高碳钢矩形坯轻压下中心负偏析形成机理

详细信息    查看全文 | 推荐本文 |

英文篇名：Formation mechanism of center negative segregation in continuous casting of high carbon rectangular billet with soft reduction 作者：曾杰 ; 陈伟庆 英文作者：ZENG Jie;CHEN Wei-qing;State Key Laboratory of Advanced Metallurgy,University of Science and Technology Beijing; 关键词：矩形坯 ; 高碳钢 ; 轻压下 ; 中心负偏析 英文关键词：rectangular billet;;high carbon steel;;soft reduction;;center negative segregation 中文刊名：IRON 英文刊名：Journal of Iron and Steel Research 机构：北京科技大学钢铁冶金新技术国家重点实验室; 出版日期：2016-03-08 09:49 出版单位：钢铁研究学报 年：2016 期：v.28 语种：中文; 页：IRON201603011 页数：5 CN：03 ISSN：11-2133/TF 分类号：54-58

摘要

高碳钢82A断面180mm×240mm矩形坯轻压下试验中,铸坯心部碳元素产生了负偏析现象。将轻压下工艺与负偏析形成条件相结合,对中心负偏析形成机理进行了探讨。结果表明,轻压下消除了枝晶间富集溶质钢液向铸坯中心流动通道,铸坯中心受枝晶间富集溶质液体流动影响较小;凝固过程中心负偏析产生条件为vx/R<-0.042 2,即液相流动速度vx和凝固速度R方向相反为形成中心负偏析的必要而非充分条件;轻压下易满足该条件并在此基础上提出了2种形成机理,即轻压下挤压作用导致心部钢液流动速度方向的改变或者脱落枝晶在铸坯心部先形核凝固导致凝固速度方向的改变都可能导致中心负偏析的形成。
        Center negative segregation of carbon was generated with soft reduction in continuous casting of high carbon 82 Arectangular billet with section size of 180mm×240mm.The formation mechanism of negative segregation was researched by combining the soft reduction process with the occurrence conditions of negative segregation.The results show that soft reduction can eliminate the segregation channel which interdendritic rich liquid of solutes flowed to center and the solidification in center may not influenced by the flow of interdendritic liquid.Center negative segregation will occur during solidification process under conditions of vx/R<-0.042 2.In other words,the formation of negative segregation must meet the conditions that the solidification velocity Rand the liquid velocity vxare in opposite direction.The velocity of center liquid changes under the reduction force or the center solidification velocity changes by nucleation and growth of crystals are the two formation mechanisms of center negative segregation.

引文

[1]Raihle C M,Fredriksson H.On the formation of pipes and centerline segregates in continuously cast billets[J].Metallurgical and Materials Transactions,1994,25B(1):123.
    [2]Krauss G.Solidification,segregation and banding in carbon and alloy steels[J].Metallurgical and Materials Transactions,2003,34B(6):781.
    [3]Oh K S,Park J K,Chang S H,et al.Development of soft reduction technique for the bloom caster at Pohang work of POSCO[C]//Steelmaking Conference Proceedings.Nashville:Iron and Steel Society of AIME,1995:301.
    [4]王羽翀,王庆娟,徐李军,等.轻压下技术在板坯连铸生产中的应用现状[J].钢铁研究学报,2012,24(3):1.
    [5]Thome R,Harste K.Principles of billet soft-reduction and consequences for continuous casting[J].ISIJ International,2006,46(12):1839.
    [6]Wang W,Hu X,Ning L,et al.Improvement of center segregation in high-carbon steel billets using soft reduction[J].Journal of University of Science and Technology Beijing Mineral Metallurgy Material,2006,13(6):490.
    [7]曹磊,祭程,杨吉林,等.轻压下帘线钢大方坯成分偏析特征及形成机制[J].钢铁,2010,45(8):44.
    [8]Flemings M C,Nereo G E.Macrosegregation,Pt.1[J].Transactions of the Metallurgical Society of AIME,1967,239(9):1449.
    [9]Flemings M C.Our understanding of macrosegregation:past and present[J].ISIJ International,2000,40(9):833.
    [10]胡汉起.金属凝固原理[M].2版.北京:机械工业出版社,2012.
    [11]高龙永.钢水凝固收缩与板坯铸机开口度参数设计[J].山东冶金,2012,34(1):24.
    [12]Choudhary S K,Ganguly S.Morphology and segregation in continuous cast high carbon steel billets[J].ISIJ International,2007,47(12):1759.
    [13]Domitner J,Wu M,Kharicha A,et al.Modeling the effects of strand surface bulging and mechanical softreduction on the macrosegregation formation in steel continuous casting[J].Metallurgical and Materials Transactions,2014,45A(3):1415.
    [14]Bridge M R,Rogers G D.Structural effects and band segregate formation during the electromagnetic stirring of strandcast steel[J].Metallurgical and Materials Transactions,1984,15B(3):581.
    [15]侯自兵,成国光,饶添荣.连铸板坯中心线偏析形成机制与轻压下技术[J].钢铁,2011,46(11):45.