In this paper, a three-dimensional finite element model has been developed to simulate the laser-TIG hybrid welding (HLAW) of stainless steel 1.4418 with thickness of 4 mm. Transient temperature profile and dimensions of the fusion zone and heat affected zone (HAZ) during welding process are calculated using finite element method (FEM) and were solved in the ABAQUS/ Standard software. The heat source model is a combination of Goldak distribution for the arc heat flux, a body Gaussian distribution for laser heat flux and a surface heat flux model. The DFLUX subroutine was used for implementation of the movable welding heat sources of the models. To validate the model, several HLAW experiments were performed with a pulsed Nd:YAG laser and TIG sources. Good agreement between the simulated and the experimental measurements revealed that the model would be appropriate for HLAW numerical simulation. Among the material properties, the material conductivity is the most important term which influences on the weld bed dimensions.
