What's the difference between industrial heat treatment intermediate frequency furnace and high frequency furnace?

Working principle of high-frequency electric furnace: high-frequency current flows through induction coil or other heating coil wound by red copper tube to generate alternating electromagnetic field. The material to be heated is placed in the induction coil, and electromagnetic induction generates eddy current in the material, which is converted into heat energy through resistance, thus increasing the temperature of the material.

Working principle of intermediate frequency furnace: When the induction coil is connected with AC power supply, an alternating magnetic field is generated in the induction coil, and its magnetic force cuts the metal charge in the crucible, resulting in induced electromotive force in the charge. Because the charge itself forms a closed loop, at the same time, an induced current is generated in the charge. When an induced current passes through a charge, it heats the charge to promote its melting.

Their working principles are basically similar, that is, different power supply frequencies have different heating effects.