Effect of casting speed on floating grains and macrosegregation ofdirect-chill cast 2024 alloy with intensive melt shearing  

熔体强剪切作用下铸造速度对半连续铸造2024铝合金铸锭中浮游晶和宏观偏析的影响

作　　者：Xu-dong LIU Qing-feng ZHU Zhi-meng LI Cheng ZHU Rui WANG Tao JIA Zhi-hao ZHAO Jian-zhong CUI Yu-bo ZUO 刘旭东;朱庆丰;李志猛;朱成;王睿;贾涛;赵志浩;崔建忠;左玉波(东北大学材料电磁过程研究教育部重点实验室,沈阳110004;东北大学材料科学与工程学院,沈阳110004;东北大学轧制技术及连轧自动化国家重点实验室,沈阳110004)

机构地区：[1]Key Lab of Electromagnetic Processing of Materials,Ministry of Education,Northeastern University,Shenyang 110004,China [2]College of Materials Science and Engineering,Northeastern University,Shenyang 110004,China [3]State Key Laboratory of Rolling and Automation,Northeastern University,Shenyang 110004,China

出　　处：《Transactions of Nonferrous Metals Society of China》2021年第3期565-575,共11页中国有色金属学报（英文版）

基　　金：the financial supports from the National Natural Science Foundation of China (51674078, 51374067)

摘　　要：The ingot was prepared by direct-chill(DC)casting technology with different casting speeds under the influence of intensive melt shearing to explore the effect of casting speed and intensive melt shearing on the floating grains and negative centerline segregation.The results indicate that the application of intensive melt shearing in DC casting process can distribute the floating grains uniformly,reduce the area fraction of the floating grains,alleviate the negative centerline segregation,and improve the uniformity of temperature field in the sump.It is also suggested that under the influence of intensive melt shearing,the casting speed plays a crucial role in the amounts and distribution of floating grains.At low casting speed,the intensive melt shearing can significantly reduce the area fraction of the floating grains and distribute them uniformly throughout the ingot.However,this effect gradually disappears with the increase of casting speed.在熔体强剪切作用下,采用不同铸造速度的半连续铸造工艺制备铸锭,研究熔体强剪切和其作用下铸造速度对浮游晶和铸锭中心负偏析的影响。结果表明,在半连续铸造过程中施加熔体强剪切可以均匀分布铸锭截面上的浮游晶,减少浮游晶的面积百分数,减弱铸锭中心负偏析,并提高熔池内熔体温度分布的均匀性。在熔体强剪切作用下的半连续铸造过程中,铸造速度对浮游晶的数量和分布起着关键作用。当铸造速度较低时,施加熔体强剪切可以显著减小浮游晶的面积分数,并使其在铸锭内均匀分布。但是,随着铸造速度的增加,这种作用效果逐渐消失。

关 键 词：direct-chill casting intensive melt shearing MACROSEGREGATION floating grains casting speed 2024 aluminum alloy 

分 类 号：TG24[金属学及工艺—铸造] TG146.21[一般工业技术—材料科学与工程]