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镁合金铸轧区温度场仿真及组织研究作者姓名：吴迪指导教师：崔建忠教授单位名称：材料与冶金学院专业名称：材料成型与控制工程东北大学2006年6月NumericalSimulationonTemperatureFieldandtheStudyonMicrostructureofCast-rollingZoneofMagnesiumAlloybyWuDiSupervisor:ProfessorCuiJianZhongNortheasternUniversityJune2006东北大学毕业设计（论文）摘要镁合金铸轧区温度场仿真及组织研究镁合金是最轻的金属结构材料，其比强度和比刚度高，阻尼性及机加工性好，具有防震、屏蔽电磁波等优异性能，近年来得到极大重视，在国防、航空航天以及3C、汽车等民用工业部门得到了广泛地应用。镁合金的双辊薄带连续铸轧技术是当今有色行业主要研究的课题之一，具有短流程、低能耗及节省投资等优点。应用模拟软件，进行镁合金双辊薄带连续铸轧过程的数值模拟，寻求最佳工艺参数，为镁合金的连续铸轧提供理论基础。本文通过大型模拟软件ANSYS研究了不同的浇注温度、不同的铸轧速度以及不同的辊带间对流换热系数对铸轧区内镁熔体温度场和流场的影响；通过轧卡实验得到一定条件下的铸轧区凝固样品，并观察其凝固组织；论文得到了如下结果：（1）随着浇注温度的升高，铸轧区内的整体流动趋势差别不大，各处温度均有所升高，液穴长度增大，液固两相区增大，轧辊咬入端附近两相区凝固壳变薄，凝固终点位置靠近轧制出口端，出口板带温度也升高。（2）随着铸轧速度的提高，铸轧区内的液穴长度增大，液固两相区增大，铸带表面温度升高，凝固壳变薄，凝固终点位置向轧制出口端靠近。铸轧区中部的两个漩涡略向轧制出口端偏移。（3）随着辊带间对流换热系数的增大，铸轧区内的液穴的长度减小，液固两相区变小，凝固壳略变厚，凝固终点位置向咬入端偏移。铸轧区中部的两个漩涡也向咬入端偏移。（4）铸轧区的凝固组织，靠近轧辊边部的晶粒比中间部位的细小且等轴化程度更高；边部的晶粒则是越靠近轧制出口端越细小。关键词：数值模拟，镁合金，铸轧，温度场，流场东北大学毕业设计（论文）AbstractNumericalSimulationonTemperatureFieldandtheStudyonMicrostructureofCast-rollingZoneofMagnesiumAlloyMagnesiumalloysarethelightestconstructionalmetalmaterials.Duetotheirexcellentpropertiessuchashighspecificstrengthandstiffness,gooddampingandmachinability,shockresistance,electromagneticshielding,magnesiumalloysaredeemedasoneofthemostpotentialmaterials,andhavereceivedmoreandmoreattention.Magnesiumalloysarerapidlyappliedtonationaldefence,aeroplane,3C,automobileandsoon.Thetechniqueoftwin-rollstripcontinuouscast-rollingofmagnesiumalloysisoneofthemainresearchtasksinnonferrousindustrynow,itpossessestheadvantagessuchasshortprocedure,lowenergyconsumption,lessinvestment.Simulativesoftwarecansimulatetheprocessoftwin-rollstripcontinuouscast-rollingofmagnesiumalloystogettheproperprocessingparameters,andprovidetheoreticalbasisforcontinuouscast-rollingofmagnesiumalloys.Inthispaper,theeffectofpointofpouring,cast-rollingspeedandheatconvectioncoefficientwasstudiedonthetemperatureandflowfieldofmagnesiummeltinthecast-rollingzonebyANSYS;alsosolidsamplewasobtainedbyexperimenttostudythesolidmicrostructureinthecast-rollingzone,andtheconclusionswereobtainedasfollow:（1）Withtheincrementofpointofpouring,theflowtendencyinthecast-rollingzoneishardlychanged,thetemperatureeverywhereinthecast-rollingzoneincreasesmoreorless,thelengthoftheliquidcaveincreases,thesemi-solidregionenlarges,thesemi-solidshellaroundthenippointthins,freezingpointisneartooutletandthetemperatureofstripinoutletalsoincreases.（2）Withtheincrementofcast-rollingspeed,thelengthoftheliquidcaveincreases,thesemi-solidregionenlarges,thesurfacetemperatureofstripincreases,thesemi-solidshellthins,freezingpointisneartooutletandthetwoeddiesinthemiddleofthecast-rollingzoneshifttooutletappreciably.（3）withtheincrementofheatconvectioncoefficient,thelengthoftheliquidcavereduces,thesemi-solidregiondiminishesandthesemi-solidshellthickensappreciably.Thefreezingpointandthetwoeddiesinthemiddleofthecast-rollingzoneareneartothenippoint.东北大学毕业设计（论文）Abstract（4）Forthesolidmicrostructureofthecast-rollingzone,thegrainsaroundtherollsarefinerandmoreequiaxialthanthoseinthemiddleofthecast-rollingzone.Forthosegrainsaroundtherolls,thenearertheyaretooutlet,thefinertheyare.Keywords:numericalsimulation，magnesiumalloy，cast-rolling，temperaturefield，flowfield东北大学毕业设计（论文）目录-1-目录任务书··································································································································i中文摘要·······························································································································iiABSTRACT······················································································································iii第1章绪论·························································································································11.1金属镁及其合金···········································································································11.1.1镁的基本性质及特点································································································11.1.2镁合金的合金成分、牌号标记及其分类·································································31.1.3镁合金的应用及国内外发展现状·············································································51.2板带铸轧技术的提出与发展现状[20]·····································································71.2.1国外简况····················································································································71.2.2国内简东北大学毕业设计（论文）目录-2-况····················································································································81.3铸轧技术的数值模拟现状························································································81.4本文研究的意义和主要内容···················································································91.4.1本文研究的意义·······································································································101.4.2本文研究的主要内容·······························································································11第2章铸轧过程数值模拟的基本理论····························