工程科学学报，第38卷，第3期：342-350,2016年3月 Chinese Journal of Engineering,Vol.38,No.3:342-350,March 2016 D0l:10.13374/j.issn2095-9389.2016.03.007:http://journals.ustb.edu.cn 高拉速连铸低碳铝镇静钢铸坯中夹杂物 苑 鹏区，王新华”，姜敏2》，冀云卿”，王万军 1)首钢技术研究院薄板研究所，北京1000432)北京科技大学治金与生态工程学院，北京100083 ☒通信作者，E-mail:shandongyuanpeng(@163.com 摘要针对高拉速板坯连铸生产的低碳铝镇静钢铸坯，采用As即x自动扫描电镜对铸坯表层夹杂物进行大面积的扫描分 析，得到不同拉速下夹杂物的变化规律，并探究流场和S含量对夹杂物分布的影响.结果表明：随着拉速增大，钩状坯壳的深 度和长度逐渐减小.对拉速大于2m~min的铸坯，由于钩状坯壳不是很发达，铸坯表层没有发现大于200μm的夹杂物.铸 坯表层尺寸介于50-200μm的夹杂物主要是由凝固坯壳所捕获，而夹杂物在凝固前沿的受力决定了夹杂物的捕获行为.随 着拉速提高，凝固前沿的钢液流速增加，随着冲刷力的增加、捕获力的减少，夹杂物被捕获的数量减少.在高拉速连铸下，如 果钢液中S含量较大，夹杂物受到明显的温度Marangoni力，会更容易被凝固坯壳捕获. 关键词低碳钢：连铸：板坯：夹杂物 分类号T777.1 Inclusions in low carbon aluminum killed steel slabs at high casting speed YUAN Peng,WANG Xin-hua?,JIANG Min2,JI Yun-qing,WANG Wan-jun2) 1)Sheet Metal Research Institute,Shougang Research Institute of Technology,Beijing 100043,China 2)School of Metallurgical and Ecological Engineering,University of Science and Technology Beijing,Beijing 100083,China Corresponding author,E-mail:shandongyuanpeng@163.com ABSTRACT Inclusions in the surface of low carbon aluminum killed steel slabs cast at high casting speed were analyzed by Aspex automated scanning electron microscopy in a large area.The changes in number and size of inclusions were tested at different casting speeds,and the influence of flow fields and sulfur content on the distribution of inclusions was explained in detail.It is found that when the casting speed increases,the depth and length of hooks decrease.Hooks in the slab subsurface is not obvious when the cast- ing speed larger than 2mmin,so inclusions larger than 200um cannot be found in the slab surface.Inclusions with the size of 50- 200 um in the slab surface are mainly entrapped by the solidified shell,and the entrapment of inclusions is influenced by forces acting on inclusions at the solidifying front.The flow velocity of molten steel increases due to increasing casting speed,then the washing force becomes large and the entrapping force becomes small,and therefore the number of entrapped inclusions decreases.If the sulfur con- tent in the steel is high at high casting speed,inclusions will be easily entrapped by the solidified shell due to the thermal Marangoni force acting on inclusions obviously. KEY WORDS low carbon steel:continuous casting;slabs:inclusions 为提高生产率和降低能源消耗，日本的很多钢厂 铸会增大结晶器流股的冲击强度，进而引起液面波动 实现了常规板坯的高拉速连铸，新日铁住金的名古屋 剧烈，导致保护渣的卷入.近年来，随着电磁制动技术 制铁厂、神户制钢的加古川制铁厂的部分铸机在生产的开发，高拉速连铸引起的结晶器液面波动得到有效 低碳、超低碳钢铸坯时的拉速均达到2.0m·min,其 抑制，卷渣不再是限制因素，此时脱氧后氧化铝不断碰 中JFE的福山厂更是达到2.5mmin1m.高拉速连 撞、聚集而形成的大尺寸簇群状氧化铝夹杂成为影响 收稿日期：20150208工程科学学报，第 38 卷，第 3 期: 342--350，2016 年 3 月 Chinese Journal of Engineering，Vol． 38，No． 3: 342--350，March 2016 DOI: 10． 13374 /j． issn2095--9389． 2016． 03． 007; http: / /journals． ustb． edu． cn 高拉速连铸低碳铝镇静钢铸坯中夹杂物 苑 鹏1) ，王新华2) ，姜 敏2) ，冀云卿2) ，王万军2) 1) 首钢技术研究院薄板研究所，北京 100043 2) 北京科技大学冶金与生态工程学院，北京 100083  通信作者，E-mail: shandongyuanpeng@ 163． com 摘 要 针对高拉速板坯连铸生产的低碳铝镇静钢铸坯，采用 Aspex 自动扫描电镜对铸坯表层夹杂物进行大面积的扫描分 析，得到不同拉速下夹杂物的变化规律，并探究流场和 S 含量对夹杂物分布的影响． 结果表明: 随着拉速增大，钩状坯壳的深 度和长度逐渐减小． 对拉速大于 2 m·min － 1 的铸坯，由于钩状坯壳不是很发达，铸坯表层没有发现大于 200 μm 的夹杂物． 铸 坯表层尺寸介于 50 ～ 200 μm 的夹杂物主要是由凝固坯壳所捕获，而夹杂物在凝固前沿的受力决定了夹杂物的捕获行为． 随 着拉速提高，凝固前沿的钢液流速增加，随着冲刷力的增加、捕获力的减少，夹杂物被捕获的数量减少． 在高拉速连铸下，如 果钢液中 S 含量较大，夹杂物受到明显的温度 Marangoni 力，会更容易被凝固坯壳捕获． 关键词 低碳钢; 连铸; 板坯; 夹杂物 分类号 TF777. 1 Inclusions in low carbon aluminum killed steel slabs at high casting speed YUAN Peng1)  ，WANG Xin-hua2) ，JIANG Min2) ，JI Yun-qing2) ，WANG Wan-jun2) 1) Sheet Metal Ｒesearch Institute，Shougang Ｒesearch Institute of Technology，Beijing 100043，China 2) School of Metallurgical and Ecological Engineering，University of Science and Technology Beijing，Beijing 100083，China  Corresponding author，E-mail: shandongyuanpeng@ 163． com ABSTＲACT Inclusions in the surface of low carbon aluminum killed steel slabs cast at high casting speed were analyzed by Aspex automated scanning electron microscopy in a large area． The changes in number and size of inclusions were tested at different casting speeds，and the influence of flow fields and sulfur content on the distribution of inclusions was explained in detail． It is found that when the casting speed increases，the depth and length of hooks decrease． Hooks in the slab subsurface is not obvious when the cast￾ing speed larger than 2 m·min － 1 ，so inclusions larger than 200 μm cannot be found in the slab surface． Inclusions with the size of 50-- 200 μm in the slab surface are mainly entrapped by the solidified shell，and the entrapment of inclusions is influenced by forces acting on inclusions at the solidifying front． The flow velocity of molten steel increases due to increasing casting speed，then the washing force becomes large and the entrapping force becomes small，and therefore the number of entrapped inclusions decreases． If the sulfur con￾tent in the steel is high at high casting speed，inclusions will be easily entrapped by the solidified shell due to the thermal Marangoni force acting on inclusions obviously． KEY WOＲDS low carbon steel; continuous casting; slabs; inclusions 收稿日期: 2015--02--08 为提高生产率和降低能源消耗，日本的很多钢厂 实现了常规板坯的高拉速连铸，新日铁住金的名古屋 制铁厂、神户制钢的加古川制铁厂的部分铸机在生产 低碳、超低碳钢铸坯时的拉速均达到 2. 0 m·min － 1 ，其 中 JFE 的福山厂更是达到 2. 5 m·min － 1［1］． 高拉速连 铸会增大结晶器流股的冲击强度，进而引起液面波动 剧烈，导致保护渣的卷入． 近年来，随着电磁制动技术 的开发，高拉速连铸引起的结晶器液面波动得到有效 抑制，卷渣不再是限制因素，此时脱氧后氧化铝不断碰 撞、聚集而形成的大尺寸簇群状氧化铝夹杂成为影响