In industry, metal materials play a very important role, related to the quality and service life of workpieces or machinery. For many industries, how to improve the performance of materials or workpieces is also an urgent need, especially deformation, which seriously affects the normal use of workpieces or machinery. In order to improve the stability of material size, it can be achieved through high-speed gear cryogenic box or heat treatment. How much do users know about Wuxi Guanya high-speed gear cryogenic box?
For many metal materials, the transformation of martensite structure after quenching is from martensite transformation point MS to martensite transformation point MF. However, the MF of many alloy steels is lower than room temperature, and there is retained austenite in the microstructure at room temperature. The residual austenite of this kind of steel can not be completely eliminated by tempering, and the existence of retained austenite will cause the decrease of workpiece performance 。 In order to eliminate the retained austenite, the cryogenic box process of high-speed gear is to continue the quenching process, which is carried out when the quenching steel order reaches room temperature and then goes below the room temperature. Deep processing is a method to treat workpiece with liquid as refrigerant at temperature lower than – 130. Deep processing can improve the hardness of the workpiece, prevent grinding cracks, improve the magnetic properties of the workpiece, reduce deformation, and stabilize the size of use. It can replace multiple tempering.
The main reason of steel deformation is the existence of internal stress or external stress in steel. The internal stress is caused by uneven temperature distribution or phase transformation, and residual stress is also one of the reasons. The deformation caused by external stress is mainly caused by the self weight of the workpiece. In special cases, the magnetic impact on the workpiece heated, or the depression caused by the clamping tool should also be considered. The deformation includes elastic deformation and expectant deformation. The size change is mainly based on the structural transformation, so it shows the same expansion and contraction. However, when there are holes or complex shape workpiece on the workpiece, it will lead to additional m deformation. If a large amount of martensite is formed at rate fire, it will expand, and if a large amount of retained austenite is produced, it will shrink accordingly. In addition, the primary chamber shrinks and the secondary hardening alloy steel expands during tempering. If the high-speed gear cryogenic box is carried out, the martensitization of retained austenite will further expand. The specific volume of these structures will increase with the increase of carbon content, so the increase of carbon content will also increase the size change.