Mathematical model and simulation of partial penetrated weld pool

The qualitative analysis on the behavior of partial penetrated weld pool transferring from pulsed peak current to base current in pulsed TIG welding is carried out in this paper. Based on the analysis results, the mathematical models for 3D liquid surface shape of partial penetrated weld pool in pulsed TIG welding are created including surface potential energy model, gravitational energy model and volumetric potential energy. The numerical simulation with these models and the experiments on low carbon steel are carried out using the software Surface Evolver. The simulation results and model are then amended with experimental results. Two important characteristic quantities, the liquid metal coverage ratio and the stripping width of liquid metal, are put forward in this paper, which paves a way for further weld pool fall penetration control.