Definition of induction Hardening

Induction hardening uses electromagnetic induction to heat the metal material above the phase transition temperature, and keeps the microstructure of the material sufficiently transformed into austenite during a certain period of time. Then, the material is cooled rapidly and the martensite microstructure is obtained. The main purpose of induction hardening is to obtain higher hardness and better wear resistance. 

Induction hardening is a non-contact process used to selectively harden areas of a part or assembly without affecting the properties of the part as a whole. The quenching depth is related to frequency and heating time: the higher the frequency, the shallower the quenched layer; the lower the frequency, the deeper the quenched layer; the longer the heating time, the deeper the quenched layer, and vice versa. Quenching hardness is related to heating temperature, material and quenching medium.

Gear hardening Video

Advantages of induction Hardening

■ Short heating time, no holding time, hence more production rate

■ No scaling, decarburizing or deformation

■ Maximum case depth is up to 8 mm

■ Selective hardening, extremely energy-efficient

■ Less brittleness, high wear and fatigue resistance

■ Easy to realize mechanization and automation

■ Clean and safe working environment

Applications of induction hardening

Induction hardening is mostly used for surface quenching of metal parts. For example: Hardware tools such as knife, pliers, wrench, clamp, hammer, ax, screwing tools and shears. Auto parts such as gear, chuck, crankshaft, camshaft, drive shaft, connection rod, pinton pin, valve, rocker arm. Machine parts such as guide rail. Metal molds and mold accessories.