Abstract: In underwater arc welding in a chamber filled with gas a consumable flux cored arc welding wire is fed to a welding torch and an arc is struck between the wire and the work to be welded so as to effect transfer of weld metal from the wire to the work. The arc welding wire contains at least one strong deoxidizer selected from the group consisting of magnesium, aluminium, zirconium, titanium, barium, lithium and calcium. A shielding gas is fed to the torch and emerges therefrom as an annular curtain of gas which shields the arc. The shielding gas also helps stabilize the arc from the effects of underwater pressure. The shielding gas comprises at least one oxygen-containing gas selected from oxygen and carbon dioxide.

Abstract: In a method of arc welding under water or at superatmospheric pressure (or both) the weld is made in a chamber containing a gaseous atmosphere. The weld metal is deposited from flux-cored welding wire whose core contains strong deoxidant(s) such as aluminium, magnesium, titanium, zirconium, lithium and calcium. A shielding gas containing a selected proportion of oxygen or oxygen-containing gas but consisting mainly of an inert gas such as argon or helium is employed to surround the arc. The shielding gas is constituted by the atmosphere in the chamber.