneal 6 hours at 1600~F. O.Q. 1900~F + T. 4 hours at 1200~F. ) 1200

100, 000 80,000 60,000 " 40,000 0. * 30,000 tn 40,000 10,000 > | | | | ~ ~ 100('l | 1 o 0. 505" radial specimens | O 0. 250" radial specimen at rim O 0.250" radial specimen at center. Tangential specimen at rim 0.0001 0.001 O. 01 Creep Rate - per cent/hour u. 1 1. U Figure 5g. - Stress-Creep Rate Curves for the Oil-Quenched and Tempered C-422 Turbine Wheel at 1000~, 1100' and 1200~F. (First Heat Treatment: O.Q. 1900~F + T. 8 hours at 1200Z F. Second Heat Treatment: Full anneal 6 hours at 1600'F. O. Q. 1900'F + T. 4 hours at 1200~F.)

100,000 80,000 60,000 40, 000 30,000 20, 000 I I -. i.. A '-I, -.4 -ZA,,IS v13%.5%0 H-40 3 I I 267% CI-422 ^ - 2O0 21 5% I., 5%01., 0% 0. I I 10% a I. I I I I I I I iooo'r - 0-*~ 5b I. I I I I Ill.-W s, p0 I f4 t5 CO Rupture Time - hours Figure 6. - Comparison of Stress-Rupture Time Curves of the Four Turbine Wheels of 434Q, "17-22A"S, H-40, and C-422 Selected for More Extensive Testing at 10000, 1100', and 1200~F. (Heat Treatment: 4340 Wheel No. 1-First Treatment, N. 1750~F + T. 2 hours at 1200ZF; Second Heat Treatment, N. 1750'F. "17-22A"S Wheel No. 3- O.Q. 1750~F + T. 8 hours at 1200F. H-40 Wheel No. 3-0.Q. 1950'F + T. 8 hours at 1200~F + Ret. 3 hours at 1200'F + Ret. 4 hours at 1250~F. C-422 Wheel No. 4-First Treatment, O.Q. 1900~F + T. 8 hours at 1200~F; Second Treatment, Full anneal 1600'F for 6 hours, O.Q. 1900'F + T. 4 hours at 1200F. )

90. O *4340 Wheel No. 1- Normalized O * C-422 Wheel No. 4-Cll-Quexhed and Temp. A a H-40 Wheel No. 3-Oil-Quenched and Temp w "17-22A"S Wheel No.3-.Ol-Qienhed ad Ter 70.4 60.4 5.t a I * 40,I k,4 En 30, Rupture Time - hours Figure 7. - Comparison of One Per Cent Total Deformation Curves for the Four Turbine Wheels of 4340, "17-22A"S, H-40, and C-422 Selected for More Extensive Testing at 10000, 1100', and 1200F. (Heat Treatment- 4340 Wheel No. 1-First Treatment, N. 1750'F + T. 2 hours at 1200F; Second Treatment, N. 1750'F. "17-22A"S Wheel No. 3-O.Q. 1750'F + T. 8 hours at 1200F. H-40 Wheel No. 3- O.Q. 1950'F + T. 8 hours at 1200F + Ret, 3 hours at 1200'F + Ret. 4 hours at 1250'F. C-422 Wheel No. 4LFirst Treatment, O.Q. 1900~F + T. 8 hours at 1200F; Second Treatment, Full anneal 1600~F for 6 hours, O.Q. 1900*F + T. 4 hours at 1200F,)