PRODUCTION METHOD OF HOT-ROLLED ROLLED STOCK FROM LOW-ALLOY STEEL Russian patent published in 2017 - IPC C21D8/02 C22C38/58 B21B1/26 

FIELD: metallurgy.

SUBSTANCE: method includes slabs heating in the temperature range of 1,230-1,250°C, subsequent multipass reversible rough and final rolling with regulated temperatures of the rolling beginning and end, and the rough rolling is completed at the temperature of not more than 1,000°C, the final rolling is started at the temperature in the range of 960-1,000°C and completed in the temperature range of 820-880°C. Final rolling includes 7-9 runs. Slab is made of steel containing in wt %: C=0.22-0.26, Si=0.30-0.40; Mn=0.75-1.10, Al=0.01-0.035, Nb=0.03-0.05, Cr not more than 0.3, Ni not more than 0.3, Cu not more than 0.3, S not more than 0.010, P not more than 0.015, N not more than 0.008, V not more than 0.05, Ti not more than 0.05, Fe - the rest. The end temperature of the final rolling is 820-850°C for sheets with thickness of 8-20 mm and 850-880°C for sheets with thickness 20.1-50.0 mm. In the hot-rolled sheet, a ferrite-pearlite structure is provided for with a grain size not larger than 9 points.

EFFECT: ensuring a high level of heat stability and impact toughness.

3 cl, 3 tbl, 1 ex