Heat treatment refers to a metal thermal processing process in which the material is heated, held, and cooled in the solid state to obtain the desired structure and properties.
In the process from the Stone Age to the Bronze Age and the Iron Age, the role of heat treatment has gradually become known.
As early as 770 BC to 222 BC, Chinese people have discovered in production practice that the performance of steel will change due to the influence of temperature and pressure deformation.
The softening treatment of white cast iron is an important process for manufacturing agricultural tools.
Metal heat treatment is one of the important processes in mechanical manufacturing.
Compared with other processing techniques, heat treatment generally does not change the shape of the workpiece and the overall chemical composition, but rather imparts or improves the performance of the workpiece by changing the microstructure inside the workpiece or changing the chemical composition of the surface of the workpiece.
It is characterized by improved intrinsic quality of the workpiece, which is generally not visible to the naked eye.
In order to make the metal workpiece have the required mechanical properties, physical properties and chemical properties, in addition to the rational selection of materials and various forming processes, heat treatment processes are often essential.
Steel is the most widely used material in the machinery industry.
The microstructure of steel is complex and can be controlled by heat treatment, so the heat treatment of steel is the main content of metal heat treatment.
In addition, aluminum, copper, magnesium, titanium can also be modified by heat treatment to obtain different mechanical properties, physical properties, and chemical properties.