Today we will talk about the characteristics of the heat treatment process of the carburized steel plastic mold:
1. For plastic molds with high hardness, high wear resistance and high toughness requirements, carburized steel should be used for manufacturing, and carburizing, quenching and low temperature tempering are the final heat treatment.
2. Requirements for the carburized layer, generally the thickness of the carburized layer is 0.8 ~ 1.5mm, when pressing plastics containing hard fillers, the mold carburized layer thickness is required to be 1.3 ~ 1.5mm, when pressing soft plastics, the carburized layer The thickness is 0.8～1.2mm. The carbon content of the carburized layer is preferably 0.7% to 1.0%. If carbon and nitrogen co-infiltration are used, the wear resistance, corrosion resistance, oxidation resistance and anti-sticking properties will be better.
3. The carburizing temperature is generally 900～920℃, and small molds with complex cavities can take 840～860℃ medium temperature carbonitriding. The carburizing heat preservation time is 5-10h, which should be selected according to the requirements for the thickness of the carburized layer. The carburizing process is suitable to adopt the hierarchical carburizing process, that is, the high temperature stage (900～920℃) is mainly to quickly infiltrate the surface of the part; the medium temperature stage (820～840℃) is mainly to increase the thickness of the carburized layer. A uniform and reasonable carbon concentration gradient distribution is established in the carburized layer, which is convenient for direct quenching.
4. The quenching process after carburizing is different according to the steel type. After carburizing, it can be used separately: reheating and quenching; direct quenching after graded carburizing (such as alloy carburized steel); direct quenching after medium temperature carbonitriding (such as industrial Small precision molds formed by cold extrusion of pure iron or low carbon steel); air quenching after carburizing (such as large and medium-sized molds made of high-alloy carburized steel).