Butt welding process and apparatus for effecting same

Abstract

Disclosure is made of a butt welding process, whereby butt ends of articles to be welded together are placed one opposite the other in a chamber containing a shielding medium. The butt ends are then heated until a layer of molten metal is formed on their surfaces, and upset in order to effect their plastic deformation and produce a weld joint. According to the invention, the heating and flashing-off of the butt ends are effected by a low-pressure arc uniformly distributed over the entire butt end surfaces of the articles being welded. The proposed method is effected through the use of an apparatus which, apart from a welding transformer whose secondary winding terminals are connected to articles being welded, comprises, in accordance with the invention, an auxiliary transformer that serves to initiate a low-pressure arc, or, successively, a glow discharge and a low-pressure arc between the butt ends of the articles being welded, as well as to stabilize said low-pressure arc, the secondary winding terminals of the auxiliary transformer being connected to the articles being welded via a valve-type breaker intended for controlling the low-pressure arc. The proposed process and apparatus for effecting this process make it possible to weld articles with different cross-sectional configurations, while making use of small deformations of articles in order to produce a weld joint. The process and apparatus of the present invention also account for a stable welding process.

Dependencies are inferred from the claim text.