METHOD FOR OBTAINING HIGH-STRENGTH HOT-ROLLED STEEL Russian patent published in 2021 - IPC C21D8/02 

FIELD: metallurgy.

SUBSTANCE: invention relates to the production of hot-rolled products from low-alloy steel, intended for the manufacture of car parts by stamping. Smelting, casting into slabs, heating of slabs, hot rolling, the first stage of water cooling, a pause in water cooling with air cooling, the second stage of water cooling and coiling are carried out. Heating of slabs is carried out to a temperature of 1150-1250°С, hot rolling is carried out with a rolling end temperature of 800-900°С. In the first and second stages, the water cooling is laminar water cooling. At the first stage, laminar water cooling is carried out to a temperature of 680-750°С, at the second stage - to a temperature of 150-350°С. The duration of the said pause in water cooling, which is 2.5-5s, is determined from the expression t_p=2,48-0,019Т_e.r+0,024Т_p, where t_p is the estimated duration of the pause in water cooling, s, Т_e.r is the end temperature hot rolling, °С, Т_p - temperature at which a pause in water cooling is carried out, °С.

EFFECT: invention provides the required level of mechanical properties and stabilization of their production.

1 cl, 2 ex