Gas shielded arc welding wire and gas shielded arc welding method

Abstract

The present invention provides a gas-shielded arc welding wire and a gas-shielded arc welding method, which can suppress welding defects such as lack of fusion and poor bead shape even with high-Cr welding materials, and realize automatic welding (continuous automatic welding). A gas-shielded arc welding wire, characterized in that, in the total mass of the wire, it contains C: 0.01-0.50%, Si: 0.01-1.50%, Mn: 0.10-2.50%, and Cr: 5-15%. , Ni: 0.05~1.50%, Mo: 0.1~2.0%, V: 0.1~1.0%, Nb: 0.01~0.20%, REM: 0.001~0.050%, S: 0.0010~0.0200%, O: 0.025% or less (including 0%), and satisfy the following formula (1). 3.0≤(Nb+10×REM) / (S+O)≤200.0...(1).

Description

technical field [0001] The invention relates to a gas shielded arc welding wire suitable for automatic welding and a gas shielded arc welding method. Background technique [0002] Power generation boilers composed of thermal power generation require materials that can be used stably for a long time in a high-temperature and high-pressure environment. Regarding welding materials, materials that are particularly excellent in high-temperature strength are also required. Conventionally, high-Cr steels have been used as such welding materials, for example, those disclosed in Patent Document 1 and Patent Document 2 can be cited. [0003] Patent Document 1 relates to a welding material for ferritic heat-resistant steel used for welding of thermal power plants and the like operating in a high-temperature and high-pressure environment. According to this document, it is disclosed that by adjusting the chemical composition within a predetermined range, as long as relatively simple and...

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Problems solved by technology

[0010] Patent Document 1 discloses focusing on the mechanical properties of high-Cr steel. As for Cr, it is necessary to make the content 8.0 to 14.0% by mass, but the influence of Cr oxides generated during welding is not particularly considered. Welding defects due to Cr oxides that hinder automation are also not considered

[0011] In addition, Patent Document 2 discloses a GMA welding material with a Cr content of 8 to 13% by weight and a welding method thereof, and discloses that the arc stability is improved by adding REM (rare earth metal elements), but the Cr oxides on the surface of the molten pool are not taken into account, because it causes obstruction of molten metal flow, and welding defects such as unfused and poor bead shape are prone to occur, so this technology is difficult to apply to automation

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