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 by changing the internal microstructure of the workpiece, or changing the chemical composition of the surface of the workpiece , To give or improve the performance 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 properties, physical properties and chemical properties, in addition to the reasonable selection of materials and forming processes, the heat treatment process is often necessary.