HEAT AND METAL TRANSFER IN GAS METAL ARC-WELDING USING ARGON AND HELIUM

This article describes a theoretical investigation on the arc paramete rs and metal transfer in gas metal arc welding (GMAW) of mild steel us ing argon and helium shielding gases. Major differences in the predict ed are parameters were determined to be due to large differences in th ermophysical properties. Various findings from the study include that an arc cannot be struck in a pure helium atmosphere without the assist ance of metal vapor, that a strong electromagnetic cathode force affec ts the fluid flow and heat transfer in the helium arc, providing a pos sible explanation for the experimentally observed globular transfer mo de and that the tapering of the electrode in an argon arc is caused by electron condensation on the side of the electrode.