20CrMnMoA high-strength high-grade carburized steel. The strength is higher than 15CrMnMoA, the plasticity and toughness are slightly lower, and the hardenability and mechanical properties are higher than 20CrMnTi. After low-temperature quenching and tempering, it has good comprehensive mechanical properties and low-temperature impact toughness. After carburizing and quenching, it has high bending strength and wear resistance, but it is easy to produce cracks when grinding. Poor weldability, suitable for resistance welding, preheating before welding and tempering after welding. Good machinability and hot workability. Firstly, carburizing heat treatment is carried out, then quenching is carried out at the heating temperature of 850℃, and oil cooling is carried out; Tempering at 200℃ and air cooling. After low temperature tempering, it has good comprehensive mechanical properties and low temperature impact toughness; After carburizing and quenching, it has high bending strength and wear resistance. It is often used to manufacture important carburized parts with high hardness, high strength and high toughness, such as crankshaft, camshaft, connecting rod, gear shaft, gear and pin shaft.
The chemical composition of 20CrMnMoA is as follows: