Numerical simulation of alloy composition in dissimilar laser welding

A three-dimensional multiphase computational fluid dynamic model was developed to investigate the meltpool fluid dynamics, dilution and alloy composition in laser welding of low carbon steel and stainless steel. Using the developed model, independent predictions on weld properties are made for a range of laser parameters, and in all cases the results of the numerical model were found to be in close agreement with experimental observations. The investigation revealed that above certain specific point energy the materials within the melt pool are predominantly homogenous. A minimum meltpool convention is required in dissimilar laser welding to obtain weld bead properties suitable for industrial applications. The present model provides a simple yet effective method to predicting the weld bead alloying concentration and homogeneity encompassing wide range of materials.