Metal Heat Treatment

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 chemical composition of the whole, but changes the microstructure of the workpiece or changes the chemical composition of the surface of the workpiece, and endows or improves the working performance of the workpiece. Heat treatment process generally includes heating, heat preservation, cooling three processes, sometimes only heating and cooling two processes. These processes are interconnected and uninterrupted. When reheating, the workpiece is exposed to the air, and oxidation and decarbonization often occur (that is, the carbon content on the surface of the steel part is reduced), which has a negative effect on the surface performance of the part after heat treatment. Therefore, the metal usually should be heated in a controlled atmosphere or a protective atmosphere, in molten salt and in vacuum, and can also be protected and heated by a coating or a packaging method to ensure that the oxygen content is processed and produced in the production process requirements.