灰铸铁激光熔融处理后的组织

Microstructure of Gray Iron Treated by Laser Surface Melting

灰铸铁（ＨＴ２００）在激光熔融处理后的组织分成熔化区、半熔化区、相变硬化区和热影响区四层。分析了各区的组织，发现在熔化和半熔化区中残留片状石墨周围先出现薄层奥氏体，其外是变态莱氏体区。

The microstructures of a gray iron (HT200) treated using laser surface melting can be divided intofour zones,i.e,melted zone,semi-melted zone, phase transformation hardening zone and heat affectedzone,analysing the microstructures of each zone revealed that the residual graphite flakes in the meltedzone and semi-melted zone are surrounded first by a thin layer of austenite,then by a abnormal ledeburite region