The influence of shot peening on mechanical properties, wear, and corrosion resistance of 42CrMo steel

Shot peening is a well-known practical method for improving the surface performance of mechanical components. In this work, shot peening was applied to 42CrMo steel components as tie bars for a double platen injection molding machine. The microstructure and morphology of the samples were studied. The residual stress and phase identification of steel samples with and without shot peening were determined by X-ray diffractometer. At the same time, the numerical simulation was carried out and compared with the actual residual stress. Microhardness, mechanical properties, wear and corrosion resistances of the shot-peened samples were studied. The results showed that shot peening treatment influence surface microstructure and properties of the steel. Plastic deformation regions and residual stress layers were formed after shot peening. The presence of these plastic deformation regions, grain refinement, and residual stress layers improved the surface hardness, fatigue life, and wear resistance of the steel. Electrochemical analysis demonstrated a reduction in the corrosion resistance of the steel after shot peening. In order to improve the corrosion resistance of the steel after shot peening, it was subjected to phosphating treatment, and its corrosion resistance performance was studied.