1. Low carbon steel has good plasticity, but low strength and hardness, good weldability and cold stamping process, and can be used to make various standard parts, shaft sleeves, containers, etc.;
2. High carbon steel has poor plasticity, high hardness, poor fatigue strength, poor machinability, and insufficient toughness for shaft parts and is easy to break. This type of steel is suitable for making static pressure-bearing and wear-resistant parts, such as heavy rails and rolls. After proper heat treatment, springs, wire ropes, etc., which require high hardness and high wear resistance, can also be made;
3. The main function of the car drive shaft is to support the rotary body and transmit power. Working conditions generally bear alternating torque and tension and compression loads, and the journal and key parts are subject to greater friction and wear. The failure forms are mainly fracture and local excessive wear, and fracture includes fatigue fracture and overload fracture. Therefore, when selecting materials, the materials should have: sufficient strength, rigidity and certain toughness, good wear resistance, high fatigue strength and good machinability. That is to say, the spindle is required to have good comprehensive mechanical properties.
4. After proper heat treatment, medium carbon steel can obtain good comprehensive mechanical properties, and achieve parts with tough core and wear-resistant surface.