Metal Parts and Induction Heating Basics

Induction heating is the process of heating a conductive material by generating a circulating flow of electrons or currents in the material. The material’s resistance to the flow of the currents generated within the material results in heat being generated.

The currents are generated by rapidly changing a magnetic field around the conductive piece. In practical terms, induction heating can best be thought of as similar to an electromagnet, but with alternating current.

We can all recall a simple science experiment in grade school science class. When a coil of wire is wrapped around an iron nail, and a direct current (DC) current is applied to the coil, the iron nail becomes magnetic.

In essence this same effect is caused by wrapping a coil or inductor around a conductive material and using alternating (AC) current. However the alternating current constantly changes the direction of the flow of electrons and currents in the conductive material. This change in direction leads to the heating of the material at a much higher rate.

The power required to generate the currents, known as Eddy currents, within the conductive material is supplied by an AC power supply. In addition to controlling the power output, it is either designed for a fixed frequency or can change the frequency of the alternating current.

The power supply sends current though the induction coil, which is either wrapped around the conductor or in close proximity. The frequency of the AC current through the coil will essentially dictate how far into the conductor the eddy currents will penetrate. Higher frequency currents will penetrate a very shallow distance while a lower frequency will penetrate much deeper.

Lou Ghinga
Estimator
Zion Industries