Metal-base flux-cored wire for gas-shielded arc welding and gas-shielded arc welding method

摘要

Ametal-base flux-cored wire for gas-shielded arc welding includes a steel hoop having a C content of 0.02% by mass or below, and a flux filled in the steel hoop and containing C in a C content between 0.07 and 0.22% by mass, Mn in a Mn content between 1.10 and 2.50% by mass, Si in a Si content between 0.40 and 1.50% by mass, F in a F content between 0.005 and 0.05% by mass, Fe in a Fe content between 11 and 23% by mass and alkali metals in an alkali metal content between 0.020 and 0.090% by mass on the basis of the total mass of the metal-base flux-cored wire. The alkali metals include Li, Na and K, and alkali metal content ratio expressed by (Li content) / (Na content + K content) is between 1.0 and 12.0. The metal-base flux-cored wire is capable of suppressing spatter generating rate and of forming beads having a sufficient throat thickness even in straight-polarity vertical down welding, and facilitating welding work for welding in welding positions other than those for straight-polarity vertical down welding.