1. Objective

After presenting the fundamental mechanisms of induction, we review the effects of a magnetic field on the behavior of free liquid metal surfaces, depending on field strength and frequency. First, the various aspects of single-frequency alternating fields are presented: electromagnetic levitation and static dome forming, dome oscillation, instability, emulsification... Then, the effects of a magnetic field with several frequencies are exploited to accelerate mass transfer in a pollution control process. This is followed by the case of a continuous magnetic field. Although the latter is generally stabilizing, its application in steel slab casting can lead to high-amplitude, low-frequency oscillations.