METHOD OF RESISTANCE SPOT WELDING FOR CONNECTION OF SHEET STEELS WITH APPLIED ZINC COATING Russian patent published in 2020 - IPC B23K11/11 C22C38/04 C22C38/06 

FIELD: technological processes.

SUBSTANCE: group of inventions relates to point resistance welding of sheet steels. Thickness of sheets (th) to be welded is 0.5 to 3 mm. At least one of sheets is made of sheet steel (A) of specified composition with applied coating from zinc or zinc alloy and is characterized by ultimate tensile strength (TS) of more than 800 MPa, wherein (TS) × (TEL) > 14000 MPa%, where (TEL) is the total elongation. Spot welding is carried out by resistance of sheet steels to obtain welded seam, characterized by depth of imprint at impression (IDepth) on surface of said steel plate (A), wherein 100 mcm ≤ (IDepth) ≤ 18.68 (Zn_sol) - 55.1, where (IDepth) is expressed in micrometres, and Zn_sol is solubility of Zn in sheet steel (A) at 750 °C, expressed in wt. %.

EFFECT: depth of possible cracks due to embrittlement is less than 20 mcm, welded joints have high mechanical operational characteristics.

21 cl, 7 tbl, 6 ex