ENGIItERING RESEARCH.INSTI"E UNIVERSITY OF 'MICHIGAN.ANN..ARBOR BIMONTHLY PROGRESS REPORT NO.. XI THERMAL SHEOCK INVESTIGATION By T. A. HUNTER L. L. THOMAS A. R. BOBROWSKY Project M949 WRIGHT AIR DEVELOPMENT CENTER, U. S. AIR FORCE CONTRACT AF 33(038)-21254: E. O. No. 605-227 SR 3a August, 1953

I, - -4 o I,-;' >9\.

ENGINEERING RESEARCH INSTITUTE ~ UNIVERSITY OF MICHIGAN TRHRAL. SHOCK INVESTIGATION OBJECT The object of this research is to evaluate optimum design of test specimens and to establish criteria which will permit the correlation of thermal-shock data with performance of the material in the form of turbine buckets. SUNMMARY Work.has been completed on the assembly of the control panels for four thermal-shock testing rigs, One complete rig has been put together, and a trial run made. The- results of the trial have been satisfactory. Completion of the three remaining rigs will greatly enlarge the testing capacity of the fac ilit ies. INTRODUCTION The testing rigs used to date were originally developed by the WADC. They were designed to test two specimens simultaneously, and were provided with a set of levers to impose an axial tensile load on the specimen in addition to the thermal shock. These rigs have been in more or less continuous use for the past two years, and in the course of their operation it has become apparent that more rigs would be highly desirable. The primary reason for building more testing units is to permit the gathering of more data in less time. This will be reflected in a marked reduction in the time required to complete a series of tests.

I ENGINEERING RESEARCH INSTITUTE ~ UNIVERSITY OF MICHIGAN Because the new units are being constructed without the axial-loading feature, it will be possible to test material either with or without axial loading on a simultaneous basis, This provides a considerable increase in the. flexibility of the testing program. It will also be possible to conduct two-stage tests, in which.the specimens are first subjected to creep deforma- - tion or stress-rpture loading before being tested in thermal shock. It has been possible to run such tests on the present equipment, but only on a very, low production basis, Experience gathered in the operation of the WADC units has provided a basis for certain design improvements which are included in the new apparatus. It has been found troublesome to observe the formation of cracks in the present equipment,: therefore the mounting of the specimen has been changed to make inspection easier and to provide for the mounting of a camera to make photographic observations in situ. The camera equipment has been developed by the Technical Photo section.of WADC. Other design improvements have been directed at increasing the accuracy of alignment of the specimen so as to reduce the geometrical irregularity between tests, The calibration process has also been revised and improved by redesign From a maintainance point of view., several changes have been made for the betterment of efficiency, The new units have been designed to operate independently of each other, thus reducing the number of complete shut downs caused by interdependency. Many of the circuit components have been relocated to provide easier access in case a defective part must be removed and replaced. This relocation has been done also with an eye to reducingthe time required to mount and change specimens, and to speed up routine maintainance procedures.. DESCRIPTION OF APPATU As in the original equipment, the new ones are composed of two basic units,: a control unit and an operating unit, The original apparatus is all designed to be used with 120,volts however the new apparatus had to be redesigned to use 230-volt-power circuits for heating purposes in order to avoid overloading,the feeders. There was enough 120-volt power available, however, to operate the control circuits alone, hence the heating and the. control.circuits were separated to gain the advantage of independence. Except for the voltage changes required, the circuits of the new and the old equipment are essentially the same. Because of space requirements, the operating units had to be located away from the control units. This feature made it necessary to include more 0 0, M. 2

ENGINEERING RESEARCH INSTITUTE ~ UNIVERSITY OF MICHIGAN pilot lights onil the new control panels in order to facilitate calibration and inspection of the apparatus by the operator, General arrangement of the control panels is shown in Fig, 1. The operating units are arranged for bench mounting, The essentials of the design are the same as in the original equipment, with the specimen being held in electrodes for heating. One of the electrodes is fixed and. the other is freely movable in the axial direction in order to allow for thermal expansion of the specimen. The temperature of the specimen is sensed by a vacuum thermocouple which operates an electronic pyrometer controller. OP3ERATION OF APPARATUS The apparatus consists of two interconnected units: the operating unit and the control unit. The operating unit comprises three elements(1) means for supporting and heating the specimen, (2) means for sensing the temperature of the specimen at the test section, and (3) means for suddenly cooling the test portion of the specimen to induce thermal shock. The control unit comprises five elements: (1) means for controlling power input to the specimen, (2) means for controlling the temperature of the specimen, (3) means for timing the various portions of the thermal-shock cycle, (4) means for measuring the total number of thermal-shock cycles and the total elapsed time for a test and., (5) necessary safety devices to permit 24-hoursper-day operation with a minimum of attention... The thermal-shock cycle may be divided into two portions, the heating time and the cooling time. In ordinary operation the length of the heating time is controlled by adjusting the power input to the specimen. In order to minimize the effects of lag in the temperature-control system the heating time must be at least one minute. It is undesirable to exceed this minimum time because the total elapsed time for each test rapidly becomes excessive as the heating time is lengthened. The length of the heating cycle is therefore held at 60 seconds, plus or minus 5 seconds, This control is performed by manual adjustment of the input voltage. Between the hours of 8 a.m. and 10 p,m. it is necessary to check the apparatus at frequenrt intervals in order to compensate for changes in the line voltage. There are also some relatively smaller changes in the contact resistance between the electrodes and the specimen which also require that the input voltage be adjusted from time to time. During the night-time hours there are only minor line-voltage variations, and the contact resistance changes only a little in that time, hence it is possible to leave the apparatus unattended from 10 p.m. until 8 a.m.

Cycle Counter and Reset Knob Voltage Regulator and Pilot Lights --- —-- Control Switches and Circuit Breakers Temperature Indicator and /C ontroller Voltmeter, Hours Amme ter — Timers Fig. 1. Control Panel Assemblies 4

ENGINEERING RESEARCH INSTITUTE ~ UNIVERSITY OF MICHIGAN Heating of the specimen is accomplished by passing a current of about 800 amperes through it. The heating effect is localized by making the test portion of a smaller cross section than the rest of the piece. This area reduction increases the electrical resistance at the test portion, and results in that portion being heated to red heat while the rest of the piece remains comparatively cool. The heating current is supplied by a step-down transformer which is fed by a Variac autotransformer. The actual control of the heating rate is acccmplished by varying the output of the TVariac. When the specimen reaches the desired maximum temperature, a vacuum thermocouple which is aimed at one of the specimen faces, causes the controller to stop the heating cycle and begin the cooling cycle. Cooling of the specimen is effected by opening the heating circuit and turning on an air Jet. The jet of air is directed at one edge of a three-sided test section. This shape of test section provides that the air jet will cool the specimen in an asymmetrical manner and thus induce thermal stresses in a very short time. Alignment of the specimen is controlled by the specimen holder. To preserve the alignment it is necessary that no deflection due to bending action be allowed while the specimen cools asymmetrically. At the same time it is necessary to permit axial expansion and contraction to take place freely in order to avoid interaction of the axial stresses with the thermal-shock stresses. If bending were allowed it would be very difficult to keep the nozzle aimed at the same region of the specimen without actually contacting the heated area with the nozzle. Such contact would necessarily introduce undesirable nonuniformities in the temperature distribution on the test section. The duration of the cooling portion of the cycle is controlled by a timer, and a standard cooling of 5 seconds is used. At the end of the cooling time, the air is cut off and the heating cycle begun again. In certain types of tests it is desirable to be able to heat the specimen to a given temperature, hold it there for a certain time, then cool it either suddenly or gradually for a certain time. Both the new and the old units have circuits for accomplishing this type of cycle. i I 5

-- ENGINEERING RESEARCH INSTITUTE * UNIVERSITY OF MICHIGAN ".KE TO LOG Column (1) (1) Relative position on bar stock 1 Specimen number Column (2).045 P-.F. 1700/5 (1718) Arrow indicates 'direction and location of cooling jet; cooling medium is air unless otherwise stated Cooling medium is water Width of cooled edge, inches 'Previously subjected to rotating beam fatigue as shown in column (6) Failed during pre-fatigue ]Number in parentheses indicates average of calibrations at beginning and end of test (Mean max test temp) Column (3) M 1500/5 P1800 +10/100 40.5.K to 1800 Column (4) A no symbol Thermal shock cycle manually controlled Automatic cycle control; maximum temperature, o, and length of cooling period, econds Dead load, 1800 lbs Starting with stated' maximum temperature, maximum temperature was increased lO~F after each 100 cycles fReversed-bending (rotating-beam) fatigue tests; maximum stress, 40,500 psi Maximum temperature held constant after 1800~F was reached Air cooling for stated number of cycles Water cooling for stated number of cycles Air cooling for stated number of cycles Column (5) 0 F C G FC PC Column (6) B A 0.14 T300/1600 G1500 No failure visible Fracture Cracks Grooves Face crack Possible crack Specimen warped due to thermal strains Area of cross section, square inch Heat treated before testing 300 hr at 1600~F Grooves first appeared at 1500 cycles A-1

.- ENGINEERING RESEARCH INSTITUTE " UNIVERSITY OF MICHIGAN - r I OH Stated maximum temperature was exceeded due to malfunction of contr ol unit BT Broke through to thermocouple hole 7%00/606 Previously subjected to' cyclic heating and cooling PV.200 23/ (Max temp) 1700/60 (Heating time, seconds) 1000 (Min temp) 1200/23 (Cooling time, seconds) 0(Number of cycles) 1000 84205/ Previously subjected to 82000 cycles at 40,500,psi 82000 R Reproducibility test. N Specimen formed a neck due to tensile strain. +100/5108 Maximum temperature was increased 1000F at 5108 cycles. eheck II Second test to determine the effect of alteration of testing procedure. P Study of crack propagation PT1 Previously subjected to tensile strain of 1% at room temperature LFRSI Long-time test at reduced severity, Test No. I T.tI Heat treated as shown in braces. Lot No. I C20/1700 Heat treated for 20 hours by heating to 1700~F and allowing to cool for 5 seconds by natural convection. A-2

TEST LOG Specimen Cross Cycle Number Type ofmarks Number Sect ion of Cycles Failure (1) (2) (3) (4) (5) (6) Type 304 Stainless Steel. 1 C) M 0 B o45 2 1600/10 4400 A C B 300 W 3 7 1600/4 1783 C 4a Fat igue 40.5K 3300 F 4b Specimens 40.5K 2600 F 5 1700/4. 1100 0 1800/4 675 C 6 1600/4 6240 0 G6500 o 1900/4 1240 C 7 Q> p~i d1500/4 4130 F A 0.16 P600 ~~ ~ ~ o A-3

TEST LOG (cont) Specimen Number (1) Cross Section (2) Cycle (3) Number: of Cycles (4) Type of Failure (5) Remarks (6) Type 304 Stainless Steel (cont) 8 K7 1600/5 1800/4 3082 517 0 C T300/1600 z9 \ 1500/3 5753 o 1600/4 1000 0 10 170oo/4 1000 o 1800/4 80 C.~~~~~~~~~~~~~~~~~~ i _ -!, l ' -.Il,. I 11 'i 1500/5 P1800 1000 F A 0.132 A 0.133 'if 1500/5 P600 P900 P1800 12 5000 1200 203 0 0 F.l i!J I I, I ~,. I, l, i l!,l!, Ill, I t Il l I I I I 'I I ~ ', I l..-..... ~ - 15 1600/4 1284 C Gl15 -— > ~, a, I'1 - ~ ilil i, I i~ i.i i,1 II I IlL I I~ - ' ' 14 1500/4 1000 F OH

TEST LOG (cont) 0 ~ ~~~~ ~ ~ ~ ~ ~ ~~~~~~~~~~~~~~,... l i. li i,1 Specimen Cross Cycle Number Type of Remarks J~~~~~ ~~Cycle Remarks Number Section of Cycles Failure (1) (2) (3) (4) (5) (6) S~~~~~ l I ~ I.... If l J.. I, I. I I. ~[ Type 304 Stainless Steel '(cont). ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ _ _. ' i i.' ~ 15 1600/5 1900 C T300/1600 | ~ ~~~ ~ ~ ~ ~ ~ ~ ~ ~~~~~~~~~~~~~~~~~~~~i ' * I 1 I I I ' II 16 1> 1600/5 409 C 17 \< 1500/5 300 F A 0.140 V 8P18oo 18 18oo00/4 1950 c G 1500 19 v 1700/3 530W. C 1` W ~ O 20 1500/3 1000 0 BT..........~~~ A-5

TEST LOG (cont) Speeimen Cross Ccle Number Type of Remarks CycleReak Number: Section. of Cycles Failure (1) (2) (3) (4) (5) (6) __ i ~...... i iii, i l l.. = 1 Type 347 Stainless Steel -.:......,.!,, 1,,,.,.. i... i ~~~~1 w 1600/4 866 C +10/100.045,,........,. -..,,.,,,,.,.,.,.,,., 2 \ ~1600/4 1147 0 +10/100.020 ~~~~~~~~,,,,,, _,,..l,..,.. 1500/4 575 C BT 4a Fatigue 54K 5200 F 40.5K 4b Specimens 54K 10400 F 82000.~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~.1... *.,..-.... 5 O/ 1500/4 1326 C V ~+10/100 1500/4 1990 C 7 r 1600/3.5 7 -- ~ +10/100 2700 G to 1800 111 [_ ] i,, h'j!. i i - -- -., i. [1,i, ill~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~i A-6

TEST LOG (cont) Specimen Cross Cycle of Remarks Specimen CrossT Cycle ofC Remarks Number Section of Cycles Failure (1) (2) (3) (4) (5) (6) Type 347 Stainless Steel (cont) 8 (Defective) 9 1600/4 2863 C R.035 10 \ 1600/4 3787 C Check II -..020 11 1600/4 2580 C.050 12 1600/4 3162 C G 736 >~.020 13 \ 1600/4 2204' C G 2072 V 020 14 1600/4 2707 C G 2604.020 A-7

TEST LOG' (cont) Specimen Cross Cycle Number Type of Remarks Number Section of Cycles Failure ~~(1) ~ (2) (3) (4) (5) (6) Type 347 Stainless Steel (cont) 15 7 1600/4 3003 ' C G2820 R...035 R 16 1600/4 2518 C R.020 17 0 1600/4 4850 0 Check I.023 18 7 Fatigue 7200 F 54K 64K 103300 19 \ 1600/4 1825 C R 37K/217100 42K/11000 20 Fatigue 4300 F 48K/35600 64K 54K/10000 59K/10400 21 1600/4 4430 C A-8

TEST LOG (cont) Specimen Cross Number Type of Cycle Remarks Number Section of Cycles Failure (,) (2) (3) (4) (5) (6) Type 347 Stainless Steel (cont) 22 (Defective) 23 1600/5 2962 C 24 Fatigue 52900 F 59K,010 25 1600/5 1562 C 54K/50000 ~~V P.F. -4.010 53K/52000 59K/12000 26 1600/5 1960 C 64K/1000 70K/1000 ->.010 75K/500 27 7 X F 53K/52000 P,.F. 59K/11300.010 53K/52000 59K/12000 28 707 1600/5 1594 C 64K/1000 P.F. 70K/1000 - >.010 75K/500

TEST LOG (cont) Specimen Cross Number Type of Remarks Number Section of Cycles Failure (1) (2) (3) (4) (5) (6) Type 347 Stainless Steel (cont) 53K/52000 59K/12000 29 X C 64K/1000 P.F. 70K/1000 75K/300 30 1600/5 1973 C - -.010 31 \7 1600/5 2764 C 32 1600/5 1500 C.010 34 P.F. 1811 C 60K/39000 (3).036 35 (Used for calibration of Heat-Eye) (2) A-10

TEST LOG (cont) Specimen Cross Number Type of Cycle Remarks Number Section of Cycles Failure (1) (2) (3) (4) (5) (6) Type 347 Stainless Steel (cont) 36 1600/5 1859 C 58K/30000 (1) - P.F. -.040 37 1600/5 4635 C ( )i.-o3o 3825 1600/5 2114 C T2/2000 G 2440 39 1600/5 2440 G Rigid Support (7) Nozzle No. 3 40 7 1600/5 3143 G Nozzle No. 4 (8) 41 1600/5 2710 C G 2000 V... Rigid Support Nozzle No. 3 42 ) (used for:calibration) A-11

TEST LOG (cont) lo.I.......m, I l,.., -. ~ II _ I. 1 Specimen Cross Number Type of N~~~ber ~~CycleReak Number Sedtion Cycle of Cycles Remarks of Cyc~esFailure ~(1) 92) (3) (4(5) (6) Type 347 Stainless Steel (cont) ~~~~~~~~~~~~~~~~~~~~~~~~~~..... ~. 'm._ r. 43 (11).02.025V 1600/5 10708 C P Rigid Support Nozzle No. 4..,....... '.,~~~~~~~~ 44 \ /1600/5 2046 C T2/2000.0 45 1600/5 1956 C T2/2000 * 250V <.0,. _i',,.. H. S. 21 (vitallitmr) Cast 1 1500/3,.5 1000 C BT L,,,,, i,,...... iiiii,. 1 l 1700/5 3552 c 2 (1718).o4. 3 _ ~ t ~1~ ~ *,_ I _ l Il l i I, _. A-12

TEST LOG (cont) Specimen CIoss Number Type Remarks Number Section of Cycles Failure (1) (2) (3) (4) (5) (6) H. S. 21 (vitallium) Cast (cont) 17D00/5 6820 C FC6003 4?: 719).4C6561.049V 5 1800/5 1252 C.o45 V / 6 1700/5 1506 C 7 (1720).o48 8 1800/5 3468 C.047 V 9 1600/5 5305 C.037 \/ (1-03) 10 ~.. A-13

TEST LOG (cont) Specimen Cross Number Type of Rerks Number Section of Cycles Fail "re (1) (2) (3) (4) (5) (6) H. S.. 21 (vitallium) Cast (cont) 11 \7\7 1600/5 17615 C.043Vi 1605 12 1700/5 7375 T51/1350 13 1800/5 3902 C.04 14 15 1600/5 15334 0.035 (1607) 16 \ ' 1700/5 14489 T51/1350.03 17 1700/5 3279 C.040 V (1708) FC.,004 A-14

TEST LOG ( cont) Specimen Cross Number Type of Remarks Number Section Cof Cycles Failure (1) (2) (3). (4) (5) (6) H. S. 21 (vitallium) Cast (coit) 19 \ / 1700/5 10060 T51/1350.051 - (1710) 20 1800/5 4147 C.039 / 21 \ /1600/5 9938 C o036 < / 22 1700/5 18411 C T51/1350.049 < Inconel 1 \o/ 1500/3 1450 C 27.015 2 \1500/3 2730 C.+10/100 /.050 3 j15~005 1500/3 428 CBT A-15

TEST LOG (cont) Specimen Cross Number Type of Number Section Cycle of Cycles Failure Remarks (1) (2) (3) (4) (5) (6) Inconel (cont) 4 1700/5 3167 C T2/500. T/3/14oo00.03. ~5 \1700/5 1819 C T2/500 0 36 1600/4 7449 C 7V.035 Tl/3/1400 1705 4706 C.035. 8 1700/5 2090 C T1/3/1400.\02 /~~Z<~~~ 1700/5 PTI.021_ v 9 Q 1700/5 6465 C T2/600.025 10 7 / 1700/5 3680 C T1/3/1400 PT10 A-16

TEST LOG (cont) Specimen Cross Number Type of Number Section Cycle of Cycles Failure Remarks (1) (2) (3) (4) (5) (6) Inconel (cont) 11 / 1700/5 2860 C T1/3/1400.028 PT5 12 1700/5 1884 C T1/3/1400 C20/1700 13.1700/5 2500 C T1/3/14oo00 14 1700/5 2527 C T1/3/1400.030 PT5 15 1700/5 2804 C T1/3/1400 PT1O 1030 V 16 1700/5 3590 C T1/3/1400.025 < 17 1700/5 2270 C T1/3/1400 1 A7/ 175PTI A-17

TEST LOG (cont) Specimen Cross Number Type of Number Section Cycle of Cycles Failure Remarks (1) (2) (3)- (4) (5) (6) Inconel (cont) 18 1700/5 2576 PC T1/3/1400 3015 C PT5 19 1700/5 1830 C T1/3/1400.02 PTO...20 \ 1700/5 2898 C T1/3/1400 ~030.030ts 1700/5 2898 PTO 21 22 1700/5 4339 FC? T1/3/1400b.0335 6866 C flex. pipe to nozzle 23 1700/5 2250 C T1/3/1400 5 V.24 - 24 25 1 5700/5 3538 FC Tl/3/1400 4229 C A-18 A-18

TEST LOG (cont) Specimen Cross Number Type of Number Section Cycle of Cycles Failure Remarks (1) (2) (3) (4) (5) (6) i_ _l _. _, i _ _. _..... s-.816 Alloy (wrought) 1500/4 A 0.08 1 \T P700 1788 0 N \No lo ad 18391 C +100/5108 +100/10000 1500/4 2 7 P1100 2657 F A 0.08 to N AP700 3 1700/4 2256 C 4 1700/4 2250 C 5 \o/ 1600/4 3870 C 6.1500/4 2650 C 77 1500/4 13280 C A-19

TEST LOG (cont) Specimen Cross Number Type of Number Section Cycle of Cycles Failure Remarks (1) (2) (3) (4) () (6) S-816 Alloy (wrought) (cont) 8 1600/4 7497 C 9 1800/5 1069- C T (1/2150 W.0371 1 10 1700/5 2426 C T f1/2150 W 0~37 7) \16/1800 11 - \ / 1600/5 5130 C T 1l/2150 W.036 < \16/1800 12 1800/5 956- C T |1/2150o W.o5887 1 \16/1800 13 1700/ 1903+ C T (1/2150 W 0.003 short \16/1800 114 \ / 1800/5 1146 C T 1/2150 W )16/1800 A-20

TEST LOG (cont) Specimen Cross Number Type of Number Section Cycle of. Cycles Failure Remarks (1) (2) (3)' (4) (5) (6) S-816 Alloy (wrought) (cont) 15 /.16oo00/4 4600 C T 1'/2150 W~ I.036 v< \6/1800 j T ( 1/2150 W I 16 \ / 1600/4 3620 C T16/1800 Average test temp. was 1615~F 17 \ / 1700/5 1956- C T 1/2150 W I 16/18oo00 J.036 18 \ 1800/5 784 C T (1/2150 W) I.384/<_ L16/1800,. ' j 19.0345 7 1700/5 2300 C T (1/2150 W Io K16/1800 o T '1/2150 W I 20 1600/5 3100' C 16/1800 Average test.0331 temp. was 1660~F 16/1800 21 1700/5 2190 C 1700032~~~~.1700/65 } 000 A-21

TEST LOG (cont).............n.. 1 I 1 U I J I Hll I i, U I l I- I I I I l, I f l, r Specimen Cross -Number Type of Number. Section Cycle of Cycles Failure Remarks (1) (2) (3)- (4) (5) (6). ~ ~~ ~ ~ ~I...ll. l. l I _. 1 l s-816 Alloy. 22. 22 (wrought) (cont )..-.j.~ — -. I, - —..._ —. K1 1700/5 2050 C T I1/2150 II \16/1800J 16oo j T 1/2150 II 16/1800 23 5 1700/5 1414 C 1700j/60.034 P _200oo/2 N-155 Alloy (wrought) 3764 FC 1 1700/5 3878 C T [1/3/2200 W I,03o8\ )4949 2C [50/1400 f 2 1700/5 3211 C T 1/s3/2200 W I.0o04 [50/14oo 3 7 / 1700/5 3248 C T,1/3/2200 W} I / 1800/5 1508 C T 1/3/2200 w I -22

TEST LOG (cont) Specimen Cross Number Type of Number Section Cycle of Cycles Failure Remarks (1) (2) (3) (4) (5) (6) N-155 Alloy (wrought). (cont) 5.036 1600/5 3886 0 T (1/3/2200 t50/1400 Removed for No crack w\ I check; 6 1700/5 3105 C T (1/3/2200 W I.o4ok 50/1400 7 1800/5 18 18C T 1/3/2200 W I.0427 L150/1400 8\ / 1700/5 3195 C T 1/3/2200 WLI 50/1400 9 7 /1700/5 2888 C T J 1/3/2200 W I.037 "/. 50/140_0.05.041 1600/ 10124 o T 11/3/2200 w I 11 \ /1800/5 2052 C T /3/220 W I.04~ ' T0/14/.00 J A-23

TEST LOG (cont) _~~~~~~i i i - 11 _i 111 m _;, i i... i, _ii1.ii Specimen Cross Number Type of Number Section 'Cyrcle of Cycles Failure Remarks (l) (2).(3)~ (4) (5) (6),.,,,..........,. - ~ N-15.5 Alloy (wrought). (cont) ~,,.. f,,,, 1 - ~,,, 1,,. '. _. '...... J.12.038V 1800/5 1228 C T 1/3/2200 W II 50/1400 ) 13 1800/5 1095 C T 1/3/2200 W II L.08.... 8.o50/400 oo.035 o/l,4oo J 15 1800/5 990 C T (1/3/2200 W II.0385i 1800/5 990 {50/1400 1 16 \7 7 1800/5 1130 C T l/3/2200 W II.0415 Vo/.4oo 17 040 1700/5 2229 C T 1/3/2200 W II [50/1400 ~18 -03657 1700/5 1995 /2200 W II A _),L

TEST LOG (cont) Specimen Cross Number Type of Number Section Cycle of Cycles Failure Remarks (1) (2) (3) (4) (5) (6) N-155 Alloy (wrought) (cont) 19.039 1600/5 5153 C.T | 1/3/22oo A I.~. 20 1700/5 2320 C T {1/3/2200 W II I, 21 V* 0433 < 1600/5 3530 'C T 1/3/2200 50/1400 w II 22 v 1600/5 7000 CT 1//2200 W II 5o/14oo.o45R < 23 \ / 1600/5 6728 C T 1/3/2200 W 11-.047 50/140o,,.,, _,,,,,,...~~,, - _ __ _,, ~J,,,,. _ *,...-, a A-25

UNIVERSITY OF MICHIGAN 39011111111111111114 8332 39015 02514 8332