Rayleigh-Taylor Instability in the Process of Clad Steel Slab Casting with Level DC Magnetic Field.

The effect of density difference between two kind of molten steels on the separation of chemical composition in the continuous casting process for clad steel slabs has been studied by experiment with a pilot caster. When the density of upper pool is lower than that of lower pool, the density difference stabilizes the separation of chemical composition. In the converse case, the density difference causes Rayleigh-Taylor instability which destabilizes the interface between the double layer inviscid fluid. As a result, the density difference promotes the mixing of chemical composition between the upper and lower pools. However, the stability analysis taking account of magnetohydromagnetic effect shows the mixing between the upper and lower pools can be suppressed by DC magnetic field. This effect of the magnetic field is classified into the term of magnetic pressure and the term of magnetic field gradient.