Influence of shot peening on the fatigue life of laser hardened 17-4PH steel

In order to improve the fatigue life of 17-4PH steel after laser hardening treatment, shot peening and dual shot peening treatments were performed on laser hardened 17-4PH steel in this paper. Characteristic changes of the roughness, hardness and residual stress distribution in three typical areas were discussed in order to gain a better understanding about the shot peening influence on laser hardened material state. Results showed that initial residual stresses had no influence on the finial residual stress distribution in shot peening influence region after shot peening treatment. The fatigue life of laser hardened 17-4PH steel increased dramatically after shot peening treatment.