What performance requirements should be met when selecting steel for injection mold production?

Injection mold in injection molding machine manufacturing plastic products in general need to carried out under the environment of high temperature of one hundred and fifty degrees to two hundred degrees Celsius, so the selection of raw materials in the process of manufacture of injection mould will need to be very attention, it will be late for the whole life and production of injection mold plastic products quality plays an important role, so when choosing injection mold steel raw material need to meet the performance requirements?
Adequate surface hardness and wear resistance
The hardness of the injection mold is usually below 50-60hrc, and the molds after heat treatment should have enough surface hardness to ensure sufficient rigidity of the mold. Because the filling and flow of the injection mold must bear great compressive stress and friction force, the mold should keep the stability of the precision of the shape and the precision of the size to ensure that the mold has enough service life. The wear resistance of the mould depends on the chemical composition and heat treatment hardness of the steel.
Two, excellent cutting processing
Most injection moulds, in addition to EMD processing, also need to carry out some cutting and fitter repair. In order to extend the service life of cutting tools, enhance cutting performance and reduce surface roughness, the hardness of steel for injection moulds must be appropriate.
Iii. The carbon steel of brand 50 has certain strength and abrasion resistance. After tempering and tempering treatment, it is mostly used in the formwork material. High carbon tool steels and low alloy tool steels have high strength and wear resistance after heat treatment. However, high carbon tool steels are only suitable for making small and simple shaped parts due to their large deformation during heat treatment.
Good thermal stability
Plastic injection mould parts shapes are more complex, difficult to process after quenching, so should choose as far as possible with good thermal stability, after the double color molding processing by heat treatment due to the linear expansion coefficient, heat treatment deformation is small, the size of the rate of change caused by the temperature difference is small, the microstructure and mould size stability, can reduce or no longer carry on the processing, can guarantee the mold size accuracy and surface roughness requirements.

Good polishing performance
High quality two - color injection molding products require a small roughness value on the cavity surface. For example, the injection mold cavity surface roughness value is required to be less than ra0.1-0.25 level, the optical surface is required to be Ra<0.01nm, the cavity must be polished to reduce the surface roughness value. For this selection of steel requires less impurities, microstructure uniform, no fiber direction, polishing should not appear pitting or orange peel defects.