liquid nitrogen cryogenic box

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liquid nitrogen cryogenic Furnace is to use liquid nitrogen as cooling medium, the temperature dropped to the cryogenic temperature box – 196 ℃, temperature controlled. The inner wall of the equipment is stainless steel. The temperature is controlled by intelligent controller, the scientific structure system easy to operate. liquid nitrogen cryogenic Furnace can continue the cooling process of the metal material after quenching and reach a certain temperature at the remote room temperature, so as to improve the performance of the metal material. Cryogenic machining technology is a new technology to improve the properties of metal materials, which is more effective and economical at present. During cryogenic treatment, a large amount of residual austenite transformed martensite is found in the metal.

Liquid nitrogen cryogenic box application:
liquid nitrogen cryogenic Furnace is to use liquid nitrogen as cooling medium, the temperature dropped to the cryogenic temperature box – 196 ℃, temperature controlled. The inner wall of the equipment is stainless steel. The temperature is controlled by intelligent controller, the scientific structure system easy to operate. liquid nitrogen cryogenic Furnace can continue the cooling process of the metal material after quenching and reach a certain temperature at the remote room temperature, so as to improve the performance of the metal material. Cryogenic machining technology is a new technology to improve the properties of metal materials, which is more effective and economical at present. During cryogenic treatment, a large amount of residual austenite transformed martensite is found in the metal, In particular, the supersaturated metastable martensite will desaturate from -196 c to room temperature, precipitate dispersion, and reduce the microscopic profit. The fine dispersed carbides can hinder the dislocation movement when the material deforms, thus strengthening the matrix structure.At the same time, because the superfine carbonization plays the role of grain boundary strengthening, the performance of the die is improved, and the hardness, impact toughness and wear resistance are significantly improved.

Liquid nitrogen cryogenic box technical application
• Increased service life of HSS and carbide cutters, cutting tools and gauges
• Improved wear resistance and service life of nozzles, springs, gears and bearings
• Increased service life and stable size of hot and cold molds
• Improved performance of diamond products
• The size of assembly parts of precision machinery is stable
• Increase the service life of mine geological drill bits and steel sheets

Liquid nitrogen cryogenic box –Model specifications:

Model	Working Size ( L×W×H )	Boundary Dimension ( L×W×H )	Volume ( L )	Freezing Capacity ( KG )
GH-SLN-50	400×350×350	1150×810×780	50	80
GH-SLN -80	500×400×400	1250×860×830	80	150
GH-SLN -150	600×500×500	1430×960×960	150	300
GH-SLN -250	700×600×600	1530×1060×1060	250	500
GH-SLN -324	900×600×600	1700×1180×1220	324	650
GH-SLN -490	1000×700×700	1800×1280×1220	490	1000
GH-SLN -768	1200×800×800	2000×1380×1320	768	1500
GH-SLN -1500	1500×1000×1000	2300×1700×1550	1500	2500
GH-SLN -1800	1800×1000×1000	2600×1700×1550	1800	3000
GH-SLN -2000	2000×1000×1000	2800×1700×1550	2000	3500

Can be designed according to customer needs.

Introduction of liquid nitrogen cryogenic process:
After heat treatment and quenching at room temperature: after quenching, the inner and outer rings must be uniformly cooled to room temperature for cold treatment, otherwise it is easy to crack, and immediately after cold treatment at room temperature (generally no more than 30min), otherwise the transformation from austenite to martensite will be suspended.

Liquid nitrogen deep freezer temperature: the temperature of cold treatment is mainly based on the martensite transition termination temperature of steel Mf, but also consider the impact of cold treatment on mechanical properties and process factors.For GCr15 steel, cold treatment is chosen – 70 ℃;Not very high accuracy ring or equipment limited, optional for cold treatment temperature – 40 ~ 70 ℃;Ultra precision bearing, can be in – between 70 ℃ ~ 80 ℃ cold treatment.The impact fatigue and contact life of bearing are affected by the temperature of undercooling.

Liquid nitrogen deep freezer: although the transformation of a large number of martensite is completed when the temperature drops to a certain temperature, in order to make the surface and core of a batch of rings uniformly reach the cold treatment temperature, a certain holding time is required, generally ranging from 1 to 1.5h.

Tempering after cryogenic treatment of liquid nitrogen: the ring is placed in the air after cold treatment, and its temperature slowly rises to room temperature before timely tempering.Temperature rise can not be too fast, otherwise easy to crack;Timely tempering, otherwise the large residual stress inside the ring will lead to the ring cracking, generally no more than 2h.

Liquid nitrogen cryogenic box features:
Improve the hardness and strength of the workpiece
Ensure the dimensional accuracy of the workpiece
Improve the workpiece wear resistance
Improve the impact toughness of workpiece
Improve the workpiece internal stress distribution, improve the fatigue strength
Improve the corrosion resistance of the workpiece

Liquid nitrogen cryogenic box — industrial application:
Cryogenic treatment process, a large number of retained austenite into martensite, especially the metastable martensitic supersaturated during from 196 ℃ to room temperature will reduce the degree of supersaturation, precipitation dispersion, size is only 20-60 a and keep coherent relationship with matrix of ultrafine carbides, can reduce martensite lattice distortion, microscopic stress is reduced, and at the time of the material to plastic deformation small dispersion carbide can hinder dislocation motion, so as to strengthen the matrix organization.At the same time because of the super fine carbide precipitation, the uniform distribution on the martensitic matrix, catalysis, weakened the grain boundary and matrix was refined already weakened the clustering degree of impurity elements in the grain boundary, and played a reinforcement of grain boundary, thus improving the performance of high speed steel, hardness, impact toughness and wear resistance are improved significantly.Mold hardness is high, its wear resistance is good, such as hardness from 60HRC to 62-63hrc, mold wear resistance increased by 30% to 40%.
It can be seen that the relative wear resistance of the mold increases by 40% after cryogenic treatment, and increases when the hardness does not change too much after cryogenic treatment.

Examples show:
(1) punch: auto high speed steel punch, without cryogenic treatment can only be used when the 100000 times, and the liquid nitrogen by – 196 ℃ by 4 h 400 ℃ tempering after cryogenic treatment, the service life of up to 1.3 million times.
(2) stamping die: the production and use results showed that the output was more than doubled after cryogenic treatment.
(3) cold stamping die for silicon steel sheet: in order to reduce the brittleness and internal stress of the die after cryogenic treatment, the combination of cryogenic treatment and tempering at medium temperature can improve the anti-destructive and other comprehensive properties of the die. The grinding life of the die can be increased by more than 3 times, and the die can be stabilized at 50,000 to 70,000 strokes.
After cryogenic or ultra-cryogenic treatment of precision measuring tools, dimensional stability, wear resistance has been significantly improved.

Application prospect of cryogenic treatment equipment in manufacturing industry
In the mold manufacturing process, the quality of the mold has a direct impact on the business situation of enterprises, the use of cryogenic treatment technology, improve the service life of the mold, increase the economic benefits of enterprises.Therefore, the low temperature modification technology has been applied in the mold industry, which has achieved good economic benefits and great practical value.Cryogenic treatment has a broad application prospect in aerospace, weapons, construction machinery, roads and Bridges, semiconductors, electrical appliances, computers and other fields.