球墨铸铁的石墨核心及其结构

Graphite Nuclei and their Structure of Spheroidal Graphite Cast Iron

使用离子刻蚀、热氧腐蚀和萃取复型等多种方法制样，用扫描电镜、透射电镜辅以电子探针综合检测了球墨核心的组成、结构及其与铁水和变质剂成分的关系。研究结果表明：球墨核心成分与原铁水及变质剂的成分有关，核心是多种多样的。电子衍射鉴定出三种核心的结构，作为基底的异质核心与石墨有良好的晶格匹配关系，错配度小于１２．５％。最后分析归纳了夹杂物作为石墨核心的条件。

Composition and structure of graphite nuclei of spheroidal graphite cast iron and the role of who composition of iron melts and inoculants were studied by using SEM and TEM complemented with EDAX and WDX. Samples were prepared with various methods including ion etching, thermal etching and extracted replica. The results show that the composition of graphite nuclei are related to the composition of iron melts and inoculants. There are a great variety of nuclei detected. structures of three kinds of nuclei were identified by electron diffraction method. An appropriate crystallographic matching with the disregistry less than 12 .5% exists between heterogeneous nuclei and graphite. Finally, conditions for nonmetallic inclusions which could turn into graphite nuclei are summarized.