METHOD FOR PRODUCING COLD-RESISTANT SHEET METAL WITH HARDNESS OF 450-570 HBW Russian patent published in 2023 - IPC C21D8/02 C21D9/46 C22C38/54 C22C38/50 C22C38/48 C22C38/46 C22C38/44 C22C38/42 

FIELD: metallurgy.

SUBSTANCE: production of rolled sheets from cold-resistant steel with a strength class of 450-570 MPa, used for the metallurgical industry, transport and heavy engineering, production of lifting mechanisms and means of transporting goods operating in extreme conditions of the Far North. The method involves continuous casting of steel into slabs, with the steel containing in wt.%: carbon 0.22-0.26, silicon 0.20-0.40, manganese 0.7-1.10, molybdenum 0.10-0 .35, aluminum 0.030-0.050, chromium no more than 0.10, nickel 1.5-2.2, copper no more than 0.30, titanium 0.010-0.030, vanadium no more than 0.010, niobium no more than 0.008, boron 0.002-0.005, nitrogen no more than 0.007, sulfur no more than 0.003, phosphorus no more than 0.013, iron - the rest. The slabs are heated to a temperature of 1180-1220°C and hot rolling is carried out to produce sheets, while the temperature of the end of finishing rolling is chosen in the range of 860-940°C. Quenching is carried out in water at a heating temperature of 850-930°C.

EFFECT: obtaining the required set of mechanical properties at temperatures down to -70°C, namely: temporary tensile strength of at least 1500 N/mm², relative elongation of at least 10%, impact work KV^-70 of at least 20 J.

1 cl, 4 tbl