在国标高铬铸铁Cr26的基础上,开发了新型的超高铬铸铁(铬含量约37%)。采用扫描电镜和X射线衍射仪对超高铬铸铁的显微组织进行分析,并对材料的硬度及冲击韧性进行了研究。在H3PO4介质条件下,利用MCF-30型腐蚀磨损试验机,研究了超高铬铸铁的腐蚀磨损性能。结果表明,超高铬铸铁中的碳化物类型为M7C3和M23C6,基体为马氏体和残余奥氏体。随着碳含量的增加,超高铬铸铁的硬度先增加而后降低,冲击韧性逐渐降低,超高铬铸铁的腐蚀磨损性能逐渐降低。超高铬铸铁的耐腐蚀磨损性能明显优于Cr26铸铁,其相对耐磨性最高为Cr26的3倍以上。
New-type super-high chromium cast iron (SHCCI) containing about 37% chromium was developed from the high chromium cast iron Cr26.The microstructure of SHCCI was investigated by SEM and XRD respectively,the hardness and the impact toughness of SHCCI were studied.Moreover,the corrosive wear properties of SHCCI were researched using MCF-30 type erosion abrasion tester with medium H3PO4.The results show that: the carbide form of SHCCI is M7C3 and M23C6,and the base is martensite and retain austenite;with the increase of carbon content,the hardness of SHCCI firstly increases and then decreases,the impact toughness decreases gradually,and the corrosive wear properties of SHCCI decreases gradually.It is obvious that the corrosive wear properties of SHCCI are superior to that of Cr26 cast iron,and its maximal relative wear resistance of SHCCI is three times that of Cr26.