Abstract
A combined electromagnetic dam to confine molten metal puddle in a twin roll caster is newly proposed. It is composed of the solid dam of an inside type and the electromagnetic dam which makes use of the electromagnetic force performed by the direct electric field imposed on metal along the casting direction and the direct magnetic field applied between rolls. In the solid dam, ferromagnetic material is buried in order to smoothly transfer the magnetic flux from one roll to the other through it and electrodes are attached separately along the side face of the solid dam for concentrating the electric current density in the gap between the dam and the roll. The electromagnetic force produced by the combined dam is much larger than that of only the previously proposed electromagnetic dam where both the magnetic flux and the electric current are imposed, but there is no solid dam.
The experimental works were carried out to find how much height of molten metal is confined by the combined electromagnetic dam. It was found that the holding height of meniscus is much higher than that of the previous works of the electromagnetic dam and can be controlled by adjusting the imposed electric current. A mathematical model of the combined electromagnetic dam was developed to predict the holding height of meniscus from the given electric and magnetic fields and verified by the experimental data.
