METHOD OF PRODUCING COLD-RESISTANT ROLLED SHEET OF INCREASED STRENGTH Russian patent published in 2019 - IPC C21D8/02 C22C38/00 C21D9/46 

FIELD: metallurgy.

SUBSTANCE: invention relates to metallurgy, particularly, to production of structural steels for use in shipbuilding, construction and other industries. Method of producing high-strength hot-rolled stock in thicknesses of 8–50 mm with high level of cold resistance involves steel making, containing, wt. %: carbon - 0.07–0.12, manganese - 0.30–0.80, silicon - 0.10–0.40, chromium - 0.20–0.50, nickel - 1.70–2.50, molybdenum - 0.20–0.50, copper - 0.35–0.60, vanadium - 0.02–0.05, aluminium - 0.01–0.06, nitrogen is not more than 0.008, sulphur is not more than 0.005, phosphorus not more than 0.015, iron - balance, steel pouring on slabs, slab heating to temperature of 1230–1260 °C, deformation to final thickness, wherein deformation is finished at temperature for thicknesses of 8.0–10.0 not more than 920 °C, and for thicknesses of 10.1–50.0 mm not more than 940 °C, further rolling is subjected to two-stage heat treatment.

EFFECT: increase strength, cold resistance and improve weldability of steel.

1 cl, 3 tbl