METHOD OF DEFORMATION-THERMAL PROCESSING LOW-ALLOY STEEL Russian patent published in 2017 - IPC C21D8/00 

FIELD: metallurgy.

SUBSTANCE: method includes homogenized annealing of the ingot at a temperature of 1423±50 K for 1 hour, hot forging of the ingot at a temperature of 1423±50 K to a true degree of deformation of, at least, 0.5, followed by cooling in air, after which each billet is heated to forging temperature, hardening is carried out at a temperature of 1373-1423 K for 30 minutes with cooling in oil, tempering for 1 hour at a temperature of 873-923 K is carried out. The billet is then rolled at a tempering temperature to a true degree of deformation of, at least, 1.2. After each pass, the billet is heated to the set temperature, the reduction per pass is, at least, 10%.

EFFECT: increasing strength properties and toughness at negative temperatures.

3 dwg, 2 ex