HOT-ROLLED SHEET PRODUCTION METHOD Russian patent published in 2025 - IPC C21D8/02 C22C38/54 C22C38/50 C22C38/44 C22C38/42 

FIELD: metallurgy.

SUBSTANCE: invention relates to metallurgy, particularly, to production of hot-rolled plates used for fabrication of bridges and other building structures. Steel is melted with the following ratio of elements, wt.%: carbon is not more than 0.12, silicon 0.8-1.1, manganese 0.5-0.8, sulphur is not more than 0.010, phosphorus not more than 0.015, chrome 0.4-1.0, nickel 0.4-1.0, copper 0.4-0.7, nitrogen not more than 0.012, aluminium 0.01-0.08, arsenic is not more than 0.08, molybdenum not more than 0.080, titanium not more than 0.04, calcium not more than 0.005, boron not more than 0.005, iron and unavoidable impurities – balance, and its casting into continuously cast billets is performed. Continuously cast billets are austenised at temperature of 1,170-1,350 °C for at least 150 minutes. Said billets are deformed by roughing and finishing rolling, wherein the finishing rolling is started at temperature 910-1,050 °C and finished at temperature of 830-930 °C, wherein billets are rolled with total reduction of not less than 85%. Performing subsequent accelerated cooling of the obtained rolled product in the mill flow at a rate of not less than 10 °C/s to temperature 560-700 °C and its further cooling in air with subsequent straightening of sheets at their temperature of not more than 300 °C.

EFFECT: obtaining rolled stock with increased strength and cold resistance.

3 cl, 3 tbl, 1 ex