Numerical studies on convection in GTA Weld Pool

Weld pool convection strongly influences the behaviour of molten metal in the melt pool during fusion welding of metals. The temperature and velocity fields in the melt pool are largely affected by different driving forces causing weld pool convection. Variations in the heat input during welding have significant effects on the peak temperature, maximum velocity in the melt pool and weld bead geometry. Buoyancy, electromagnetic and surface tension are the major driving forces. In the present work, the effects of weld pool convection on weld bead geometry of stainless steel during Gas Tungsten Arc (GTA) welding have been studied for individual and combined driving forces. A two dimensional finite volume model has been used to simulate the welding process. The model uses a modified Gaussian heat distribution to provide the three dimensional effect of linear welding.