1、STD-AGMA 75FTMS-ENGL 199.5 Ob87575 0004b78 113 95FTM5 The Surface Fatigue Life of Contour Induction Hardened AIS1 1552 Gears A by: Dennis Townsend, NASA Lewis Research Center, an Turza, Reliance Electric Company, and Mike Chaplin, Contour Hardening, Inc. American Gear Manufacturers TECHNICAL PAPER S
2、TD-AGMA 95FTM5-ENGL I995 m b87575 b99 5T The Surface Fatigue Life of Contour Induction Hardened AISI 1552 Gears Dennis Townsend, NASA Lewis Research Center, Alan Wza, Reliance Electric Company, and Mike Chaplin, Contour Hardening, Inc. Dhe statements and opinions contauied hain are those of the auth
3、or and should not be construed as an official acaon or opinion of the American Gear Manufacturers Associatioal Abstract Two groups of spur gears mandamred from two different materias and heat treatments were endurance tested for swhcefatiguelife. One group wasmanufacturedfiom AISI 1552andwas fnished
4、 -dto 0.4 pm (16ph) mis dace nnishaud the0 diial fquency tourhductionhmhed. The secondgroup wasmanufamredom CEVMAiSI9310 and was cabuxized, hardened, and ground to a0.4 pm (16 ph rms slafrtce finish. The gear pitch diameter was 8.89 cm (35 in.). Test conditions were amaximum Hertz stressof 1.71 GPa
5、ksi), ab Ohue, Y.; and Karasuno, I.: A Study of Fatigue Strength of Induction-Hardened Sintered Powder Metal Gears. Proceedings of JSh4E MpT91 International Con- ference on Motion and Power Transmissions Nov. 23-26, 1991 Hiroshima, Japan pp. 757-762. 2 Yoshida, A; Fujita, K; Miyanishi, K; and Ohue,
6、 Y.: Estimation of Fatigue Stren,gh for Surface Failure of Surface-Hardened Steel Rollers and Gears. Proceedings of International Con- ference on Gearing Nov. 5-10 1988 Zhengzhou China 3 Storm, J.M.; and Chaplin, M.R.: Dual Frequency Induction Hardening. ASME Proceedings of The 1989 International Po
7、wer Transmission and Gearing Conference. Vol. 2 Chicago illinois April 25-28,1989 4 Aida, T.; and Oda, S.: Bending Fatigue Strength of Gears. Bulleton of JSME vol. 9, No. 36, 1966 pp. 793-806. 5 Kirk, D.: Neims, P.R.: and Arnold, B.: Residual Stress and Fatigue Life of Case-Carburized Gears. Metailu
8、rgica, Vol. 74,446, Dec. 1966, p. 255. 6 Cretu, S.S.: Influence of Compressive Residual Stresses on Ball Bearing Fatigue Life. Bull. of Iasi Polytech. Inst., Rev. Roum. Sci. Techn.-Mec. Appl., Tome 32, N 5, 7 Townsend, Dennis P.: Improvement in The Surface Fatigue Life of Hardened Gears by High inte
9、nsity Shot Peening. NASATM-105678, AVSCOM TR 9 1-C-042. Presented at the Sixth International Power Transmission and Gearing Conference Sept. 13-16 1992. SI Dowson, D.; and Higginson, G.R.: Elasto-Hydrodynamic Lu- brication. Pergamon Press, 1966, p. 96. 9 Townsend, D.P. and Akin, L.S., 1981, “Analyti
10、cal and Experi- mental Spur Gear Tooth Temperature as Affected by Operating Variables, Journal of Mechanical Design, Vol. 103, pp. 219-226 101 Johnson, L.G.: The Statistical Treatment of Fatigue Expen- ments. Elsvier Pub. Co., 1964. Vol. 2, pp. 515-518. pp. 547-560, Bucarest, 1987. Manganese Silicon
11、 Sulfur Phosphorous Iron - 0.63 1.35 0.27 - 0.005 0.03 0.005 0.03 Bal. Bal. 1 I 3 Step Process Temperature Time, K hr OF 4 I Copper piate ail over I l 2 I 5 I Reheat I 922 I 1,200 I 2.5 -I - - -I- Preheatinair Carburize 1.172 1.650 8 Air cool to room temperature 3 Air cool to room temperature TABLE
12、3.-UC“T TREATMENT FOR AISI 1552 GEARS I I I 8 9 10 I step I Oilquench _-I_ -_- - Subzerocool 180 -120 3.5 DoubletemDer 450 350 2each Process TABLE 4.PPUR GEAR DATA Gear Tolerance per P Number of teeth Diametral pitch Circular pitch, cm (in.) Whole depth, cm (in) Addendum, cm (in) Chordal tooth thick
13、ness (reference), cm (in.) Tooth width, cm (in.) Pressure angle, deg Pitch diameter, cm (in.) Outside diameter, cm (in.) Fillet radius, cm (in.) Measurement over pins, cm (in.) Pin diameter, cm (in.) Backlash reference, cm (in.) Tip relief, cm (in.) ma Class 12.1 28 8 0.9975 (0.3297) 0.762 (0.300) 0
14、318 (0.125) 0.485 (O. 19 1) 0.635 (0.25) 20 8.890 (3.500) 9.525 (3.750) 0.102 to 0.152 (0.04 to 0.06) 9.603 to 9.630 (3.7807 to 3.7915 0.529 (0.2 16) 0.001 to 0.0015 (O.ooo4 to O.ooo6) 0.0254 (0.010) . 4 STD-AGMA 95FTM5-ENGL 1995 9 Ob87575 O004704 247 D Material Effective case depth to Rc 50 mm (in
15、) AIS1 0.63 (0.025) 1552 AIS1 0.81 (0.032) 9310 Case Core hardness hardness Rc Rc 60.5 35 61 38 TABLE 6.-PROPERTIES OF SYNTHETIC PARAFFINIC LUBRICANT I Additive Kinematic viscosity, cm2/sec (CS) at- 244 K (-20 OF) 311 K(100 OF) 373 K (210 OF) 477 K (400 OF) Flash point, K (OF) Fire point, K (OF) Pou
16、r point, K (OF) Specific gravity Vapor pressure at 3 1 1 K (100 OF), mm Hg (or torr) Specific heat at 31 1 K (100 OF) Jkg k (BtUnb OF) Additive, Lubrizol5002 (5 Y additive: phosphorus, 0.6 wt %; sulphur, 18.5 wt %. Gears AIS19310 AISI 1552 Luntizol 52a 10-percent 50- percent Slope Failure Confidence
17、 life, life index a number? cycles cycles percent 21 x lo6 45 x lo6 2.4 19/20 _ 36x lo6 220x lo6 1.04 5/10 75 2500x 1 O-2 (2500) 3 1.6 lo- (3 1.6) 5.7x10- (5.7) 2.0x10-2 (2.0) 508 (455) 533 (500) 219 (-65) 0.8285 o. 1 676 (0.523) .- %); content of 5 Slzws-rystem oil inlet 7, Vi A-A Figure 1 .-NASA L
18、ewis Research Centers gear fatigue test apparatus. (a) Cutaway view. (b) cchematic dia- gram. Figure 2.4ross SeCaon of a dual frequency induction case hanieneci AISI 1552 test gear. 6 STD-AGMA 95FTM5-ENGL 1795 Ob87575 000470b OLT - (cf .O25 cm Figure 3.-Photornicrograph of case, core and case-core i
19、nter- face of dual frequency induction hardened AISI 1552 test gear. (a) Case. (b) Core. (c) Case core interface. Figure 4.-Photornicrographs of case and core of AISI 931 O test gear. (a) Carburized and hardened case of the CNM AISI 931 O gear showing high carbon fine grain martensitic structure. (b
20、) Core structure of CWM AISI 931 O gear showing low carbon refined austenitic grain size. 7 c O.oo0 0.005 0.010 0.015 0.020 0.025 0.030 0.035 Depth, in. 62 58 v) g54 346 E 2% o - s 8 42 38 34 a I l o.oO0 0.020 0.040 0.060 0.080 0.100 Depth, in. Figure 5.4ardnesc profile of AISI 1552 steel tesi gear
21、con- tour hardened case and a carburized and hardened AiSI 931 O gear. (a) AISI 1552 gear. ) Carburized and hardened AISI 9310 gear. Residual stress, ksi O -40 -80 -120 -160 I I I l I Residual stress, MPa o -200 400 400 -800 -lo00 O Or r *- 2 o, 3 t 24 o Z6 5 88 n P 4 E $8 -t 2 12 I 8 16 P 520 8 24
22、28x1 I6 Residual stress, ksi 0102030405060708090 1 Residual stress, MPa o -100 -200 -300 400 600 -600 - O - 250 f - 8 o, 8 7 -= 500 - 2 750 5 Q P - loo0 -0 Figure 6.4esidual stress versus depth for carburized, hardened and ground AiSI 931 O test gears and dual fre- quency induction hardened AISI 155
23、2 gears. (a) AISI 931 O. (b) AISI 1552. 8 STD-AGHA 95FTM5-ENGL 149.5 Ob87575 0004708 972 O -99 r I a 22 1 1 O0 -9 90 70 E fn a E 10 a P 1 1 o 1 o2 103 Stress cycles, millions 100 1 o 1 o2 1 03 104 Stress cycles, millions 1 O0 1 o 1 o2 103 104 Stress cycles, millions Figure 7.Curface fatigue lives of
24、 surface hardened AISI 931 O and AISI 1552 test gears. Speed 1 O O00 rpm; maximum Hertz stress, 1 .71 GPa (250 ksi); temperature, 350 K (1 70 OF); lubricant, synthetic paraffinic with $percent by volume EP additive. (a) AISI 931 O. (b) AISI 1552. (c) Summary. Figure 8.-Typical fatigue spall for test gear. (a) AISI 931 O test gear. (b) AISI 1552 test gear. 9
