Alloy/high alloy cemental steel cementing quenching method in low-carbon

[0009] example 1:

[0010] The driving wheel of the rear axle of the car is made of low-carbon medium alloy carburized steel, the grade is: 22CrMoH, the surface hardness is HRC58-63 for carburizing and quenching, and the tooth root is HRC30-40. The carburizing and quenching method is as follows: put the workpiece in a carburizing furnace, carburize at a temperature of 930°C, and diffuse; then, pre-cool the workpiece to 830-840°C during carburizing; Take out the workpiece from the medium and quench it directly in water with a temperature ≥ 60 °C. Wherein, the water temperature in the quenching tank is controlled by the cooled circulating water.

[0011] After quenching in water with the above parts after carburizing, no cracks appeared, and there was no immediate tempering afterwards, and after being placed for as long as 3 months, no cracks were observed after grinding. In this regard, analysis The reason why it does not crack is because the low-carbon alloy carburizing steel h

[0012] Example 2:

[0013] Take the side shaft gear in the automobile differential as an example, its material is low carbon medium alloy carburizing steel, the brand is: 20CrMnTi, the original process is quenching in No. 10 oil after carburizing, there are half shaft parts in production practice The phenomenon that the spline hole shrinks too much to form a "horn hole". Adopt the method of the present invention to carry out carburizing and quenching to the side shaft gear, the specific steps are as follows: put the workpiece in the carburizing furnace, carburize at the temperature of 925-935 ℃, and diffuse; then, put the workpiece in the carburizing furnace Pre-cooling to 830-840°C; then, take out the workpiece from the carburizing furnace and directly quench it in water with a temperature ≥ 60°C. Wherein, the water temperature in the quenching tank is controlled by the cooled circulating water.

[0014] After quenching with high-temperature water, it was checked that there wa