What is the heat treatment method for making the shaft made of 45 steel? What is the microstructure after heat treatment?
Sorbites (tempered sorbite) is on the formation of martensite tempering, in the optical microscope magnification of 500~600 or more to distinguish, the ferrite in the distribution of the carbides (including cementite) composite tissue pellets. It is also a tempering structure of martensite, a mixture of ferrite and granular carbides. At this point the ferrite has no carbon supersaturation, and carbide is a stable carbide. At normal temperature is a balanced tissue
The method of heat treatment after quenching and tempering at high temperature is called quenching and tempering. High temperature tempering means tempering between 500-650 degrees centigrade. Quenching and tempering can make the properties and material of steel be adjusted greatly. The strength, plasticity and toughness of the steel are better, and it has good comprehensive mechanical properties. The tempered bainite is obtained after quenching and tempering.
The microstructure before heat treatment is a mixture of ferrite and cementite. Because it belongs to quenched and tempered steel, the conventional heat treatment is quenched and then tempered at high temperature. The microstructure after heat treatment is tempered bainite.
