Flux-cored wire

Abstract

The invention provides a flux-cored wire with excellent high-temperature crackle forming property. Rosin flux filling rate in mass percentages of the flux-cored wire relative to total mass of welding wire is 10-20%, relative to the total mass of the welding wire, the flux-cored wire contains: in weight percentages, C 0.03-0.08%, Si (sum of Si amount calculated from total Si source contained in the welding wire): 0.10-1.00%, Mn (sum of Mn amount calculated from total Mn source contained in the welding wire): 2.30-3.75%, Ti 0.15-1.00%, TiO2: 5.0-8.0%, Al: 0.05-0.50%, Al2O3: 0.05-0.50%, and the rest amount is composed of Fe and unavoidable impurity, and, the Ti amount calculated from the Ti is used as a calculation amount, and the sum of the Si amount calculated from total Si source contained in the welding wire is used as a Si calculation amount, which satisfies the relationship (Ti calculation amount / Si calculation amount)>0.20.

Description

technical field [0001] The invention relates to a flux-cored welding wire used in gas-shielded arc welding. Background technique [0002] Conventionally, as a flux-cored wire used in gas-shielded arc welding, the following structures have been proposed. For example, Patent Document 1 describes a welding flux-cored wire that contains a predetermined amount of C, Si, Mn, and TiO with respect to the total mass of the wire. 2 and N, and describe that the flux-cored wire may contain one or more of Ti, B, Ni, Cr, Mo, Al, Mg, Nb and Ta in a predetermined amount in addition to the above-mentioned components. In addition, Patent Document 2 discloses a welding wire for gas shielded arc welding in which the flux contains a predetermined amount of TiO with respect to the total mass of the welding wire. 2 , rare earth fluorides, Mg, Al, Si, Mn, B and Ni, and does not substantially contain metallic Ti. [0003] [Patent Document 1] JP-A-62-33094 [0004] [Patent Document 2] JP-A-63-273...

AI Technical Summary

Problems solved by technology

[0005] However, the flux-cored wire of Patent Document 1 improves the impact characteristics by improving the toughness of the welded part, and can also improve the welding workability, but it has a problem that it cannot satisfy high temperature cracking resistance.

In addition, although the flux-cored wire of Patent Document 2 has a low amount of diffusible hydrogen and has excellent low-temperature toughness, it also has a problem that it cannot satisfy high-temperature cracking resistance.

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