METHOD OF PRODUCING HOT-ROLLED SHEETS FROM LOW-ALLOY STEEL Russian patent published in 2024 - IPC C21D8/02 C21D9/46 B21B1/38 C22C38/42 C22C38/44 C22C38/48 C22C38/50 C22C38/54 

FIELD: metallurgy.

SUBSTANCE: invention refers to metallurgy, namely to rolling production, and can be used in production of sheets at reversing mills with application of controlled rolling. Method of producing hot-rolled sheets from low-alloy steel includes austenisation of continuously cast billets, rough and finish hot rollings. Continuously cast billets are austenised from low-alloy steel containing components at the following ratio, wt.%: carbon 0.07–0.14, silicon 0.5–0.9, manganese 1.2–1.8, sulphur not more than 0.010, phosphorus not more than 0.020, chromium not more than 0.20, nickel not more than 0.20, copper not more than 0.20, aluminium 0.01–0.08, niobium 0.005–0.08, vanadium not more than 0.05, titanium 0.005–0.08, molybdenum not more than 0.05, calcium not more than 0.010, arsenic not more than 0.10, nitrogen not more than 0.010, tin not more than 0.10, boron not more than 0.005, iron – the rest, while the carbon equivalent of steel C_e≤0.43, finishing hot rolling of the rolled stock obtained after rough rolling is started at temperature of 890–1,020 °C and terminated at temperature of 840–890 °C, and then the sheets are cooled in air. Carbon equivalent C_e is calculated by formula: C_e = C + Mn/6 + Si/24 + Cr/5 + Ni/40 + Cu/13 + V/14 + P/2, where C, Mn, Si, Cr, Ni, Cu, V, P – content of corresponding components, wt.%.

EFFECT: sheets have high mechanical properties and are characterized by flatness after separate heating (up to Ac3 temperature) during processing.

7 cl, 3 tbl, 1 ex