Simulation and Experimental Research on Surface Damage Repair of Alloy Steel by Laser Cladding and Shock Strengthening

To achieve remanufacturing of damaged alloy steel stamping die, laser cladding repair technology has emerged. However, conventional laser cladding repair may result in an increase in porosity and microcracks on the surface undergoing repair. The present study investigated the potential of laser shock strengthening treatment on the surface of laser cladding repair molds. This treatment could reduce surface defects and introduce residual compressive stress to strengthen the mold surface. The experimental results demonstrated that the grain structure of the melted surface underwent significant refinement following laser shock strengthening treatment, with a substantial increase in microhardness from 541.26 to 760.54 HV. Furthermore, residual compressive stresses of −496 MPa were introduced. Furthermore, the corrosion resistance and friction wear performance of the sample surface were enhanced. The corrosion current density decreased by approximately 18%, the polarization resistance increased by around 73.84%, and the surface friction wear coefficient was significantly reduced. Concurrently, a numerical model of the laser shock process was established by Abaqus to simulate the spatial distribution of residual compressive stress on the sample surface. The experimental results exhibited a high degree of consistency with the simulation results.