塑料模具钢性能要求 随着制造业快速发展，塑料模具是塑料成型加工中不可缺少的工具，在总的模具产量中所占的比例逐年增加，随着高性能塑料的发展和不断生产，塑料制品的种类日益增多，用途不断扩大，制品向精密化、大型化、复杂化发展。成型生产向高速化发展，模具的工作条件也越趋复杂。
With the rapid development of manufacturing industry, plastic mould is an indispensable tool in plastic forming and processing. The proportion of plastic mould in total mould output increases year by year. With the development and continuous production of high-performance plastics, the types of plastic products are increasing, their uses are expanding, and the products are becoming more and more precise. Large-scale and complex development. With the development of high-speed moulding production, the working conditions of moulds become more and more complex.
1)型腔表面的磨损和腐蚀
1) Abrasion and Corrosion of Cavity Surface
塑料熔体以一定的压力在模腔内流动，凝固的塑件从模具中脱出，都对模具成型表面造成摩擦，引起磨损。造成塑料模具磨损失效的根本原因就是模具与物料间的摩擦。但磨损的具体形式和磨损过程则与许多因素有关，如模具在工作过程中的压力、温度、物料变形速度和润滑状况等。当塑料模具使用的材料与热处理不合理时，塑料模具的型腔表面硬度低，耐磨性差，其表现为:型腔面因磨损及变形引起的尺寸超差;粗糙度值因拉毛而变高，表面质量恶化。尤其是当使用固态物料进入塑模型腔时，它会加剧型腔面的磨损。加之塑料加工时含有氯、氟等成分受热分解出腐蚀性气体HC1、HF，使塑料模具型腔面产生腐蚀磨损，导致失效。如果在磨损的同时又有磨损损伤，使型腔表面的镀层或其他防护层遭到破坏，则将促进腐蚀过程。两种损伤交叉作用，加速了腐蚀一磨损失效。
Plastic melt flows in the cavity with a certain pressure, and solidified plastic parts come out of the mould, which cause friction and wear on the surface of the mould. The fundamental cause of plastic die wear failure is friction between die and material. However, the specific form of wear and the wear process are related to many factors, such as the pressure, temperature, material deformation speed and lubrication condition of the die in the working process. When the material and heat treatment used in plastic mould are unreasonable, the surface hardness of the cavity surface of plastic mould is low and the wear resistance is poor, which is manifested as: the dimension of the cavity surface is over-tolerant due to wear and deformation; the roughness value is increased due to drawing, and the surface quality is deteriorated. Especially when solid material is used to enter the plastic model cavity, it will aggravate the wear of the cavity surface. In addition, when plastics are processed, chlorine and fluorine are decomposed into corrosive gases HC1 and HF by heating, resulting in corrosive wear and tear on the cavity surface of plastic mould, leading to failure. If wear is accompanied by wear damage, the coating or other protective layer on the surface of the cavity will be damaged, which will promote the corrosion process. The interaction of two kinds of damage accelerates corrosion-wear failure.
2)塑性变形失效
2) Plastic Deformation Failure
塑料模型腔表面受压、受热可引起塑性变形失效，尤其是当小模具在大吨位设备上工作时，更容易产生超负荷塑性变形。塑料模具所采用的材料强度与韧性不足，变形抗力低;塑性变形失效另一原因，主要是模具型腔表面的硬化层过薄，变形抗力不足或工作温度高于回火温度而发生相变软化，而使模具早期失效。
Plastic deformation failure can be caused by pressure and heat on the surface of plastic model cavity, especially when small dies work on large tonnage equipment, it is easier to produce overload plastic deformation. Another reason for plastic deformation failure is that the hardened layer on the surface of the die cavity is too thin, the deformation resistance is insufficient or the working temperature is higher than the tempering temperature, which causes the phase transformation softening and causes the early failure of the die.