Efficient Finite Element Modeling of Fiber Laser Welding Process under Conduction Regime on 316 Stainless Steel Plate

Abstract

The research on a number of welding problems, for instance microstructural evolution, weld induced distortion and welding residual stresses, necessitates comprehensive information about the thermal history of the weldment and welded structures. In the present work, an efficient thermal model using finite element method (FEM) is developed for linear fiber laser welding process on 316 stainless steel of 3mm thick plate. In this modeling approach, the thermal conductivity of molten material is increased artificially for several folds to account the enhanced heat transfer due to high convective flow of liquid molten metal within the weld pool. In order to validate the developed FE model, a series of welding experiments are carried out using highly focused fiber laser with 800 W - 1000 W laser power and 13.33 mm/s - 18.33 mm/s laser scanning speed. The computed weld pool shapes and dimensions are compared with the experimental results at similar welding conditions. Relatively fair agreement between the numerical simulation and experimental results designates the robustness of the modeling approach followed here.