What is the heat treatment processing of 42CrMo steel?

42CrMo steel undergoes cryogenic treatment, which can precipitate highly dispersed ultrafine carbides from the quenched martensite. After subsequent low-temperature tempering at 200°C, these ultra-fine carbides can be transformed into carbides. Martensite without cryogenic treatment, after low-temperature tempering, only a small amount of carbides are precipitated in some local areas. 42CrMo alloy steel sheet adopts low temperature chemical heat treatment method. On the basis of maintaining the high hardness and high wear resistance of the sheet, ion nitriding, gas nitrocarburizing, and salt bath thiocyanate are commonly used in low temperature chemical heat treatment.

Heat treatment processing of 42CrMo steel:

When the heating temperature is 1150 ~1200°, the starting temperature is 1130 ~1180°, and the ending temperature is> 850°φ> 50mm, then slowly cool down.

The normalizing temperature is 850~900°, and the furnace is air cooled.

High temperature tempering

The tempering temperature is 680~700°, and the furnace is air-cooled.

Quenching and tempering

Preheating temperature 680 ~ 700°, Quenching temperature 840 ~ 880° oil cooling, tempering temperature 580° water cooling or oil cooling, hardness ≤ 217HBW.

Quenching temperature 900°

Tempering temperature 560° Hardness (37±1) HRC

Induction hardening and tempering

The quenching temperature is 900°, the tempering temperature is 150~180°, and the hardness is 54~60HRC.