Laser-Enhanced Ar-GMA Welding* by Terumi Nakamura ** A fiber laser was used to achieve stable consumable-electrode welding with pure Ar shielding gas (Ar-GMA). Ar-GMA welding produces a long column of liquid molten metal (CLM) at the wire tip, which causes irregular short-circuit and an unstable arc. The length of the CLM must be kept short to ensure stable welds. We have developed a method for cutting the CLM by means of a fiber laser. We investigated the cutting conditions for cold wire without an arc and the cutting conditions using a fiber laser with a pulse peak power of 6.0 kW and peak pulse time of 10 ms. Our experiments revealed that the laser irradiation position at the wire was crucial for achieving stable cutting, mainly because the recoil pressure force bends the CLM. After determining the optimum irradiation positions for cutting the CLM, laser-enhanced Ar-GMA welding was carried out. Stable welding was possible and excellent joints were obtained.