METHOD FOR MANUFACTURING STRUCTURAL STEEL SHEETS Russian patent published in 2023 - IPC C21D8/02 C22C38/48 C22C38/46 C22C38/44 C22C38/42 

FIELD: ferrous metallurgy.

SUBSTANCE: production of rolled sheets from structural steels used for the manufacture of vessel bodies operating at high temperatures and under pressure. A continuous cast billet is produced from steel containing components in the following ratio of components, wt.%: C 0.04–0.30, Si 0.10–0.50, Mn 0.20–0.90, Cr 1.50–3.00, Ni no more than 0.40, Cu no more than 0.30, Al no more than 0.05, V no more than 0.06, Nb no more than 0.06, Mo 0.40-1.0, N no more than 0.02, S no more than 0.02, P no more than 0.02 , if necessary, B is not more than 0.005, the rest - iron and inevitable impurities. The continuous cast billet is heated to an austenitization temperature of 1150-1300°C. Hot rolling of this billet is carried out, with rough rolling completed at a temperature of 900-1100°C, finishing rolling begins at a temperature of 800-1050°C and finish at a temperature of 730-990°C. The sheets are cooled in air to a temperature of no more than 50°C, after which they are heat treated. During the heat treatment process, heating is carried out to a temperature of 850-1000°C with holding at the specified temperature for 20-90 minutes, accelerated cooling to a temperature of no more than 350°C, heating to a temperature of 600-800°C and air cooling of sheets.

EFFECT: high mechanical properties.

7 cl, 3 tbl