What is Induction Heating?

Induction heating is a method by which electrically conducting materials (generally metals), are heated by a non-contact method in an alternating magnetic field.

What are the most common applications for induction heating?

Heat treatment of metals - induction hardening, induction tempering, and induction annealing.
Induction heating prior to deformation - forging, swaging, upsetting, bending, and piercing.
Induction brazing and induction soldering - brazing of steel, brass, and copper to each other in combination and aluminum to aluminum.
Induction for shrink fitting - In any manufacturing process, for example, shrinkfitting of motor rotors to shafts, shrink fitting of shell casings for compressors.
Induction heating prior to coating - Of dissimilar metals, prior to insulation, and curing, such as paint.
Induction melting - Of all types and amounts of metals and precious metals.
Other applications include crystal growing, cap sealing, sintering, carbon vapor deposition, levitation, exitaxial deposition, and plasma generation.

Basically how does induction heating work?

Induction heating occurs when an electrically conducting object (generally metal) is placed in a varying electric magnetic field. Induction heating occurs due to the magnetic quality and resistivity of the material. The magnetic qualities are only present in magnetic steel. The varying electric magnetic field induces a current inside the component being heated in a similar way to that of a transformer.

What makes induction heating different from other methods of heating such as resistance or conduction?

Induction heating is a non-contact method. The heat is generated only in the part, not in the surrounding area except by radiation. The location of the heating can be defined to a specified area on the metal component and achieves accurate and consistent results. As heating occurs in the object itself, induction heating is considered more efficient than alternative methods.

What does an induction heating system comprise of?

An induction heating system comprises a basic induction power source which provides the required power output at the required power frequency, complete with matching components, an induction coil assembly, a method of material handling, and some method of water cooling. Most induction heating systems are water cooled with the exception of small, low powered units.

The methods of material handling and the induction coil arrangement are dependant entirely upon the application. The choice of induction power source is related to the application requirements and to production rate.

If I have an application that I feel can utilize induction heating who should I contact?

Contact us email at sales@radyne.com or filling in this form. Radyne also has checklists for specific applications which can be completed and e-mailed or faxed (414-481-8303) to us so that we can provide a fast response.

Where can I find other references regarding induction heating?

Other references include Basics of Induction Heating by Chester Tudbury (paperback) or
Handbook of Induction Heating by Valery Rudnev, Don Loveless, Raymond Cook and Micah Black (800 pages hardcover) - contact Radyne sales@radyne.com for information on how to purchase a copy.

Elements of Induction Heating by Zinn and Semiatin
Induction Heat Treatment of Steel by Semiatin and Stutz
Induction Heating Handbook by Davis and Simpson
Induction Heating for Forging - FIA Plant Engineering Committee. Contact the Forging Industry Association at www.forging.org

There are many other references within organizations such as the SME (Society of Manufacturing Engineers), ASM (American Society of Metals), FIA (Forging Industry Association), and WAI (Wire Association International) to which many papers have been written on induction heating. Significant contributions have been given by Radyne.

If I have other questions regarding induction heating who should I contact?

Please contact Radyne by email at sales@radyne.com. You can be assured of a fast response.