ASSEMBLY UNIT CONTAINING AT LEAST TWO METAL SUBSTRATES Russian patent published in 2021 - IPC B23K11/11 B23K11/16 

FIELD: welding.

SUBSTANCE: invention relates to the production by welding of an assembly unit containing at least two metal sheet parts used for the manufacture of an automobile. One piece is a hardened steel sheet coated with an aluminum-based alloy coating (4) containing zinc, silicon, optionally magnesium, on the surface of which a layer of natural oxide is located. A resistance spot welding cycle is carried out using a spot welding machine containing welding electrodes and an inverter power source. One current ripple in the first stage ensures the rupture and removal of at least part of the oxide layer and/or alloyed coating, and immediately after that welding is carried out. The welding current is limited to the minimum and maximum values ​​with a regulation limit equal to or greater than 1 kA, and the ripple current Cp is greater than the welding current Cw, and the ripple duration is shorter than the welding duration.

EFFECT: method can be easily applied to production lines for the production of hardened parts coated with special coatings based on aluminum or zinc.

22 cl, 5 dwg, 3 tbl, 3 ex