摘要
针对某些企业在生产HT200和HT250的中、小铸件时,由于金相检验认为有C型石墨存在而引起客户拒收的情况,指出C型石墨只有在过共晶灰铸铁中才会出现,不会出现在亚共晶灰铸铁中。介绍了国际标准和国家标准中C型石墨的定义,建议对国家标准中灰铸铁石墨的分布类型早日进行修订。此外还指出金相试样抛光不良也可能导致所谓"块状石墨"的假象而引起误判。
Seeing that there was so-called ＂C-type graphite＂ found by the metallographic inspection when producing small and medium size castings with HT200 or HT250 grade gray irons in some foundries, and as a result the clients refused to accept the castings, the author pointed out that C-type graphite doesn＇t present itseff in hypoeutectic gray irons, but only in hypereutectic gray irons. The definitions of C-type graphite in both the International Standard and China Standard were introduced, and it＇s suggested to revise as earlier as possible the classification of graphite types in China＇s gray irons standard. Besides, it was also pointed out that poor polishing of the metallographic specimen might also cause the false image of so-called ＂C-type graphite＂ and lead to a wrong conclusion.
出处
《现代铸铁》
CAS
2008年第4期99-102,共4页
Modern Cast Iron
关键词
C型石墨
亚共晶灰铸铁
F型石墨
金相试样抛磨
C-type graphite
hypoeutectic gray irons
F-type graphite
polishing of metallographic specimen
