HOT-ROLLED STEEL SHEET AND METHOD OF ITS MANUFACTURING Russian patent published in 2024 - IPC C21D8/02 C22C38/12 C22C38/14 C22C38/22 C22C38/24 C22C38/26 C22C38/28 C22C38/32 C22C38/34 C22C38/38 C22C38/44 C22C38/46 C22C38/48 C22C38/50 C22C38/54 C22C38/58 C22C38/60 

FIELD: metallurgy.

SUBSTANCE: invention relates to production of hot-rolled steel sheet used as structural material or for production of industrial equipment. Hot-rolled steel sheet has a composition which includes the following elements, wt.%: 0.18 ≤ carbon ≤ 0.3, 1.8 ≤ manganese ≤ 4.5, 0.8 ≤ silicon ≤ 2, 0.001 ≤ aluminum ≤ 0.2, 0.1 ≤ molybdenum ≤ 1, 0.001 ≤ titanium ≤ 0.2, 0 ≤ phosphorus ≤ 0.09, 0 ≤ sulfur ≤ 0.09, 0 ≤ nitrogen ≤ 0.09, optionally, at least one of the following elements: 0.0001 ≤ boron ≤ 0.01, 0 ≤ chromium ≤ 0.5, 0 ≤ niobium ≤ 0.1, 0 ≤ vanadium ≤ 0.5, 0 ≤ nickel ≤ 1, 0 ≤ copper ≤ 1, 0 ≤ calcium ≤ 0.005 and 0 ≤ magnesium ≤ 0.0010, rest is iron and unavoidable impurities. Microstructure of the steel sheet contains, in area fractions of at least 75% of martensite, consisting of tempered martensite and fresh martensite, and from 8 to 25% of residual austenite, note here that aspect ratio of residual austenite ranges from 4 to 12.

EFFECT: sheet has the required set of mechanical properties.

16 cl, 4 tbl