Abstract
On TIG-MIG hybrid welding process, MIG arc is stable even though pure Ar shielded condition. Therefore, this process has a possibility as new type of welding process with high quality and high efficiency. However, the mechanism of this process is not clear due to complex interaction between TIG arc and MIG arc. In this study, we simulated arc phenomena in TIG-MIG hybrid welding process by using three-dimensional numerical model. Consequently, it was found that the direct path of electrical current into TIG electrode from MIG electrode is provided by the arc plasma distributed between TIG and MIG electrodes. Furthermore, the predicted penetration depth by simulation result which includes the influence of convective flow in the weld-pool is about in agreement with the experimental result, and there is remarkable difference in thermal efficiency and the detail of MIG arc current on base metal surface by whether the model includes the convictive flow in weld pool.
