Shot Peening Treatment and Characterization of 18CrNiMo7-6 Steel after Carburizing and Quenching

18CrNiMo7-6 steel after carburizing and quenching was treated by traditional shot peening and dual shot peening, and the residual stress, grains size, austenite content, micro-hardness and surface roughness after shot peening were studied. The results show that comparing with the conventional shot peening, the dual shot peening could not only further improve residual compressive stress, refine microstructure, reduce residual austenite content and increase micro-hardness, but also effectively reduce surface roughness.