Ce变质处理对含硼过共晶高铬铸铁组织与性能的影响  

Effect of Ce Modification on Microstructure and Properties of Boron-Containing Hypereutectic High Chromium Cast Iron

作　　者：王新华 焦玉琳 WANG Xin-hua;JIAO Yu-lin(Henan Police College,Zhengzhou 450046,Henan,China)

机构地区：[1]河南警察学院,河南郑州450046

出　　处：《铸造》2023年第7期810-818,共9页Foundry

基　　金：国家高等职业教育创新发展行动计划基金项目(XM-16-2019);河南省科技攻关基金项目资助(232102320205)。

摘　　要：采用金属型分别铸造Ce变质处理前、后过共晶高铬铸铁,提高其耐磨性。借助于OM、SEM、XRD、硬度计和磨损试验机等仪器设备研究分析了Ce变质前、后过共晶高铬铸铁组织与性能。结果表明:变质处理前、后过共晶高铬铸铁组织均由初生M_(7)C_(3)+共晶M_(7)C_(3)+奥氏体+马氏体组成。与变质前相比,变质后初生M_(7)C_(3)的形貌由长六边形转变为圆整的六边形,尺寸减小了44.9%,体积分数增大了30.2%。铸铁的洛氏硬度、冲击韧性和抗弯强度分别提高了5.0%、43.4%和39.2%,磨损失重减少了50.7%。Ce的化合物Ce_(2)O_(2)S作为M_(7)C_(3)异质形核核心的有效性是中等的,Ce对夹杂物有球化、净化作用。细化了的初生碳化物与基体相互保护,提高了铸铁表面耐磨性。变质前铸铁的磨损机制以微切削为主,断裂脱落为辅,变质后铸铁的磨损机制变为以微切削为主。The wear resistance of hypereutectic high chromium cast iron was improved by metal mold casting before and after Ce modification.By means of OM,SEM,XRD,hardness tester and wear testing machine,the microstructure and properties of hypereutectic high chromium cast iron before and after Ce modification were studied.The results show that the microstructure of hypereutectic high chromium cast iron before and after modification is composed of primary M_(7)C_(3)+eutectic M_(7)C_(3)+austenite+martensite.Compared with the pre-modification M_(7)C_(3),the morphology of the primary M_(7)C_(3) transformed from a long hexagon to a rounded hexagon,the size decreased by 44.9%,and the volume fraction increased by 30.2%.The Rockwell hardness,impact toughness and bending strength of cast iron are increased by 5.0%,43.4% and 39.2% respectively,and the weight loss is reduced by 50.7%.The compound Ce_(2)O_(2)S of Ce is moderately effective as the heterogeneous nucleation core of M_(7)C_(3),and Ce can spherodize and purify the inclusions.The refined primary carbides protect each other with the matrix,which improves the surface wear resistance of cast iron.The wear mechanism of the cast iron is changed from micro-cutting mainly and fracture shedding as auxiliary.

关 键 词：过共晶高铬铸铁 变质处理 组织性能强韧性机理 干滑动磨损 

分 类 号：TG143[一般工业技术—材料科学与工程]