双辊连续铸造制备A1-Mg-Mn合金板材的组织和性能研究  

Study on Microstructure and Properties of Al-Mg-Mn Alloy Slab Prepared by Twin-roll Continuous Casting Process

作　　者：张敬宇 付金禹 许光明 李勇[2] ZHANG Jingyu;FU Jinyu;XU Guangming;LI Yong(State Key Laboratory of Rolling and Automation,Northeastern University,Shenyang 110819,China;Key Laboratory of Electromagnetic Processing of Materials,Ministry of Education,Northeastern University,Shenyang 110819,China)

机构地区：[1]东北大学材料电磁过程研究教育部重点实验室,辽宁沈阳110819 [2]东北大学轧制技术及连轧自动化国家重点实验室,辽宁沈阳110819

出　　处：《热加工工艺》2025年第3期125-129,共5页Hot Working Technology

基　　金：国家自然科学基金项目(51790485)。

摘　　要：采用光学显微镜(OM)、扫描电镜(SEM)、差示扫描量热仪(DSC)、电导率和硬度测试等方法,对双辊连续铸造Al-Mg-Mn合金板坯的组织和性能进行研究。分析了双辊连续铸造工艺的优化机制。结果表明,半凝固状态下的熔体受到冷却水的强烈作用,热量由铸轧区后端传向前端,初始枝晶沿与热流相反方向生长形成柱状晶,且靠近心部生长方向近乎水平,液穴的形状发生较大变化,有效改善了宏观偏析缺陷。随着板坯厚度增加,液穴形状的变化更加显著,同时冷速逐渐降低,合金元素扩散充分;当厚度达到20 mm时,冷速最慢,宏观偏析和微观偏析缺陷基本消失,合金元素分布最为弥散,固溶体过饱和度最高,具有最高的硬度和最低的电导率,分别为92.26 HV和17.74 MS/m。The microstructure and properties of twin-roll continuous casting Al-Mg-Mn alloy slab were studied by optical microscopy(OM),scanning electron microscopy(SEM),differential scanning calorimetry(DSC),electrical conductivity and hardness test.The optimization mechanism of twin-roll continuous casting process was analyzed.The results show that melt in semi-solidified state is strongly affected by cooling water.Heat is transferred forward from the back end of the cast-rolling zone,and the initial dendrite grows in the direction opposite to the heat flow,and the growth direction near the center is almost horizontal.The shape of the sump changes greatly,which effectively improves the macro-segregation defect.With the increase of slab thickness,the shape of sump changes more significantly,and the cooling rate decreases gradually,and the alloying elements diffuse fully.When the thickness reaches 20 mm,the cooling rate is the slowest,and the defects of macro-segregation and intergranular segregation basically disappear.The alloying element distribution is the most diffuse,the solid solution has the highest supersaturation,and the alloy has the highest hardness and the lowest conductivity,which are 92.26 HV and 17.74 MS/m,respectively.

关 键 词：双辊连续铸造工艺 Al-Mg-Mn合金 水平凝固方式 偏析缺陷 力学性能 

分 类 号：TG249.7[金属学及工艺—铸造]