Effect of laser shock peening and carbonitriding on tribological properties of 20Cr2Mn2Mo steel alloy under dry sliding conditions

Abstract

In this study, the effect of laser shock peening and low-temperature vacuum carbonitriding on the tribological properties of 20Cr2Mn2Mo steel alloy was investigated. The original sample and samples treated by laser shock peening with different laser energy and number of impacts were carbonitrided in vacuum at 760 °C. The effect of laser shock peening parameters on surface roughness, microhardness, coefficient of friction, and wear properties was studied. The results indicated that the surface roughness and microhardness increase with respect to laser energy and number of impacts. For exceedingly high laser energy or number of impacts, the coefficient of friction evidently increases. Furthermore, laser shock peening and carbonitriding lead to high-density dislocations and second-phase particles. With increasing laser energy and number of impacts, the primary wear mechanism changes from abrasive wear to a mix of abrasive and adhesive wear.