Weld Bead Shape and Formation Prediction for Robotic MIG Welding Process Using Numerical Calculation

To optimize the robotic MIG welding process for joining 316 L stainless steel sheets and to clearly understand the process, a new numerical model for a combined heat source, based on a Gaussian surface and Gaussian cylinder, was developed using ANSYS software. After confirming the proper welding parameter combination for producing a weld bead with a good appearance, the model could be developed using the parameter combination. The influence of four parameters—effective heat delivery radius, the depth and heat distribution coefficients of the Gaussian surface, and the Gaussian cylinder heat source effects on the bead width and penetration—was explored using the model, and then a general and convenient method was proposed to effectively and reasonably set the parameters of the combined heat source. Finally, the numerical calculation results for the shape of the fusion line of the weld bead section could be obtained under different input powers and different welding speeds. The numerical calculation results had small errors compared to the experiments results. Hence, this model could realize temperature field simulation and weld bead formation prediction. This work can be used to accurately and effectively predict the robotic MIG welding process in the academic research and supply references for actual production.