XRD investigation of microstructure strengthening mechanism of shot peening on laser hardened 17-4PH

► We analyzed the microstructure of shot peened component. ► We estimated the domain size, the microstrain and dislocation density of specimen via XRD profile method. ► The domain size increased and microstrain as well as dislocation density decreased with depth increasing. ► The surface domain size decreased to nano-scale after shot peening treatment. ► The surface dislocation density increased about one order magnitude after shot peening treatment.