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

Metals ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 418 ◽  
Author(s):  
Xiaobo Yan ◽  
Boran Jia ◽  
Qiangqiang Wang ◽  
Shengping He ◽  
Qian Wang
Keyword(s):  
Liquid Film ◽  
Molten Steel ◽  
Liquid Slag ◽  
Shell Growth ◽  
Oscillation Mode ◽  
Quantitative Prediction ◽  
Multiphase Model ◽  
Obvious Effect ◽  
Mold Slag ◽  
Mold Oscillation

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.

scholarly journals A 1D Analytical Model for Slag Infiltration during Continuous Casting of Steel under Non-Sinusoidal Mold Oscillation

Metals ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1389
Author(s):  
Hyunjin Yang
Keyword(s):  
Continuous Casting ◽  
Analytical Model ◽  
Superposition Principle ◽  
Oscillation Mode ◽  
Positive Pressure ◽  
Continuous Casting Of Steel ◽  
Slag Film ◽  
Model Calculations ◽  
Mold Oscillation ◽  
Infiltration Behavior

A 1D analytical model for slag infiltration during continuous casting of steel is developed to investigate the slag behavior in the mold–strand gap. The superposition principle and Fourier expansion are applied to obtain the analytical solution for transient slag flow under arbitrary mold oscillation including non-sinusoidal oscillation mode. The validated model using literature data partially explains several controversies such as slope of slag film channel, mechanism of non-sinusoidal mold oscillation, and timing of slag infiltration. The model shows that a converging slag film into the casting direction is required to open the mold–strand gap if compression is applied in between. Also, model calculations imply that higher slag consumption is achievable from non-sinusoidal mold oscillation by means of the increase of film thickness through longer positive pressure with higher peak pressure. The model demonstrates a time difference between slag flow and pressure near the meniscus and the discrepancy in timing of infiltration between previous works is attributed to the mismatch. The model provides a concise but reliable tool to understand slag infiltration behavior and design mold oscillation settings.

scholarly journals Lubrication Phenomena in a Mold and Optimum Mold Oscillation Mode in High-speed Casting

1986 ◽  
Vol 72 (14) ◽  
pp. 1862-1869 ◽  
Author(s):  
Hideaki MIZUKAMI ◽  
Kiminari KAWAKAMI ◽  
Toru KITAGAWA ◽  
Mikio SUZUKI ◽  
Shigetaka UCHIDA ◽  
...  
Keyword(s):  
High Speed ◽  
Oscillation Mode ◽  
Mold Oscillation ◽  
High Speed Casting

3-D Multiphase Flow Modeling of Bubble Growth and Burst in Spray Cooling Using Parallel Computing

2007 ◽  
Author(s):  
R. Panneer Selvam ◽  
Joseph Johnston ◽  
Suranjan Sarkar
Keyword(s):  
Heat Transfer ◽  
Parallel Computing ◽  
Multiphase Flow ◽  
Liquid Film ◽  
Convective Flow ◽  
Bubble Dynamics ◽  
Thin Liquid Film ◽  
Spray Cooling ◽  
Droplet Impact ◽  
Multiphase Model

In this paper, we present an extension of the level set method from 2D into 3D for solving multiphase flow problems using distributed parallel computing. The model solves the incompressible Navier-Stokes equations to study the behavior of a bubble immersed in a thin liquid film at microscale as found in a spray cooling environment. Since modeling all aspects of spray cooling, including nucleation, bubble dynamics, droplet impact, convection and thin film evaporation is very difficult at this time; these phenomena have been divided and studied separately in order to study the heat transfer behavior of each phenomenon individually. We studied the droplet impact effect as seen in spray cooling by our 3D multiphase model in earlier studies. Through the 3D multiphase model this study simulates the dynamics of a nucleating bubble in a thin liquid film that merges with the ambient atmosphere above the film. In this study we did not consider the droplet impact effect to concentrate on the vapor bubble dynamics in thin liquid film and its effect on heat transfer. The effect of convective flow is not considered to keep the 3-D model simple. However the 2D model was modified to simulate the effect that a horizontal flow of constant velocity has on the growth and detachment of a nucleating bubble and discussed in the second part of the paper. This study illustrates the importance of considering the convective flow effect in our 3-D multiphase flow model in future with droplet impact for spray cooling modeling studies.

Research on the oxygen content in 304L stainless steel during VOD-LF-CC process based on IMCT

2019 ◽  
Vol 116 (6) ◽  
pp. 626
Author(s):  
Xingrun Chen ◽  
Guoguang Cheng ◽  
Yao Li ◽  
Yuyang Hou
Keyword(s):  
Stainless Steel ◽  
Oxygen Content ◽  
Molten Steel ◽  
Oxide Inclusion ◽  
Smelting Process ◽  
304L Stainless Steel ◽  
Total Oxygen ◽  
Obvious Effect ◽  
Si Content ◽  
Equilibrium Oxygen

The total oxygen in 304L stainless steel produced by the VOD-LF-CC process is investigated in this research. The equilibrium oxygen content in the molten steel during the smelting process is calculated based on the ion-molecule coexistence theory. The results show that it is feasible to use the developed thermodynamic model for calculating the equilibrium oxygen content in CaO–SiO2–Al2O3–MgO–FeO–Cr2O3 slags equilibrated with 304L molten steel. The variation law for total oxygen is in good agreement with the equilibrium oxygen content. The oxygen content of the oxide-inclusion decreases with the number density of inclusions, which decrease at different stages in the process. The content of FeO and Cr2O3 in the slag has no obvious effect on the equilibrium oxygen content when the basicity of the slag remains constant. Combining the proposed method with industrial practice, the optimum VOD process parameters for obtaining a low equilibrium oxygen content are as follows: 1600–1650 °C of the temperature after the VOD stage, 0.4–0.5% of the Si content after reduction, and 2.2–2.5 of the slag basicity.

scholarly journals Analysis of Sticking Breakout with Mechanical Model of Solidifying Shell Growth Considering a Mold Oscillation

2015 ◽  
Vol 101 (9) ◽  
pp. 479-487
Author(s):  
Toshiaki Mizoguchi ◽  
Yoshiyuki Ueshima ◽  
Shigeaki Ogibayashi ◽  
Tooru Matsumiya
Keyword(s):  
Mechanical Model ◽  
Shell Growth ◽  
Mold Oscillation

scholarly journals Development of a new mold oscillation mode for high-speed continuous casting of steel slabs.

1991 ◽  
Vol 31 (3) ◽  
pp. 254-261 ◽  
Author(s):  
Mikio Suzuki ◽  
Hideaki Mizukami ◽  
Toru Kitagawa ◽  
Kiminari Kawakami ◽  
Shigetaka Uchida ◽  
...  
Keyword(s):  
Continuous Casting ◽  
High Speed ◽  
Oscillation Mode ◽  
Continuous Casting Of Steel ◽  
Mold Oscillation ◽  
Steel Slabs

Design of Mechanically Driven Non-Sinusoidal Mold Oscillation

2013 ◽  
Vol 365-366 ◽  
pp. 24-27
Author(s):  
Min Zhi Yu ◽  
Xian Kui Li
Keyword(s):  
Superposition Principle ◽  
Sinusoidal Oscillation ◽  
Slab Caster ◽  
Obvious Effect ◽  
Steel Making ◽  
Production Practice ◽  
Driven System ◽  
Mold Oscillation ◽  
Hydraulic Servo ◽  
New Type

Based on an superposition principle, a new type of mechanically driven non-sinusoidal oscillation device has been designed. It has been proved by production practice that the device has much more advantages of investment, operation, maintenance and reliability than hydraulic-servo driven system. Now the oscillation device has been used at CC slab caster at No.1 Steel-making Plant of Shougang Corp. and obvious effect has been obtained.

Numerical Investigation of Inclusion Motion at Molten Steel–Liquid Slag Interface During Ruhrstahl Heraeus (RH) Process

JOM ◽  
2018 ◽  
Vol 70 (12) ◽  
pp. 2877-2885 ◽  
Author(s):  
Wei Liu ◽  
Shufeng Yang ◽  
Jingshe Li ◽  
Hongbo Yang
Keyword(s):  
Numerical Investigation ◽  
Molten Steel ◽  
Liquid Slag ◽  
Rh Process ◽  
Inclusion Motion

scholarly journals Kinetic study on compositional variations of inclusions, steel and slag during refining process

2018 ◽  
Vol 115 (4) ◽  
pp. 415 ◽  
Author(s):  
Ying Zhang ◽  
Ying Ren ◽  
Lifeng Zhang
Keyword(s):  
Mass Transfer ◽  
Transfer Coefficient ◽  
Mass Transfer Coefficient ◽  
Mathematical Simulation ◽  
Molten Steel ◽  
Gas Flow ◽  
Current Model ◽  
Steel Slag ◽  
Refining Process ◽  
Multiphase Model

A steel-slag-inclusion-alloy-refractory-air multiphase model, which combined the kinetic analysis and the consideration of fluid flow in argon-stirred ladle, was established to investigate the compositional changes during refining process. The steel-slag reaction, the steel and inclusion reaction, the refractory-steel reaction, the refractory dissolution into the slag, the reoxidation of the molten steel, the removal of inclusions by floating, and the alloy dissolution were all considered in the current model. The stirring energy, the average speed of the molten steel in the plume, the horizontal speed of the molten steel in the open eye, the speed of the molten steel near the side wall, the speed of the molten steel at the bottom of the ladle and the volume fraction of the plume were obtained by mathematical simulation. The mass transfer coefficient of the molten steel is obtained by mathematical simulation. Meanwhile, it is assumed that the mass transfer coefficient of inclusions is influenced by the temperature. The calculation results are in accordance with the experimental ones. The influence of different slag compositions, different gas flow rates, and different inclusion diameters on system compositions were also investigated using the current model. It is indicated that the content of T.O. in the molten steel was influenced by the gas flow rate and the removal rate of inclusions goes up with the increasing inclusion diameter.

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