Coupled Numerical Simulation Of Solidification Transport Behaviours In Electromagnetic Continuous Casting Of Steel Ingots

The solidification transport phenomena (STP), i.e. heat, mass and momentum transfer in alloy solidification systems are very important and complicated due to the strong coupling among them. When an electromagnetic filed (EMF) is applied to the solidifying system, that coupled correlations will becom even more complicated. Research on the coupled solidification transport phenomena and the influence of EMF on the solidified process of steel ingot can give advice to improve the quality of ingots, and is very meaningful.The aim of the present thesis is to establish an EM-coupled continuum model for STP in the electromagnetic continuous casting (CC) processes of steel ingots based on the previous work of our research group, using the method of theoretical modeling and computer simulation. The main work inclued:The mathematical model in a continuum form and the corresponding numerical formula for the electromagnetic STP of the steel ingot in EMC process are established, which is under both gravity and electromagnetic fields and with a movement velocity V0 relatively to the static lab coordinate. Computer codes in FORTRAN language is developed for numerical simulation of the EMC-STP processes.The ANSYS software is explored to analyze the static and traveling magnetic fileds applied to the EMC system. Conversion of the EMF-data from ANSYS finite element method (FEM) format, included the B vector field, induction current density, Joule heat and so on, to finite different method (FDM) format is performed using our own data processing FORTRAN program.Coupling the conversed EMF-data to the STP simulation program, preliminary computational results, including the liquid flow velocity, temperature filed, solid volume fraction filed, Lorentz force filed and so on in EM-continuous casting processes of steel ingots, indicate that the present computer modeling is successful.The coupled simulation results for the CC-STP behaviors under different static and traveling EMFs show that, application of a static magnetic field to the steel ingot continuous casting process can effectively suppress the bulk liquid flow, and the braking effects enhance with the increase of the magnetic field's intensity; the application of traveling magnetic field can obviously change the liquid flow patterns.