COLD-ROLLED STEEL SHEET WITH COATING AND METHOD OF ITS MANUFACTURING Russian patent published in 2024 - IPC C21D8/02 C21D9/46 C22C38/02 C22C38/04 C22C38/06 C22C38/12 C22C38/18 C23C2/02 

FIELD: metallurgy.

SUBSTANCE: invention relates to cold-rolled steel sheet with coating, and can be used for vehicles. Cold-rolled steel sheet with coating, in which steel contains in wt.%: 0.30 ≤ carbon ≤ 0.45, 1 ≤ manganese ≤ 2.5, 0.9 ≤ silicon ≤ 2.2, 0 ≤ aluminum ≤ 0.09, 0.001 ≤ niobium ≤ 0.09, 0 ≤ phosphorus ≤ 0.02, 0 ≤ sulfur ≤ 0.03, 0 ≤ nitrogen ≤ 0.09 and optionally one or more of the following elements: 0 ≤ molybdenum ≤ 0.5, 0 ≤ chromium ≤ 0.6, 0 ≤ titanium ≤ 0.06, 0 ≤ vanadium ≤ 0.1, 0 ≤ calcium ≤ 0.005, 0 ≤ boron ≤ 0.010, 0 ≤ magnesium ≤ 0.05, 0 ≤ zirconium ≤ 0.05, 0 ≤ cerium ≤ 0.1, the rest is iron and unavoidable impurities, wherein the microstructure of said steel sheet contains 35–65% of distributed martensite as the main structural phase, 15–40% of bainite, 14–30% of residual austenite, 4–15% of ferrite and 0–10% of fresh martensite in area fractions.

EFFECT: sheet has tensile strength of 1,170 MPa and more, yield strength of 730 MPa and more, elongation of 18% and more.

16 cl, 4 tbl, 5 ex