DISPERSION-SOLID STEEL THICK SHEET FOR HOT STAMPING AND METHOD OF ITS PRODUCTION Russian patent published in 2018 - IPC C21D8/02 C21D9/46 C22C38/00 

FIELD: metallurgy.

SUBSTANCE: invention relates to the field of metallurgy, in particular to the production of a thick sheet of low alloyed dispersion hardening steel. To provide a complex of properties corresponding to the strength classes of K60-K65, a sheet with a thickness of up to 52 mm is obtained with a strength level of at least 590 MPa, made of steel containing, mass %: carbon 0.04–0.07, silicon 0.20–0.35, manganese 0.70–1.30, aluminum 0.02–0.05, sulfur is not more than 0.005, phosphorus is not more than 0.012, chromium 0.20–0.45, nickel 0.40–0.65, copper 0.90–1.35, titanium 0.015–0.030, niobium 0.02–0.05, vanadium 0.02–0.06, the total content of elements of vanadium, niobium, titanium is not more than 0.16; nitrogen is not more than 0.01, iron and impurities the rest with a carbon equivalent (CE_IIW) not more than 0.45 %. Method for producing the sheet includes austenization of a continuous casting preform to a temperature of 1,190–1,230 °C, rough rolling with a regulated compression per pass at a starting temperature of at least 950 °C and before the intermediate thickness is reached, providing a total reduction at the stage of final rolling at least 50 %, caving of the rolling, finishing rolling at the onset temperature, determined by the ratio Tofr = (-2.5×h + 870)±15 °C, where Tofr – onset finishing rolling temperature, [°C], h is the thickness of the sheet, [mm], 2.5 is the empirical coefficient, [°C/mm] and complete at a temperature of 770–820 °C, after which the sheet is accelerated to a temperature below 550 °C.

EFFECT: providing a set of properties corresponding to the strength classes of K60-K65.

2 cl, 3 tbl