采用硬度测量、冲击韧度测试、光学金相及扫描电子显微镜分析壁厚为90 mm高铬铸铁件的性能及组织特征。结果表明,采用合理的铸造工艺,得到了连续分布的Cr7C3型碳化物组织,保证了大厚壁铸件的硬度分布基本均匀。与壁厚20 mm的试样相比,室温下冲击值略有下降,冲击断口由多个裂纹源形成,有撕裂的痕迹存在。 Hardness measurement, impact toughness test, optical metallography and scanning electron microscopy were used to analyze the properties and microstructure of high chromium cast iron with a thickness of 90 mm. The results show that the continuous distribution of Cr7C3 carbide structure is obtained by a reasonable casting process, which ensures that the hardness distribution of large thick wall castings is basically uniform. Impact values ​​decreased slightly at room temperature compared to specimens with a wall thickness of 20 mm. Impact fractures were formed by multiple sources of cracks, with evidence of tearing.