WELDING METHOD FOR THE MANUFACTURE OF A PREFABRICATED STRUCTURE OF AT LEAST TWO METAL SUBSTRATES Russian patent published in 2022 - IPC B23K11/11 B23K11/16 

FIELD: welding technology.

SUBSTANCE: invention can be used to manufacture a prefabricated structure of metal sheet parts by contact spot welding, used, in particular, in the manufacture of a mechanical vehicle. The metal sheet part (3) has an aluminum-based alloy coating (4) containing zinc, silicon, optionally magnesium, and on top of it is a natural oxide layer of micrometer thickness containing ZnO and optionally MgO. The contact spot welding cycle (21, 31, 41, 51) includes the first stage, including one pulsation (22, 32, 42, 52) at the Cp current and immediately after that the welding stage (23, 33, 43, 53), characterized by a welding current Cw, which is limited by its minimum and maximum values with a control limit equal to or greater than 1 kA. Welding force is applied in the range between 50 and 350 daN. The value of the pulsation current Cp differs from the welding current Cw, and the duration of the pulsation time is shorter than the duration of the welding time.

EFFECT: welding of sheet parts is provided, which, due to the thickness and hardness of the pure oxide coating layer, are difficult to weld.

21 cl, 5 dwg, 3 tbl, 3 ex