Nowadays, with the improvement of people's living standards, the requirements for plastic products have become higher and higher, and many requirements have been put forward for the appearance and performance of the products. Therefore, continuous innovation in the injection mold industry is also required. Pay more attention when selecting raw materials for injection molds. Then, what performance requirements are needed when selecting raw materials for injection mold steel?
1. Good surface hardness and wear resistance
The hardness of the injection molding mold is usually below 50-60HRC. The surface hardness of the heat-treated mold should be high. The mold must withstand greater compressive stress and friction due to the filling and flow of injection molding during work. The mold must maintain the accuracy and size of the shape. The stability of precision increases the service life of the mold. The wear resistance of the injection mold depends on the chemical composition and heat treatment hardness of the steel. Therefore, strengthening the hardness of the mold can enhance its wear resistance.
2. Good machinability
In addition to EMD processing, most injection molds require cutting processing and fitter repair. In order to increase the service life of cutting tools and enhance cutting performance, the surface roughness of injection molds should be reduced. The hardness of the steel used for injection molds should be appropriate.
3. Good thermal stability
The shape of the parts of the injection mold is often complicated and difficult to process after quenching. Therefore, it should be selected with good thermal stability as much as possible. When the mold is formed by heat treatment, the linear expansion coefficient is small, the heat treatment deformation is small, and the dimensional change rate caused by the temperature difference is small, the metallographic structure and the size of the mold are stable, which can be reduced or not processed.
4. Good polishing performance
The surface roughness value of the injection mold cavity is required to be less than Ra0.1～0.25, and the optical surface requires Ra<0.01nm. The cavity must be polished to reduce the surface roughness value. For this reason, the selected steel requires less material impurities and fine and uniform organization, there should be no pitting or orange peel defects during polishing.