PROCESS FOR PRODUCING ARC-WELDED STRUCTURAL MEMBER

摘要

[Problem] To provide excellent liquid metal embrittlement cracking resistance to an arc-welded structural member using a Zn-Al-Mg based alloy coated steel plate member without restriction of the species of steel for a base steel for coating and without much increase in cost. [Solution to Problem] In a method for producing an arc-welded structural member containing a step of joining steel members by gas-shielded arc-welding to manufacture a welded structural member, at least one of the members to be joined is a hot dip Zn-Al-Mg based alloy coated steel plate member, and a shielding gas is a gas that is based on an Ar gas, a He gas or an Ar-He mixed gas and has a CO 2 concentration C CO2 (% by volume) satisfying the following expression (2) in relation to a welding heat input Q (J/cm):