高强韧铝合金半连铸凝固过程数值模拟及热裂纹形成机理研究  

Numerical Simulation of Solidification Process and Hot Crack Formation Mechanism of High Strength and Toughness Aluminum Alloy Semi-continuous Casting

作　　者：姜凯曦 何生平 詹磊 王新璋 叶强 杨林 王依山 单长智 郝海[1,4] JIANG Kaixi;HE Shengping;ZHAN Lei;WANG Xinzhang;YE Qiang;YANG Lin;WANG Yishan;SHAN Changzhi;HAO Hai(Key Laboratory of Solidification Control and Digital Preparation Technology(Liaoning Province),School of Materials Science and Engineering,Dalian University of Technology,Dalian 116024,China;SDIC Ningxia Qingtongxia New Material Co.,Ltd.,Qingtongxia 751603,China;SPIC Aluminum&Power Investment Co.,Ltd.,Yinchuan 750003,China;Ningbo Institute of Dalian University of Technology,Ningbo 315016,China)

机构地区：[1]大连理工大学材料学院辽宁省凝固控制与数字化制备技术重点实验室,辽宁大连116024 [2]国电投宁夏青铜峡新材料有限公司,宁夏青铜峡751603 [3]国家电投集团铝电投资有限公司,宁夏银川750003 [4]大连理工大学宁波研究院,浙江宁波315016

出　　处：《铸造技术》2023年第12期1100-1108,共9页Foundry Technology

基　　金：国家自然科学基金(52171030);校企合作项目(GDTXCL-QYGL-kjcx-2022-002)。

摘　　要：2024铝合金油气滑半连铸产品中出现的热裂纹问题严重影响了其工业化生产及综合性能。本文利用ProCAST铸造分析软件,基于移动边界法的宏观温度场模型,利用CAFE(cellular automata finite element)模块模拟铸锭微观组织对比实际晶粒尺寸,验证了模型可靠性;基于热弹塑性模型模拟了铸锭所受的主应力、等效应力以及切应力,分析了热裂纹的产生原因。对铸锭进行热裂纹敏感性判据HTI(hot tearing indicator)分析,结果表明,沿半径方向距离边缘约40 mm处裂纹倾向性最大且成环状,与实际铸锭中的裂纹位置和形状一致。基于第三强度理论,得到了φ254 mm的2024铝合金半连铸最佳工艺区间,铸造温度为685~695℃,铸造速度为59~62 mm/min。经验证,获得了表面质量良好,无裂纹的2024铝合金铸锭。Hot cracking easily occurs in the semi-continuous casting of 2024 aluminum alloy,further seriously affecting its industrial production and comprehensive performance.Numerical simulation technology is an important method to solve the problem of hot cracks.The CAFE(cellular automata finite element)module of ProCAST casting analysis software was used to simulate the solidification microstructure.First,the macroscopic temperature field of the semi-continuous casting process is simulated by the moving boundary method.Macroscopic temperature fields are used for microstructure simulation.The actual grain size is consistent with the simulated grain size.Therefore,the model is proven to be reliable.Principle stress,equivalent stress and shearing stress on the ingot were simulated based on the thermo-elasticity model.The causes of cracks were analysed by stress field simulation.In addition,the hot tearing indicator(HTI)was used to judge the crack tendency in ProCAST.The results show that the cracking tendency is greatest along the radius direction at a distance of approximately 40 mm from the edge and in a ring shape.The crack location and shape in the simulated ingot are consistent with those in the actual ingot.Based on the third strength theory,the optimal process of semi-continuous casting of 2024 aluminum alloy withφ254 mm was explored.A casting temperature of 685~695℃and a casting speed of 59~62 mm/min are the most reasonable process parameters.After test verification,2024 aluminum alloy ingots with good surface quality and no cracks are obtained.

关 键 词：2024铝合金 CAFE HTI 热裂纹分析 

分 类 号：TG146[一般工业技术—材料科学与工程]