铝合金连铸过程中电磁场对液穴形态及微观组织的影响  

Effects of Electromagnetic Field on Sump Shapes and Microstructure of Al Alloy Produced by Continuous Casting

作　　者：张勤 崔建忠[1] 路贵民[1] 

机构地区：[1]东北大学材料电磁过程教育部重点实验室,辽宁沈阳110006

出　　处：《铸造》2003年第4期230-234,共5页Foundry

基　　金：国家重大基础发展规划项目("973"项目编号G199906490501)。

摘　　要：在低频交变电磁场作用下,对7075铝合金CREM法半连铸过程中,熔体弯液面形状随磁场强度及磁场频率的变化、以及15Hz条件下,液穴状态及相应的微观组织结构随磁场强度的变化进行了试验研究。结果表明:随着磁场强度及磁场频率的增大,弯液面曲率半径减小;并且当磁场频率一定时,随着磁场强度增加,弯液面曲率半径及熔体与结晶器接触高度减小,初凝壳形成位置点降低,液穴深度变浅。相应地,铸锭中近球形组织增加,蔷薇形组织减少,整体组织变得更加细小和均匀。Under the effect of electromagnetic field with low frequency,the evolution of surface meniscus with electromagnetic intensity and electromagnetic frequency as well as of the sump shape and microstructure of ascast ingot with electromagnetic intensity at the steady electromagnetic frequency of 15Hz, have been experimentally investigated. The results showed that the curvature of surface meniscus decrease with the enhancement of intensity and frequency of electromagnetic field,and with the increase of electromagnetic intensity at a steady electromagnetic field,the curvature of surface meniscus, sump height and the height of contact line between melt and mold as well as the forming position of primary solidified shell all decrease.Meanwhile, the quantity of spheroidshaped grains increase and rosetteshaped grains decrease accordingly,the whole microstructure of the ingot becomes more fine and uniform.

关 键 词：电磁场 半连铸 7075铝合金 弯液面形状 液穴形态 微观组织 

分 类 号：TG292[金属学及工艺—铸造] TG249.7