Flux-cored wire, manufacturing method of welded joint, and welded joint

Abstract

A flux-cored wire according to an aspect of the present invention includes: a steel sheath; and a flux filling the inside of the steel sheath, in which the flux contains 0.11% or more in total of a fluoride in terms of F-equivalent value, 4.30% to 7.50% of a Ti oxide in terms of TiO2 equivalent, 0.30% to 2.40% in total of an oxide in terms of mass %, and 0% to 0.60% in total of a carbonate in terms of mass %, the amount of a Ca oxide in terms of CaO is less than 0.20% in terms of mass %, the amount of CaF2 is less than 0.50%, a chemical composition of the flux-cored wire is within a predetermined range, a Z value is 2.00% or less, a V value is 5.0 to 27.0, and Ceq is 0.30% to 1.00% or less.

1 . A flux-cored wire comprising:
 a steel sheath; and   a flux filling the inside of the steel sheath,   wherein an amount of diffusible hydrogen in a weld metal obtained by performing DC gas shielded arc welding using the flux-cored wire under a condition specified in JIS Z 3118 is 1.0 ml/100 g or less, and   a weight of spatter generated per welding time when DC gas shielded arc welding is performed using the flux-cored wire under a condition that a wire side is positive, a welding position is downhand, a current value is 270 A, a voltage value is 30 V, a welding rate is 30 cm/min, a kind of a shielding gas is 100% CO 2  gas, and a flow rate of the shielding gas is 25 L/min is 3.5 g/min or less.   
     
     
         2 . A flux-cored wire comprising:
 a steel sheath; and   a flux filling the inside of the steel sheath,   wherein the flux-cored wire contains, in terms of mass % with respect to a total mass of the flux-cored wire, Al: 0.08% to 0.70%, Ni: 0% to 0.60%, a Ti oxide in terms of TiO 2  equivalent: 4.30% to 7.50%,   an amount of diffusible hydrogen in a weld metal obtained by performing DC gas shielded arc welding using the flux-cored wire under a condition specified in JIS Z 3118 is 1.0 ml/100 g or less, and   a weight of spatter generated per welding time when DC gas shielded arc welding is performed using the flux-cored wire under a condition that a wire side is positive, a welding position is downhand, a current value is 270 A, a voltage value is 30 V, a welding rate is 30 cm/min, a kind of a shielding gas is 100% CO 2  gas, and a flow rate of the shielding gas is 25 L/min is 3.5 g/min or less.