Metal Induction Hardening

Metal parts often require heat treatment to obtain improved mechanical properties. A common method used is induction hardening, in which induced heat is combined with rapid cooling (also known as quenching) to increase the hardness and durability of the steel.

Heating by induction is preferred because only the part to be hardened is heated. This is a flame-free, non-contact process that quickly produces intense, localized and controllable heat. The necessary cooling is achieved by quenching.

Rapid quenching is performed by spraying the workpiece with a suitable liquid medium. There are a number of quenchants that are used with induction heating. Polyalkylene Glycol (PAG) is commonly preferred because it exhibits inverse solubility in water, providing great flexibility of cooling rate.

The efficiency of the of the quenching system is dependent on the percentage of PAG in the water. Vaisala K-PATENTS® Sanitary Process Refractometer PR-43-AC is installed directly in the pipe before the induction tool to monitor in real-time the concentration of quenchant.

Download the application note in PDF by filling the form.

Go back to all Chemicals & Allied Products applications