Mold Nonsinusoidal Oscillation Mode and Its Effect on Slag Infiltration for Lubrication and Initial Shell Growth during Steel Continuous Casting

The effect of nonsinusoidal oscillation at different modification ratios (α) on slag lubrication was investigated during mold oscillation. A validated and reliable multiphase model was employed, which involved flow and solidification of the molten steel and mold slag. The main results revealed that a large amount of liquid slag at the entrance of the mold–strand channel reflowed into the slag pool at the middle of the negative strip period. The phenomenon was more distinct, with an increase in the modification ratio. The modification ratio had no obvious effect on the average thickness of the liquid film at different depths below the meniscus. A modification ratio of 0.5 caused less fluctuation of the transient liquid film. Quantitative prediction of slag consumption indicated that as the modification ratio increased from 0.2 to 0.5 to 0.8, the average values were 0.278, 0.286, and 0.279 kg/m2, respectively. Shell solidification and growth near the meniscus mainly occurred when the mold was descending, which not only depended on the heat flux, but also on the liquid slag flow, the pressure driven by slag rim, and the mold oscillation. Optimization of the modification ratio of nonsinusoidal oscillation could be an alternative to delay growth of the initial shell towards the molten steel. A modification ratio of 0.5 had the least robust shell tip at the meniscus, thereby reducing entrapment of inclusions and bubbles by the shell tip.

[1]  Lifeng Zhang,et al.  Entrapment of Inclusions by Solidified Hooks at the Subsurface of Ultra-Low-Carbon Steel Slab , 2018, Metallurgical and Materials Transactions B.

[2]  Lifeng Zhang,et al.  Three-Dimensional Distribution of Hooks in Al-Killed Low-Carbon Continuous Casting Steel Slabs , 2018, Metallurgical and Materials Transactions B.

[3]  Qiangqiang Wang,et al.  Study of Mold Oscillation Parameters and Modes on Slag Lubrication in Slab Continuous Casting , 2018, JOM.

[4]  김선효.  Effect of Mold Oscillation on Powder Consumption and Hook Formation in Ultra Low Carbon Steel Slabs , 2018 .

[5]  Q. Wang,et al.  Study of the Mechanism of Liquid Slag Infiltration for Lubrication in Slab Continuous Casting , 2018, Metallurgical and Materials Transactions B.

[6]  R. L. Field,et al.  Influence of surface reconstruction on dopant incorporation and transport properties of GaAs(Bi) alloys , 2016 .

[7]  B. Thomas,et al.  Transient Thermo-fluid Model of Meniscus Behavior and Slag Consumption in Steel Continuous Casting , 2014, Metallurgical and Materials Transactions B.

[8]  Junliang Yang,et al.  Experimental Study on Mold Flux Lubrication for Continuous Casting , 2014 .

[9]  Xiang-ning Meng,et al.  Hydrodynamic Lubrication during Non-Sinusoidal Oscillation for a Continuous Casting Mould , 2014 .

[10]  Xu-dong Wang,et al.  Online Measurement for Transient Mold Friction Based on the Hydraulic Oscillators of Continuous-Casting Mold , 2013, Metallurgical and Materials Transactions B.

[11]  K. Mills,et al.  Industrial application of a numerical model to simulate lubrication, mould oscillation, solidification and defect formation during continuous casting , 2012 .

[12]  B. Santillana,et al.  A Unified Mechanism for the Formation of Oscillation Marks , 2012, Metallurgical and Materials Transactions B.

[13]  G. Li,et al.  Dynamic pressure in mould flux channel during mould non-sinusoidal oscillation , 2010 .

[14]  K. Mills,et al.  Explicit Modelling of Slag Infiltration and Shell Formation during Mould Oscillation in Continuous Casting , 2010 .

[15]  Wang Xudong,et al.  The Shell Surface Force Caused by Mould Friction during Slab Continuous Casting , 2008 .

[16]  Joydeep Sengupta,et al.  Measurement and Prediction of Lubrication, Powder Consumption, and Oscillation Mark Profiles in Ultra-low Carbon Steel Slabs , 2006 .

[17]  H. Yamamura,et al.  Infiltration Phenomena of Molten Powder in Continuous Casting Derived from Analysis Using Reynolds Equation Part 2 : Unsteady Analysis , 2006 .

[18]  E. A.,et al.  Modelling molten flux layer thickness profiles in compact strip process moulds for continuous thin slab casting , 2002 .

[19]  M. Nakada,et al.  Estimation of mold powder consumption in continuous casting , 1998 .

[20]  Kenji Misawa,et al.  Formation of a Solidified Hook-like Structure at the Subsurface in Ultra Low Carbon Steel , 1996 .

[21]  Kiminari Kawakami,et al.  Development of a New Mold Oscillation Mode for High-speed Continuous Casting of Steel Slabs , 1991 .

[22]  H. Horiguchi,et al.  A formation mechanism of transverse cracks on CC slab surface. , 1990 .

[23]  J. K. Brimacombe,et al.  The formation of oscillation marks in the continuous casting of steel slabs , 1984 .

[24]  Yasuo Suzuki,et al.  Effects of Mould Oscillation Conditions on Oscillation Marks of Stainless Steel Casts , 1983 .

[25]  Mikio Suzuki,et al.  Fundamental Study and Its Application of Surface Defects of Powder Cast Strands , 1981 .

[26]  Lilong Zhu,et al.  Study on Reaction Performances and Applications of Mold Flux for High-Aluminum Steel , 2016 .

[27]  Brian G. Thomas,et al.  A new mechanism of hook formation during continuous casting of ultra-low-carbon steel slabs , 2006 .

[28]  Mikio Suzuki,et al.  Effect of Mold Oscillation Curves on Heat Transfer and Lubrication Behaviour in Mold at High Speed Continuous Casting of Steel Slabs , 1992 .

[29]  Y. Komatsu,et al.  Lubrication Phenomena in a Mold and Optimum Mold Oscillation Mode in High-speed Casting , 1986 .