Abstract: A flux-cored wire includes by mass %: C in a skin of 0.04 to 0.08% w.r.t. a total mass of the skin, w.r.t. a total mass of the wire by a sum of the skin and flux: C: 0.05 to 0.12%, Si: 0.1 to 0.6%, Mn: 1.5 to 3.5%, B: 0.002 to 0.015%, a sum of Al2O3 conversion value of Al and Al2O3 conversion value of an Al oxide: 0.3 to 1.5%, and w.r.t. the total mass of the wire in the flux: Mg: 0.2 to 0.8%, and sums of TiO2 conversion value of a Ti oxide: 5 to 10%, SiO2 conversion value of a Si oxide: 0.2 to 0.7%, ZrO2 conversion value of a Zr oxide: 0.1 to 0.6%, F conversion value of a fluorine compound: 0.02 to 0.15%, and Na2O conversion value and a K2O conversion value of a Na compound and a K compound: 0.03 to 0.20%.

Abstract: A flux-cored wire for gas-shielded arc welding, including, in terms of mass % relative to a total mass of the wire, in the total of the steel outer sheath and the flux, C: 0.03 to 0.08%, Si: 0.1 to 0.6%, Mn: 1.5 to 2.8%, Cu: 0.01 to 0.5%, Ni: 0.35 to 0.98%, Ti: 0.05 to 0.25%, and B: 0.002 to 0.015%, Al: 0.05% or less, and including, in the flux, TiO2 conversion value: 3 to 8%, Al2O3 conversion value: 0.1 to 0.6%, SiO2 conversion value: 0.2 to 1.0%, ZrO2 conversion value: 0.20 to 0.65%, Mg: 0.2 to 0.8%, F conversion value: 0.05 to 0.25%, Na conversion value: 0.02 to 0.10%, and K conversion value: 0.05 to 0.20%.

Abstract: A flux-cored wire for gas shielded arc welding includes C: 0.03 to 0.09%, Si: 0.1 to 0.6%, Mn: 1.3 to 3.0%, Ti: 0.05 to 0.50%, B: 0.002 to 0.015%, and Al2O3 converted value: 0.4 to 1.0%, as the total content in the steel sheath and the flux in mass % relative to the total mass of the wire; and TiO2 converted value: 5.0 to 9.0%, SiO2 converted value: 0.2 to 0.7%, ZrO2 converted value: 0.1 to 0.6%, Mg: 0.2 to 0.8%, total of F converted value: 0.02 to 0.20%, and total of Na2O converted value and K2O converted value: 0.03 to 0.20%; as a content in the flux; in which a content of C in the steel sheath is 0.03% or less in mass % relative to the total mass of the steel sheath.