ZY019 Ultra Deep Cryogenic Equipment

During the cryogenic treatment process, a large amount of residual austenite transforms into martensite, especially supersaturated metastable martensite, which reduces supersaturation and precipitates ultrafine carbides with a size of only 20-60A and maintains a coherent relationship with the matrix during the process from -196 ℃ to room temperature. This can reduce lattice distortion and micro stress in martensite, while fine dispersed carbides can hinder dislocation movement during material plastic deformation, thereby strengthening the matrix structure. At the same time, due to the precipitation of ultrafine carbide particles evenly distributed on the martensitic matrix, the catalytic effect of grain boundaries is weakened. The refinement of the matrix structure not only reduces the degree of impurity element segregation at grain boundaries, but also plays a role in grain boundary strengthening, thereby improving the performance of high-speed steel, significantly increasing hardness, impact toughness, and wear resistance. If the hardness of the mold is high, its wear resistance is also good. For example, increasing the hardness from 60HRC to 62-63HRC increases the wear resistance of the mold by 30% -40%.

It can be seen that the relative wear resistance of the mold increases by 40% after cryogenic treatment. After extending the cryogenic treatment time, the relative wear resistance increases without much change in hardness. Give an example to illustrate:
(1) Convex mold: High speed steel convex molds from automobile factories can only be used 100000 times without deep cooling treatment. However, by using liquid nitrogen for deep cooling treatment at -196 ℃ for 4 hours and then tempering at 400 ℃, the service life is increased to 1.3 million times.
(2) Stamping die: The production and use results show that the output is more than doubled after cryogenic treatment.
(3) Silicon steel sheet cold stamping die: In order to reduce the brittleness and internal stress of the mold after deep cold treatment, deep cold treatment is combined with medium temperature tempering to improve the mold's resistance to damage and other comprehensive properties. The grinding life of the mold is increased by more than three times and stabilized at 50000 to 70000 strokes.

Precision measuring tools that have undergone cryogenic or ultra cryogenic treatment have significantly improved dimensional stability and wear resistance.