Precision gears need to be quenched, so what is the principle of quenching?
When quenching, the precision gear should be placed in the inductor (coil). When an alternating current of a certain frequency is applied to the inductor, an alternating magnetic field is generated around the inductor.
The electromagnetic induction of the alternating magnetic field produces a closed induced current in the precision gear - eddy current. The distribution of the induced current on the section of the precision gear is very uneven, and the surface current density is high and gradually decreases inward. This phenomenon is called the skin effect.
The high-density current of the precision gear surface is converted into heat energy, which raises the temperature of the surface layer, that is, achieves surface heating. The higher the current frequency, the greater the difference in current density between the surface of the precision gear and the inside, and the thinner the heating layer. Surface quenching can be achieved by rapidly cooling after the temperature of the heating layer exceeds the critical point temperature of the steel.