Download or read book Modeling Transient Multiphase Flow and Mold Top Surface Behavior in Steel Continuous Casting written by and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Modelling of the Liquid Slag Behaviour in the Continuous Casting Mould written by Zacharias Kountouriotis and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This work presents a fluid dynamics model of a continuous caster mould region, including the transient behaviour of the steel/slag interface. The research was carried out in collaboration with ArcelorMittal Research (AMR), based in Maizieres-les-Metz in France. The industrial objective of the thesis was to understand the factors affecting the transient behaviour of the liquid slag layer covering the steel and its interaction with the Submerged Entry Nozzle (SEN) jet supplying the steel from the tundish to the Continuous Casting (CC) mould. The study includes the very complex phenomenon of argon bubble transport which also affects the behaviour of the slag layer and SEN jet. The model developed in this study is based on the finite volume method with the liquid regions (steel, slag) solved in an Eulerian scheme on a fixed unstructured mesh. The interface behaviour is modelled using a number of VOF type schemes, including the time-efficient Counter Diffusion Method (CDM). A coupled Lagrangian particle tracking scheme is used to represent the presence of argon bubbles and their influence on the flowfield (mainly due to buoyancy) in conjunction with the fluctuating surface dynamics. The bulk of the research concerns comparisons against flowfield and interface data obtained from an experimental water/oil study of the process. However, the model is extended to include predictions of heat transfer and phase change in the steel and flux powder regions in an industrial CC unit and validation against available data. The three-phase model is developed making use of the unstructured mesh multi-physics finite volume code PHYSICA [1]. As stated, the main goal of this particular work has to do with the study of the dynamic behaviour of the steel/slag interface, including the effects of casting speed and injected gas. Because of the great difficulty in physical experiments with a real caster, the research is supported with water model experiments and mathematical simulation. Comparisons of observed interface profiles, measured and predicted mean and fluctuating velocities, gave an insight to the degree of coupling between interface behaviour and the fluid dynamics within the mould region. In particular, a spectral analysis of the dominant fluctuation frequencies in the water/oil experiment suggests a strong link between the upper and lower recirculation loops generated by the SEN jet as it splits after contact with the narrow face for the mould. The presence of gas bubbles alters the spectral picture, since the buoyancy induced in the flow affects the behaviour of the jet, leading to the one/two loop behaviour known from experiments. Good qualitative and quantitative agreement was achieved between the numerical results and water-model experimental data. The main observations drawn from the water model simulation and experiment are as follows: - An increase in casting speed, which is equivalent to an increase in SEN velocity leads to an increase in the amplitude of interfacial fluctuations. - At the highest SEN velocities, the oil layer is pushed away from the narrow ends of the mould, exposing the water surface to air. - When there is no oil on top of the water surface, the surface remains for all practical purpose flat. - Air entering through the SEN influences the flowfield in the mould and also disturbs the oil/water interface when it passes through it. - The ratio of water to air flow rate seems to be the most important parameter, with high air/water flow ratios leading to a change in flowfield at the top of the mould as the gas buoyancy lifts the SEN jet towards the surface. To achieve a good correlation between the experiments and the simulations a number of factors in the numerics were found to be important. These are: - The quality of the mesh used, especially in the complex transition from the SEN geometry - essentially a cylinder with two outlets set at a specific angle of 20o to the vertical, to the thin rectangular geometry of the mould which is designed to cast flat products. - The turbulence model, which was initially found to suppress interface oscillations whenever an oil layer was introduced. Various approaches were followed to overcome this problem, (a)removing the turbulence model from the oil layer, (b) using a low frequency filter to remove resolved turbulence kinetic energy from the k-[epsilon] model, (c)opting for the high order SMART numerical scheme in preference to the default Hybrid. - The interface tracking algorithm used as a default in the code PHYSICA is essentially a VOF technique with options for a Van-Leer (TVD) scheme [2] or alternative the popular Donor Acceptor scheme [3,4], both options work well but they are explicit and therefore extremely expensive computationally. Due to the size of the mesh and the CFL limit for stability, timesteps as small as 10-3s become necessary, meaning a 600s simulation could take up to 8 weeks! To overcome this, the implicit CDM scheme [5] was used, which allows the interface to spread by diffusion but then pushed back against the gradient to re-sharpen at the end of each timestep. With this scheme, timesteps up to 2 orders of magnitude larger become possible, the limit then governed by the frequency range to be resolved. A non-standard approach to the Lagrangian particle tracking scheme was adopted in the simulation with the following characteristics: - The amount of gas entering was divided into packets of equal bubble diameter and then each packet was further divided into individual tracks. The transport of 1000 and more particles tracks was used to ensure a realistic dispersion. - Tracks were updated at regular time intervals (but not necessarily at each Eulerian timestep) and then followed until they exited the calculation domain. - The residence time of particles in each cell provided information for the gas content of the cell and therefore its density. With this approach, the Navier-Stokes equations then solve for mixture (gas and liquid) and lighter cells are influenced by buoyancy. - The bubble tracks are affected by the mean velocity of the surrounding fluid and also by a stochastic component derived from the turbulence model. However, there is no direct feedback to fluid turbulence from the bubbles. To extend simulations to a real caster, heat transfer and phase change were introduced in the model, in addition to the property changes (water to steel, oil to slag, air to argon). Of importance here was the development of a solidified skin of steel on the water-cooled mould walls and also the melting of flux powder into a liquid layer on the top surface. This last component of the research was introduced to enable comparisons against plant data obtained by AMR. Of particular interest in this study was the transition from a double to a single roll recirculation in the top section of the mould, as a function of the relative quality of argon entering the SEN. The model was able to reproduce this behaviour for the cases studied. Although much has been done in developing this model of the continuous casting process it is evident that much more research is needed, especially in the case of a real caster. For example, the thermophysical property variations in the slag due to temperature, composition and mass transfer were ignored. A very simple approach was used for the phase change in steel and flux powder, although since the PHYSICA framework is modular, more sophisticated alternatives can be easily introduced. The boundary conditions for heat transfer remain uncertain and the values used in this study were obtained from the industrial partner from earlier experiments. In spite the aforementioned limitations, the model is very useful, especially in understanding the dynamic interactions between the SEN jets, and the slag/steel interface and in this respect in advance of other models used by industry.

Download or read book Materials Processing Fundamentals 2019 written by Guillaume Lambotte and published by Springer. This book was released on 2019-02-09 with total page 293 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book includes contributions from the Materials Processing Fundamentals Symposium held at the TMS 2019 Annual Meeting & Exhibition in San Antonio, Texas. This volume includes contributions on the physical and numerical modeling of materials processing, and covers a range of metals and minerals. Authors present models and results related the basics of processing such as extraction, joining, separation, and casting. The corresponding fundamentals of mass and heat transport as well as physical and thermodynamics properties are addressed, allowing for a cross-disciplinary vision of the field.

Download or read book Fluid Flow and Heat Transfer Behavior of Top surface Flux Layers in Steel Continuous Casting written by Robert Michael McDavid and published by . This book was released on 1994 with total page 584 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book TMS 2020 149th Annual Meeting Exhibition Supplemental Proceedings written by The Minerals, Metals & Materials Society and published by Springer Nature. This book was released on 2020-02-13 with total page 2046 pages. Available in PDF, EPUB and Kindle. Book excerpt: This collection presents papers from the 149th Annual Meeting & Exhibition of The Minerals, Metals & Materials Society.

Download or read book Fluid Flow Related Phenomena and Inclusion Motion in Continuous Casting Strands written by Yufeng Wang and published by . This book was released on 2010 with total page 310 pages. Available in PDF, EPUB and Kindle. Book excerpt: "To improve the efficiency of the continuous casting process and the quality of its products, this dissertation mainly investigated fluid flow related phenomena and inclusion motion in continuous casting. Mathematical simulation was performed for this purpose. Both a slab caster and a billet caster were investigated. In the study of the slab caster, the application of electromagnetic brake field on the slab mold was evaluated. The results indicated that the magnetic force decelerated the high speed steel jet, stabilized the top fluctuation, and prevented the bias flow inside the mold. The other study of this slab caster involved the fluid flow features during the transient casting process. It included casting start, casting speed variation, and temperature fluctuation. Especially for the casting start, the entire process was simulated using the volume of fluid multi phase model and dynamic mesh method. The results indicated the serious entrainment of air during the filling process and large fluctuations in the top surface level at the beginning of dummy bar moving. In the billet caster study, billet samples were collected from an industrial trial. The features of the nonmetallic inclusions were characterized by automated particle analysis and the size and spatial distribution of nonmetallic inclusions were determined. Mathematical models were developed to predict the entrapment locations of inclusions in the solidifying shell and compared to the industrial results. The distribution of inclusions predicted through mathematical modeling in the cross section of billet was in good agreement with the sample measurements"--Abstract, leaf iii.

Download or read book Transient Fluid Flow in the Mold and Heat Transfer Through the Molten Slag Layer in Continuous Casting of Steel written by Sivaraj Sivaramakrishnan and published by . This book was released on 2000 with total page 386 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Modeling of Multiphase Turbulent Flow in Continuous Casting of Steel written by Hyunjin Yang and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Modeling of In mold Heat Transfer in Continuous Casting of Steel written by Kenneth Paul Michalek and published by . This book was released on 1985 with total page 262 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Modeling of the Surface Marks Formation in an Immovable Mold During Continuous Casting of Steel written by Seguei D. Mikloukhine and published by . This book was released on 2007 with total page 276 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Tundish Technology for Clean Steel Production written by Yogeshwar Sahai (Ph. D.) and published by World Scientific. This book was released on 2008 with total page 329 pages. Available in PDF, EPUB and Kindle. Book excerpt: Continuous casting of steel has become a widely used process and an important step in steel production. The worldwide share of continuously cast steel has increased significantly in the last 25 years or so. However, concurrent with this increase in production levels are stringent quality requirements that have become crucial in the face of progressively increasing machine throughputs and larger product dimensions. As a result, steel cleanliness and strict composition control are now the primary concern of steelmakers.The tundish is the last metallurgical vessel through which molten metal flows before solidifying in the continuous casting mold. During the transfer of metal through the tundish, molten steel interacts with refractories, slag, and the atmosphere. Thus, the proper design and operation of a tundish are important for delivering steel of strict composition and quality. This pioneering book is the first of its kind to cover all aspects of tundish technology, ranging from fundamental aspects and theory necessary for understanding the basic concepts of tundish operations to operational aspects of the tundish. Written by internationally recognized experts in continuous casting technology in general and tundish technology in particular, this book is sufficiently fundamental to serve as a graduate-level textbook on process metallurgy or as an important reference for metallurgical researchers; at the same time, it is comprehensive enough to contribute to the understanding of scientists and engineers engaged in research and development in the steel industry.

Download or read book Fluid Flow Heat Transfer and Solidification in Continuous Casting Mold written by Manish Kamal and published by . This book was released on 2003 with total page 374 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Analysis of Thermomechanical Behavior of Mold for Continuous Casting of Steel in Function of the Copper Alloy written by Anne-Charlotte Deglin and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The mold is one of the most important components of the continuous casting machine since the mold controls the shape and initial solidification of the steel product, where quality is either created or lost. During casting, the mold is submitted to heat flux from liquid steel on one side whereas the other side is water cooled, leading to the generation of large temperature gradients. It is also submitted to other stresses such as ferrostatic pressure and clamping forces. Casting can last several dozens of hours whereas the cooling step of the mold, when liquid steel is not poured anymore into the mold, can last only a few minutes. Maintaining a reliable, crack-free mold within close dimensional tolerances is crucial to safety and productivity. In order to withdraw the right amount of heat and to prevent mold distortion, mold is generally made of copper alloys that have the thermal and mechanical properties required for this function. The two copper alloys most widely used for casting mold are Cu-Ag and Cu-Cr-Zr. They present a wide range of thermal and mechanical properties due to the different treatments to which they can be submitted. The present master thesis aims to study the influence of thermomechanical properties of copper alloys on continuous casting mold behavior during casting and cooling, and more precisely on mold for continuous casting of steel slabs using realistic finite element models of heat transfer and stress. After realizing a literature review of the most widely used copper alloys, three finite elements models were developed in order to study the influence of three copper alloy grades on mold thermomechanical behavior. The three finite elements models were a 2D simplistic transverse section of the mold model, a 2D transverse section of the mold model that includes bolts and the backup plate and a 3D quarter mold model. Simulations of casting and cooling step were performed with ABAQUS 6.10® for the two most widely used copper alloys and a copper alloy that was previously submitted to a heat treatment. Simulations results show that the two copper alloys most widely used lead to similar mold behavior. Besides, the material submitted to a heat treatment does not lead to a critical behavior but can lead to a necessity of more frequent re-machining of the mold.

Download or read book Materials Processing Fundamentals written by Lifeng Zhang and published by Springer. This book was released on 2016-12-01 with total page 315 pages. Available in PDF, EPUB and Kindle. Book excerpt: This collection provides researchers and industry professionals with complete guidance on the synthesis, analysis, design, monitoring, and control of metals, materials, and metallurgical processes and phenomena. Along with the fundamentals, it covers modeling of diverse phenomena in processes involving iron, steel, non-ferrous metals, and composites. It also goes on to examine second phase particles in metals, novel sensors for hostile-environment materials processes, online sampling and analysis techniques, and models for real-time process control and quality monitoring systems.

Download or read book Inverse Heat Conduction written by James V. Beck and published by James Beck. This book was released on 1985-10-02 with total page 336 pages. Available in PDF, EPUB and Kindle. Book excerpt: Here is the only commercially published work to deal with the engineering problem of determining surface heat flux and temperature history based on interior temperature measurements. Provides the analytical techniques needed to arrive at otherwise difficult solutions, summarizing the findings of the last ten years. Topics include the steady state solution, Duhamel's Theorem, ill-posed problems, single future time step, and more.

Download or read book Thermo fluid Dynamics of Two Phase Flow written by Mamoru Ishii and published by Springer Science & Business Media. This book was released on 2006-09-28 with total page 462 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book has been written for graduate students, scientists and engineers who need in-depth theoretical foundations to solve two-phase problems in various technological systems. Based on extensive research experiences focused on the fundamental physics of two-phase flow, the authors present the detailed theoretical foundation of multi-phase flow thermo-fluid dynamics as they apply to a variety of scenarios, including nuclear reactor transient and accident analysis, energy systems, power generation systems and even space propulsion.

Download or read book Hot Embossing written by Matthias Worgull and published by William Andrew. This book was released on 2009-09-28 with total page 368 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is an overview of replication technology for micro- and nanostructures, focusing on the techniques and technology of hot embossing, a scaleable and multi-purpose technology for the manufacture of devices such as BioMEMS and microfluidic devices which are expected to revolutionize a wide range of medical and industrial processes over the coming decade.The hot embossing process for replicating microstructures was developed by the Forschungszentrum Karlsruhe (Karlsruhe Institute of Technology) where the author is head of the Nanoreplication Group. Worgull fills a gap in existing information by fully detailing the technology and techniques of hot embossing. He also covers nanoimprinting, a process related to hot embossing, with examples of actual research topics and new applications in nanoreplication. - A practical and theoretical guide to selecting the materials, machinery and processes involved in microreplication using hot embossing techniques - Compares different replication processes such as: micro injection molding, micro thermoforming, micro hot embossing, and nanoimprinting - Details commercially available hot embossing machinery and components like tools and mold inserts