Editor's Note: Cryogenic treatment technology is a new technology to improve the performance of metal parts in recent years, is the most effective and most economical technical means. Cryogenic treatment technology and research and development of cryogenic processing equipment for the different parts of the cooling, heating rate, cryogenic treatment of strict implementation and low temperature aging provides a strong guarantee. By the warm pursuit of low-temperature valve manufacturers, where we also cryogenic processing technology to do some introduction, hoping to make more businesses and individuals have an understanding of this new technology, here we also sincerely thank Yongjia Shen high valve Co., Ltd. Li Bai and provide us with the information. Cryogenic technology is the use of refrigerant medium as a cooling medium, the quenched metal material cooling process continues to reach far below a room temperature (-196 ℃), so as to achieve the purpose of the performance of metal materials. Cryogenic technology is emerging in recent years, a performance of metal parts of the new technology, is the most effective and most economical technical means. During the cryogenic processing, a large number of residual austenite in the metal is transformed into martensite. In particular, supersaturated metastable martensite will reduce supersaturation and precipitation during the temperature from -196 ℃ to room temperature, and the size is only 20 ~ 60A and maintain a coherent relationship with the matrix of ultrafine carbides, can reduce the martensite lattice distortion, micro-stress reduction, and fine dispersed carbide in plastic deformation can impede dislocation movement, thereby strengthening the matrix organization. At the same time, as the ultrafine carbide particles are uniformly distributed on the martensite matrix after precipitation, the grain boundary embrittlement is weakened, while the refinement of the matrix structure not only weakens the degree of segregation of impurity elements at the grain boundaries but also plays a role of grain boundaries Strengthen the role, thereby improving the performance of tooling, so that hardness, impact toughness and wear resistance were significantly improved. Cryogenic technology to improve the effect is not limited to the work surface, which penetrates into the workpiece, reflecting the overall effect, so the workpiece can be re-grinding, repeated use, but also to reduce the workpiece quenching stress and enhance the role of dimensional stability. About cryogenic, ultra-cryogenic treatment precipitated finer diffuse carbide Means - under the microscope to see the picture: Deep cold, ultra-deep cooling after the Markov slab size was significantly smaller, indicating the original thick martensite slab in the deep Cold and ultra-cryogenic treatment of the process of fragmentation, low-carbon martensite fragmentation and cryogenic treatment caused by martensitic decomposition. In cryogenic and ultra-cryogenic treatment, the lattice constant of Fe decreases as the volume shrinks at -190 ° C, while the martensitic supersaturation increases at lower temperatures , But also to reduce the level of empty flat 蘅. These all increase the driving force for the segregation of carbon atoms. However, atoms move at low temperatures and the diffusion distance is very short. The supersaturated carbon atoms in martensite tend to segregate near the dislocation line, The formation of ultrafine carbide core, after the fall of martensite micro-decomposition, the internal sub-unit size smaller: low-carbon martensite in the quenching process will occur tempering phenomenon, carbon partial segregation and a fine Carbides are precipitated but are still supersaturated solid solutions of carbon in α-Fe. Cryogenic and ultra-cryogenic treatment promotes the more dispersed segregation of carbon atoms and the formation of an ultrafine carbide core that decomposes the martensite and increases the interfacial area within the martensite. In the cryogenic, ultra-cryogenic treatment temperature rise phase carbon atoms greatly increased the ability to diffuse, and with temperature rise vacancy equilibrium concentration also increased, so as to more rapid diffusion of carbon atoms. The fine carbides produced by self-tempering promote the polymerization and growth of carbides, and the ultrafine carbides formed by cryogenic and ultra-cryogenic treatment gradually polymerize and grow up during the warm-up process and room temperature maintenance. Therefore, cryogenic, ultra-deep cold martensite carbide particles increased the number and larger size. The role of cryogenic treatment: Paralympic transformation can be changed to improve the hardness and wear resistance of the workpiece, the stability of the size of the workpiece. Can be precipitated carbide, to improve the wear resistance of the workpiece; can refine the grain, improve the impact toughness of the workpiece. Can be doubled to improve the corrosion resistance of martensitic stainless steel to improve the polishing performance of the workpiece. Non-ferrous metals can improve the conductivity and corrosion resistance. Can reduce mold deformation, cracking. Improve the dimensional accuracy of the workpiece.