凸透镜形结晶器内铸坯凝固传热行为  

Heat transfer behavior of slab solidification in convex lens-shaped mold

作　　者：贲东阳 蔡兆镇 朱苗勇 徐栋 赵和明 BEN Dongyang;CAI Zhaozhen;ZHU Miaoyong;XU Dong;ZHAO Heming(School of Metallurgy,Northeastern University,Shenyang 110819,Liaoning,China;Xinjiang Bayi Iron and Steel Co.,Ltd.,Urumqi 830022,Xinjiang,China;Jingye Yingkou Medium Plate Co.,Ltd.,Yingkou 115099,Liaoning,China)

机构地区：[1]东北大学冶金学院,辽宁沈阳110819 [2]新疆八一钢铁股份有限公司,新疆乌鲁木齐830022 [3]敬业营口中板有限公司,辽宁营口115099

出　　处：《中国冶金》2024年第11期32-43,116,共13页China Metallurgy

基　　金：国家重点研发计划资助项目(2021YFB3702001);国家自然科学基金资助项目(52174307);兴辽英才计划资助项目(XLYC2203196);中央高校基本科研业务专项资金资助项目(N2425008)。

摘　　要：宽厚板轧制过程边部高发宽度45~120 mm的边线裂纹是钢铁行业的共性技术难题。制备窄面为内凹弧面结构的宽厚板坯,可有效防止轧制过程中间坯窄面翻转至宽面,从而大幅减小宽厚板边线裂纹的宽度。为了制备窄面凹形弧面宽厚板坯,设计了1种窄面为凸形弧面结构的结晶器(称为凸透镜形结晶器),并构建了1/4铸坯-结晶器系统的三维传热与力学耦合有限元模型,对比分析了铸坯在凸透镜形结晶器和传统窄面平面形结晶器内凝固过程坯壳动态变形、坯壳/铜板界面传热介质分布、凝固坯壳与铜板传热规律。结果表明,凸透镜形结晶器内铸坯宽面角部在出口处的坯壳-结晶器界面间隙最大为1.26 mm,由此造成铸坯宽面角部的最大气隙厚度为0.71 mm,最厚保护渣分布于偏离角区域,最大厚度约1.13 mm;窄面最大界面间隙位于弯月面下500 mm处的铸坯角部,达1.40 mm,最大气隙厚度为0.53 mm,最厚保护渣为偏离角区域的1.35 mm。相比于传统窄面平面形结晶器,凸透镜形结晶器在铸坯宽面和窄面角部区域的最大间隙分别减小0.29 mm和0.33 mm,最大气隙厚度分别减小0.23 mm和0.18 mm,保护渣最大厚度分别减小0.35 mm和0.34 mm。为此,铸坯宽面和窄面偏离角部高温区的分布范围横向分别减少了36 mm和17 mm,最高温度分别降低35℃和44℃,提高了铸坯温度均匀性。同时,受益于凸透镜形结晶器窄面铜板水缝均匀化设计,弯月面附近的窄面铜板温度横向分布较均匀,热面最高温度降低15℃。The frequent occurrence of edge linear cracks with a width of 45-120 mm at the edge of wide and thick plates during rolling process is a common technical problem in the steel industry.Producing wide and thick slabs with a concave arc structure on the narrow can effectively prevent the narrow face of slab turn to the wide side during rolling process,thus it can significantly reduce the width of edge linear cracks in wide and thick plates.In order to make the wide and thick slabs with narrow concave curved faces,a mold with convex curved structure narrow face copper plates(called a convex lens-shaped mold)was designed.Based on this,a 3D coupled thermo-mechanical finite element model for the 1/4 slab-mold system was established,and the laws of dynamic deformation of slab shell,the distribution of heat transfer medium in the gap between slab and copper plate,and the temperature evolution of solidified slab and the copper plate in the convex lens-shaped mold and a traditional mold were comparatively analyzed.The results show that the maximum interface gap of slab-mold around mold wide face corner is 1.26 mm at the mold exit in the convex lens-shaped mold.As a result,the maximum thickness of the air gap is 0.71 mm,and the thickest slag film in the off-corner area is about 1.13 mm.As to the narrow face,the maximum interface gap forms at the mold corner at the position of 500 mm below meniscus.The maximum thickness is 1.40 mm.Accordingly,the maximum thickness of the air gap is 0.53 mm at the corner,and the thickest slag is 1.35 mm in the off-corner area.Compared with the traditional mold,the maximum interface gap in the wide and narrow corners of convex lens-shaped mold reduce by 0.29 mm and 0.33 mm than that of in traditional mold,respectively.Also,the maximum thicknesses of the air gap and slag film reduce by 0.23 mm,0.18 mm and 0.35 mm and 0.34 mm,respectively.As a result,the distribution ranges of high temperature areas in the wide and narrow off-corner of the slab reduce by 36 mm and 17 mm,respectively,and the maxim

关 键 词：边线裂纹 凸透镜形结晶器 窄面凹形坯 气隙与保护渣分布 连铸 

分 类 号：TF777[冶金工程—钢铁冶金]