Heat transfer and heat flux to anode affected by current transition time in pulsed arc welding with iron vapor

摘要

Gas tungsten arc welding is a high-quality joining technology. However, the TIG welding cannot melt the welding pool deeply. Therefore, the weld defect sometimes occurs because of this poor heat transfer to the anode and ability of melting deeply. The welding parameter should be controlled in order to improve the welding productivity and prevent the weld defect. The pulsed arc welding has been developed because it can control the heat transfer with the current waveform. The shape of welding pool is decided by the temperature distribution, the current density distribution at the arc and welding pool and driving force in the welding pool. Especially, the Lorentz force is very important factor in order to become deep welding pool. These phenomenons are derived from current waveform, especially the current peak, base, and transition time. Especially, this research focuses on the role of iron vapor and current transition time for heat transfer. The heat transfer and heat flux to anode affected by current transition time in pulsed arc welding with iron vapor is elucidated. As a result, when the current transition time decreases, the heat transfer and heat transfer becomes small under consideration of iron vapor. When the current transition time decreases, the total heat transfer decreases because of decrement of the thermal conduction term at the heat transfer equation. Therefore, the current transition time plays important role for making welding pool.