INTERACTION OF METAL MELT FLOWS WITH A QUASI-SOLID FILM ON THE METAL SURFACE UPON A CHANGE IN THE AMPLITUDE OF AN ALTERNATING MAGNETIC FIELD

This work is devoted to induction melting of heat-resistant nickel alloys, in particular, to the problem of stability of
the oxidation film on the melt surface. The mathematical model describes heat and mass transfer in the metal melt
in an alternating magnetic field and elastically stressed states of the film on the melt surface. The main equations of
the problem and dimensionless parameters are presented. The states of the surface film are studied using numerical
simulation. It is shown how a change in the magnetic field strength affects the flow of the metal melt at different
frequencies. It is found that at different frequencies a change in the field strength leads to damping oscillations
in the velocity field. The causes of these oscillations are discussed in detail. Loading and destruction of thin films
during melt motion are considered. The mechanisms responsible for the primary destruction of the original film and
of its fragments are revealed. Rupture of a quasi-stable film at different frequencies is investigated. It is shown that
the result of the effect on the state of the film with an increase in the magnetic field strength depends on the field
frequency. A frequency range has been found in which the surface film is strong enough to prevent intensification of
the melt flow with increasing magnetic field strength. This effect ensures film stability

Author:  I. L. Nikulin, V. A. Demin, S. A. Nikulina
Keywords:  induction melting, surface cleaning, nonstationary flow, forced convection, Lorentz force, stress–strain state, film rupture
Page:  1298