摘要 |
PURPOSE:To improve a welding operation, and to make a weld metal have a high strength and a high toughness by specifying the content of C, Si, Mn, Cr, and Mo being essential components, in a welding steel wire for using an Ar-CO2 mixed gas. CONSTITUTION:In a welding steel wire for using an Ar-CO2 mixed gas or using this mixed gas as a shield gas, 0.04-0.12wt% C, 0.25-0.60% Si, 0.65-1.20% Mn, 2.70-3.50% Cr, and 0.90-1.20% Mo are contained as essential components. Also, two kinds or more of 0.04-0.75% V, 0.02-0.10% Nb, and 0.006% B are contained. Or, moreover, <=0.40% Cr, and <=0.015% N are contained. By this composition range, a weld metal having simultaneously a high strength and a high toughness is obtained, and an application range in various welding fields for welding a Cr-Mo low alloy heat resisting steel is expanded. |