Effect of carburizing process on high cycle fatigue behavior of 18CrNiMo7-6 steel

• DOI: 10.1016/j.jmrt.2021.12.074
• Publication Date: 2021-12-18T07:07:42Z
• Authors: Shengwei Qin; Chenghao Zhang; Bang Zhang; Haiyang Ma; Minghao Zhao
• Keywords: Carburizing; Fatigue limit

Carburizing heat treatment is widely used in the fabrication of gears to improve their fatigue performance. The effects carburizing process on material properties surface hardness, residual stresses, retained austenite case-hardened 18CrNiMo7-6 and consequential strength have not been studied detail. In this research, high-cycle performance uncarburized carburized gear steel were studied. addition, evolution processes microstructure stress specimens during test observed quasi-in situ. initiation cracks was also analyzed by SEM transformation TEM. results showed that has an increase-decrease trend with increase effective case depth. Besides, failure mode changes from internal after being carburized, which plays important part. if a large amount exists specimen failure, high-density twin martensite region formed can act as crack site, harmful