The characteristics of treated zone processed by pulsed Nd-YAG laser surface remelting on hot work steel

In this study, the surface of H13 steel was treated using laser surface remelting. Some important characteristics of the treated zone (biomimetic strengthening units) were investigated, e.g. size, cross-sectional morphology, microstructure and hardness as functions of average peak power density and effective peak power density. The results indicate that different combinations of average peak power density and effective peak power density could vary the appearance of cross-sectional morphology, microstructure and hardness. An appropriate range of EPPD for preparing the treated zone was acquired: 595–1448W/mm2. In this range, the depth/width ratio of 0.31–0.47 and microhardness of 559–667HV were obtained. •The effects of average peak power density and effective peak power density were investigated.•The depth/width ratio of the molten pool was studied. An appropriate range was suggested.•The roles of pulse frequency and scanning speed in peak power densities were studied.•Varied shapes of the molten pool were coupled with corresponding laser parameters.