Abstract: This seamless wire containing welding flux is formed by filling a steel sheath with flux, the amount of Fe in the flux per total mass of the wire being 2-15 mass %, and the flux filling ratio being 10-30 mass %. When the amount (mass %) of Fe in the flux per total mass of the wire is X and the flux filling ratio (mass %) is Y, expression (1) is satisfied. By means of this seamless wire containing welding flux, variation in the flux cross-sectional area relative to the wire cross-sectional area, which is caused by a reverse airflow generated during a diameter reduction step, is reduced, and wire breakage during the diameter reduction step is prevented.

Abstract: Disclosed herein is a flux-cored wire for gas-shielded arc welding containing, based on total mass of the wire: C: from 0.03 to 0.12 mass %; Si in terms of Si in Si alloy and Si compound: from 0.20 to 0.70 mass %; Mn: from 1.0 to 4.0 mass %; Ti in terms of Ti in Ti alloy and Ti compound: from 2.4 to 4.5 mass %; Al: from 0.005 to 0.050 mass %; Ca: from 0.03 to 1.0 mass %; at least one of Ni: from 0.30 to 3.50 mass % and B: from 0.0008 to 0.012 mass %; and Fe: 80 mass % or more, and satisfies: (Ti+Mn+Al+Ca)/Si?12; and Ca/Si: from 0.07 to 0.35.

Abstract: A flux-cored wire for gas-shielded arc welding, contains, based on the total mass of the wire: C: from 0.03 to 0.12 mass %; Si in terms of Si in Si alloy and Si compound: from 0.10 to 0.50 mass %; Mn: from 1.0 to 4.0 mass %; Ti in terms of Ti in Ti alloy and Ti compound: from 2.4 to 4.5 mass %; Al: from 0.005 to 0.050 mass %; at least one of Ni: from 0.30 to 3.50 mass % and B: from 0.0008 to 0.012 mass %; and Fe: 80 mass % or more, and satisfies (Ti+Mn+Al)/Si?15.