THERMAL MODELING OF GAS TUNGSTEN ARC-WELDING PROCESS WITH NONAXISYMMETRIC BOUNDARY-CONDITIONS

A numerical study of three-dimensional heat transfer and fluid flow in a moving gas tungsten are welding (GTAW) process is performed by cons idering nonaxisymmetric boundary conditions. The current density distr ibution and the resulting Lorentz force field are evaluated by numeric ally solving Maxwell's equations in the domain of the workpiece. The n umerical modeling of the melting/solidification process is done by app ropriately applying the enthalpy-porosity approach to the GTAW process . Numerical computations of the heat transfer and flow characteristics are carried out by including the effects of buoyancy, surface tension , and electromagnetic forces. The weld-pool dynamics is found to be st rongly dependent on the relative locations of the clamp and electrode.