Numerical Simulation Of AZ31B Magnesium Alloy In DE-GMAW Based On ANSYS

As a reliable material processing technology, welding is widely used in many industrial areas, plays a significant role in sustainable development of social economy. In recent years, the traditional welding methods are increasingly difficult to meet the producing requirements of high-quality and high-efficiency with the continuous growing of manufacturing industry, many high-efficiency welding methods have been proposed, and the DE-GMAW(Double-electrode gas metal arc welding) is one of them. According to the finite element analysis theory of welding temperature field and stress field, the AZ31 B magnesium alloy is used as the experiment material, the numerical simulation of this novel welding technology is studied to obtain the bypass arc thermal efficiency and the distribution rule of welding temperature field and stress field in this paper. The research is beneficial to optimize the DE-GMAW welding process parameters.Firstly, the experimental molten pool images of AZ31 B magnesium alloy in DE-GMAW welding process were captured by a molten pool image collection system in this paper. Then, the molten pool size is extracted by using VC++ software.Secondly, a finite element model and a heat source model which are suitable for the features of AZ31 B magnesium alloy in DE-GMAW welding process are established by using ANSYS software, the temperature field in DE-GMAW welding is simulated. On the basis of the simulated molten pool sizes and the experimental measured values, the range of the bypass arc thermal efficiency is confirmed. The effect of bypass current in DE-GMAW welding on the molten pool size and the workpiece heat input is discussed; the simulated results are in good accordance with the experimental observations, it also proves the validity of the finite element model and the heat source model.Finally, after the temperature field distribution of the workpiece is obtained, the stress field distribution of the workpiece is coupling calculated indirectly by ANSYS software. The dynamic stress and residual stress distribution rule of AZ31 B magnesium alloy in DE-GMAW welding is obtained by the analysis of simulation results, the simulation results match with the welding theory. The effect of DE-GMAW welding speed and welding current on the distribution rule of workpiece residual stress is explored; the effect of different initial temperature of workpiece on the distribution rule of workpiece residual stress is also studied, the results showed that the residual stress of workpiece can reduces effectively when the initial temperature is 50-100℃.