Characteristics and Application of Induction Heating

The main advantages of induction heating are:①not the overall heating,the workpiece deformation is small,small power consumption.②pollution-free.③heating speed,the workpiece surface oxidation decarbonization lighter.④surface hardened layer can be adjusted according to need,easy to control.⑤heating equipment can be installed in the mechanical processing production line,easy to mechanize and automation,easy to manage,and can reduce transportation,saving manpower,improve production efficiency.⑥hardened layer of fine martensite,hardness,strength,toughness are higher.⑦surface hardening after the workpiece surface has a larger compression stress,the workpiece anti-fatigue breaking capacity is higher.Induction heating heat treatment also has some drawbacks.Compared with the flame quenching,induction heating equipment is more complex,and poor adaptability,for some of the complex shape of the workpiece is difficult to guarantee the quality.Induction heating is widely used in surface quenching of gears,shafts,crankshafts,cams,rolls and other workpieces.The aim is to improve the wear resistance and fatigue resistance of these workpieces.The rear axle of the car is heated by induction heating,and the number of fatigue cycles under design load is about 10 times higher than that of quenching and tempering treatment.Induction heating surface quenching of the workpiece material is generally medium carbon steel.In order to meet the special needs of certain parts,has developed for induction heating surface hardening for the low hardenability of steel.High-carbon steel and cast iron manufacturing of the workpiece can also be used induction heating surface hardening.Quenching medium commonly used water or polymer solution.Equipment induction heating heat treatment equipment mainly by the power supply equipment,quenching machine and sensor components.

The main function of the power supply is the output frequency of the appropriate alternating current.High-frequency current power supply equipment with high-frequency tube generator and SCR inverter two.IF current power supply equipment is the generator set.General power supply equipment can only output a frequency of current,some equipment can change the current frequency,can also be directly with 50 Hz frequency current induction heating.The choice of induction heating equipment is related to the depth of the heating layer required by the workpiece.Heating the depth of the workpiece,should use the current frequency of low power equipment;heating layer of shallow parts,should use the current frequency of high power equipment.Another condition for selecting a power supply is the device power.The heating surface area increases,the required power supply power increases accordingly.When the heating surface area is too large or the power supply is insufficient,can be used continuous heating method,so that the workpiece and the sensor relative movement,the front heating,cooling behind.But it is best to heat the entire heating surface once.This can use the workpiece heart heat to harden the surface of the surface tempering,so that the process is simplified,but also save energy.The main function of induction heating quenching machine is to locate the workpiece and carry out the necessary movement.It should also be accompanied by a device that provides a quenching medium.Quenching machine can be divided into standard machine tools and special machine tools,the former applies to the general workpiece,which is suitable for mass production of complex parts.In order to ensure the heat treatment quality and improve the thermal efficiency,it is necessary to design and manufacture the appropriate sensor according to the shape and requirements of the workpiece.Commonly used sensors are outside the surface heating sensor,the hole heating sensor,the plane heating sensor,general-type heating sensor,special type heating sensor,a single type of heating sensor,composite heating sensor,melting furnace,etc.