Abstract: The object of this invention is to prevent the occurrence of welding defects such as undercuts, overlaps and faulty angles of fusion, and to increase the efficiency of welding in the horizontal position. Auxiliary wires 5a and 5b are inserted into molten pool 12, and a unidirectional current is made to flow between them. A magnetic field 9 is induced which is approximately orthogonal to the surface of the parent material so as to generate an upward Lorentz force (opposite the pull of gravity) in molten pool 12. This force supports the molten metal and prevents it from dripping, resulting in a better-shaped bead.

Abstract: The object of this invention is to prevent a defect which occurs in overhead or vertical welding when gravity causes molten metal to drip downward so that the top of the gap has an undercut and the bead has a bulge along the weld line (i.e., a convex bead is created). During overhead or vertical welding, a unidirectional current is made to flow in the molten pool in the direction of the weld line. When the aforesaid current flows in conjunction with a magnetic field, a Lorentz force is exerted in the molten pool in an upward direction towards the upper top side of the groove. This prevents the molten metal from dripping downward and improves the shape of the bead.

Abstract: The invention relates to a welding torch for welding underwater and to a method of underwater welding using the welding torch. A high speed stream of water is directed from a nozzle on the welding torch obliquely onto a member or members to be welded to form a flared-out curtain of water. Gas is injected into the volume enclosed by the curtain of water to create a gaseous atmosphere and welding is carried out in the gaseous atmosphere.

Abstract: The invention relates to a welding torch for welding underwater and to a method of underwater welding using the welding torch. A high speed stream of water is directed from a nozzle on the welding torch obliquely onto a member or members to be welded to form a flared-out curtain of water. Gas is injected into the volume enclosed by the curtain of water to create a gaseous atmosphere and welding is carried out in the gaseous atmosphere.