Resistance spot welding method for joining galvanized steel sheets

摘要

The resistance spot welding method comprises the following successive steps:-providing at least two steel plates having a thickness (th) of 0.5 to 3 mm, wherein at least one of the steel plates has a tensile strength (TS) higher than 800 MPa (TS ) And (TS)x(TEL) 14000 MPa% 14000 MPa%, which is a zinc or zinc alloy plated steel sheet (A), and the composition of the steel substrate of the steel sheet (A) is, by weight As, 0.05% ≤ C ≤ 0.4%, 0.3% ≤ Mn ≤ 8%, 0.010% ≤ Al ≤3%, 0.010% ≤ Si ≤ 2.09%, 0.5% ≤ (Si+Al) ≤ 3.5%, 0.001% ≤ Cr ≤ 1.0%, 0.001% ≤ Mo ≤ 0.5%, and optionally 0.005% ≤ Nb ≤0.1%, 0.005% ≤ V ≤ 0.2%, 0.005% ≤ Ti ≤ 0.1%, 0.0003% ≤ B ≤ 0.005%, 0.001% ≤ Ni Providing said at least two steel sheets containing? 1.0%, the balance being Fe and unavoidable impurities; -On the surface of the steel plate (A) A step of performing resistance spot welding of the at least two steel sheets so as to create a weld having an indentation depth (IDepth) equal to, (IDepth) is a unit of micrometer, and Zn _sol is a weight% of the steel sheet (A ), which is the solubility of Zn in, resistance spot welding of the at least two steel sheets.