The physical foundation of induction heating, the metal conductor, in general, have an alternating current coil, according to the principle of electromagnetic induction, in under the action of the alternating magnetic field, can produce and the coil current in the conductor in the opposite direction, size, the same, the same frequency induction current, use the induced current in the conductor to make the heating method is called “induction heating.
Two ways of induction heating:
1. Penetration-type heating: When heating the parts, the penetration depth of the current is greater than the depth of the hardening layer, and the thermal energy of the hardening layer is all generated by eddy currents, and the temperature in the whole layer is basically uniform. This method is suitable for parts with higher frequency and power, and the depth of the hardening layer is shallow.
2.Conductive heating: when heating parts, the heat penetration depth of the current is less than that of the hardened layer, the heat generated by the hardened layer can only be generated by eddy currents in the heat penetration depth, beyond this layer of metal, its temperature increase is completely dependent on the surface heat through heat conduction. This method is suitable for low power equipment and the depth of the hardening layer requires deeper parts.
Application of induction heating:
The process of heat treatment by induction heating is called induction heat treatment.
According to the different USES of the workpiece can be local or overall induction hardening, annealing, tempering, normalizing, and tempering treatment.
For example, in modern automobile manufacturing technology, induction heating is also used in smelting, brazing, diathermy, thermal assembly, bonding and curing of metal parts, drying of coatings, and other fields.
1. Diathermy:
Mainly used for various parts (such as automobile crankshaft, connecting rod). The forging or diathermy of leaf spring, stamping welding axle housing, various gear parts, etc. Its advantages are high heating efficiency, high temperature control precision, good heating uniformity, small equipment floor space, energy saving, can improve the environment.
2. Aluminum-magnesium alloy semi-solid casting:
The semi-solid forming technology of nonferrous metal is the technology that heats the metal to the mixed state of solid and liquid, USES the high pressure to shoot the molten metal into the mold cavity, and forms by casting or pressure machining. Induction heating technology is widely used in this process, which has the advantages of fast heating speed, energy saving, and high efficiency, good composition, and tissue uniformity and mechanical properties after parts are formed, and the process equipment meets the requirements of environmental protection.
3. Heat treatment:
In order to improve the fatigue properties and wear resistance of the parts, induction hardening technology has been widely used, such as the typical automobile parts have crankshaft, half shaft, shaft, shaft, shifting fork, shifting fork shaft, guide shoe, rocker, rocker arm shaft, steering rack, spline shaft fork, output flange, shaft head, ball headpin, steering knuckle, etc; The local induction annealing of auto parts can improve the mechanical properties of carburized parts, mainly reducing the brittleness of the parts and improving the toughness. It is widely used in thread annealing of driving gear reducer, replacing the traditional lead furnace heating, improving the working environment, and meeting the requirements of environmental protection.
4. Casting smelting:
It is mainly used for melting and heat preservation of iron and steel materials and non-ferrous metals (aluminum alloy, brass, and other alloy die casting pieces). Its advantages are high heating speed, high productivity, good temperature uniformity, less equipment investment, and good liquid metal composition uniformity, which can improve the quality of the casting.
5. Curing adhesion:
When hot rigid adhesives are used to bond parts such as automobile parts (metal to metal, metal to rubber, metal to glass, etc.), the adhesives need to be cured by heating. Its advantage: do not have a solder joint, do not destroy the antirust layer, adhesive to seal while still can reduce vibration. Local heating can be realized by using induction heating technology, which has the characteristics of energy saving, high efficiency, small deformation of parts, and stable quality.
6: Induction brazing:
Mainly used for brazing all kinds of metals (such as steel and less steel, steel and copper, copper and copper, copper and stainless steel, stainless steel and aluminum alloy, etc.).Its advantages are fast heating speed, good temperature uniformity, small heat affected area of local heating parts, easy to realize automation, and production line connection.
7: Induction preheating:
Preheating the parts to be processed by induction heating can ensure the uniformity and stability of the preheating temperature, improve the quality of the mold or parts casting and achieve the purpose of energy saving and high efficiency.
Advantages of KETCHAN ELECTRONIC induction heat treatment equipment:
Energy saving – direct heating of inductive current inside the induction power supply, less loss in the energy conversion process
Environmental protection – The power supply and transformer are cooled by the internal circulation water cooling structure, which can reduce water resource pollution, air pollution, and clean production environment.
Improve performance – refine grain and increase strength.
High efficiency – high heating speed, coaxial transformer volume, easy to achieve automation.
Intelligent – All digital intelligent induction heating power supply combined with modern advanced automatic control idea, the temperature can be adjusted and monitored.