scholarly journals On Modelling Parasitic Solidification Due to Heat Loss at Submerged Entry Nozzle Region of Continuous Casting Mold

Metals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1375
Author(s):  
Alexander Vakhrushev ◽  
Abdellah Kharicha ◽  
Menghuai Wu ◽  
Andreas Ludwig ◽  
Yong Tang ◽  
...  
Keyword(s):  
Continuous Casting ◽  
Steel Slag ◽  
Phase Interface ◽  
Steel Production ◽  
Submerged Entry Nozzle ◽  
Casting Process ◽  
Material Model ◽  
Slag Layer ◽  
Continuous Casting Mold ◽  
High Production Rate

Continuous casting (CC) is one of the most important processes of steel production; it features a high production rate and close to the net shape. The quality improvement of final CC products is an important goal of scientific research. One of the defining issues of this goal is the stability of the casting process. The clogging of submerged entry nozzles (SENs) typically results in asymmetric mold flow, uneven solidification, meniscus fluctuations, and possible slag entrapment. Analyses of retained SENs have evidenced the solidification of entrapped melt inside clog material. The experimental study of these phenomena has significant difficulties that make numerical simulation a perfect investigation tool. In the present study, verified 2D simulations were performed with an advanced multi-material model based on a newly presented single mesh approach for the liquid and solid regions. Implemented as an in-house code using the OpenFOAM finite volume method libraries, it aggregated the liquid melt flow, solidification of the steel, and heat transfer through the refractory SENs, copper mold plates, and the slag layer, including its convection. The introduced novel technique dynamically couples the momentum at the steel/slag interface without complex multi-phase interface tracking. The following scenarios were studied: (i) SEN with proper fiber insulation, (ii) partial damage of SEN insulation, and (iii) complete damage of SEN insulation. A uniform 12 mm clog layer with 45% entrapped liquid steel was additionally considered. The simulations showed that parasitic solidification occurred inside an SEN bore with partially or completely absent insulation. SEN clogging was found to promote the solidification of the entrapped melt; without SEN insulation, it could overgrow the clogged region. The jet flow was shown to be accelerated due to the combined effect of the clogging and parasitic solidification; simultaneously, the superheat transport was impaired inside the mold cavity.

Effect of Bottom Structure of Submerged Entry Nozzle on Flow Field in Ultra-Thick Slab Continuous Casting Mold

2010 ◽  
Vol 154-155 ◽  
pp. 840-845 ◽  
Author(s):  
Xin Xie ◽  
Deng Fu Chen ◽  
Qiang Liu ◽  
Jia Long Shen ◽  
Zheng Peng ◽  
...  
Keyword(s):  
Continuous Casting ◽  
Flow Pattern ◽  
Submerged Entry Nozzle ◽  
Casting Process ◽  
Surface Flow ◽  
Water Model ◽  
Continuous Casting Mold ◽  
Flat Bottom ◽  
Thick Slab ◽  
Flow Intensity

Submerged entry nozzle (SEN) bottom structure plays an important role in determining the flow pattern in continuous casting process. This work applies a water model to evaluate the pointed-bottom, flat-bottom and recessed-bottom nozzle performance in ultra-thick slab mold. The jet properties and surface flow are compared for the three kinds of nozzles quantitatively. The results show that flat-bottom and recessed-bottom nozzles are similar in flow pattern, but the pointed-bottom nozzle has smaller jet angle, thinner flow pattern, larger surface asymmetry rate, and higher surface flow intensity.

scholarly journals Analysis of the Depth of Immersion of the Submerged Entry Nozzle on the Oscillations of the Meniscus in a Continuous Casting Mold

Metals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 596 ◽  
Author(s):  
F. Saldaña-Salas ◽  
E. Torres-Alonso ◽  
J.A. Ramos-Banderas ◽  
G. Solorio-Díaz ◽  
C.A. Hernández-Bocanegra
Keyword(s):  
Continuous Casting ◽  
Fluid Dynamic ◽  
Submerged Entry Nozzle ◽  
Dynamic Structure ◽  
Slag Layer ◽  
Three Dimensions ◽  
Scale Model ◽  
Continuous Casting Mold ◽  
Casting Mold ◽  
High Elevations

In this study the effects of the depth of immersion of the Submerged Entry Nozzles (SEN) on the fluid-dynamic structure, oscillations of the free surface and opening of the slag layer, in a continuous casting mold for conventional slab of steel were analyzed. For this work, a water/oil/air system was used in a 1:1 scale model, using the techniques of Particle Image Velocimetry (PIV), colorimetry and mathematical multiphase simulation. The results of the fluid dynamics by PIV agree with those obtained in the mathematical simulation, as well as with the dispersion of dye. It was observed that working with immersion depths of 100 mm or less could be detrimental to steel quality because they promote surface oscillations of a higher degree of Stokes with high elevations and asymmetry in their three dimensions. In addition, this generates an excessive opening of the oil layer which was corroborated through the quantification of the F index. On the other hand, with depths of immersion in the range of 150–200 mm, lower oscillations were obtained as well as zones of low speed near the wall of the SEN and a smaller opening of the oil layer.

scholarly journals Influence of EMS on Asymmetric Flow with Different SEN Clogging Rates in a Slab Continuous Casting Mold

Metals ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1288
Author(s):  
Bin Li ◽  
Haibiao Lu ◽  
Yunbo Zhong ◽  
Zhongming Ren ◽  
Zuosheng Lei
Keyword(s):  
Flow Field ◽  
Continuous Casting ◽  
Submerged Entry Nozzle ◽  
Casting Process ◽  
Continuous Casting Mold ◽  
Continuous Casting Process ◽  
Slab Continuous Casting ◽  
Safe Level ◽  
Mold Flow ◽  
Slag Entrapment

Submerged entry nozzle (SEN) clogging is a troublesome phenomenon in the continuous casting process that can induce the asymmetric mold flow, and thus, lowering the steel product quality. In this paper, a mathematical model coupling the electromagnetic and flow fields, was developed to investigate the influence of the SEN clogging rate on the flow field and the influence of electromagnetic stirring (EMS) on the asymmetric mold flow. Slag entrapment index Rc was introduced to quantify the possibility of slag entrapment, and symmetric index S was introduced to quantify the symmetry of the flow field. The results show that as the SEN clogging rate increased, the slag entrapment index Rc increased, while the symmetric index S decreased. EMS can greatly improve the symmetry of the flow field with SEN clogging, but it cannot remove the asymmetric phenomenon completely because the stirring intensity should be controlled below the safe level to avoid slag entrapment.

scholarly journals Numerical and Physical Parametric Analysis of a SEN with Flow Conditioners in Slab Continuous Casting Mold

2017 ◽  
Vol 62 (2) ◽  
pp. 927-946 ◽  
Author(s):  
J. Gonzalez-Trejo ◽  
C.A. Real-Ramirez ◽  
R. Miranda-Tello ◽  
F. Rivera-Perez ◽  
F. Cervantes-de-la-Torre
Keyword(s):  
Fluid Flow ◽  
Continuous Casting ◽  
Submerged Entry Nozzle ◽  
Casting Process ◽  
Continuous Casting Mold ◽  
Fluid Exchange ◽  
Standard Equipment ◽  
Symmetric Pattern ◽  
Physical Simulations ◽  
Flow Symmetry

AbstractSome of the most recent technologies that improves the performance in continuous casting process has installed infrastructure outside the mold to modify the natural fluid flow pattern to obtain a quasi-steady condition and promote a uniform solidified shell of steel. The submerged entry nozzle distributes the liquid steel in the mold and can be used to obtain the flow symmetry condition with external geometry improvements. The fluid flow conditioners were located near the outlet ports of the nozzle. The aim of the modifiers is to impose a pseudo symmetric pattern in the upper zone of the mold by inhibiting the fluid exchange between the zones created by conditioners. This work evaluates the effect of the thickness and length of the fluid-flow modifiers on the overall performance of the submerged nozzle. These properties of the fluid-flow modifiers were normalized based on two of the geometric dimensions of the standard equipment. Numerical and physical simulations suggest that the flow modifier should be as thin as possible.

scholarly journals An Approach for Modelling Slag Infiltration and Heat Transfer in Continuous Casting Mold for High Mn–High Al Steel

Metals ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 51 ◽  
Author(s):  
Jie Yang ◽  
Dengfu Chen ◽  
Mujun Long ◽  
Huamei Duan
Keyword(s):  
Heat Transfer ◽  
Continuous Casting ◽  
Steel Slag ◽  
Casting Process ◽  
Al2o3 Content ◽  
Continuous Casting Mold ◽  
Casting Mold ◽  
Formation And Evolution ◽  
Meniscus Region ◽  
Complex Phenomena

To clarify the characteristics of slag infiltration and heat transfer behaviors in the meniscus region during the casting of high Mn–high Al steel, a mathematical model of a continuous casting mold that couples fluid flow with heat transfer, and solidification is developed. The model is based on the change in slag composition and properties caused by the steel/slag reaction. The formation and evolution of the meniscus profile and slag films for different mold fluxes during mold oscillation are described. The results show that the rapid growth of the slag rim with a high Al2O3 content approaches and deforms the meniscus so that a series of casting problems such as slag infiltration blocking, large fluctuations in heat flux, and even meniscus breaking occur in the continuous casting process. Predictions are in good agreement with plant measurements. These findings provide an improved understanding of the complex phenomena occurring in the meniscus region and give new insights into the evaluation and optimization of mold flux properties for high Mn–high Al steel casting.

scholarly journals An improved imperialist competitive algorithm for hybrid flowshop rescheduling in steelmaking-refining-continuous casting process

2020 ◽  
pp. 002029402096018
Author(s):  
Kunkun Peng ◽  
Xudong Deng ◽  
Chunjiang Zhang ◽  
Quan-Ke Pan ◽  
Liang Ren ◽  
...  
Keyword(s):  
Continuous Casting ◽  
Optimal Schedule ◽  
Steel Production ◽  
Casting Process ◽  
Imperialist Competitive Algorithm ◽  
Initial Population ◽  
Hybrid Flowshop ◽  
Iron And Steel ◽  
Competitive Algorithm ◽  
Iron And Steel Production

Steelmaking-refining-Continuous Casting (SCC) is a key process in iron and steel production. SCC scheduling is to determine an optimal schedule for the SCC process, which is a worldwide and important problem. High-quality SCC scheduling methods will help to allocate production resources effectively and increase the productivity. However, dynamic events (e.g. machine breakdown) may happen in the realistic SCC process, which will make the SCC schedule inexecutable or not optimal. In this case, SCC rescheduling is essential in order to obtain a new optimal schedule suitable for the current production environments. The SCC rescheduling can be modeled as hybrid flowshop rescheduling. In this paper, an Improved Imperialist Competitive Algorithm (IICA) is proposed to address the SCC rescheduling. In the proposed IICA, an empire initialization is first devised for constructing an initial population with diversity and certain quality. Moreover, multiswap-based local search and imperialist competition are designed to improve the exploitation ability of the IICA, while revolution and restart strategy are devised to enhance the exploration ability of the IICA. Comparison experiments with three kinds of ICA have shown the efficiency of the IICA.

scholarly journals Numerical Simulation of Fluid Flow, Heat Transfer, Species Transfer, and Solidification in Billet Continuous Casting Mold with M-EMS

Metals ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 66 ◽  
Author(s):  
Wenjie Zhang ◽  
Sen Luo ◽  
Yao Chen ◽  
Weiling Wang ◽  
Miaoyong Zhu
Keyword(s):  
Fluid Flow ◽  
Continuous Casting ◽  
Swirling Flow ◽  
Casting Process ◽  
Longitudinal Section ◽  
Current Intensity ◽  
Continuous Casting Mold ◽  
Casting Mold ◽  
Billet Continuous Casting ◽  
Negative Segregation

Electromagnetic stirring in mold (M-EMS) has been widely used in continuous casting process to improve the solidification quality of the steel strand. In the present study, a 3D multi-physical-field mathematical model was developed to predict the macro transport phenomena in continuous casting mold with M-EMS using ANSYS commercial software, and was adopted to investigate the effect of current intensity (0, 150, 200, and 240 A) on the heat, momentum, and species transports in the billet continuous casting mold with a size of 160 mm × 160 mm. The results show that when the M-EMS is on, the horizontal swirling flow appears and shifts the high-temperature zone upward. With the increase of current intensity, two swirling flows form on the longitudinal section of continuous casting mold and become more intensive, and the flow velocity of the molten steel at the solidification front increases. Thus, the wash effects of the fluid flow on the initial solidified shell become intensive, resulting in a thinner shell thickness at the mold exit and a significant negative segregation of carbon at the billet subsurface.

Interfacial Heat Flux Estimation in a Funnel Shaped Mould and Analysis of Solidification Characteristics in Thin Slab Continuous Casting

2021 ◽  
Author(s):  
Pedduri Jayakrishna ◽  
Ananda Vaka ◽  
Saurav Chakraborty ◽  
Suvankar Ganguly ◽  
Prabal Talukdar
Keyword(s):  
Heat Flux ◽  
Continuous Casting ◽  
Molten Steel ◽  
High Speed ◽  
Thermal Characteristics ◽  
Submerged Entry Nozzle ◽  
Casting Process ◽  
Transfer Model ◽  
Thin Slab ◽  
Slab Continuous Casting

Abstract An inverse heat transfer model based on Salp Swarm optimization algorithm is developed for prediction of heat flux at the hot faces of a mould in thin slab continuous casting. The industrial mould considered in this work is a funnel-shaped mould having complex arrangement of cooling slots and holes. Significant variations of heat flux along the casting direction, as well as across the width are observed. Subsequently, the obtained heat flux profile estimated by the inverse method is used to analyse the fluid flow and thermal characteristics of the solidifying steel strand inside the mould. Three different recirculatory zones are present due to molten steel flow, affecting the thermal and solidification characteristics significantly. The effect of these recirculatory flows on remelting phenomenon, and consequent formation of thinner shell at the mould outlet leading to quality control issues in the casting process have been discussed. Another practical issue of depression in the wide face shell thickness at the mould outlet has been identified, and its cause has been related to the location of the Submerged Entry Nozzle and the high speed of the molten steel inflow.

scholarly journals Optimization of Submerged Entry Nozzle Depth in CC Mould / Optymalizacja Zanurzenia Wylewu W Krystalizatorze Cos

2015 ◽  
Vol 60 (4) ◽  
pp. 2927-2932
Author(s):  
J. Pieprzyca ◽  
T. Merder ◽  
M. Saternus
Keyword(s):  
Carbon Steel ◽  
Continuous Casting ◽  
High Carbon Steel ◽  
Low Carbon Steel ◽  
Submerged Entry Nozzle ◽  
Casting Process ◽  
Low Carbon ◽  
High Carbon ◽  
Steel Continuous Casting

The way and speed of steel flux flowing into mould of continuous casting (CC) machine belong to the important parameters characterizing the steel continuous casting process. Such flux causes determined kinds of steel circulation, which together with simultaneous steel crystallization influence the creation of ingots primary structure and quality of its surface. The article presents the results of modelling research which aim was to determine the optimal location of submerged entry nozzle in square moulds (130 x 130 mm and 160 x 160 mm) of CC machine. Such a research was carried out for two different grades of steel (low-carbon steel and high-carbon steel), which feature different parameters of casting.

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