Effect of prior cold rolling on the dry wear performance of GCr15 bearing steel with multiphase microsturcture

Abstract

Abstract In this work, the effect of cold rolling on the wear performance of GCr15 bearing steel with multiphase microstructure has been investigated. The microstructural observation shows that prior cold rolling facilitates to the dissolution of carbides into prior austenite, reduction of the large-scale carbides and refinement of martensitic lath. In addition, with the increase of cold rolling reduction, the residual austenite content is increased after multiphase heat treatment due to the carbon enrichment in austenite induced by increasing dissolution of carbides. The wear results indicates that friction coefficient as well as wear quality distinctly decreases with the increase of rolling reduction. There are fewer plow grooves and peeling pits on the wear marks after 40% cold rolling reduction. It is also found that the transformation of martensite from residual austenite induced by frictional stress increases the surface compressive stress and hardness for the rolled specimens. This transformation effectively diminishes the depth of plow grooves and reduces the number of peeling pits, which finally leads to the enhancement of dry wear resistance.