Finite element modeling of three-dimensional transient heat transfer in stainless steel (304) pulsed GTA weldments

Pulsed current gas tungsten arc welding involves a large number of process parameters, and hence makes it difficult, if not impractical, to develop the procedure for a given application. A numerical model such as the finite element model will be of great use to study the effect of process parameters on heat transfer and attendant characteristics. A procedure for development of a three-dimensional transient nonlinear finite element model is presented in this article. Sensitivity analysis has been carried out to check the response of the model to constant and temperature-dependent material properties, heat loss due to vaporization of alloying elements, and total number of nodes to model the solution domain. Experimental work on thermal profiles and weld bead dimensions has been carried out to validate the results predicted by the model. Finally, parametric studies have been carried out to study the combined effects of parameters that influence the heat input.