When the equipment is in the process of processing, in the processing area of the Dry Powder Pressing Mold, and its adjacent area, there will be a sharp drop in temperature, and when the temperature drops to the critical point of the workpiece material, The structure of the phase changes. If it is for the general and more common way of cutting, then the basic will not appear to increase the phenomenon.
But we are grinding in the processing, not only grinding in the pressure will be relatively large, and the grinding speed is very high, the metal in the power loss on the cut, Dry Powder Pressing Mold this approach is actually undesirable , Due to the energy consumed in the processing, and ultimately the basic will be converted into heat, and such a larger part of the heat, it will be directly transferred to the processing process to go, Dry Powder Pressing Mold and ultimately lead to dry powder mold in the processing of more High temperature.
If it is to deal with the quenching of the Dry Powder Pressing Mold, the higher the temperature will lead to the surface of the technology in the metallographic structure changes, to promote the entire metal surface in the hardness of a serious reduction, resulting in the workpiece oxide film color, such phenomena We can call it grinding burns, because the grinding of the processing is more often change the way, so in the grinding and processing process, often the phenomenon of burns, and ultimately lead to the use of the machine Functional decline.
The mature powder metallurgy process is widely used in machinery and other industries. The quality and life of the powder are the important factors that determine the quality and life of the powder metallurgy parts Dry Powder Pressing Mold . Therefore, it is very important to improve the quality and life of the mold. The use of cryogenic treatment can improve the wear resistance of steel in order to achieve the quality and life of the mold, parts quality and life will be increased.
Dry Powder Pressing Mold is usually caused by wear and tear caused by parts of the size of the deviation. Tool steel in the heat treatment in the metallographic phase will usually leave a lot of austenite, the use of molds prone to organizational changes, resulting in tissue stress, resulting in early damage from the mold, especially when the residual austenite more than 5% of the time, will be obvious Reduce the strength and abrasion resistance of the material.
In the powder metallurgy industry widely used Gr15 steel as a mold material Dry Powder Pressing Mold , but in use with Gr15 steel mold quality and life are low, so the use of cryogenic treatment to improve the wear resistance of steel, and ultimately improve the dry powder mold The quality and longevity.
After a series of experiments, Gr15 steel in the normal heat treatment still remains more austenite, cryogenic treatment is the best way to reduce the austenite residue Dry Powder Pressing Mold . When the temperature of the cryogenic treatment is reduced to -140 ° C or less, the amount of retained austenite is substantially stable.
After the cryogenic treatment, the toughness of the GR15 steel is not changed, but the strength is slightly increased. This is because the cryogenic treatment changes the austenite to the martensite, the organization is more refined and the hardness is enhanced. Therefore, the overall strength of the GR15 steel Improved, and thus the quality of Dry Powder Pressing Mold significantly improved.
Experiments show that the Dry Powder Pressing Mold reduces the amount of austenite after cryogenic treatment, increases the toughness and strength, thus significantly improves the quality and life of the mold, and the economy of the mold is further improved. Cryogenic treatment is a method worthy of promotion and use, on the basis of which we have to continue to study the effect of a better way to make dry powder mold quality and life again.