METHOD OF MAKING BUTT WELDS ON PIPES Russian patent published in 2007 - IPC B23K28/02 B23K31/02 B23K37/08 

FIELD: mechanical engineering; welding.

SUBSTANCE: invention relates to plastic metal working, particularly, to process of forming butt welds in making of pipe studs. According to proposed method, preparatory operations are carried out and pipes are assembled with subsequent argon-arc welding of pipe ends by non-consumable electrode with use of filler material. Two butt welds are made with subsequent hot deformation. Ends of pipes to be connected are expanded from cylinder to cylinder and, during assembling, by means of mandrel, filling material in form of bushing with ring groove on inner surface is installed between ends pipes to provide contact between mated end face surfaces of ends of pipes calibrated by expansion with end face surfaces of bushing. Welds are formed by welding of pipe material with material of intermediate member. Intermediate member is heated and then hot radial upsetting of intermediate member is carried out by concentrating initially its deformation in inner layers according to location of ring groove, welds and near-weld zones on mandrel, and outer diameter is formed of size equal to initial outer diameter of pipes.

EFFECT: improved quality of weld owing to cladding of pipe butt joint, reduced input of hand labor.

7 dwg