With the continuous development of machinery industry, the requirement for metal materials is becoming higher and higher. How to improve the mechanical properties and service life of metal workpieces as far as possible under the premise of material and heat treatment process is established has become a problem that many people in the heat treatment industry think and explore. After heat treatment, the hardness and mechanical properties of steel are greatly improved, but the following problems remain after heat treatment:
1. Retained austenite. The proportion of austenite is about 10%-20%. Because of the instability of austenite, it is easy to transform into martensite when it is affected by external force or environmental temperature. The specific volume of austenite and martensite is different, which will cause irregular expansion of materials and reduce the dimensional accuracy of workpieces.
2. Coarse grain size and supersaturation of carbides.
3. Residual internal stress. The residual internal stress after heat treatment will reduce the fatigue strength and other mechanical properties of the material, and easily lead to the deformation of the workpiece in the process of stress release.
How to solve these problems has been studied by many metal materials researchers at home and abroad. Cryogenic and ultra-cryogenic treatment processes are considered to be the best way to solve these problems.
The XFL series programmable cryogenic treatment box is made of corrosion resistant SUS304 stainless steel. It has strong structure, beautiful appearance and safe operation. The equipment can realize full/semi-automatic programming for the process. It uses liquid nitrogen as refrigerant, vaporization and heat absorption of liquid nitrogen and low temperature nitrogen as heat absorption refrigeration. The temperature control accuracy is accurate, the cooling process is slow and uniform, which greatly reduces the impact of low temperature on the workpiece and avoids the risk of workpiece cracking.
Cryogenic Box Structure Four Structures of Cryogenic Box
Box: The whole box structure is made of double-layer SUS304 stainless steel by bending and welding, and then reinforced by steel bars to support and protect the equipment. Engineering plastic (PTFE) supports with high strength and excellent thermal insulation performance are installed at the bottom of the inner cavity to ensure the safety and thermal insulation performance of the equipment under heavy load. The bottom of the box body is equipped with special casters to facilitate the movement of the box body and is equipped with fixed locking (no casters for large furnace type). In addition, for different types of furnace opening, we provide two configurations of booster spring support rod and pneumatic cylinder opening for customers to operate easily.
Cooling system: The system is composed of liquid nitrogen bottle outside, solenoid valve, disperser, stirring fan and exhaust hole in inflatable pipe and equipment. The system uses the principle of liquid nitrogen sublimation, heat absorption and heat balance to realize refrigeration.
Xinfeng vertical cryogenic box is mainly divided into: standard size cryogenic box, modular combination cryogenic box (roller cryogenic treatment box), nitrogen recovery cryogenic box, cryogenic assembly box, valve cryogenic air tightness testing device and so on.