IF钢连铸坯凝固钩数学模拟与试验
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摘要
根据IF钢连铸坯凝固钩的形成机理,通过建立二维纵向切片传热模型,模拟了凝固钩的演变行为;结合金相试验结果分析了连铸工艺参数对凝固钩深度的影响。结果表明,在初始凝固过程中,凝固钩中经历了形成、熔化及生长等阶段,在数学模拟条件下,当结晶器内由浸入式水口流出的钢液温度为1 555℃、拉速为1.3m/min时,在距离弯月面55.12mm处,即凝固钩生长达到稳定状态,其深度为2.368mm。当拉坯速度、结晶器内钢水温度、振动频率增加时,凝固钩深度均减小。凝固钩数学模拟结果符合实际生产。
A two dimensional longitudinal slice heat transfer model of the initial solid shell was built to simulate the hook growing behavior according to the hook formation mechanism in the IF steel slab.The effect of casting parameters on the hook depth was discussed by combining metallographic experiments results.The research results show that the initial solidification process of the hook undergoes the stages of forming,melting and growing.Under the mathematical simulation condition,when the temperature of the liquid steel in the mold flowing out from the SEN is1 555℃,the casting speed is 1.3 m/min and the shell runs away from the meniscus about 55.12 mm,the hook growth reaches a steady state,and the hook depth is 2.368 mm.The hook depth decreases with the increasing of the casting velocity,the oscillation frequency and the liquid steel temperature in the mold.The mathematical simulation result of the hook is basically consistent with the actual production practice.
A two dimensional longitudinal slice heat transfer model of the initial solid shell was built to simulate the hook growing behavior according to the hook formation mechanism in the IF steel slab.The effect of casting parameters on the hook depth was discussed by combining metallographic experiments results.The research results show that the initial solidification process of the hook undergoes the stages of forming,melting and growing.Under the mathematical simulation condition,when the temperature of the liquid steel in the mold flowing out from the SEN is1 555℃,the casting speed is 1.3 m/min and the shell runs away from the meniscus about 55.12 mm,the hook growth reaches a steady state,and the hook depth is 2.368 mm.The hook depth decreases with the increasing of the casting velocity,the oscillation frequency and the liquid steel temperature in the mold.The mathematical simulation result of the hook is basically consistent with the actual production practice.
引文
[1] Lee G-G,Shin H-J,Thomas B G,et al.Prediction and control of subsurface hooks in continuous cast ultra-low-carbon steel slabs[J].Ironmaking and Steelmaking,2009,36(1):39.
[2] Emi T,Nakato H,Tachibana R,et al.Influence of physical and chemical properties of mold powders on the solidification and occurrence of surface defects of strand cast slabs[C]//Natl Open Hearth Basic Oxygen Steel Conference 61st Proceeding.Chicago:[s.n.],1978:350.
[3]蔡开科.连铸结晶器[M].北京:冶金工业出版社,2008.(CAI Kai-ke.Continuous Casting Mould[M].Beijing:Metallurgical Industry Press,2008.)
[4]雷作胜.连铸板坯表面振痕形成机理及其电磁控制技术[D].上海:上海大学,2004.(LEI Zuo-shen.Formation Mechanism of Oscillation Marks in Continuous Casting of Billets and Its Control with Electromagnetic Field[D].Shanghai:Shanghai University,2004.)
[5] Tomono H,Kurz W,Heinemann W,et al.The liquid steel meniscus in molds and its relevance to the surface quality of castings[J].Metall Trans B,1981,12(2):409
[6] Pavel E Ramirez Lopez,Kenneth C Mills,Peterd Lee,et al.A unified mechanism for the formation of oscillation marks[J].Metallurgical and Materials Transactions B,2012(43):109.
[7] Joydeep Sengutpa,Brian G Thomas,Shin Ho-Jung,et al.A new mechanism of hook formation during continuous casting of ultra-low-carbon steel slabs[J].Metallurgical and Materials Transactions B,2006,37(A):1597.
[8] Shin Ho-Jung,Kim Seon-Hyo,Brian G Thomas,et al.Measurement and prediction of lubrication,powder consumption and oscillation mark profiles in ultra-low carbon steel slabs[J].ISIJ,2006,46(11):1635.
[9] Thomas B G,Jenkins M S,Mahapatra R B,et al.Investigation of strand surface defects using mould instrumentation and modelling[J].Ironmaking and Steelmaking,2004,31(6):485.
[10] Mills K C,Ramirez-Lopez P,Brian G Thomas,et al.Looking into continuous casting mould[J].Iron Making and Steel Making,2014,41(4):242.
[11] Pavel E Ramirez Lopez,Ulf Sjostrom,Kenneth C Mills.Industrial application of a numerical model to simulate lubrication,mold oscillation,solidification and defect formation during continuous casting[J].Materials Science and Engineering,2012(33):1.
[12] Badri A,Natarajan T T,Synder C C,et al.A mold simulator for the continuous casting of steel:Part I.The development of a simulator[J].Metallurgical and Materials Transactions B,2005(36):355.
[13] Badri A,Natarajan T T,Synder C C,et al.A mold simulator for continuous casting of steel:Part II.The formation of oscillation marks during the continuous casting of low carbon steel[J]. Metallurgical and Materials Transactions B,2005(36):373.
[14]张海辉.结晶器内坯壳热力耦合分析[D].唐山:河北理工大学,2012.(ZHANG Hai-hui.Analysis on Couples of ThermalMechanical for Initial Shell in Continuous Casting Mould[D].Tangshan:Hebei United University,2012.)
[15]盛义平,孔祥东,杨永利.连铸结晶器传热边界条件研究[J].中国机械工程,2007,18(13):1615.(SHENG Yi-ping,KONG Xiang-dong,YANG Yong-li.Study on thermal conditions in the mold for continuous casting[J].China Mechanical Engineering,2007,18(13):1615.)
[16]车芳,程常桂,赵威,等.物性参数对连铸结晶器传热模型计算结果的影响[J].过程工程学报,2010,18(13):1615.(CHE Fang,CHENG Chang-gui,ZHAO Wei,et al.Study on influence of physical property parameter on mould calculation results of heat transfer in the continuous casting mould[J].The Chinese Journal of Process Engineering,2010,18(13):1615.)
[2] Emi T,Nakato H,Tachibana R,et al.Influence of physical and chemical properties of mold powders on the solidification and occurrence of surface defects of strand cast slabs[C]//Natl Open Hearth Basic Oxygen Steel Conference 61st Proceeding.Chicago:[s.n.],1978:350.
[3]蔡开科.连铸结晶器[M].北京:冶金工业出版社,2008.(CAI Kai-ke.Continuous Casting Mould[M].Beijing:Metallurgical Industry Press,2008.)
[4]雷作胜.连铸板坯表面振痕形成机理及其电磁控制技术[D].上海:上海大学,2004.(LEI Zuo-shen.Formation Mechanism of Oscillation Marks in Continuous Casting of Billets and Its Control with Electromagnetic Field[D].Shanghai:Shanghai University,2004.)
[5] Tomono H,Kurz W,Heinemann W,et al.The liquid steel meniscus in molds and its relevance to the surface quality of castings[J].Metall Trans B,1981,12(2):409
[6] Pavel E Ramirez Lopez,Kenneth C Mills,Peterd Lee,et al.A unified mechanism for the formation of oscillation marks[J].Metallurgical and Materials Transactions B,2012(43):109.
[7] Joydeep Sengutpa,Brian G Thomas,Shin Ho-Jung,et al.A new mechanism of hook formation during continuous casting of ultra-low-carbon steel slabs[J].Metallurgical and Materials Transactions B,2006,37(A):1597.
[8] Shin Ho-Jung,Kim Seon-Hyo,Brian G Thomas,et al.Measurement and prediction of lubrication,powder consumption and oscillation mark profiles in ultra-low carbon steel slabs[J].ISIJ,2006,46(11):1635.
[9] Thomas B G,Jenkins M S,Mahapatra R B,et al.Investigation of strand surface defects using mould instrumentation and modelling[J].Ironmaking and Steelmaking,2004,31(6):485.
[10] Mills K C,Ramirez-Lopez P,Brian G Thomas,et al.Looking into continuous casting mould[J].Iron Making and Steel Making,2014,41(4):242.
[11] Pavel E Ramirez Lopez,Ulf Sjostrom,Kenneth C Mills.Industrial application of a numerical model to simulate lubrication,mold oscillation,solidification and defect formation during continuous casting[J].Materials Science and Engineering,2012(33):1.
[12] Badri A,Natarajan T T,Synder C C,et al.A mold simulator for the continuous casting of steel:Part I.The development of a simulator[J].Metallurgical and Materials Transactions B,2005(36):355.
[13] Badri A,Natarajan T T,Synder C C,et al.A mold simulator for continuous casting of steel:Part II.The formation of oscillation marks during the continuous casting of low carbon steel[J]. Metallurgical and Materials Transactions B,2005(36):373.
[14]张海辉.结晶器内坯壳热力耦合分析[D].唐山:河北理工大学,2012.(ZHANG Hai-hui.Analysis on Couples of ThermalMechanical for Initial Shell in Continuous Casting Mould[D].Tangshan:Hebei United University,2012.)
[15]盛义平,孔祥东,杨永利.连铸结晶器传热边界条件研究[J].中国机械工程,2007,18(13):1615.(SHENG Yi-ping,KONG Xiang-dong,YANG Yong-li.Study on thermal conditions in the mold for continuous casting[J].China Mechanical Engineering,2007,18(13):1615.)
[16]车芳,程常桂,赵威,等.物性参数对连铸结晶器传热模型计算结果的影响[J].过程工程学报,2010,18(13):1615.(CHE Fang,CHENG Chang-gui,ZHAO Wei,et al.Study on influence of physical property parameter on mould calculation results of heat transfer in the continuous casting mould[J].The Chinese Journal of Process Engineering,2010,18(13):1615.)