Flux-cored wire for stainless steel arc welding

Abstract

A flux-cored wire for stainless steel arc welding including an outer sheath made of stainless steel and flux filled up in the outer sheath contains, as percentage to the total mass of the wire, Cr: 22.0-30.0 mass %, Ni: 6.0-12.0 mass %, Mo: 2.0-5.0 mass %, N: 0.20-0.35 mass %, TiO2: 4.0-9.0 mass %, SiO2: 0.1-2.0 mass %, ZrO2: 0.5-4.0 mass %, total of Li2O, Na2O and K2O: 0.50-1.50 mass %, metal fluoride in terms of fluorine amount: 0.10-0.90 mass %, and rare earth element component: 0.10-1.00 mass %, limits C to 0.04 mass % or below, W to 4.0 mass % or below, Cu to 2.0 mass % or below, Bi2O3 to 0.01 mass % or below, and limits oxides other than the above to 3.0 mass % or below. With such a composition, it is possible to obtain a weld bead which is excellent in the weldability in welding in all attitudes and is more excellent in the low temperature toughness while keeping excellent pitting corrosion resistance in arc welding of duplex stainless steel and the like.

Description

Technical field [0001] The present invention relates to a stainless steel arc welding flux-cored wire used in arc welding of austenitic phase and ferrite phase duplex stainless steel, etc., and particularly relates to a stainless steel arc welding flux-cored wire that is excellent in pitting resistance and low temperature toughness, and is welded in all positions Stainless steel arc welding flux-cored wire with good welding operability. Background technique [0002] Historically, structural components such as chemical machinery, oil or natural gas excavation oil well pipes, pipeline steel pipes, chemical tankers and sluices have mainly required stress corrosion cracking (SCC) resistance in environments containing chloride ions such as seawater. Excellent resistance and pitting corrosion resistance, and has high strength. Therefore, as a member that satisfies these requirements, for example, JIS SUS 329J3L, SUS 329J4L, and ASTMS31803 duplex stainless steels are used. [0003] In t...

AI Technical Summary

Problems solved by technology

However, the above existing flux-cored wires cannot meet the recent demands for pitting resistance and low-temperature toughness.

[0007] In addition, the flux-cored welding wire of US Patent Application Publication No. 2008 / 0093352 has a small content of alkali metal components, and the stability of the arc cannot be obtained especially in upward vertical welding, and the welding workability is reduced.

[0008] In addition, Japanese Patent Application No. 2008-221292, flux-cored wire for welding duplex stainless steel, ZrO 2 The content of slag is small, especially in vertical welding and upward welding, good slag coating cannot be obtained, so slag stripping and pitting resistance are deteriorated, and welding workability is reduced

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