Full analysis of the principle and industrial application of high-frequency induction heating technology

With the rapid development of modern manufacturing, induction heating technology, with its significant advantages of high efficiency, energy saving, and environmental protection, has been widely used in various industrial fields such as metal heat treatment, welding, and melting. As a non-contact heating method, high-frequency induction heating plays an irreplaceable role in improving production efficiency and ensuring product quality.

[ 1. Basic Working Principle of Induction Heating ] ()

The core principle of high-frequency induction heating is based on the law of electromagnetic induction and Joule heating effect. When high-frequency alternating current passes through an induction coil, an alternating magnetic field is generated around the coil. The metal workpiece in the magnetic field generates eddy currents due to electromagnetic induction. When the eddy currents flow inside the workpiece and encounter resistance, they generate heat, thereby heating the metal workpiece.

Unlike traditional methods such as flame heating and resistance heating, induction heating generates heat directly inside the workpiece without the need for conduction or radiation from the outside. Therefore, the heating speed is extremely fast, the thermal efficiency is high, and there is less oxidation and decarburization, resulting in less deformation of the workpiece.

[ II. Differences and Applicable Scenarios between High Frequency, Super Audio, and Medium Frequency ] ()

Induction heating equipment can be divided into three categories based on their operating frequency: high frequency (above 100kHz), ultrasonic frequency (20-100kHz), and medium frequency (1-20kHz). Different frequencies result in varying heating depths and applicable processes.

**High frequency equipment has a shallow heating depth, generally between 0.5-2mm, and is mainly used for surface quenching, brazing, small part heating and other processes, such as surface hardening treatment of cutting tools, gears, and shaft parts.

**The heating depth of the ultrasonic equipment is centered, about 2-5mm, suitable for heat transfer, quenching, and welding of medium diameter workpieces. It is widely used in the fields of standard part hot forging and hardware tool heat treatment.

**Intermediate frequency equipment has a large heating depth of over 5mm, suitable for processes such as large piece heat transfer, melting, and heating before bar forging. It is most commonly used in the forging and casting industries.

[ III. Main Industrial Application Fields ] ()

**Heat treatment industry: including surface quenching, annealing, tempering and other processes for gears, shafts, guide rails, cutting tools and other workpieces, which can accurately control the depth of the hardened layer and significantly improve the wear resistance and fatigue strength of the workpiece.

**Welding industry: The production of high-frequency straight seam welded pipes is a typical application. The edges of the steel pipe are quickly heated to the welding temperature through high-frequency current, and the welding is completed under the action of the extrusion roller. The production efficiency is high and the weld quality is good. In addition, high-frequency induction heating is widely used for brazing hard alloy cutting tools and drill bits.

**Forging and Heat Transfer: Standard parts such as bars, bolts, nuts, etc. are heated as a whole before forging. Intermediate frequency equipment can achieve fast and uniform heat transfer, improve forging quality, and reduce oxidation losses.

*Smelting industry: * Medium frequency induction melting furnace is used for the smelting of steel, non-ferrous metals, and precious metals. It has the advantages of fast heating, low burning loss, uniform metal composition, environmental protection and cleanliness.

[ IV. Technical Advantages of Baoding Jinfan ] ()

Baoding Jinfan High Frequency Equipment Co., Ltd. has been dedicated to the research and manufacturing of induction heating equipment for many years. Our products cover a full range of MOSFET solid-state high-frequency, IGBT ultrasonic and intermediate frequency power supplies, matched with quenching machines, water cooling systems and automation devices, providing users with complete induction heating solutions. Compared with traditional electronic tube models, the company's solid-state series products can save more than 30% electricity, have low maintenance costs, small size, and easy installation, which are widely recognized by users.