METHOD FOR FUSION WELDING OF ONE OR MULTIPLE STEEL SHEETS MADE OF PRESS-QUENCHED STEEL Russian patent published in 2023 - IPC B23K26/21 B23K26/322 B23K26/64 B23K26/73 B23K26/26 B23K101/18 B23K101/34 

FIELD: metallurgy.

SUBSTANCE: invention relates to a method for fusion welding of one or multiple steel sheets (1, 2) made of press-quenched steel, preferably boron-containing manganese steel, wherein a particular sheet or at least one of the steel sheets has an aluminium-containing metal coating (4). The fusion welding is performed while feeding the filler material (11) into the welding bath (9) formed using at least one laser beam. In order to improve the quenching capacity of the weld (14), regardless of whether the steel sheets subject to being welded together are steel sheets made of the same-grade or different-grade material and/or steel sheets with different thicknesses, a single laser focal spot (16) with a different energy distribution is generated using one or multiple optical elements over the welding bath so that the laser focal spot (16) has a smaller region (16.1) of the laser focal spot and a larger region (16.2) of the laser focal spot. The larger region of the laser focal spot subjects to the effect of radiation a surface with an area of at least twice that of the surface subjected to the effect of radiation of the smaller region of the laser focal spot. An output laser power emitted per unit surface on the smaller region of the laser focal spot is greater than that on the larger region of the laser focal spot.

EFFECT: creation of a weld with the strength and hardness after hot forming (press-quenching) comparable to those of the base material, wherein the method is characterised by relatively low energy consumption.

32 cl, 4 dwg, 1 ex