抄録
Arc discharge phenomena and erosion mechanism of electrode were fundamentally studied to improve automatic Gas Tungsten Arc Welding system. The arc sometimes strike on wrong part of weld metal. This is caused by erosion of the electrode and turbulence of electro-magnetic force during arc welding. Arc phenomena on arc ignition stage were captured by ultra high speed video system to analyze sputtering and erosion mechanism in various combination of electrodes and shielding gas. Plasma and electrode surface temperature distributions were measured simultaneously. Some experiments were carried out in vacuum chamber to discuss anode and cathode behaviors.