Aluminium Window Door Hardware

For example, for a 20CrMnTiH gear, the forging weight is 2.1kg. After forging, the air-cooling has uneven structure and high hardness. The cooling can be controlled in a steel box with thermal insulation material. That is, normalizing with the waste heat of forging, the forging is reduced from 900°C to 700°C in about 1h, and then slowly cooled from 700°C to 660°C in about 3h, and finally the forging is quickly cooled out of the incubator to obtain a mixed structure of ferrite and pearlite, and the hardness is It is 156HBW~162HBW, which is lower than the air-cooled hardness after forging, and has a small hardness fluctuation range, which is convenient for cutting and processing. More importantly, it is controlled to cool to room temperature after forging and then carburized at 930°C and oil quenched at 790°C to obtain a grade of 9 Uniform austenite grains and no coarse grain heritability, which is ready for future heat treatment.

Please contact us at zhang@pride-cnc.com