METHOD FOR THERMAL TREATMENT OF CAST DETAILS FROM LOW-ALLOYED AND CARBON STEELS

摘要

1. A method for thermocyclic treatment of cast parts from low alloy and carbon steels, including high-temperature austenitization, multiple heating and cooling at a rate that ensures pearlite, or sorbitol, or bainitic, or martensitic transformation to a temperature of 50-100 ° C below A, or B, or Mi final cooling in air or in quenching liquid and stepwise high-temperature tempering, characterized in that high-temperature austenitization is carried out at a temperature of 100-150 ° C above point A, with exposure oh 2.5-3.0 min per 1 mm of the section of the part, and multiple heating and cooling are carried out in the intercritical interval. 2. The method according to claim 1, characterized in that the number of heating and cooling cycles in the intercritical interval is at least 3.3. The method according to p. 2, characterized in that the stage of high-temperature tempering is selected at a temperature of 400 ° C, with a shutter speed of 1.5-2 hours