Finite element modeling of GTA weld surfacing applied to hot-work tooling

A finite element modeling of GTA weld-surfacing process is performed using abaqus computer code. The model is used to optimize welding parameters by analyzing temperature transients during welding, as well as deformation and residual stresses as a result of repair-weld surfacing of complex-geometry H13 tooling. In addition to computational analysis, an extensive experimental study is performed. Both remelting and surfacing are performed by GTA welding. A series of welds are prepared using different welding parameters. The temperature transients are measured at a number of positions in the material and macrosections of the welds are prepared. The data are used to develop a relationship between the welding parameters and characteristic weld dimensions, to select the most appropriate geometry of the heat source, and finally to verify the model. The model developed is applied to predict deformation and residual stresses and detect areas critical to cracking at repair-welding of complex-geometry tooling. Understanding these parameters is significant for quality improvement of weld-surfaced tooling and thus essential for extension of in-service life of refurbished tooling.