Induction heating and heat treatment equipment is mainly composed of power supply equipment, quenching machine tool and inductor.
The main function of power supply equipment is to output alternating current with appropriate frequency. There are two kinds of high-frequency current power supply equipment: electron tube high-frequency generator and thyristor frequency converter. The medium frequency current power supply equipment is a generator set. General power supply equipment can only output current of one frequency. Some equipment can change the current frequency or directly use power frequency current of 50 Hz for induction heating.
The selection of power supply equipment is related to the required heating layer depth of the workpiece. For the workpiece with deep heating layer, the power supply equipment with low current frequency shall be used; For workpieces with shallow heating layer, power supply equipment with high current frequency shall be used. Another condition for selecting a power supply is the power of the device. As the heating surface area increases, the required power supply power increases accordingly. When the heating surface area is too large or the power supply power is insufficient, the continuous heating method can be adopted to make the workpiece and the sensor move relatively, heating in the front and cooling in the back. However, it is better to heat the whole heating surface at one time. In this way, the waste heat in the core of the workpiece can be used to temper the hardened surface, so as to simplify the process and save electric energy.
The main function of induction heating quenching machine tool is to position and move the workpiece. In addition, a device for providing quenching medium shall be attached. Quenching machine tools can be divided into standard machine tools and special machine tools. The former is suitable for general workpieces and the latter is suitable for complex workpieces produced in large quantities.
During induction heating heat treatment, in order to ensure the heat treatment quality and improve the thermal efficiency, the inductor with appropriate structure must be designed and manufactured according to the shape and requirements of the workpiece. Commonly used inductors include outer surface heating inductor, inner hole heating inductor, plane heating inductor, etc. For shaft parts with variable cross-section, half circle inductor can be used for heating by transverse magnetic field. According to the heating method, the inductor can be divided into simultaneous heating inductor and continuous heating inductor. In order to improve production efficiency, inductors that can heat multiple workpieces at the same time can also be designed for small workpieces. In order to improve the thermal efficiency of small hole and plane heating inductors and obtain an ideal heating profile, a magnet can be installed on the inductor to make the current distribution reasonable.