What are the material requirements of injection mold

According to the different working conditions and processing methods of injection mold, the basic performance requirements of injection mold steel are summarized: enough surface hardness and wear resistance. The hardness of injection mold steel is usually below 50-60hrc. The injection mold after heat treatment should have enough surface hardness to ensure that the injection mold has enough hardness. Because the injection mold is filled under high pressure, high friction and high flow, the accuracy of the injection mold is required to maintain the stability of the shape and dimensional accuracy of the mold, so as to ensure the service life of the injection mold. The wear resistance of injection mold depends on the chemical composition and heat treatment hardness of steel, so as to improve the hardness of injection mold. 2。 Good processability. In addition to EMD processing, most plastic forming molds also need certain cutting and assembly. In order to prolong the service life of the mold, improve the cutting performance and reduce the surface roughness, the hardness of the mold must be appropriate. 3. Good polishing performance. High quality plastic products require less cavity surface roughness. For example, the surface roughness of injection mold cavity should be less than ra0.1 ~ 0.25, while the optical surface should be less than 0.01nm. In order to reduce the surface roughness, the cavity must be polished. The selected steel requires less impurities, uniform microstructure, no fiber orientation, and no pitting or orange peel defects during polishing. 4. Good thermal stability. The shape of plastic injection mold parts is more complex, and it is difficult to quench process, so we should choose to have good thermal stability as much as possible. After the mold is processed with small linear expansion coefficient, the heat treatment deformation is small, the temperature difference caused by the change rate is small, the microstructure and mold size are stable, and the processing can be reduced or stopped, which can ensure the dimensional accuracy and surface roughness requirements of the injection mold.