Induction surface hardening
It is based on the principle of rapid heating and cooling of a material placed in the middle or across an electric magnetic field.
Induction surface hardening is used in many different applications, especially in the automotive industry.
Steels containing 0.3-0.5% carbon are suitable for surface hardening by induction. The desired hardness depth in the part depends on the intensity (kW), frequency (kHz) and time of the energy applied to the material.
High alloy steels tend to crack because they cannot withstand the shock caused by rapid heating and cooling during this process.
Case hardening steels cannot respond to induction surface hardening due to the low carbon they contain.
Suitable qualities,
SAE 1040, Ck 45, SAE 1050, SAE 4140, AISI 420 and GGG - 60
CQI-9 Table D is used for this heat treatment technique in the automotive industry.