Heat treatment characteristics of common carburized steel plastic mould
1. For the plastic mold with high hardness, high wear resistance and high toughness requirements, we should choose carburizing steel to manufacture, and the carburizing, quenching and low temperature tempering as the final heat treatment.
2. The requirements of the carburizing layer, the thickness of the general carburizing layer is o.8-1.5mm, when the plastic containing hard filler is pressed, the thickness of the mold carburizing layer is required to be 1.3 ~15mm, and the thickness of the carburizing layer is 0.8~ 1.2mm when the soft plastic is pressed.The carbon content of carburizing layer is 0.7% ~ 1.0%.If the use of carbonitriding, the wear resistance, corrosion resistance, oxidation resistance, anti viscosity is better.
3. Carburizing temperature is generally between 900 and 920 degrees Celsius, complex cavity of the small mold (mold steel) desirable 840-860 degrees Celsius medium temperature carbonitriding.Carburizing holding time is 1~l0h.It should be selected according to the requirement of permeable layer thickness.Carburizing process to use grading carburizing process is appropriate, that is, the high temperature stage (900-920 degrees Celsius) to quickly penetrate carbon into the surface of parts.The medium temperature stage (820~840 ℃) is mainly to increase the thickness of the carburizing layer, so as to establish a uniform and reasonable gradient distribution of carbon concentration in the carburizing layer, which is convenient for direct quenching.
4. After carburizing and quenching process according to different steel grade, after carburizing can be respectively used: reheated quenching, classification directly after carburizing and quenching (e.g., alloy carburizing steel), medium temperature direct quenching after carbonitriding (such as the use of industrial pure iron or mild steel cold extrusion forming of small precision mold), carburizing after cold hardening, such as high alloy carburizing steel manufacturing large and medium-sized mold).
