Hardfacing MIG-arc welding wire and hardfacing MIG-arc welding process

Abstract

A wire is adopted to hardfacing MIG-arc welding using a pure argon gas as a shielding gas. The wire is a flux-cored wire prepared through drawing a steel hoop or steel pipe as a sheath in which a flux is filled. The flux contains, based on the total mass of the wire, C: 0.12 to 5.00 percent by mass, Si: 0.50 to 3.00 percent by mass, Mn: 0.30 to 20.00 percent by mass, P: 0.050 percent by mass or less, S: 0.050 percent by mass or less, and at least one of TiO2, ZrO2, and Al2O3 (TiO2+ZrO2+Al2O3) in a total content of 0.10 to 1.20 percent by mass and has a total content of silicon and manganese (Si+Mn) of 1.20 percent by mass or more. The wire has a ratio of the total mass of the flux to the mass of the wire of 5 to 30 percent by mass.

Description

technical field [0001] The present invention relates to a MIG arc welding wire for hard facing (also referred to as hard facing) which requires excellent wear resistance, and a MIG arc welding method for hard facing. Background technique [0002] In general, in the base metal, where there is a possibility of wear due to contact with sand or metal, the surface of the base metal is hard-surfacing to reduce the wear. image 3 It is a schematic diagram showing the state where hardfacing is performed. like image 3 As shown, hardfacing metal 101 is formed on the surface of base material 50 by hardfacing. Although the hardfacing metal 101 has martensite or austenite containing a large amount of Cr as the metal structure, it often contains a large amount of carbon with a high effect of increasing hardness compared with generally used carbon steel. For example, Japanese Patent No. 3548414 discloses a hardfacing flux-cored wire containing a predetermined amount of carbon. [0003] ...

AI Technical Summary

Problems solved by technology

However, if a flux-cored wire is used, a large amount of slag is generated, and there are problems such as occurrence of slag inclusions and the need for slag removal work.

[0006] In addition, there is another problem that, as the shape of the weld bead, if the penetration of the weld bead is deep, the hardened surfacing metal will be affected by the composition of the base metal, and the quality of the hardened surfacing metal will be unstable.

However, such a solid wire has a lower degree of freedom in composition design than a flux-cored wire, and the problems of smoke, spatter, penetration depth, and weld bead shape exist as with the flux-cored wire, and the composition of the combined shielding gas is also different from that of the flux-cored wire. Cored wire is the same, so less commonly used than flux cored wire

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