Effect of pre-wear on the rolling contact fatigue property of D2 wheel steel

Abstract

In this work, the effect of pre-wear under air condition on the rolling contact fatigue life (RCF) of D2 wheel steel under oil lubrication was thoroughly studied based on the rolling wear experiment. The results show that dry pre-wear can improve the RCF life of wheel sample under oil lubrication during RCF process before the sample surface forms the fatigue wear cracks during pre-wear process. Dry pre-wear can change largely pre-wear surface, such as increasing surface layer dislocation density, refining ferrite grains, dissolving lamellar cemetite in pearlite, forming fibrous microstructure and reducing surface roughness. These microstructural changes contribute to an improvement of the surface strength and RCF life of samples. However, when fatigue wear occurs on the contact surface during pre-wear process. The fatigue wear crack causes the flaking of hardening layer, and is a RCF crack source to accelerate the formation of the RCF crack. It can lead to reduce the RCF life of the sample.