Metal heat treatment is one of the important processes in mechanical manufacturing. Compared with other processing processes, heat treatment generally does not change the shape and overall chemical composition of the workpiece, but endows or improves the serviceability of the workpiece by changing the microstructure inside the workpiece or changing the chemical composition of the surface of the workpiece.
Its characteristic is to improve the internal quality of the workpiece, which is generally not visible to the naked eye. In order to make the metal workpiece have the required mechanical, physical and chemical properties, in addition to the reasonable selection of materials and various forming processes, heat treatment process is often essential.
Steel is the most widely used material in the mechanical 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 and their alloys can also change their mechanical, physical and chemical properties through heat treatment to obtain different service properties.