The half shaft of the car is made of 40Cr:

1. 40Cr is my country"s national standard steel grade, and 40Cr steel is one of the most widely used steels in machinery manufacturing;

2. After quality treatment, it has good comprehensive mechanical properties, good low temperature impact toughness and low notch sensitivity;

3. The quenching effect of steel is good, water quenching can be adjusted to 28～60mm, oil quenching can be adjusted to 15～40mm, this kind of steel is suitable for cyanide and high frequency quenching in addition to treatment;

4. The cutting performance is better. When the hardness is 174～229HB, the relative machinability is 60%. The steel is suitable for making medium-sized plastic molds.