Pure ar gas shielded welding MIG flux-cored wire and MIG arc welding method

摘要

A pure Ar-MIG welding wire for welding steel according to the present invention is formed of a flux-cored wire. The flux-cored wire is formed in the manner that a formation formed by welding a carbon steel hoop into a pipe shape or a seamless pipe is used as an outer sheath, the outer sheath is filled with a flux, and a wire drawing process is performed. The flux accounts for 7 to 27 mass% of the total wire mass. The wire contains graphite in the amount of 0.16 to 2.00 mass% on the basis of the total wire mass and iron powder in the amount of 20 mass% on the basis of the total flux mass. According to the construction, neither expensive metal resource nor a greenhouse effect gas is used, slag and fume generation is inhibited, and a weld joint having a high static tensile strength and fatigue strength can be obtained.