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为了提高高铬铸铁材料的服役寿命,用4因素、3水平正交试验方法研究了碳、铬含量、淬火温度和回火温度对高铬铸铁力学性能的影响,确定获得最佳性能的稳定工艺。结果表明、当高铬铸铁的碳、铬的含量(质量分数)分别为2.7%和18%时,进行1040℃淬火+280℃回火的试样综合力学性能最高,其洛氏硬度为62 HRC,冲击韧度为8.2 J/cm~2。从显微组织可以看出,综合力学性能最好的高铬铸铁试样晶粒细小,碳化物的析出量减少,并且出现了球状碳化物。由XRD分析显示,综合力学性能最低的高铬铸铁试样中奥氏体含量高于综合力学性能最高的试样。此外,EDS能谱分析显示析出的碳化物主要为M_7C_3型碳化物。
In order to improve the service life of high-chromium cast iron, the influence of carbon, chromium content, quenching temperature and tempering temperature on the mechanical properties of high-chromium cast iron was studied by 4-factor and 3-level orthogonal test methods to determine the stable process . The results show that when the contents of carbon and chromium (mass fraction) of high chromium cast iron are 2.7% and 18% respectively, the samples with 1040 ℃ quenching and 280 ℃ tempering have the highest mechanical properties with Rockwell hardness of 62 HRC , Impact toughness of 8.2 J / cm ~ 2. As can be seen from the microstructure, the best high-chromium cast iron composite mechanical properties of fine grain, carbide precipitation decreased, and the emergence of spherical carbides. The XRD analysis shows that the austenite content of the high chromium cast iron with the lowest comprehensive mechanical properties is higher than that of the sample with the highest comprehensive mechanical properties. In addition, EDS EDS analysis showed that the precipitated carbides are mainly M_7C_3 carbides.