| |
|
|
1
On Continuous Casting Modeling (2)
Solidification analysis
Casting process is to turn the liquid steel into solid, so the solidification
is the primary portion of the cast. For the solidification Modeling, the types
of analyses available and their benefits are listed below [246].
Heat Flow Analysis
- Macroporosity (isolated hot spots)
- Macroporosity (empirical criteria, e.g. Niyama)
- Primary dendrite-arm spicing, (empirical criteria)
- Secondary dendrite-arm spacing, (empirical criteria)
Fluid Flow Analysis
- Better representation of the thermal field during and after mold filling
- Darcy flow for interdendritic porosity models
Solidification Kinetics
- Grain size of castings via nucleation and growth laws
- Secondary dendrite-arm spacing, (coarsening relations)
- Solidification path
Species Flow Analysis
- Prediction of macrosegregation
- Prediction of microsegregation
- Enhanced representation of the solidification kinetics, fluid flow, and
heat transfer
Thermomechanical Analysis
- Physics-based solidification shrinkage
- Hot tearing from yield criteria
- Prediction of air gap with modification of heat transfer
- Prediction of residual stresses and casting dimensional control
In the solidification simulation, three types of data are handled:
- Input data: material properties for both metal and mold, boundary
conditions such as interface heat transfer coefficient, etc.
- Interactive data: in another word, it's input and output. During the
simulation, some input data need to be modified to during the model
optimization process. Examples of such data are microstructure evolution
(grain size, dendride arm spacing, etc.), mushy zone fluid flow (macro
segregation), rigging design, etc.
- Output data: After the model is set up, calculated results as output are
such as: stress state (shrinkage distortion), defect prediction (macro and
micro parosity, misrun, etc.).
References
[1] J.K. Brimacombe and A.W.Cramb: Steelmaking, casting and modelling.
Proc. 10th PTD Conf., ISS, Toronto, April 1992
[246] ASM: Modeling in Welding, Hot Deformation and Casting. 1997. ISBN
0-87170-616-4. Ed. By L. Kalsson.
[247] J. Herbertson and P. Austin: The Application of Mathematical Models for
Optimisation of Continuous Casting. Modeling of Casting, Welding and Advanced Solidification Processes - VI. Proceedings. TMS 1993. ISBN 0-87339-209-4.
|
|
|
|
|
|
