METHOD OF PRODUCING HIGH-STRENGTH HOT-ROLLED STOCK Russian patent published in 2025 - IPC C21D8/02 C22C38/40 C22C38/54 B21B1/26 

FIELD: metallurgy.

SUBSTANCE: invention relates to metallurgy and can be used in production of hot-rolled steel for critical purposes in machine building, for example, manufacturing of lifting-and-conveying machines, frames of side members. Method of producing high-strength hot-rolled stock involves steel melting, steel casting to produce a billet, its austenitizing, hot rolling, cooling and coiling the strip. Steel is melted, wt.%: carbon – 0.01-0.10, silicon – 0.02-0.6, manganese – 1.4-2.3, sulphur – more than 0.01, phosphorus – not more than 0.03, chrome – not more than 0.7, nickel – not more than 0.7, copper – not more than 0.7, aluminium – 0.01-0.10, molybdenum – not more than 0.10, vanadium – not more than 0.02, titanium – 0.08-0.30, niobium – 0.01-0.20, boron – not more than 0.001, nitrogen – not more than 0.01, iron and unavoidable impurities – the rest.

EFFECT: obtained rolled stock has a microstructure consisting of ferrite in amount of not less than 90%, and is characterized by yield point of not less than 700 MPa, ultimate strength of 750-930 MPa, relative elongation of not less than 12%, impact strength by KCV at -40 °C not less than 50 J/cm² and impact strength by KCU at -40 °C not less than 44 J/cm².

3 cl, 2 tbl, 1 ex