METHOD FOR HEAT TREATMENT OF FORGINGS MADE OF LOW-ALLOY STEEL Russian patent published in 2022 - IPC C21D1/25 C21D6/00 

FIELD: metal processing.

SUBSTANCE: invention relates to a method for heat treatment of forgings made of low-alloy steel. The method includes quenching, exposure and subsequent cooling in water, while the first quenching is carried out at a temperature of 930-950°C with a holding time of 1.8 h for every 100 mm of forging thickness, then cooling is carried out in water for at least 10-15 minutes, then the second quenching is carried out at a temperature of 930-950°C with a holding time of 1.8 h for every 100 mm of the forging thickness, then cooled in water for at least 10-15 minutes, after which they are released at a temperature of 570-650°C for 2.5-3 hours for every 100 mm of the forging thickness, next, the forgings are cooled in a quenching tank in water for at least 10 minutes until the forging surface temperature reaches no higher than 50°C, while the water temperature in the quenching tank is no more than 20°C at the start and no more than 25°C at the finish, after which the forgings are cooled in air.

EFFECT: increase in the strength properties of forgings and increase the level of impact operation at a test temperature below -40°C to obtain a given set of mechanical properties.

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