铸态中铬硅铸铁价电子结构与M_7C_3体积分数  

Valence electron structure of cast medium chrome-silicon cast iron and volume percentage of eutectic carbide M_7C_3

作　　者：李卫[1] 胡世涛[1] 

机构地区：[1]暨南大学材料科学与工程系,广东广州510632

出　　处：《材料科学与工艺》2007年第6期805-808,共4页Materials Science and Technology

基　　金：广东省科技计划重点引导项目(2004B10301001)

摘　　要：为提高中铬铸铁共晶碳化物中M7C3比例,研究了中铬硅铸铁(290Cr8Si2).建立了铸态中铬硅铸铁基体的价电子结构,运用固体与分子经验电子理论(EET)分析了中铬硅铸铁中Si的作用.分析和实验结果表明,中铬硅铸铁基体含C、Cr、Si的γ-Fe晶胞中,C原子与Si原子的结合力强于C原子与Cr原子的结合力,较高的含Si量降低了铸铁基体的含Cr量,提高了共晶碳化物的含Cr量,进而提高了共晶碳化物中M7C3的比例.耐磨损中铬硅铸铁(290Cr8Si2)共晶碳化物(M7C3+M3C)中M7C3占94.2%(体积分数),明显高于中铬铸铁(290Cr8Si1)共晶碳化物中的M7C3的71.7%(体积分数).The medium chrome-silicon cast iron （290Cr8Si2） is studied for increasing the M7C3content in eutectic carbide in medium chrome cast iron. The valence electron structure of cast medium chrome-silicon cast iron matrix was set up and the effect of Si was analyzed by empirical electron theory of solids and molecules （EET）. The analysis and experimental results show, that the affinity between C and Si is stronger than that between C and Cr in γ- Fe lattice of medium chrome-silicon cast iron matrix containing C, Cr and Si. The higher content of Si reduces the content of Cr in cast iron matrix and improves the content of Cr in eutectic carbide, therefore, the volume percent of M7C3 in eutectic carbide is improved. The MTC3content in eutectic carbide （M7C3 ＋ M3C） is 94. 2% （volume percent） in the wear-resistant medium chrome-silicon cast iron （290Cr8Si2）, which is obviously higher than that （71.7%） in medium chrome cast iron （290Cr8Sil）.

关 键 词：中铬铸铁 固体与分子经验电子理论 碳化物 价电子结构 硅 

分 类 号：TG143[一般工业技术—材料科学与工程]