induction hardening

Induction hardening is a surface-hardening technique used to increase the hardness of steel objects, making them more resistant to wear. This process involves heating the surface of a ferrous alloy using electromagnetic induction to a temperature above its transformation point, followed by rapid cooling (quenching).123

The heating is achieved by passing an alternating electric current through a coil surrounding the workpiece, which induces eddy currents within the material. These currents generate heat, allowing for precise control over the depth and distribution of the hardened surface. This method is widely applied in metalworking for applications like gears and bearings, where a hard surface and a softer core are desirable for strength and flexibility.21