Study on sliding friction and wear behavior of M50 bearing steel with rare earth addition

This study aims to investigate the influence of rare earth (RE) addition on the friction and wear behavior of M50 bearing steel. The results show that RE addition has little effect on friction coefficient, but can reduce wear volume especially under harsh wear conditions. This mainly results from modification of RE elements to primary carbides. M50 steel without RE addition has bigger proportion slenderer rod-like M2C carbides, which are more likely to cause carbides fracture broken or peeling off, forming bigger wear debris with irregular shape to aggravate the wear. However, M50 steel with RE addition has more spherical MC carbides, which are more easily worn into spherical crowns, forming smaller wear debris which could not increase the subsequent wear.