铸态亚共晶高铬铸铁重熔时先共晶相的演变  

Evolution of Primary Phase in As-cast Hypoeutectic High Cr Cast Iron During Remelting

作　　者：张玲[1] 王铁旦[2] 周荣锋[1,2] 蒋业华[1] 周荣[1] 

机构地区：[1]昆明理工大学材料科学与工程学院 [2]昆明理工大学分析测试研究中心

出　　处：《特种铸造及有色合金》2010年第9期827-830,共4页Special Casting & Nonferrous Alloys

基　　金：高等学校博士学科点专项科研基金资助项目(20060674002);云南省自然科学基金资助项目(2004E0018M;2005E0013Q);云南省中青年学术和技术带头人后备人才培养基金资助项目(2009CI024)

摘　　要：通过观察常规铸态亚共晶高铬铸铁在固液区间等温重熔过程中先共晶奥氏体形貌的变化情况,研究其演变规律及机理。结果表明,在等温重熔过程中,网状枝晶的粗化、熔断和晶粒的球化、合并长大是先共晶奥氏体演变的4个主要阶段。在较低温度下重熔,其演变过程以枝晶长大粗化及熔断为主,奥氏体枝晶网状结构难以完全消除;在较高温度下重熔,组织的演变过程以晶粒的球化及合并长大为主。在适当温度下(1330℃)保温一定时间(35min)可以获得较为圆整且尺寸均匀分布的先共晶奥氏体组织,但加热温度过高,保温时间过长,奥氏体晶粒会严重长大粗化。By observing the morphological changes of primary austenite grains in as-cast hypoeutectic high Cr cast iron during isothermal remelting process in liquid-solid phase region,mechanism of its evolution was described. The results reveal that during isothermal remelting process,primary austenite phase is evolved from coarseness of net dendrite to fusion to spheroidization of grain and then to consolidation. Dendrite coarsening and fusing are dominant in evolution process at a lower remelting temperature,resulting in the difficulty of net austenite dendrite to be completely eliminated,while grain spheroidization and consolidation are dominant in evolution process at a higher remelting temperature. The equiaxed and uniform pre-eutectic austenite phase can be obtained in the high Cr cast iron at 1330℃ for 35 min. However,with increasing in heating temperature and in holding time,austenite phase can be seriously coarsened.

关 键 词：亚共晶高铬铸铁 初生奥氏体 重熔 演变 

分 类 号：TG143.7[一般工业技术—材料科学与工程]