1. School of Metallurgical and Ecological Engineering,University of Science and Technology Beijing,Beijing 100083,China 2. Shougang Research Institute of Technology,Shougang Group Corporation,Beijing 100041,China
Abstract:A distinctive microstructural feature called a “hook” is often observed on the subsurface of low carbon aluminum- killed steel slabs during continuous casting processes. Inclusions and bubbles are easy to be entrapped by the hooks,which makes Al2O3 cluster and “Ar+Al2O3” type inclusions gathered in subsurface layer of the slabs. A large number of samples were obtained from wide face,narrow face,and corner of the slab in this experiment. The characteristics of hooks in different positions of the slab were investigated. The results showed that in the wide face the center of hooks are deeper than others,in the narrow face the hook depth increase when close to the corner of slab,and hooks near the corners of the slab exhibited three- dimensional morphology. Furthermore,a mechanism of hooks entrapping alumina inclusions and argon bubbles was proposed,which suggested that marangoni force in the process of continuous casting plays an important role on the entrapment of alumina inclusions and argon bubbles. By investigating the behavior of inclusions and bubbles in solidification front of hooks,this mechanism explained the process of how hooks entrapping large side inclusions and bubbles well. From the result,the countermeasure of reduction of hooks and inclusions was proposed.
Awajiya Y, Kubota Y, Takeuchi S.Inclusion Entrapment Location in Solidified Shell of Ultra Low Carbon Steel Slab[C] // AISTech Proceedings Charlotte, NC; USA, 2005: 65.
[1]
Awajiya Y, Kubota Y, Takeuchi S.Inclusion Entrapment Location in Solidified Shell of Ultra Low Carbon Steel Slab[C] // AISTech Proceedings Charlotte, NC; USA, 2005: 65.
[2]
Mizukami H, Hiraki S, Kawamoto M, et al.Initial Solidification Behavior of Ultra-low,Low and Middle Carbon Steel[J].ISIJ International, 1999, 39(12):1262-
[2]
Mizukami H, Hiraki S, Kawamoto M, et al.Initial Solidification Behavior of Ultra-low,Low and Middle Carbon Steel[J].ISIJ International, 1999, 39(12):1262-
[3]
Takeuchi E, Brimacombe J K.The Formation of Oscillation Marks in the Continuous Casting of Steel Slabs[J].Metallurgical and Materials Transactions B, 1984, 15(3):493-
[3]
Takeuchi E, Brimacombe J K.The Formation of Oscillation Marks in the Continuous Casting of Steel Slabs[J].Metallurgical and Materials Transactions B, 1984, 15(3):493-
[4]
Brimacombe J K, Sorimachi K.Crack Formation in the Continuous Casting of Steel[J].Metallurgical and Materials Transactions B, 1977, 8(2):489-
[4]
Brimacombe J K, Sorimachi K.Crack Formation in the Continuous Casting of Steel[J].Metallurgical and Materials Transactions B, 1977, 8(2):489-
[5]
Takeuchi E, Brimacombe J K.Effect of Oscillation-mark Formation on the Surface Quality of Continuously Cast Steel Slabs[J].Metallurgical and materials transactions B, 1985, 16(3):605-
[5]
Takeuchi E, Brimacombe J K.Effect of Oscillation-mark Formation on the Surface Quality of Continuously Cast Steel Slabs[J].Metallurgical and materials transactions B, 1985, 16(3):605-
[6]
Sengupta J, Shin H J, Thomas B G, et al.Micrograph Evidence of Meniscus Solidification and Sub-surface Microstructure Evolution in Continuous-cast Ultralow-carbon Steels[J].Acta Materialia, 2006, 54(4):1165-
[6]
Sengupta J, Shin H J, Thomas B G, et al.Micrograph Evidence of Meniscus Solidification and Sub-surface Microstructure Evolution in Continuous-cast Ultralow-carbon Steels[J].Acta Materialia, 2006, 54(4):1165-
[7]
Schmidt K D, Friedel F, Imlau K, Jager W, Muller KT.Consequent Improvement of Surface Quality by Systematic Analysis of Slabs[J].[J].Steel Research International, 2003, (74):659-
[7]
Schmidt K D, Friedel F, Imlau K, Jager W, Muller KT.Consequent Improvement of Surface Quality by Systematic Analysis of Slabs[J].[J].Steel Research International, 2003, (74):659-
[8]
Birat J-P, Larrecq M, Lamant J-Y, PetegiefJ.The Continuous Casting Mold: A Basic Tool for Surface Quality and Strand Productivity[J], [J].Steelmaking Conference Proceedings, 1991, (74):39-
[8]
Birat J-P, Larrecq M, Lamant J-Y, PetegiefJ.The Continuous Casting Mold: A Basic Tool for Surface Quality and Strand Productivity[J], [J].Steelmaking Conference Proceedings, 1991, (74):39-
[9]
Shin H J, Thomas B G, Lee G G, et al.Analysis of Hook Formation Mechanism in Ultra Low Carbon Steel using CON1D Heat Flow-Solidification Model[J][J].Materials Science & Technology,, 2004, :11-
[9]
Shin H J, Thomas B G, Lee G G, et al.Analysis of Hook Formation Mechanism in Ultra Low Carbon Steel using CON1D Heat Flow-Solidification Model[J][J].Materials Science & Technology,, 2004, :11-
[10]
Sengupta J, Thomas B G, Shin H J, et al.A New Mechanism of Hook Formation during Continuous Casting of Ultra-low-carbon Steel Slabs[J].Metallurgical and Materials Transactions A, 2006, 37(5):1597-
[10]
Sengupta J, Thomas B G, Shin H J, et al.A New Mechanism of Hook Formation during Continuous Casting of Ultra-low-carbon Steel Slabs[J].Metallurgical and Materials Transactions A, 2006, 37(5):1597-
[11]
Sengupta J, Thomas B G, Shin H, et al.Mechanism of Hook Formation in Ultralow-carbon Steel Based on Microscopy Analysis and Thermalstress Modeling[J].Iron and Steel Technology, 2007, 4(7):83-
[11]
Sengupta J, Thomas B G, Shin H, et al.Mechanism of Hook Formation in Ultralow-carbon Steel Based on Microscopy Analysis and Thermalstress Modeling[J].Iron and Steel Technology, 2007, 4(7):83-
[12]
Lee G G, Thomas B G, Kim S H, et al.Microstructure Near Corners of Continuous-cast Steel Slabs Showing Three-dimensional Frozen Meniscus and Hooks[J].Acta Materialia, 2007, 55(20):6705-
[12]
Lee G G, Thomas B G, Kim S H, et al.Microstructure Near Corners of Continuous-cast Steel Slabs Showing Three-dimensional Frozen Meniscus and Hooks[J].Acta Materialia, 2007, 55(20):6705-
Yamamura H, Mizukami Y, Misawa K.Formation of a Solidified Hook-like Structure at the Subsurface in Ultra Low Carbon Steel[J].ISIJ International, 1996, 36(Suppl):S223-
[14]
Yamamura H, Mizukami Y, Misawa K.Formation of a Solidified Hook-like Structure at the Subsurface in Ultra Low Carbon Steel[J].ISIJ International, 1996, 36(Suppl):S223-
[15]
Deng X-X, Li L-P, Wang X-H, et al.Subsurface Macro-Inclusions and Solidified Hook Character in Aluminum-Killed Deep-Drawing Steel Slabs[J].International Journal of Minerals, Metallurgy and Materials, 2014, 21(6):531-
[15]
Deng X-X, Li L-P, Wang X-H, et al.Subsurface Macro-Inclusions and Solidified Hook Character in Aluminum-Killed Deep-Drawing Steel Slabs[J].International Journal of Minerals, Metallurgy and Materials, 2014, 21(6):531-
[16]
Wang Z, Mukai K, Lee I J.Behavior of Fine Bubbles in Front of the Solidifying Interface[J].ISIJ International, 1999, 39(6):553-
[16]
Wang Z, Mukai K, Lee I J.Behavior of Fine Bubbles in Front of the Solidifying Interface[J].ISIJ International, 1999, 39(6):553-
[17]
Lee S M, Kim S J, Kang Y B, et al.Numerical Analysis of Surface Tension Gradient Effect on the Behavior of Gas Bubbles at the SolidLiquid Interface of Steel[J].ISIJ International, 2012, 52(10):1730-
[17]
Lee S M, Kim S J, Kang Y B, et al.Numerical Analysis of Surface Tension Gradient Effect on the Behavior of Gas Bubbles at the SolidLiquid Interface of Steel[J].ISIJ International, 2012, 52(10):1730-
[18]
Mukai K, Lin W.Behavior of Non-metallic Inclusions and Bubbles in Front of Solidifying Interface of Liquid Iron[J].Tetsu-to-Hagan, 1994, 80(7):533-
[18]
Mukai K, Lin W.Behavior of Non-metallic Inclusions and Bubbles in Front of Solidifying Interface of Liquid Iron[J].Tetsu-to-Hagan, 1994, 80(7):533-
[19]
Mukai K, Zeze M.Motion of Fine Particles under Interfacial Tension Gradient in Relation to Continuous Casting Process[J].Steel Research International, 2003, 74(3):131-
[19]
Mukai K, Zeze M.Motion of Fine Particles under Interfacial Tension Gradient in Relation to Continuous Casting Process[J].Steel Research International, 2003, 74(3):131-
[20]
Matsushita T, Mukai K, Zeze M.Correspondence between Surface Tension Estimated by a Surface Thermodynamic Model and Number of Bubbles in the Vicinity of the Surface of Steel Products in Continuous Casting Process[J].ISIJ International, 2013, 53(1):18-
[20]
Matsushita T, Mukai K, Zeze M.Correspondence between Surface Tension Estimated by a Surface Thermodynamic Model and Number of Bubbles in the Vicinity of the Surface of Steel Products in Continuous Casting Process[J].ISIJ International, 2013, 53(1):18-
[21]
Miyake T, Morishita M, Nakata H, et al.Influence of Sulphur Content and Molten Steel Flow on Entrapment of Bubbles to SolidLiquid Interface[J].ISIJ international, 2006, 46(12):1817-
[21]
Miyake T, Morishita M, Nakata H, et al.Influence of Sulphur Content and Molten Steel Flow on Entrapment of Bubbles to SolidLiquid Interface[J].ISIJ international, 2006, 46(12):1817-
[22]
Belton G R.Langmuir Adsorption,the Gibbs Adsorption Isotherm,and Interracial Kinetics in Liquid Metal Systems[J].Metallurgical and Materials Transactions B, 1976, 7(1):35-
[22]
Belton G R.Langmuir Adsorption,the Gibbs Adsorption Isotherm,and Interracial Kinetics in Liquid Metal Systems[J].Metallurgical and Materials Transactions B, 1976, 7(1):35-
[23]
Sahoo P, DebRoy T, McNallan M J.Surface Tension of Binary Metal—Surface Active Solute Systems under Conditions Relevant to Welding Metallurgy[J].Metallurgical and Materials Transactions B, 1988, 19(3):483-
[23]
Sahoo P, DebRoy T, McNallan M J.Surface Tension of Binary Metal—Surface Active Solute Systems under Conditions Relevant to Welding Metallurgy[J].Metallurgical and Materials Transactions B, 1988, 19(3):483-
[24]
Mukai K, Lin W.Motion of Small Particles in Solution with a Interfacial Tension Gradient and Engulfment of the Particles by Solidifying Interface[J].Tetsu-to-Hagan, 1994, 80(7):527-
[24]
Mukai K, Lin W.Motion of Small Particles in Solution with a Interfacial Tension Gradient and Engulfment of the Particles by Solidifying Interface[J].Tetsu-to-Hagan, 1994, 80(7):527-
[25]
Lee G G, Shin H J, Kim S H, et al.Prediction and Control of Subsurface Hooks in Continuous Cast Ultra-low-carbon Steel Slabs[J].Ironmaking & Steelmaking, 2009, 36(1):39-
[25]
Lee G G, Shin H J, Kim S H, et al.Prediction and Control of Subsurface Hooks in Continuous Cast Ultra-low-carbon Steel Slabs[J].Ironmaking & Steelmaking, 2009, 36(1):39-