Dynamics and control of solidification of molten metal flows

Firth, Andrew Robert; Gray, N. B.; Kyllo, A. K.; Williams, Geoffrey K.

doi:10.1007/s11663-001-0019-5

Cited by 3 publications

(2 citation statements)

References 14 publications

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“…[73][74][75][76] Nevertheless, the effect of flow dynamics on heat transfer has been analysed considerably less, 8,[77][78][79] while their combined influence on solidification is a relatively new topic. 8,80,81) Despite the extensive research on these phenomena, their effects on lubrication have been rarely addressed or even analysed in the context of defect formation during casting. This is possibly due to the fact that the slag phase has not been included in the calculations.…”

Section: Effect Of Flow Dynamics Heat Transfer and Solidificationmentioning

confidence: 99%

Key Lubrication Concepts to Understand the Role of Flow, Heat Transfer and Solidification for Modelling Defect Formation during Continuous Casting

López¹,

Jalali

Sjöström³

et al. 2018

ISIJ Int.

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Surface defects are recurrent problems during Continuous Casting of steel due to the introduction of new grades that are often difficult to cast, as well as the everlasting pursuit for higher quality and improved yield. Accordingly, numerical modelling has become a ubiquitous tool to analyse the formation mechanisms of such defects. However, industrial application of simulations is often hampered by oversimplifications and omissions of important process details such as variations in material properties, specific casting practices or shortcomings regarding fundamental metallurgical concepts. The present manuscript seeks to create awareness on these issues by visiting key notions such as slag infiltration, interfacial resistance and Lubrication Index. This is done from a conceptual point of view based on industrial observations and numerical modelling experiences. The latter allows a re-formulation of outdated concepts and misconceptions regarding the influence of fluid flow, heat transfer and solidification on lubrication and defect formation. Additionally, the manuscript addresses common challenges and constraints that occur during industrial implementation of numerical models such as the lack of high-temperature material data for slags. Finally, the manuscript provides examples of improvements on product quality and process stability that can be achieved through a holistic approach which combines modelling with laboratory tests, experiences from operators and direct plant measurements.KEY WORDS: numerical modelling; Continuous Casting; defects; lubrication; powder consumption.introduced as an alternative to study such issues in a more cost-efficient way than using traditional trial-error tests in the plant. Starting in the late 70's and 80's with the advent of personal computers, the first generation of models managed to predict the overall behaviour of the caster based on empirical data. 5-7) Subsequently, models in the 90's added Computational Fluid Dynamics (CFD) and solidification to casting simulations. [8][9][10] Faster computers and improved codes allowed huge progress regarding multi-phase applications (e.g. bubbles and inclusions) combined with calculations of flow and solidification in the past decade. 11-14)Currently, a wide variety of commercial and in-house codes are available for CC modelling such as PROCAST, COMSOL, TEMPSIMU, CON1D/2D, etc. [15][16][17] Moreover, a recent trend is the development of thermo-mechanical models coupled to flow dynamics for solving the combined problem of flow, solidification and stress-strain during casting. 18,19) Of all these, PHYSICA and THERCAST are two of the most promising approaches; which allow: a) 3D unstructured -mesh, multi-physics model using a combina-

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Section: Effect Of Flow Dynamics Heat Transfer and Solidificationmentioning

confidence: 99%

Key Lubrication Concepts to Understand the Role of Flow, Heat Transfer and Solidification for Modelling Defect Formation during Continuous Casting

López¹,

Jalali

Sjöström³

et al. 2018

ISIJ Int.

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“…It is reported that the growth of the solidified layer is strongly influenced by the superheat, the Rayleigh number and the axial position. The internal solidification of molten metal flows has been mathematically modeled for both steady and transient cases in [13]. The model predicts the solidified layer thickness and the metal flow rate, and an experimental verification of the mathematical model is reported using molten tin.…”

Section: Introductionmentioning

confidence: 99%

Heat Transfer and Solidification of Molten Iron in a Pipe

Barrón

Lopez²,

Medina

2014

AIR

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The effect of the pipe wall temperature on the heat transfer and the internal solidification phenomena during the pouring of pure molten iron in a pipe is studied in this work. A mathematical model consisting in the motion, mass balance and heat equations is proposed. The Reynolds Stress Model is employed to simulate turbulence. The mathematical model considering transient three-dimensional simulations is numerically solved using the Computational Fluid Dynamics technique. To simplify the mushy zone problem, pure iron considered. Numerical simulations show that a pipe wall temperature of 300 K promotes early solidification and blockage, and yields strong internal gradients of velocity and temperature. Besides, a pipe wall temperature of 1000 K prevents solidification and promotes a more homogeneous flow and temperatures contours of molten iron in the pipe.

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