6061铝合金半连铸圆坯组织瞬态数值模拟研究  

Transient numerical simulation of 6061 aluminum alloy semi-continuous cast round billet

作　　者：呼京龙 乐启炽 胡文鑫[2] HU Jinglong;LE Qichi;HU Wenxin(School of Materials Science and Engineering,Northeastern University,Shenyang 110819,China;Baotou Research Institute of Rare Earths,Baotou 014020,China)

机构地区：[1]东北大学材料科学与工程学院,辽宁沈阳110819 [2]包头稀土研究院,内蒙古包头014020

出　　处：《兵器材料科学与工程》2024年第5期25-33,共9页Ordnance Material Science and Engineering

基　　金：国家自然科学基金(52274377)。

摘　　要：本文建立了6061铝合金半连铸过程传热模型和元胞自动机-有限元(CAFE)耦合模型,采用边界跟踪法模拟了瞬态条件下不同铸造工艺对凝固组织演变的影响。经试验验证,该模型可模拟6061铝合金半连铸的凝固组织。用其预测不同铸造温度、速度和传热系数下的凝固组织。结果表明:铸造温度升高,等轴区宽度从219.1 mm降至187.4 mm,柱状晶和等轴晶均粗化;铸造速度增加,液穴深度增大,等轴晶区的宽度由222.1 mm降至202.4 mm,柱状晶尺寸增大,等轴晶细化;传热系数增大,铸坯边部温度梯度增大,柱状晶粗化,但中心熔体冷却速度增大,对等轴晶有一定细化效果。用半连铸方法生产6061铝合金铸锭,适当降低铸造温度,增大铸造速度和冷却水量有利于形成细小的凝固组织。A heat transfer model and cellular automata-finite element(CAFE)coupling model of 6061 aluminum alloy semi-continuous casting process were established in this paper.The effects of different casting processes on solidification structure evolution under transient conditions were simulated by boundary tracking method.The experimental results show that the model could simulate the solidification structure of 6061 aluminum alloy.It was used to predict the solidification structure under different casting temperature,speed and heat transfer coefficient.The results show that the width of the equiaxial zone decreases from 219.1 mm to 187.4 mm with the increase of casting temperature,and both the columnar and equiaxial crystals are coarsened.With the increase of casting speed and liquid hole depth,the width of equiaxed crystal zone decreases from 222.1 mm to 202.4 mm,the size of columnar crystal increases,and equiaxed crystal is refined.The heat transfer coefficient increases,the temperature gradient at the edge of the billet increases,the columnar crystal coarsens,but the cooling rate of the central melt increases,and the equal-axis crystal has a certain thinning effect.In the production of 6061 aluminum alloy ingot by semi-continuous casting,proper reduction of casting temperature,increase of casting speed and cooling water is conducive to the formation of fine solidification structure.

关 键 词：边界追踪法 凝固组织 元胞自动机-有限元法 6061铝合金 

分 类 号：TG292[金属学及工艺—铸造]