According to the different conditions and processing methods of plastic mold steel, the basic performance requirements of plastic mold steel are as follows:

山东塑料模具钢
shandongplastic die steel

优良的切削加工性

Excellent machinability

大多数塑料成型模具，除EMD加工外还需进行一定的切削加工与钳工修配。为延长切削刀具的使用寿命，增强切削性能，减少表面粗糙度，塑料模具用钢的硬度必须适当。

In addition to EMD processing, most plastic molding molds need to be machined and repaired by fitters. In order to prolong the service life of cutting tools, enhance the cutting performance and reduce the surface roughness, the hardness of plastic mould steel must be appropriate.

良好的热稳定性

Good thermal stability

塑料注射模的零件形状往往比较复杂，淬火后难以加工，因此应尽量选用具有良好的热稳定性的，当双色模具成型加工经热处理后因线膨胀系数小，热处理变形小，温度差异引起的尺寸变化率小，金相组织与模具尺寸稳定，可减少或不再进行加工，即可保证模具尺寸精度与表面粗糙度要求。

The shape of parts of plastic injection mold is often complex, and it is difficult to process after quenching. Therefore, we should try our best to choose the one with good thermal stability. When the two-color mold is processed by heat treatment, the linear expansion coefficient is small, the heat treatment deformation is small, the size change rate caused by temperature difference is small, and the metallographic structure and mold size are stable, so the mold size can be reduced or no longer processed Inch accuracy and surface roughness requirements.

良好的抛光性能

Good polishing performance

高品质的双色注塑塑料制品，要求型腔表面的粗糙度值小。例如，注塑模型腔表面粗糙度值要求小于Ra0.1～0.25的水平，光学面则要求Ra<0.01nm，型腔须进行抛光，减小表面粗糙度值。为此选用的钢材要求材料杂质少、组织微细均一、无纤维方向性、抛光时不应出现麻点或桔皮状缺陷。

The surface roughness of the cavity is required to be small for high quality two-color injection molded plastic products. For example, the surface roughness of injection mold cavity is required to be less than ra0.1-0.25, while the optical surface is required to be RA < 0.01nm. The cavity must be polished to reduce the surface roughness. For this reason, the selected steel requires less impurities, fine and uniform microstructure, no fiber directionality, and no pitting or orange peel defects during polishing.

足够的表面硬度与耐磨性

Sufficient surface hardness and wear resistance

塑料模的硬度通常在50-60HRC以下，经过热处理的模具应有足够的表面硬度，以保证模具有足够的刚度。模具在工作中由于塑料的填充与流动要承受较大的压应力与摩擦力，要求模具保持形状的精度与尺寸精度的稳定性，保证模具有足够的使用寿命。模具的耐磨性取决于钢材的化学成分与热处理硬度，因此增强模具的硬度有利于增强其耐磨性。

The hardness of plastic mold is usually below 50-60hrc. The surface hardness of heat-treated mold should be enough to ensure the mold has enough rigidity. Due to the filling and flowing of plastic, the mold must bear large compressive stress and friction force, which requires the mold to maintain the stability of shape accuracy and dimensional accuracy, so as to ensure that the mold has sufficient service life. The wear resistance of the die depends on the chemical composition of the steel and the hardness of the heat treatment.

碳素钢具有一定的强度与耐磨性

Carbon steel has certain strength and wear resistance

经调质处理后多用于模架材料。高碳工具钢、低合金工具钢经过热处理后具有较高的强度与耐磨性，多用于成型零件。但高碳工具钢因其热处理变形大，仅适用于制造尺寸小、形状简单的成型零件。

After quenching and tempering, it is mostly used for mold base material. High carbon tool steel and low alloy tool steel have high strength and wear resistance after being overheated, which are mostly used for forming parts. However, high carbon tool steel is only suitable for small size and simple shape parts because of its large deformation during heat treatment.

此外，在选择材料时还须考虑防止擦伤与胶合，如两表面存在相对运动的情况，则尽量避免选择组织结构相同的材料，特殊状况下可将一面施镀或氮化，使两面具有不同的表面结构。

In addition, in the selection of materials, it is also necessary to consider the prevention of scuffing and gluing. If there is relative movement between the two surfaces, the material with the same microstructure should be avoided as far as possible. Under special conditions, one side can be plated or nitrided to make the two sides have different surface structures.