It is characterized by improving the 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 rational selection of materials and various forming processes, the heat treatment process It is 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. Therefore, the heat treatment of steel is the main content of metal heat treatment. In addition, aluminum, copper, magnesium, titanium, and the like can also be modified by heat treatment to obtain different mechanical properties, physical properties, and chemical properties.
The quenching and tempering treatment of the coupling is generally called the quenching and tempering treatment of heat treatment combined with quenching and high temperature tempering. Quenching and tempering treatment is widely used in a variety of important structural parts, especially those that work under alternating loads, such as connecting rods, bolts, gears and shafts. After the quenching and tempering treatment, the tempered sorbite structure is obtained, and its mechanical properties are superior to the normal-fired sorbite structure of the same hardness. Its hardness depends on the high temperature tempering temperature and is related to the tempering stability of the steel and the cross-sectional dimensions of the workpiece, generally between HB200 and 350.