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前言 目前国内外最常用的耐磨性高的冷模具钢是高碳高铬钢,其中含有12％左右的铬和1.2～2.35％的碳,有时加入少量其他元素如Mo、W、V等。我国常用的这类钢为Cr12MoV。每年的使用量很大。 Cr12MoV钢具有较高的淬透性、变形较小。这种钢既可以得到一次硬度、又可以得到二次硬度。较低的温度淬火和低温回火时,得到一次硬度,此时硬度较高,但回火稳定性不足。高温淬火和高温回火可以得到二次硬度,有较高的回火稳定性,但大量的残余奥氏体不易消除。这类钢中含有较多的共晶碳化物,这些共晶碳化物在钢中的分布是很不均匀的,热压力加工后,这些碳化物呈带状分布使钢具有明显的各向异性,碳化物不均匀性标号高的钢,其横向强度比纵向低30～40％,而塑性低1/2～2/3。各向异性还使钢的变形难于控制,这类钢中含有大量的铬,不适合我国资源条件。因此很需要研究出更经济的少铬的性能更好的高耐磨微变形钢来全面代替高碳高铬钢。
Preface At present, the most commonly used wear-resistant cold-tool steel at home and abroad is high-carbon high-chromium steel containing about 12% chromium and 1.2-2.35% carbon, sometimes adding a small amount of other elements such as Mo, W, V and the like. This type of steel commonly used in our country is Cr12MoV. Every year a lot of usage. Cr12MoV steel has a higher hardenability, deformation is smaller. This steel can be both a hardness, but also can be secondary hardness. Lower temperature quenching and tempering at low temperature, get a hardness, then the hardness is higher, but the lack of stability of the tempering. High temperature quenching and tempering can get secondary hardness, high tempering stability, but a large number of residual austenite is not easy to eliminate. This type of steel contains more eutectic carbides, the distribution of these eutectic carbides in the steel is very uneven, hot processing, these carbides strip distribution of the steel has significant anisotropy, Steel with a high carbide inhomogeneity has a lateral strength 30 to 40% lower than the machine direction and a low plasticity of 1/2 to 2/3. Anisotropy also makes it difficult to control the deformation of the steel, which contains a large amount of chromium, not suitable for China’s resource conditions. Therefore, it is necessary to develop a more economical and less chromium high performance wear-resistant micro-deformation of steel to fully replace the high-carbon high-chromium steel.