Abstract
The purpose of this study is to investigate the influence of shot peening on the surface durability of case-hardened steel rollers under a sliding-rolling contact condition. The compressive residual stress, the hardness and the surface roughness of the rollers increased by the shot peening. The failure mode of the rollers was spalling. The failure depth agreed almost with the depth where the amplitude A (τ_<yz>/HV) of the ratio of orthogonal shear stress to Vickers hardness became maximum near the case-core boundary. The surface durabilities of the shot-peened rollers were higher than that of the unpeened roller in these experiments. The coefficient of friction between the rollers decreased during the test, since the surface roughness of the rollers decreased by the running-in effect. The increases of the compressive residual stress and the hardness by the stronger shot peening contributed to the longer fatigue lives of the shot-peened rollers. Therefore, it could follows from this that the strong shot peening should be selected in order to improve the surface durability of the steel rollers in these experimental range.
