Assessment of Critical Vortexing Height to Prevent Slag Entrapment During Tundish Teeming

2021 ◽  
Author(s):  
Antariksh Gupta ◽  
Rakesh Kumar ◽  
Rajeev Kumar Singh
Keyword(s):  
Slag Entrapment

scholarly journals Optimization on Reducing Slag Entrapment in 150 × 1270 mm Slab Continuous Casting Mold

Materials ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 1774 ◽  
Author(s):  
Yang Wang ◽  
Shufeng Yang ◽  
Feng Wang ◽  
Jingshe Li
Keyword(s):  
Numerical Simulation ◽  
Continuous Casting ◽  
Casting Speed ◽  
Surface Velocity ◽  
Continuous Casting Mold ◽  
Slab Continuous Casting ◽  
Eddy Simulation ◽  
Submerged Entrance Nozzle ◽  
Dynamics Simulations ◽  
Slag Entrapment

To reduce slag entrapment in 150 × 1270 mm slab continuous casting molds at the Tang Steel Company, the effect of submerged entrance nozzle (SEN) depth and casting speed on the phenomenon was studied by computational fluid dynamics simulations. Then, the slag entrapment behavior in continuous casting molds, utilizing Large Eddy Simulation (LES) by coupling the volume of fluid (VOF) method, was also used. Finally, the effect of several common oils usually used to simulate slag in water modelling on slag entrapment was discussed and the water modelling results were used to validate the numerical simulation findings. The results showed that the optimum scheme is a submerged depth of SEN 90 mm and a casting speed of 1.6 m/min. Under optimal conditions, the maximum surface velocity is smallest (0.335 m/s) and the maximum slag entrapment ratio (0.44%) appears in the position of 0.1 m below the meniscus after 15 s. The water modelling results were in good agreement with the numerical simulation results.

Analysis of critical slag entrapment speed at the steel–slag interface

2020 ◽  
pp. 1-8
Author(s):  
Huajie Wu ◽  
Yinghui Liu ◽  
Yue Sun ◽  
Fangjie Jiang ◽  
Qiaoqi Li ◽  
...  
Keyword(s):  
Steel Slag ◽  
Slag Entrapment

scholarly journals Physical Simulation of Molten Steel Homogenization and Slag Entrapment in Argon Blown Ladle

Processes ◽  
2019 ◽  
Vol 7 (8) ◽  
pp. 479 ◽  
Author(s):  
Yang ◽  
Jin ◽  
Zhu ◽  
Dong ◽  
Lin ◽  
...  
Keyword(s):  
Flow Rate ◽  
Molten Steel ◽  
Physical Simulation ◽  
Mixing Time ◽  
Water Model ◽  
Steel Ladle ◽  
Argon Flow Rate ◽  
Argon Flow ◽  
Slag Thickness ◽  
Slag Entrapment

Argon stirring is one of the most widely used metallurgical methods in the secondary refining process as it is economical and easy, and also an important refining method in clean steel production. Aiming at the issue of poor homogeneity of composition and temperature of a bottom argon blowing ladle molten steel in a Chinese steel mill, a 1:5 water model for 110 t ladle was established, and the mixing time and interface slag entrainment under the different conditions of injection modes, flow rates and top slag thicknesses were investigated. The flow dynamics of argon plume in steel ladle was also discussed. The results show that, as the bottom blowing argon flow rate increases, the mixing time of ladle decreases; the depth of slag entrapment increases with the argon flow rate and slag thickness; the area of slag eyes decreases with the decrease of the argon flow rate and increase of slag thickness. The optimum argon flow rate is between 36–42 m3/h, and the double porous plugs injection mode should be adopted at this time.

Research on MRT3-BA Steel in Macro Inclusions

2013 ◽  
Vol 634-638 ◽  
pp. 1855-1858
Author(s):  
Shuo Ming Wang ◽  
Jian Xing Wang ◽  
Ju Gao
Keyword(s):  
Technological Process ◽  
Technological Processes ◽  
Large Inclusion ◽  
Slag Entrapment

The research about the macro-inclusions of three processes: BOF→ LF→ CC, BOF→ RH→ CC and BOF→ LF→ RH→ CC, shows that: The types of inclusion are SiO2-Al2O3-CaO-TiO2-MnO, SiO2 and SiO2-Al2O3. The content of SiO2-Al2O3- CaO-TiO2-MnO in the three processes are 34.2%、23.5% and 27%; The content of SiO2 are 24.4%、47% and 27%; The content of SiO2-Al2O3 are 26.8%、17.6% and 9%. Large inclusion>300μm takes up 69.8%~85% of the total inclusion in billet in three technological processes, and the inclusion, containing K and Na, is the most; slag entrapment in mould is really serious. Considering the cleanliness and cost, the better technological process of MRT3-BA stamping steel is BOF→ RH→ CC.

Research on Surface Cracks of Thin Slab

2011 ◽  
Vol 295-297 ◽  
pp. 193-196
Author(s):  
Shuo Ming Wang ◽  
Dan Dan Ji ◽  
Li Guang Zhu ◽  
Cai Jun Zhang ◽  
Qing Gang Liu
Keyword(s):  
Heat Transfer ◽  
Surface Crack ◽  
Surface Cracks ◽  
High Melting ◽  
Thin Slab ◽  
High Melting Point ◽  
Normal Forces ◽  
High Sulfur Content ◽  
Mould Flux ◽  
Slag Entrapment

This paper probes into the reasons about surface crack on the SS400 steel through analyzing FTSC. The results show that: the surface crack is mainly produced by the high content inclusion in SS400 steel and the fluctuation of inclusion makes the mould flux have bad performance. The protective slag is not filled fully which worsens the condition of heat transfer and makes the solidified shell uneven, thus it is easy to produce crack in the normal forces. Secondly , the slag entrapment and high content of sulfur is the another reason . There are a lot of calcium-aluminate ,silicates, sulfides which have high melting point and low plasticity in crack inside and around and their content gravely deviates from normal state. The effect of inclusion to crack is three times than the slag entrapment and just as the slag entrapment to high sulfur content

Water Modelling on the Effect of Trapezoidal Nozzle on Vortex during Teeming in Ladle

2011 ◽  
Vol 295-297 ◽  
pp. 716-719
Author(s):  
Rui Lin ◽  
Zheng Guo Yan ◽  
Tao Liu ◽  
Jing Kun Yu
Keyword(s):  
Cross Section ◽  
Late Stage ◽  
Model Experiment ◽  
Critical Level ◽  
Research Work ◽  
Water Model ◽  
Steel Ladle ◽  
Critical Height ◽  
Slag Entrapment

Based on approximation principle, water model experiment was carried out during teeming in a 60t steel ladle. Based on the previous research work, trapezoidal nozzlein with lager upper cross section was used to decrease the critical level of vortex in order to reduce the slag entrapment to the tundish. Different shape and height of upper part of the nozzle was investigated mainly to inhibit the vortex at the late stage of ladle teeming. When upper shape of trapezoidal nozzle is square, upper height is 20mm and 17mm, and eccentricity of nozzle is 3/4, critical height of vortex is about 34mm and 31mm. In this case, slag entrapment is controlled effectively and metal utilization is optimized more completely.

Study on Cleanliness of Ultra-Low Carbon Steel First Slab

2012 ◽  
Vol 524-527 ◽  
pp. 2037-2043
Author(s):  
Qi Chun Peng ◽  
Xue Sen Yu ◽  
Wei Xiong ◽  
Liu Yang ◽  
Liang Zhou Zhang ◽  
...  
Keyword(s):  
Comparative Analysis ◽  
Carbon Steel ◽  
Liquid Steel ◽  
Steel Slag ◽  
Low Carbon Steel ◽  
Low Carbon ◽  
Metallographic Examination ◽  
Ultra Low Carbon Steel ◽  
Casting Length ◽  
Slag Entrapment

By means of Oxygen and Nitrogen Analyzer, Metallographic Examination, SLIME, SEM, EDS, etc, the cleanliness of ultra-low carbon steel first slab produced by LD-RH-CC, and the comparative analysis with the cleanliness of normal slab is studied. The results show that T[O] and [N] are obviously decreasing with the increasing of casting length. The micro-inclusions and large-inclusions are generally decreasing with the increasing of casting length. The micro-inclusions of the first slab are mainly from deoxidization products and reoxidation of liquid steel. And the sources of large-sized inclusions mainly are reoxidation of liquid steel, slag entrapment in mould or tundish and stuffing sand. The cleanliness of ultra-low carbon steel first slab is closed to those normal slabs at the length of 3.5m.

scholarly journals Effect of Na2O and Rb2O on Inclusion Removal in C96V Saw Wire Steels Using Low-Basicity LF (Ladle Furnace) Refining Slags

Metals ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 691 ◽  
Author(s):  
Changyong Chen ◽  
Zhouhua Jiang ◽  
Yang Li ◽  
Meng Sun ◽  
Kui Chen ◽  
...  
Keyword(s):  
Melting Zone ◽  
Refining Process ◽  
Ladle Furnace ◽  
Refining Slag ◽  
Dramatic Decrease ◽  
Inclusion Removal ◽  
Wire Steel ◽  
Al2o3 Inclusion ◽  
Lf Refining ◽  
Slag Entrapment

Inclusion removal and modification of C96V saw wire steel using Na2O- and Rb2O- containing novel low-basicity LF (ladle furnace) Refining Slags have been researched. The results indicated that the addition of Na2O deteriorates inclusion removal; by contrast, the addition of Rb2O seems to significantly enhance inclusion removal. In detail, Rb2O can improve the cleanliness in the as-quenched C96V saw wire steel melts compared to preexisting synthetic LF refining slag compositions: (i) The average inclusion diameter experienced a remarkable decrease after reaction between the liquid steel and the synthetic LF refining slag; (ii) In addition, the number of inclusions also suffered from a dramatic decrease, with the reaction time increasing from 900 to 2700 s (15 to 45 min); (iii) Furthermore, both of the MnO-SiO2-Al2O3 and CaO-SiO2-Al2O3 inclusion system mainly concentrated in the low melting zone when the composition of Rb2O in synthetic refining slag was ≥5.0 wt%. This is mainly because Na2O significantly reduces the viscosity of refining slag, while Rb2O increases it. Then, there are two remarkable influences causing the increase of viscosity of refining slag with the addition of Rb2O: the inclusions can be sufficiently entrained within the slag once absorbed due to the significant increase in the viscosity; and the slag entrapment during refining process weakened dramatically.

scholarly journals Large Eddy Simulation of Multi-Phase Flow and Slag Entrapment in Molds with Different Widths

Metals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 374
Author(s):  
Xianjiu Zhao ◽  
Xianglong Li ◽  
Jieyu Zhang
Keyword(s):  
Large Eddy Simulation ◽  
Transverse Velocity ◽  
Flaw Detection ◽  
Interface Velocity ◽  
Dimensionless Number ◽  
Particle Model ◽  
Three Dimensional Model ◽  
Eddy Simulation ◽  
Large Eddy ◽  
Slag Entrapment

Slag entrapment is a critical problem that affects the quality of steel. In this work, a three-dimensional model is established to simulate the slag entrapment phenomenon, mainly focusing on the slag entrapment phenomenon at the interface between slag and steel in molds with different widths. The large eddy simulation (LES) model and discrete particle model (DPM) are used to simulate the movements of bubbles. The interactions between phases involve two-way coupling. The accuracy of our mathematical model is validated by comparing slag–metal interface fluctuations with practical measurements. The results reveal that the average interface velocity and transverse velocity decrease as the mold width increases, however, they cannot represent the severity of slag entrapment at the interface between slag and steel. Due to the influence of bubble motion behavior, the maximum interface velocity increases with mold width and causes slag entrapment readily, which can reflect the severity of slag entrapment. On this basis, by monitoring the change of impact depths in different molds, a new dimensionless number “C” is found to reveal the severity of slag entrapment at the interface between slag and steel. The results show that the criterion number C increases with mold width, which is consistent with the results of flaw detection. Therefore, criterion number C can be used to reflect the severity of slag entrapment in different molds.

Minimisation of slag entrapment and cold drops in Sidetur billets

2003 ◽  
Vol 30 (6) ◽  
pp. 511-515 ◽  
Author(s):  
B. Santillana ◽  
M. Dziuba ◽  
J. Madías ◽  
M. Oropeza ◽  
E. Fernández
Keyword(s):  
Slag Entrapment
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