Good thermal stability
Plastic injection mold parts are often more complex in shape. After quenching it will be very difficult to process again, so you should try to use a mold with good thermal stability. When the cell phone case mold molding process after heat treatment because of the coefficient of linear expansion is relatively small, after heat treatment deformation is small, the temperature difference caused by the rate of change in size will be reduced, metallurgical organization and mold size is more stable, can be reduced or no longer processed, you can ensure the mold size accuracy and surface roughness requirements.
Adequate surface hardness and wear resistance
The hardness of plastic bucket mold is usually below 50-60HRC, and the hardness of the mold surface after heat treatment must be enough to make the mold have enough rigidity. Mold in the work of the plastic filling and flow will be subjected to large compressive stress and friction, so the mold must be required to maintain the accuracy of the shape and dimensional accuracy of stability, to ensure that the mold has sufficient service life. However, the wear resistance of the mold depends on the chemical composition and heat treatment hardness of the steel, so improving the hardness of the mold is beneficial to improve its wear resistance.
Good polishing performance
Cell phone case high quality plastic products, require cell phone case mold cavity surface roughness value must be small. For example, injection mold cavity surface roughness value must be less than Ra0.1 ~ 0.25 level, the optical surface must be Ra < 0.01nm, the cavity shall be polished, thereby reducing the surface roughness value. For this reason, the material impurities of the selected steel must be less, the organization of micro-fine uniformity, no fiber directional, should not appear in the polishing of pitting or orange peel defects.