稀土镁变质对金属型铸造高铬铸铁Cr26耐磨性的影响  

Effect of Rare Earth Magnesium Modification on Wear Resistance of Permanent-mould High Chromium Cast Iron Cr26

作　　者：郭克星 夏鹏举[1] GUO Ke-xing;XIA Peng-ju(School of Materials Science and Engineering,Shaanxi University of Technology,Hanzhong 723000,China)

机构地区：[1]陕西理工大学材料科学与工程学院,陕西汉中723000

出　　处：《稀有金属与硬质合金》2019年第2期39-44,共6页Rare Metals and Cemented Carbides

基　　金：国家自然科学基金(51201094);陕西理工学院专项科研基金(SLGQD13-22)

摘　　要：通过金相显微镜、扫描电子显微镜、洛氏硬度计和动载磨料磨损试验机研究了不同含量的稀土镁变质处理对Cr26高铬铸铁组织、硬度及耐磨性的影响,通过磨损量以及磨痕形貌之间的关系探讨磨损机理。结果表明:稀土镁的加入使得碳化物的形成和长大环境发生改变,使碳化物形貌,由长片状和长条状分布转变为团块状和近似圆球状分布,减小了对基体的割裂程度。当稀土镁的加入量为0.6%时,组织和碳化物的分布达到最佳状态。稀土的主要作用是净化合金液,细化合金的铸态组织;镁的主要作用是脱氧、脱硫、净化铁液和减少夹杂物。磨痕的形貌主要是犁沟、卷曲、凹坑和少量的微裂纹。磨损的主要机制有切削磨损、多次塑变和凿削磨损。The effect of rare earth magnesium modification concentration on the structure,hardness and wear resistance of Cr26 high chromium cast iron was studied by metallographic microscope,scanning electron microscopy,Rockwell hardness tester and dynamic abrasive wear tester,and the wear mechanism was discussed through the relationship between wear amount and wear trace morphology.The results show that the addition of rare earth magnesium changes the formation and growth environment of carbides,the morphology of carbides changes from long sheet and strip distribution to lump and nearly spherical distribution,and reduces the degree of matrix splitting.When the addition amount of rare earth magnesium reaches 0.6%,the microstructure and the distribution of carbides reaches its optimal state.The main role of rare earth is to purify the alloy liquid,refine the as-cast structure of the alloy,and the main role of magnesium is to deoxidize,desulfurize,purify the molten iron and reduce inclusions.The morphology of wear marks is mainly plough grooves,curls,pits and a small number of microcracks.The main wear mechanisms are cutting wear,multiple plastic deformation and chisel wear.

关 键 词：高铬铸铁 稀土镁 变质处理 铸态组织 耐磨性 

分 类 号：TG143[一般工业技术—材料科学与工程]