There were severe pitting corrosions on the surface of transmission gears in diesels. The cause of metal fatigue pitting of gear surface is analyzed in the paper, which based on the contact fatigue experiment of 18Cr2Ni4WA carburizing and quenching gears used in the diesel engine. Causes of pitting on harden tooth surface are studied from three aspects: gear surface residual stress field, oil f...

To reduce the processing time for in-line carburizing, we performed ultra-rapid carburizing and quenching using induction heating. Conventional gas vacuum (low-pressure carburizing) are treated at 1203–1323 K, which is lower than eutectic temperature. In contrast, in this study, temperature of 1523 K was higher speeding up process. The SCM420 sample rapidly heated to treatment by CH4 N2 were mi...

Fatigue behavior of case hardened parts depend to a great extent on the type of residual stresses developed in the components. Topography and metallurgical effects were the two elements which contribute much to surface integrity. Micro hardness of the gas carburized (EN 33 and EN 36) and Induction hardened (AISI 1040 and AISI 6150) specimens obtained during experiments, showed that there was gr...