抄録
In an oxidizing gas welding atmosphere of Ar-O2, Ar-CO2 or CO2-O2 gas mixture, mechanical properties of steel weld metal such as ultimate tensile strength and Charpy impact property have been investigated, using a popular Fe-Si-Mn electrode wire (YGW 12) and rolled steel for welded structure (SM 400B). As an addition of oxygen to argon-based mixture, both the tensile strength and toughness tend to decrease. As an addition of carbon-dioxide to argon-based mixture, the tensile strength decreases and then improves, and impact property reveals complex behavior. As an addition of oxygen to carbon-dioxide-based mixture, changes in atmospheric gas composition have a minor effect on the mechanical properties of steel weld metal.
