The hot work die steel in die steel works is mainly used to manufacture the dies that need high temperature pressing, such as hot die casting dies, hot stamping dies, hot deformation dies (hot upsetting dies), hot extrusion dies, etc. Therefore, the steel has high requirements for thermal hardness, high temperature wear resistance, thermal fatigue strength, thermal conductivity and hardenability, and good formability is also very necessary.

根据热作模具钢的性能特点，分为低耐热高韧性模具钢、中耐热高韧性模具钢、高耐热热作模具钢和专用热作模具钢。

According to the properties of hot work die steel, it can be divided into low heat resistance and high toughness die steel, medium heat resistance and high toughness die steel, high heat resistance hot work die steel and special hot work die steel.

使用不同的温度。冷加工模具钢用于低温(100℃以下)，主要用于冲压模具。热作模具钢用于高温，主要用于压铸模具。

Use different temperatures. Cold working die steel is used for low temperature (below 100 ℃), mainly for stamping die. Hot work die steel is used for high temperature, mainly for die casting die.

冷加工模具钢注重硬度和耐磨性。含碳量高，合金元素主要增加淬透性和耐磨性。冷加工模具钢包括落料用模具(落料冲孔模具、切边模具、冲头和剪刀)、冷镦模具、冷挤压模具、弯曲模具和拉丝模等。

Cold working die steel pays attention to hardness and wear resistance. With high carbon content, alloying elements mainly increase hardenability and wear resistance. Cold working die steel includes blanking die (blanking punching die, trimming die, punch and scissors), cold heading die, cold extrusion die, bending die and drawing die, etc.

具有冲击载荷和薄工具空间的冷加工模具。如上所述，冷加工模具前三种钢的使用性能要求主要是高耐磨性，因此采用高碳过共析钢甚丛林钢。但有些冷加工模具，增加了切边底板和落料模，对应的比较薄，在使用过程中受到冲击载荷时，应该主要要求高的冲击韧性。

Cold working die with impact load and thin tool space. As mentioned above, the performance requirements of the first three kinds of cold working die steel are mainly high wear resistance, so high carbon hypereutectoid steel and even jungle steel are used. However, some cold working dies, with the addition of trimming bottom plate and blanking die, are relatively thin. When they are subjected to impact load in the process of use, they should mainly require high impact toughness.

为了这一矛盾，可以采取以下措施:①降低碳含量，采用亚折叠钢，避免钢的韧性因一次碳化物和二次碳化物而降低；②加入Si、Cr等合金元素，提高钢的回火稳定性和回火温度(240-270℃回火)，有利于充分淬火应力，提高硬度而不降低；②添加W等难熔碳化物形成元素，细化晶粒，提高韧性。高韧性冷加工模具常用的钢有6SiCr和4CrW2Si。，5CrW2Si等。

In order to solve this contradiction, the following measures can be taken: ① reduce the carbon content and use sub folded steel to avoid the reduction of toughness due to primary and secondary carbides; ② add Si, Cr and other alloy elements to improve the tempering stability and tempering temperature (240-270 ℃) of the steel, which is conducive to fully eliminate the quenching stress and improve the hardness without reducing; ② add W and other refractory carbides Forming elements, refining grains and improving toughness. 6sicr and 4crw2si are commonly used for high toughness cold working dies. 5CrW2Si et al.