Numerical simulation of temperature field and stress field of laser remelting synthesizing Fe-Al coating

The remelting process of aluminum coating on Q235 steel substrate was simulated using the finite element software ABAQUS. A Gaussian surface heat source was selected to emulate the laser beam, and the latent heat of coating and substrate was also considered in FEM model. The effects of laser power and scanning speed on the temperature field and stress field were investigated, respectively. The simulation results indicate that comparing with the laser power, the scanning speed has less impact on the temperature field, inversely, its effect on the stress field is more than that of the laser power. As laser power increasing, the width of molten pool increases rapidly, which results in a rough coating surface while the depth of molten pool has little change. Tensile stress in the coating and substrate alloyed zone along the laser scanning direction is larger than that along perpendicular scanning direction in the remelting process. Residual stress in the coating interface zone is proportional to the scanning speed but inversely proportional to the laser power. These simulation results are verified by subsequent experiments.