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Metals Processing Simulation Laboratory
Department of Mechanical Science and Engineering
University of Illinois at Urbana-Champaign
345 Mechanical Engineering Bldg.
1206 West Green Street, Urbana, IL 61801
Phone: 217-244-4656, 217-244-2859
Fax: 217-244-6534
Purpose
This facility, combined with the expertise of our research group, allows the simulation of fluid flow, heat transfer, and stress generation of a range of metallurgical processes, and especially, the continuous casting of steel slabs.
Computational Facilities
1) Two state of the art computational facilities, located in 345 MEB, UIUC and W470-I Brown Bldg, CSM, are dedicated to the modeling and simulation of metals processes using advanced, but computationally demanding software tools. The laboratories together currently feature more than 20 computer workstations and about ten researchers.
2) These CCC facilities both have access to the Blue Waters Supercomputer, located at the University of Illinois as part of NCSA (National Center for Supercomputing Applications at the University of Illinois). This is enabled by over 30 years of almost continuous grants of supercomputing time and access to supercomputing resources at NCSA (since 1986). In addition, the top NCSA experts on both ANSYS FLUENT fluid flow modeling software and ABAQUS stress analysis software are associated with the CCC research group, and assist CCC students in the CCC in the successful use of NCSA supercomputers for CCC projects.
3) A set of supercomputing nodes on the “mio” HPC (high-performance computing) system at the Colorado School of Mines is dedicated to the needs of our research group.
4) The Computational Fluid Dynamics Laboratory at UIUC, run by Professor Pratap Vanka is the home of CUFLOW and related CFD software and computers that are used in CCC related projects.
5) The Controls Lab at UIUC, run by Prof. Joseph Bentsman is currently being used for the development of CONONLINE, related graphical interface, and other software for online prediction and control of spray cooling continuous casting of steel slabs. This software has been implemented and running at Nucor Decatur Steel for more than 10 years (since 2006).
Software
Programs currently running on the Metals Process Simulation Laboratory computer systems include several in-house simulation programs:
| CON2D |
•2-D transient thermal-stress analysis of the solidifying steel shell, featuring robust algorithm to integrate the elastic-plastic-creep constitutive equations for different steel grades, generalized plane model for full 3-D predictions, gap and contact model for step-wise coupling between heat transfer and shrinkage calculations, and including effects of fluid flow driven superheat dissipation on heat transfer and mold distortion on gaps
• Based on finite-element method, with easy coupling with con1d model output.
• Used for more accurate taper calculations, simulating strand shape, depression, and crack formation mechanisms,etc.
This legacy Fortran code is not user-friendly, however, and requires a dedicated researcher. The functionality of CON2D has been implemented into ABAQUS via special-purpose user subroutines. |
CON1D
ROUND1D
STRIP1D |
•1-D transient heat transfer analysis of the solidifying steel shell in continuously-cast slabs, (including thin-slabs and square billets), round billets, and thin strip, featuring a detailed analysis of heat, mass, and force balances in the interfacial flux layers in the mold / shell gap, superheat flux from flowing liquid steel, and the spray and rolls in secondary cooling zones,
• Based on finite difference method and analytical solutions and correlations.
• The model runs in seconds on a PC and is designed for easy calibration with mold thermocouples, cooling water heatup, breakout shells (if available), mold friction data, (if available), and strand thermocouples or pyrometers (if available). After calibration, the model can be used for prediction of mold and strand temperature, boiling in the water channels, optimum taper design, surface crack danger due to complete flux solidification in the interfacial gap, mold friction, and the location of defects down the strand, and parametric analysis of the effect of casting conditions on both shell and mold behavior. |
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| MIX1D |
•1-D transient model of intermixing in the tundish and strand during grade changes, including prediction of composition distribution in blooms or slabs.
• Based on finite-difference calculation with empirical constants tuned to match 3D model calculations and coupled with mixing box solutions of the tundish and upper mold.
• User-friendly input to the model includes the composition and specifications of the two grades and the casting conditions during the grade change. The model runs in seconds and outputs the complete composition distribution through the thickness and along the strand length, including the location of any region that must be downgraded. |
| EQPRECIP |
A thermodynamics calculator that predicts equilibrium precipitate phases and amounts for a given plain low-carbon steel composition, with similar functionality as THERMOCALC and JMAT-Pro for these specific reactions. The program can be edited to enable calibration with new measurements, and can be used as a subroutine for other models, such as the CCC kinetic model for non-equilibrium prediction of precipitate formation, including particle size distributions. |
The Laboratory also makes use of commercial software, including:
| ABAQUS |
•Non-linear finite element codes, used for thermal-stress and mold distortion analysis. Special-purpose user subroutines, including UMAT and UMATH, have been developed to solve highly-nonlinear constitutive equations to implement realistic temperature-dependent thermal-mechanical properties of different steel grades at high temperature. |
ANSYS
CFX
FLUENT
FLOW3D
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•Finite difference fluid flow, mass transfer, and heat transfer code, used for modeling
multiphase flow and inclusion motion in the mold, tundish, and RH degassers
•Finite difference fluid flow code used for modeling free-surface problems, such as gas bubble injection. |
| FIDAP |
Coupled finite-element fluid flow and heat transfer code, used for modeling nozzle, top-surface powder layers, and graphics visualization. |
| TECPLOT |
Graphics visualization software. |
Materials Evaluation Facilities
The Advanced Steel Processing and Products Research Center (ASPPRC) at the Colorado School of Mines is one of several facilities that can provide equipment and services for microstructure evaluation of steel samples. In addition, the CCC has access to state-of-the art sample analysis facilities in the ME department, including a VHX-5000 digital microscope.
The Materials Research Laboratory at the University of Illinois provides equipment and services for microstructure evaluation through the Center for Microanalysis of Materials. The center facilities include SEM, Auger, SIMS, XPS, PIXE, X-Ray Diffraction, and TEM. Extensive facilities are also available for testing of mechanical properties. A complete machine shop and metallography laboratory are available in the Mechanical Science and Engineering Department for sample preparation, including polishing wheels, etching facilities, and optical microscopes.
Experimental Validation Facilities
Physical water model facilities are available at the research laboratories of several of the companies participating in the consortium, and have been used by our group to study flow in the liquid pool of the continuous casting mold region. Experiments, data collection, and measurements have also been performed on the production casters of the consortium members, to obtain calibration and input data, validate the models, and test the suggested improvements.
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