Points to be noted for plastic mold heat treatment operations

In the process of plastic mold processing, cracks or deformation, easy oxidation and decarburization of the surface are mainly due to the failure of the mold. The reason for the failure of the plastic mold is mainly due to the improper heat treatment process of the mold, such as the selection of the heat treatment process parameters such as the heating temperature, the holding time, and the cooling speed.
First, it is about the effects of oxidation and decarburization, mainly because the quenching of the mold is stopped at a high temperature, but it cannot be strictly controlled. In addition, after decarburization of the outer surface of the mold, due to the difference in the internal and external layer structure, a large structural stress is exhibited during cooling, which causes quenching cracks.
The second is about the speed of heating. Because the mold steel contains more carbon and alloy elements and has poor thermal conductivity, the heating speed should not be too fast, and it should be stopped slowly to avoid deformation and cracking of the mold. When heating and quenching in an air furnace, in order to avoid oxidation and decarbonization, boxing is used for maintenance and heating. At this time, the heating rate should not be too fast, and the diathermy should be slow.
If the mold is heated fast and the heat penetration is fast, a large thermal stress is generated inside and outside the mold. If the control is not good, such as deformation or cracks, it is very easy to occur, in the prevention, it is necessary to use preheating or slow down the heating rate.