Influence of microstructure and residual stress on the stages of case crushing

Abstract The influence of microstructure and residual stress on the stages of the development of contact fatigue cracks in case-hardened steel was investigated by tracing crack propagation drawings. The results of the investigation show that oxide impurities may result in the initiation of contact fatigue cracks. Higher strength and tangential residual compressive stress are beneficial in extending the stable propagation life. Increased austenite occurring in the surface layer may lengthen the branching propagation life.