עקרון העבודה של ציוד מרווה בתדירות גבוהה

Using the principle of electromagnetic induction, the bearing is placed in the inductor (coil), and an alternating current of a certain frequency is passed into the inductor to generate an alternating magnetic field. The electromagnetic induction of the alternating magnetic field produces a closed induced current in the workpiece—eddy current.

The distribution of the induced current on the cross section of the workpiece is very uneven, and the current density on the surface of the workpiece is very high and gradually decreases inward. This phenomenon is called the skin effect. The electric energy of the surface current of the workpiece is converted into heat energy, which increases the temperature of the surface layer, that is, the surface heating is realized. The higher the current frequency, the greater the current density difference between the surface layer and the inside of the workpiece, and the thinner the heating layer. Surface quenching can be achieved by rapid cooling after the temperature of the heating layer exceeds the critical point temperature of the steel.