What are the methods of DIN 1.2379 steel heat treatment

    Thermal processing of DIN 1.2379 steel:
Start temperature 1050 °C, end temperature 850 °C, furnace cooling.
    Softening annealing treatment:
In the protection of gas, heating to 800~850 °C, then by 10 °C /h speed cooling to 600 °C, then the air cooling, the hardness is less than or equal to 250HBw.
    To eliminate stress treatment:
If want to eliminate the residual stress generated after rough machining, mold should be heated to 650 °C, heat 2h, and then with the furnace cooling to 500 °C, then followed by air cooling.
    DIN 1.2379 steel quenching and tempering:
The first preheating temperature 550 ~ 600 °C, maintained at about 30min per 25mm; the second preheating temperature 800 ~ 850 °C, maintained at about 30min per 25mm; austenitizing temperature 975 ~ 1040 °C, maintained at about 30min per 25mm , oil cooling (40 ~ 70 °C) or gas cooling, cooled to 50 ~ 70mm immediately tempered.
1) low-temperature tempering: tempering temperature 150 ~ 200 °C, each 25mm for about 60min above, air cooling, hardness ≥61HRC. Tempering should choose a lower austenitizing temperature 975 ~ 1025 °C.
2) high-temperature tempering: tempering temperature 480 ~ 540 °C, each 25mm for about 60min or more, air cooling, more than twice tempered, hardness ≥58HRC. Tempering should use a higher austenitizing temperature 1000 ~ 1040 °C.
    Cryogenic treatment of 1.2379 steel:
After hardening, the workpiece is immediately cooled to between -80℃~ -70 °C, maintaining 3 ~ 4h, then tempering. Cryogenic treatment can improve the hardness 1 ~ 3HRC.
    The aging treatment:
Temperature of 110 ~ 140 °C, thermal insulation 25 ~ 100h, in order to ensure that the workpiece size and stability during use.

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