Study on shot peening strengthening 42CrMoA steel and its fretting wear properties

In order to improve the tribological properties of 42CrMoA steel, it was shot peened using different parameters. The surface morphology, residual stresses, hardness, and micromotor properties of the treated specimens were thoroughly evaluated. The results showed that it led to substantial plastic deformation, increased surface roughness, grain refinement, and introduction of residual compressive stresses. In addition, a significant increase in microhardness and depth of hardened layers on the specimen surfaces was observed. Furthermore, a positive correlation between the effect of the shot peening process and the peening duration was observed. As revealed by the investigation, the shot peening process not only advances the wear resistance of the specimens but also leads to a reduced wear volume compared to untreated specimens. Furthermore, this treatment triggers a shift in the wear mechanism from the predominant occurrence of severe adhesive wear, fatigue wear, and abrasive wear in untreated specimens to a predominant mode of abrasive wear, accompanied by a minor occurrence of adhesive wear.