On 2018-08-08 14:48:54
Heat treatment characteristics of plastic mold
(1) heat treatment characteristics of carbon steel plastic mold
1. For the plastic mold with high hardness, high wear resistance and high toughness requirements, to use carburizing carbon steel to manufacture, and carburizing, quenching and low temperature tempering as the final heat treatment.
2. For the requirements of carburizing layer, the thickness of the general carburizing layer is 0.8 ~ 1.5mm, when pressing the plastic containing hard filler, the thickness of the carburizing layer is 1.3 ~ 1.5mm, when pressing soft plastic, the thickness of the carburizing layer is 0.8 ~ 1.2mm. The carbon content of carburized layer is 0.7% ~ 1.0%. If carbon, nitriding, wear resistance, corrosion resistance, oxidation resistance, anti - viscosity is better.
3. The carburizing temperature is generally in the 900 ~ 920℃, the complex cavity of the small mold can be used for 840 ~ 860℃ medium temperature carbon nitrogen co-permeability. Carburizing insulation time is 5 ~ 10h, specific should be based on the requirements of the thickness of the layer to choose. The carburizing process is suitable for the use of graded carburizing process, that is, in the high temperature stage (900 ~ 920℃) to quickly infiltrate the carbon into the surface of parts. In the middle temperature stage (820 ~ 840℃), the thickness of carburized layer is mainly increased, so a uniform and reasonable gradient distribution of carbon concentration is established in the carburized layer, which is convenient for direct quenching.
4. According to different steel types, after carburizing, the quenching process can be adopted: re-heating and quenching; Direct quenching after graded carburizing (such as alloy carburized carbon steel); Direct quenching after medium temperature carbonitriding (such as the use of industrial pure iron or low carbon steel cold extrusion forming small precision mold); Carburized after air quenching (such as high alloy carburized carbon steel made of large and medium-sized mold).