METHOD FOR HYBRID LASER-ARC WELDING OF THICK-WALL PIPES Russian patent published in 2022 - IPC B23K26/26 B23K26/348 B23K33/00 B23K37/08 B23K101/06 

FIELD: welding.

SUBSTANCE: invention relates to a method for hybrid laser-arc welding of thick-wall pipes, in particular to welding of longitudinal rectilinear joints of a tubular billet with a wall thickness from 15.0 mm, made of doped steels. The tubular billet is molded, edges are converged without preliminary cutting, and a billet of a root welded joint is made from an outer side. The root joint is made by combined impact on a surface of edges with a laser beam and an electric arc, which is located in front of the laser beam and is directed with inclination to the surface of edges. When making the root joint from the outer side of the billet, a defocused laser beam with a diameter of 1-1.5 mm is directed at an angle to welded surfaces from a side opposite to the electric arc, leaving, from an inner side, a non-melted part of edges with a thickness of no more than 3 mm. Then, a facing joint is made from the inner side with electric-arc welding to a depth of no more than 5-7 mm.

EFFECT: increase in the quality of welded straight-joint pipes due to a decrease in a width of a thermal impact zone and obtainment of an equal-strength welded pipe, while saving mechanical properties.

2 cl, 1 tbl, 3 dwg