Fe-3%Si合金渗碳层中SiO_2形成及性能  

SiO_2 formation in carburized layer of Fe-3%Si alloy and its property

作　　者：李艳霞[1] 刘芳[2] 刘杰 张巨成[1] 刘俊友 

机构地区：[1]北华航天工业学院材料系,河北廊坊065000 [2]北京科技大学材料科学与工程学院,北京100083 [3]北科德瑞冶金工程技术有限公司,北京100083

出　　处：《材料热处理学报》2013年第4期172-176,共5页Transactions of Materials and Heat Treatment

摘　　要：设计了一种新型的铁基二元合金—Fe-3%Si合金,并对其进行表面渗碳处理。借助于SEM、XRD、EPMA、硬度测定及摩擦实验等分析手段,研究了合金渗碳层的组织及其性能。结果表明:Fe-3%Si合金渗碳层组织中形成大量SiO2颗粒,基体主要由马氏体和残余奥氏体组成。渗碳初期,Si元素促进了碳在奥氏体中扩散并有利于奥氏体稳定性提高。但氧原子沿奥氏体晶界扩散并与晶界及其附近的Si结合形成网状SiO2,阻碍碳原子进一步扩散.渗碳处理后的Fe-3%Si表面硬度达到66 HRC,干摩擦条件下抗平面滑动摩擦磨损性能优于高铬铸铁。A Fe-3% Si alloy was fabricated and carburized. Microstructure and properties of the carburized layer were studied by means of SEM, XRD, EMPA, hardness testing and friction experiment. The results show that the microstructure of the carburized layer is mainly consisted of SiO2 particles,martensite matrix and retained austenite. Si element promotes the diffusion of carbon atom in austenite at the early stage of carburization and is advantageous to the austenite stability. The oxygen atoms diffuse along the grain boundaries of austenite and react with silicon to form dense SiO2 particle at austenite grain boundaries and nearby, which hinders the further diffusion of carbon atom. Hardness of that of Fe-3% Si alloy after carburization is 66HRC and the wear resistance in the dry sliding condition is better than that of high chromium cast iron.

关 键 词：铁硅合金 渗碳 SIO2 颗粒 摩擦 磨损 

分 类 号：TG156.8[金属学及工艺—热处理]