Through analyze the MIG groove welding process and the welding experimental result

the physical process of 3D welding was simplified as a two dimensional mathematical model. For mathematical model establishment

based on the analysis of experimental results

established a two-dimensional mathematical model of welding seam section welding physical process. This model included the welding heat source model and molten pool phase change flow CFD model. The moving Gauss heat source model was used to describe the heat effect of arc and workpiece. By introducing scalar of liquid fraction

mushy region dynamic character which was described using "Darcy" model proposed for porous media

and phase change which was taken into account using source-based method

new CFD model was established to simulate transient heat and mass transfer phenomena in welding process. Comparative analysis the numerical simulation result and the metallographic figure

corrected the moving gauss heat source model parameters. Analyze the molten pool shape influenced by thermal buoyancy and Marangoni force in CFD model. Through comparative analysis the results of numerical simulation and experimental

verified the accuracy of the mathematical model. A further discussion on Gauss heat source parameters and the driving force mechanism model of molten pool flow was made. Results showed that through the reasonable model parameters selection

two-dimensional mathematical model can accurate analysis the evolution of V groove molten pool during MIG welding.