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Induction Heating Since 2000

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Induction Heat Treating

What’s Induction Heat Treating?

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  Surface induction heat treatment in which the workpiece is heated locally by induction current. This induction heat treating process is often used for surface induction hardening, local induction annealing or induction tempering, and sometimes for overall induction hardening and tempering.  In the early 1930s, the United States and the Soviet Union began to apply induction heating methods for parts surface induction hardening. With the development of industry, induction heating and induction heat treatment technology has been improved and its application has been expanded. 

  Induction heating and induction heat treatment equipment is mainly composed of induction heating power supply equipment, induction quenching machine and induction inductor.  The main function of induction heat treating machine is to output alternating current at a suitable frequency. There are two kinds of high frequency current power supply equipment: electron tube high frequency generator and SCR converter. Medium frequency current power supply equipment is a generator set.  General power supply equipment can only output a frequency of current, some equipment can change the current frequency, can also directly use 50 hz power frequency current induction heating.

Why use Ketchan Induction Heat Treating Equipment?

  As a leading induction heat treating machine manufacturer in China, we have done thousands of induction heat treating solutions since established. And the advantages of the induction heat treating machine are as followings:

  • Surface induction heat treating: Surface induction quenching makes the workpiece have a hard shell and a tough core. Therefore, it can replace part of the carburizing, induction hardening and tempering, and oxidation processes to save the alloying elements of the material. Due to the heating period, the oxide scale is very small and the deformation is also small.
  • Local induction heat treating: It can precisely heat the parts where the workpiece needs to be quenched, especially in the case of magnetic conductors and high power densities.
  • Energy-saving heat treatment: its energy consumption and carburizing, oxidation, induction hardening, and tempering compared with a great advantage, when the quenching part of the workpiece quality and the overall quality of the greater the difference, its advantage is also more significant. Induction heat treatment often has high added value.
  • Rapid induction heat treatment: induction hardening heating time in seconds, generally within 2~10s, the production cycle is also short, especially in the use of self-tempering or random induction tempering, this process is similar to the machining process. For this purpose, modern induction quenching equipment has been arranged in the production line or automatic line.
  • Clean induction heat treatment: the induction hardening liquid used for induction quenching is generally water or water solution with additives. When induction hardening, there is almost no oil smoke and the working environment is good.
  • Convenient for mechanization and automation: mass production of induction hardening parts, generally equipped with step feeding, manipulator to take the workpiece, and robot control sensors and other devices to reduce physical labor.

How to Select Suitable Induction Heat Treating Solutions?

  The choice of induction heat treatment solution is related to the depth of the heating layer required by the workpiece. For the workpiece with a deep heating layer, should choose the medium frequency induction heating machine. For the workpiece with a shallow heating layer, should choose the high frequency induction heating machine.

  The power supply equipment with low current frequency should be used;  Another criterion for selecting a power supply is the machine power. As the heating surface area increases, the induction heat treating machine power required increases accordingly.

  When the heating surface area is too large or the induction heat treating power supply is insufficient, the continuous heating method can be adopted to make the workpiece and the induction heating coil move relative, first heating and then cooling.

  But it’s best to heat the entire surface at once. In this way, the waste heat of the workpiece core can be used to temper the hardened surface layer, thus simplifying the process and saving electric energy. The main function of the induction heating and quenching machine is to position the workpiece and carry out the necessary movement. An induction heat treating system for providing a quenching medium shall also be attached. CNC induction hardening machine tools can be divided into standard machine tools and special machine tools, the former is suitable for the general workpiece, and the latter is suitable for mass production of the complex workpieces. 

  In order to ensure the quality of induction heat treatment and improve the thermal efficiency, the inductor with proper structure must be designed and manufactured according to the shape and requirement of the workpiece. Common induction coils include outer surface induction heating coil, inner hole induction heating coil, plane induction heating coil, and so on.

What is the Induction Heat Treating Application Field?

  Normally, the heat treatment process realized by induction heating is called induction heat treatment.
  Different applications can do the workpiece partial or whole induction quenching, induction hardening, induction annealing, induction normalizing, induction tempering, and induction quenching and tempering treatment.

  Application: in modern automobile manufacturing technology, induction heating treating is also used in melting, brazing, blank heating (diathermic), thermal assembly, metal parts after bonding curing, coating drying and other fields.

  • Billet, round bar, square bar induction forging: It is mainly used for induction heat treating various automobile parts (such as crankshaft, connecting rod, leaf spring, punching welding axle housing, various gears, and other parts) induction forging through heating treating.
      The advantages are high heating efficiency, high-temperature control precision, good temperature uniformity of the blank, the small footprint of the equipment, energy-saving saving, and can improvement of the working environment.
  • Aluminium-magnesium alloy semi-solid casting: Non-ferrous metal semi-solid forming technology is to heat the metal to a solid-liquid mixing state, the use of high pressure will be molten metal shot into the cavity, through casting or pressure processing molding technology. Induction heating treatment technology is widely used in this process, which has the advantages of fast heating speed, energy saving, and high efficiency, good composition and organization uniformity after forming parts, good mechanical properties, and the process equipment meets the requirements of environmental protection. In the automotive manufacturing technology of advanced companies for aluminum alloy and aluminum magnesium alloy parts forming.
  • Induction heat treating: Induction heat treating technology has been widely used in order to improve the fatigue performance and wear resistance of automobile parts. Typical parts are crankshaft, half shaft, camshaft, through the shaft, variable speed fork, variable speed fork shaft, guide block, rocker arm, rocker arm shaft, steering rack, spline shaft fork, output edge, shaft head, ball head pin, steering knuckle, and other parts;  Local induction annealing of automobile parts can improve mechanical properties of carburized parts. It is mainly used to reduce the brittleness of parts and improve their toughness. It is widely used in the thread induction annealing of driving gear – a reducer, instead of the traditional lead furnace induction heating.
  • Induction melting casting: It is mainly used for induction smelting and heat preservation of iron and steel materials and non-ferrous metals (aluminum alloy, brass, and other alloy die castings).            The advantages are fast heating rate, high productivity, good temperature uniformity, less equipment investment, and good composition uniformity of liquid metal, which can improve the casting quality.
  • Auto parts are cured by induction heating after bonding: In the use of thermo-rigid adhesive to automotive parts (metal and metal, metal and rubber, metal and glass, etc.) after bonding through induction heat treating to make the adhesive curing. 

  Advantages: no solder joints, do not destroy the rust layer, and the adhesive can reduce vibration while playing a seal. The induction heating technology can realize local induction heat treating, which has the characteristics of energy saving, high efficiency, small deformation of parts, and stable quality. 

  Applications: it is widely used in companies with advanced automobile manufacturing technology. Faw-Volkswagen Jetta, Balai, and Kaidi have 20 sets of this induction heat treating equipment in use. It is mainly used for curing the door, trunk cover, and engine cover after bonding, and is connected with the automatic production line.  All the equipment above is imported technology, and the research on this technology has not been carried out in China.

  • High frequency welded tube
  • Induction braze welding: It is mainly used for induction brazing welding various auto parts (such as brazing of iron and steel materials, iron and steel materials, copper and copper materials).

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