Steel wire for carbon dioxide shielded arc welding and welding process asing the same

Abstract

In carbon dioxide arc welding by use of shielding gas comprised of carbon dioxide as main component, a welding wire that enables spray transfer of globules, and provides an excellent bead shape in addition to reduction of amount of spatters even in a high-speed welding, and a welding method using the welding wire are proposed. As the specific means, a welding steel wire for use in carbon dioxide arc welding in DC-electrode negative, comprising a bar steel having a composition that contains 0.003 to 0.20% by mass of C, 0.05 to 2.5% by mass of Si, 0.25 to 3.5% by mass of Mn, 0.015 to 0.100% by mass of REM (rare-earth elements), 0.001 to 0.05% by mass of P, and 0.001 to 0.05% by mass of S, or further contains 0.0100% by mass or less of O, or further contains one or two or more of 0.02 to 0.50% by mass of Ti, 0.02 to 0.50% by mass of Zr, and 0.02 to 3.00% by mass of Al, or further contains 0.0001 to 0.0150% by mass of K, or further contains 3.0% by mass or less of Cr, 3.0% by mass or less of Ni, 1.5% by mass or less of Mo, 3.0% by mass or less of Cu, 0.015% by mass or less of B, 0.20% by mass or less of Mg, 0.5% by mass or less of Nb, 0.5% by mass or less of V, and 0.020% by mass or less of N, and contains Fe and unavoidable impurities as residue is used.

Description

technical field [0001] The present invention relates to a welding wire for positive polarity carbon dioxide gas shielded arc welding, and more particularly to such a wire for carbon dioxide gas shielded arc welding (hereinafter referred to as welding wire) that can use the welding wire on the positive side (i.e., the positive pole) and realize the optimum Stable droplet transfer morphology, resulting in excellent weld bead shape due to low spatter. Background technique [0002] with CO 2 Gas shielded arc welding due to CO 2 Gases are cheap and efficient and are widely used for welding steel materials. In particular, with the rapid spread of automatic welding, the welding method has been used in various fields such as shipbuilding, construction, bridges, automobiles and civil engineering machinery. In the fields of shipbuilding, construction and bridges, this welding method is mostly used for high-intensity current multi-layer welding of thick plates, while in the fields o...

AI Technical Summary

Problems solved by technology

[0011] However, when the spray transfer of droplets can be used in typical mixed gas shielded arc welding (CO 2 The mixing ratio of gas and Ar gas is 2-40% by volume), when using CO 2 In the welding of shielding gas whose gas mixing ratio exceeds 40% by volume, it is difficult to achieve spray transfer