METHOD OF LASER-ARC WELDING OF THE FORMULATED PIPE STOCK JOINT Russian patent published in 2018 - IPC B23K26/348 B23K26/282 B23K101/06 

FIELD: technological processes.

SUBSTANCE: invention relates to a method of laser-arc welding of the formulated pipe stock joint of a large diameter carbon steel from 530 to 1,420 mm with a wall thickness from 8 to 45 mm and a gap of up to 1 mm. Welding surface is affected by hybrid laser-arc welding with a consumable electrode to form a single weld pool. Then the formed first welded joint, which has not cooled to the state at which the crystallization of the root metal occurs, is influenced by submerged welding. Method provides a fixed width and height of flux, depending on the width of a welded joint. Favourable conditions for the crystallization of the weld pool after laser-arc welding are provided. Favourable conditions are created for submerged welding with a guaranteed penetration with filling of the gap between the edges of up to 1 mm.

EFFECT: optimization of the microstructure of welded joints, reduction of welding defects such as through holes, crater pipes, blind pips and slag inclusions; improvement of the weld pool degassing both at the stage of laser-arc welding and at the stage of submerged welding, which minimizes or eliminates the risk of formation of defects such as crystallization cracks and blind pips.

1 cl, 2 dwg