Numerical Simulation For Dynamic Behavior Of Molten Pool In Tungsten Inert Gas Welding With Reserved Gap

A 3-dimensional transient numerical analysis model of tungsten inert gas (TIG) welding with a reserved gap was established in this study. The loss of the total heat input and change in arc pressure due to the reserved gap were considered in this model. The dynamic variations of the flow field and deformation in weld pool were analyzed. Simulated results indicate that the maximum sag of weld pool is larger, and the top surface area of weld pool is smaller as the reserved gap increases. The flow tendency of the molten metal is mainly backward, and the top surface of the weld pool is higher in the front part and lower in the rear part. The liquid metal flows from both sides to the middle, bringing heat into the gap. The liquid metal in front of the weld pool flows to the back of weld pool through the gap, which facilitates weld penetration.