In the past, there was no special plastic mold steel in China. Generally, the plastic mold was made of normalized 45 and 40Cr after quenching and tempering, so the hardness of the mold was low, the wear resistance was poor, the surface roughness value was high, the appearance quality of the processed plastic products was poor, and the service life of the mold was low. The precision plastic mold and the high hardness plastic mold were made of crwmo, Cr12MoV and other alloy tool steel, which not only made by mechanical machining It is difficult to process complex cavity and solve the problem of heat treatment deformation.

由此，国内对专用塑料模具用钢进行了研制，并获得了一定的进展。我国已有了自己的专用模具钢系列，目前已纳入标准的有两种，即3Cr2Mo和3Cr2MnNiMo，纳入行业标准的已有20多种，已在生产中推广应用十多种新型塑料模具钢，初步形成了我国塑料模具用钢体系。

Therefore, special steel for plastic mould has been developed in China, and some progress has been made. China has its own series of special die steel. At present, there are two kinds of plastic die steel, 3Cr2Mo and 3cr2mnnimo, which have been included in the industry standard. More than 20 kinds of new plastic die steel have been popularized and applied in production, and China's plastic die steel system has initially formed.

塑料模具钢的具有以下特点

Plastic mold steel has the following characteristics

1. 塑料模具用钢涵盖广泛，从普通钢材到专用钢才都有。这在塑料模具初期更加明显，如今已日趋正规。专门用钢已自成体系，模具用钢的化学成分和合金工具钢的基本相同，但其冶金质量更高，加工精良，对热处理有利。

1. Plastic mould steel covers a wide range, from ordinary steel to special steel. This is more obvious in the early days of plastic mold, and now it has become more and more formal. The chemical composition of die steel is basically the same as that of alloy tool steel, but it has higher metallurgical quality and better processing, which is beneficial to heat treatment.

2. 塑料模具钢性能要求严格，热处理难度大。

2. The performance requirements of plastic mold steel are strict, and the heat treatment is difficult.

3. 为避免模具零件在强韧化过程中的变形或其他热处理问题，模具钢以预硬化形式供应市场已较普遍。

3. In order to avoid the deformation or other heat treatment problems of die parts in the process of strengthening and toughening, it is common for die steel to be supplied to the market in the form of pre hardening.

4. 以石化产品为原料的塑料制品，某些度不同的腐蚀性，所以耐蚀钢应用也较多。

4. Plastic products with petrochemical products as raw materials have different degrees of corrosion, so corrosion-resistant steel is widely used.

5. 配合预硬化钢、非调质刚的应用，易切削性也是塑料模具钢的特点。

5. With the application of pre hardened steel and non quenched and tempered steel, free cutting is also the characteristic of plastic mold steel.