METHOD FOR PRODUCTION OF HOT-ROLLED SHEET FROM SPARINGLY ALLOYED COLD-RESISTANT STEEL WITH STRENGTH LEVEL OF NOT LESS THAN 950 MPA Russian patent published in 2025 - IPC C21D8/02 C22C38/42 C22C38/44 C22C38/46 C22C38/48 C22C38/50 C22C38/54 B21B3/00 

FIELD: metallurgy.

SUBSTANCE: invention relates to metallurgy, particularly to production of hot-rolled sheet from sparingly alloyed cold-resistant steel with yield point of not less than 950 MPa, intended for making critical elements of welded structures of heavy-duty equipment, including those operated at low climatic temperatures of Arctic and Far North. Method of production of hot-rolled sheet from sparingly alloyed cold-resistant steel with yield point of not less than 950 MPa involves melting steel containing, wt.%: carbon 0.17-0.23, silicon 0.20-0.40, manganese 0.7-1.20, molybdenum 0.10-0.35, aluminium 0.020-0.060, chromium not more than 0.10, nickel 1.10-1.70, copper not more than 0.30, titanium 0.010-0.030, vanadium not more than 0.015, niobium not more than 0.010, boron 0.002-0.005, nitrogen not more than 0.007, sulphur not more than 0.003, phosphorus not more than 0.013, iron – balance. Continuous casting of steel into slabs, their heating to temperature of 1200 °C, hot rolling of sheets with rolling end temperature in range of 860-940 °C, cooling in air to room temperature and quenching with water at heating temperature 850-930 °C.

EFFECT: obtaining quality rolled sheet from sparingly alloyed steel with high strength properties while maintaining sufficient ductility and impact strength at temperatures of up to minus 70 °C: yield point is not less than 950 MPa; tensile strength is not less than 1200 MPa; relative elongation of not less than 10%; Brinell hardness of not less than 350 HBW; impact strength KCV^-70 not less than 30 J/cm².

1 cl, 4 tbl