METHOD FOR CONTROLLING THE THERMAL CYCLE OF MULTIPLE-PASS LASER WELDING OF NON-ROTARY ANNULAR CONNECTIONS IN A NARROW-GAP PREPARATION WITH FILLER WIRE Russian patent published in 2021 - IPC B23K26/21 B23K33/00 

FIELD: welding.

SUBSTANCE: invention relates to a method for automatic laser welding in the environment of protective gases of non-rotary annular joints of steel pipes. The method includes feeding filler wire and exposing said wire to continuous laser emission into a narrow-gap preparation of welded edges. Preliminary uniform heating of the welded edges to a temperature of 100 to 130°C at a width of no less than 75 mm in each direction from the welded edges is performed. Laser welding is performed with scanning a laser beam with single-roll formation of filling, facing and annealing welds with heat input in each welding pass from 0.45 to 0.84 kJ/mm. Laser welding of each layer of a weld is performed simultaneously with two welding heads, providing an interlayer temperature of 50 to 200°C.

EFFECT: technical result consists in increasing the quality of welded connections of steel pipes by ensuring the distribution of hardness over the cross-section of a weld and the impact strength in accordance with the requirements of regulatory and technical documentation for welding pipe steels of various strength classes.

1 cl, 3 dwg