Analysis of Amount of Metal Vapor Affected by Welding Speed in TIG Arc Welding

In TIG welding, the anode is melted by the heat of the arc. Craftsmen change the welding speed according to the condition of anode. This technique is difficult and complex. However, the number of TIG craftsmen in Japan is decreasing. Thus, digital transformation of TIG welding is required. In this research, the amount of metal vapor affected by welding speed was analyzed. Specifically, the arc was analyzed under consideration of the movement of welding torch using three-dimensional electromagnetic thermal fluid simulation. In addition, thermal conductivity and specific heat were considered in the heat transfer between arc and anode. As a result, the amount of metal vapor decreased with increasing welding speed. This is because the heat input to the anode decreases with increasing welding speed. In addition, the arc temperature above the anode surface was maintained when the anode was at melting point. This is because latent heat of fusion was also considered in the heat transfer. Therefore, it is possible to analyze the melting of the metal vapor and the anode when the welding speed changes. In the future, arcs with transient changes in welding speed and applied external magnetic field plays an important role for the digital transformation of TIG welding.