The Surface Fatigue Life of Contour Induction Hardened AISI 1552 Gears.
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION CLEVELAND OH LEWIS RESEARCH CEN TER
Pagination or Media Count:
Two groups of spur gears manufactured from two different materials and heat treatments were endurance tested for surface fatigue life. One group was manufactured from MSI 1552 and was finished ground to a 0.4 um 16 um. rms. surface finish and then dual frequency contour induction hardened. The second group was manufactured from CEVM AISI 9310 and was carburized, hardened, and ground to a 0.4 um 16 uin. rms. surface finish. The gear pitch diameter was 8.89 cm 3.5 in.. Test conditions were a maximum Hertz stress of 1.71 OPa 248 ksi, a bulk gear temperature of approximately 350 K 170F and a speed of 10000 rpm. The lubricant used for the tests was a synthetic paraffinic oil with an additive package. The test results showed that the 10 percent surface fatigue pitting life of the contour hardened AISI 1552 test gears was 1.7 times that of the carburized and hardened AISI 9310 test gears. Also there were two early failures of the AlSI 1552 gears by bending fatigue. MM
- Machinery and Tools