Simulation of Stress Field of Laser Welding in Cold Rolled Sheet Strip and Welding Process Parameters Study

Taking DP980 high strength steel sheet as an example, the relationship between residual stress, welding deformation and welding process parameters in the process of laser welding was studied, the laser welding process of strip steel was simulated by using the method of thermal-mechanical coupling, and the reliability of the model was verified through experiments. Finally, different working conditions were set to analyze the influence of welding process parameters on the residual stress and deformation. The results show that the welding residual stress and deformation decrease with the increase of welding speed. When the welding speed is 2.0-3.0 m/min, the welding residual stress and deformation amount are small.The residual stress and deformation of welding increase slightly with the drop of the focus position, but the variation range is small. The addition of annealing is beneficial to reduce the residual stress of welding. When the annealing current is 80-100 A,the residual stress decreases most significantly.