球墨铸铁石墨球核心组成及形核机制的研究  

Phase Composition and Nucleation Mechanism of Spheroidal Graphite Nucleus in Ductile Iron

作　　者：申志清[1] 田学雷[1] 郑洪亮 李桐桐[1] 徐岩[1] 许荣福[1] 张宁[2] 

机构地区：[1]山东大学材料液固结构演变与加工教育部重点实验室,山东济南250061 [2]北京航星机器制造公司,北京100013

出　　处：《铸造》2012年第4期357-361,共5页Foundry

基　　金：2009年度山东省优秀中青年科学家科研奖励基金计划(BS2009ZZ005)

摘　　要：通过浇注相同球化剂、不同孕育剂处理的球墨铸铁楔形和激冷试样，采用FE—SEM对石墨球核心的形貌、尺寸、物相组成进行分析，对核心物质与石墨的失配度进行计算。结果表明，石墨球核心形状各异，主要有球形、锥形以及片状。核心的尺寸为0．6～7μm。核心物质主要由硫化物、氧化物、碳化物等组成。石墨球异质核心既有单个核心结构，也有双重和多重核心。大部分核心物质与石墨的失配度δ低，可以直接成为石墨形核衬底，但SiO2与石墨失配度高，需要SiC结合才能间接成为石墨形核衬底。The morphology, size and composition of spheroidal graphite （SG） nuclei were researched by casting a series of different samples which were treated by the same nodulizer and different inoculants. Wedge and chill test pieces used for chemical analysis were cast. The observation of the SG nucleus was done by using of FE-SEM. The results indicate that the morphologies of SG nuclei are different, including spherical, conical, polygonal and so on. The SG nucleus consist of sulfide, oxide and carbide, and the size is about 0.6-7 μm. Not only single core but also double and multiple cores are found in SG nuclei. The mismatch between most nuclei compounds and graphite is small, so compounds are good nucleating sites for SG. For the δ between the SiO2 and graphite is large, SiO2 can act as spherical graphite substrate only after the combination with SiC.

关 键 词：球墨铸铁 石墨球核心 异质形核 形核机理 

分 类 号：TG143.5[一般工业技术—材料科学与工程]