In addition to strengthening the forging process, a cryogenic treatment process is added to the normal die heat treatment. Cryogenic treatment is actually the continuation of quenching, which uses the degree of subcooling to increase the driving force of martensite transformation. As the cryogenic temperature decreases and the degree of undercooling increases, the transformation of retained austenite to martensite becomes more complete. In addition, cryogenic treatment can promote the precipitation of ultra-fine carbides from the martensite formed after quenching. The amount and degree of diffusion are significantly greater than those without cryogenic treatment. These highly dispersed carbides precipitated from martensite can make The compressive strength of the matrix is increased, and the impact toughness is increased, that is, the strength and toughness are improved. The precipitation of these carbides will significantly improve the wear resistance, heat resistance, hardness and other properties of the material. After the punch is oil-quenched at 1030°C, place the mold in liquid nitrogen for cryogenic treatment within ≦25min; after cryogenic treatment, the material is tempered at 220°C. Using the new process to process 52 sets of punches. Under the condition of punching the same batch of silicon steel sheets, compare experiments with the punches processed by the original process. Of the 52 sets of punches treated by cryogenic treatment, the pass rate reaches more than 95%, and the service life is improved. 8 times.
Due to the improvement of toughness and fatigue strength, the fracture of the punch is avoided, the service life of the punch is significantly improved, the production cost of silicon steel sheets for motors is reduced, and the economic benefits of the production plant are improved. Fourth, the application prospect of cryogenic treatment in the manufacturing industry In the manufacturing process of molds, the quality of molds directly affects the operating conditions of the enterprise. The use of cryogenic treatment technology can improve the service life of molds and increase the economic benefits of enterprises. Therefore, low-temperature modification technology has been applied in the mold industry and has achieved good economic benefits, and it has great practical value when it is extended. Cryogenic treatment has broad application prospects in the fields of aerospace, weapons, construction machinery, roads and bridges, semiconductors, electrical appliances, and computers. Mold cold treatment, life is nothing compared!