摘要
采用能显示奥氏体的彩色金相法，从宏观角度研究厚壁球墨铸铁的凝固形貌发现，随壁厚增加，铸件断面出现大量从表向里生长的奥氏体枝晶；当超过某一临界厚度时，凝固方式由糊状向海绵状过渡。凝固形貌的改变使偏析由共晶团间的微观偏析转变成枝晶间的宏观偏析；使力学性能的不均性加大，产生明显的方向差别；同时使铸件的补缩变得困难。
An investigation has been carried out into solidification morphology of the thick-wall ductile ironmacroscopically, it is found that numerous austenitic dendrites were formed from surface to center inthe section of the castings with increasing wall thickness.When exceeding a critical thickness, the solidification style transforms from the pasty state to the spongy.The variation of the solidification morphology leads to changing from the microsegregation between the eutectic grains to the macro-segregation between the dendrites,thus increasing heterogeneity of the mechanical properties in the variousdirections and simultaneously, rendering the feeding of castings very difficult
出处
《铸造》
CAS
CSCD
北大核心
1996年第1期1-7,共7页
Foundry
