High-frequency quenching is mostly used for surface quenching of industrial metal parts, which is a metal heat treatment method that generates a certain induced current on the surface of the workpiece, rapidly heats the surface of the part, and then rapidly quenches. Induction heating equipment, that is, the workpiece is induction heating to carry out surface hardening equipment. Principle of induction heating: The workpiece is placed in the sensor, the sensor is generally input medium frequency or high frequency AC (1000-300000Hz or higher) hollow copper tube. The generation of alternating magnetic field in the workpiece produces the same frequency of induction current, the distribution of this induction current in the workpiece is not uniform, strong on the surface, and in the interior is very weak, to the heart is close to 0, using this skin effect, can make the surface of the workpiece rapidly heated, in a few seconds the surface temperature rises to 800-1000 ° C, and the heart temperature rise is very small.