Principle of cryogenic treatment technology
?????The cryogenic treatment uses the refrigerant as a cooling medium to continue the process of cooling the quenched metal material to a temperature far below room temperature (-196 ° C), thereby achieving the purpose of improving the performance of the metal material. Cryogenic processing technology is a new process technology that has improved the performance of metal materials in recent years.
?????During the cryogenic treatment, a large amount of retained austenite in the metal is transformed into martensite, especially the supersaturated metastable martensite reduces the saturation, precipitates and reduces the microscopic stress during the process from -196 °C to room temperature. The finely dispersed carbides can hinder dislocation motion during plastic deformation of the material, thereby strengthening the matrix structure. At the same time, the ultrafine carbonization exerts a grain boundary strengthening effect, thereby improving the performance of the tooling, and the hardness, impact toughness and wear resistance are remarkably improved.
?????For the cryogenic treatment of cemented carbide, the internal stress of the cemented carbide can be adjusted, that is, the generation of microcracks is reduced, the fatigue strength is improved, the toughness is improved, the bond to carbide is increased, the carbide peeling is reduced, and the wear resistance is improved. ability.
?????The improvement effect of the cryogenic technology is not limited to the surface of the workpiece. It penetrates into the interior of the workpiece and reflects the overall effect. Therefore, the workpiece can be reground and reused, and the workpiece can be reduced in quenching stress and dimensional stability