HIGH-STRENGTH COLD-ROLLED AND ANNEALED GALVANIZED STEEL SHEET AND METHOD FOR ITS MANUFACTURE Russian patent published in 2023 - IPC C21D8/02 C21D9/46 C22C38/38 

FIELD: metallurgy.

SUBSTANCE: cold-rolled and annealed galvanized steel sheet, comprising, wt.%: C 0.15-0.25, Mn 2.4-3.5, Si 0.30-0.90, Cr 0.30-0.70, Mo 0.05-0.35, Al 0.001-0, 09, Ti 0.01-0.06, B 0.0010-0.0040, Nb 0.01-0.05, P≤0.020 S≤0.010 and N≤0.008, the rest of the composition is made up of iron and inevitable impurities resulting from melting. The sheet has a microstructure consisting of 80-90% martensite in the surface fractions, the rest is ferrite and bainite.

EFFECT: sheet has a tensile strength of 1450 MPa or more.

8 cl, 5 tbl, 5 ex