Induction heating is the use of electromagnetic induction to generate electricity inside the heated material (ie, the workpiece), relying on the energy of these eddy currents for heating purposes. The basic components of an induction heating system include induction coils, AC power, and workpieces. The coils can be made into different shapes depending on the heating target. The coil is connected to a power source that supplies an alternating current to the coil, and the alternating current flowing through the coil produces an alternating magnetic field that passes through the workpiece, which causes the workpiece to vortex to heat. Induction heating started with the birth of the automotive industry and the tractor industry. Because of its high heating efficiency, high speed, controllability and easy to achieve mechanization and automation.

The most effective heat treatment processes currently in use have the following applications: surface quenching, diathermy quenching, tempering and stress relieving (low temperature), annealing and normalizing (high temperature), weld annealing, powder metal sintering, and the like. It has been widely used in industries such as melting, casting, bending, hot forging, welding and surface heat treatment. In the aspect of casting, the double smelting process is rapidly developing, that is, the medium frequency furnace heat preservation modification is used to carry out precision casting of ductile iron or alloy steel; in the forging aspect, the use of dare to heat to achieve rapid diathermy hot forging not only reduces the scale loss. Moreover, the life of the forging die is greatly increased, the material utilization rate can reach 85%, and the surface roughness of the forging piece can be less than 50 μm; in the aspect of welding and quenching, the foreign side is devoted to developing a high-power all-solid-state high-frequency power source, on the one hand To develop highly automated heat treatment complete processing systems. At present, China needs about 10 million tons of castings per year, and the foundry industry is still mainly based on cupola melting and casting of general cast iron. The tonnage is small, resulting in large fluctuations in temperature and composition, and high scrap rate. The better casting industry scrap rate is also between 6% and 15%, while the average foundry's scrap rate is as high as 30%.