This article focuses on the frequently encountered causes of induction coil failures and typical failure modes in fabrication of hardening inductors, tooth-by-tooth gear-hardening inductors, clamshell inductors, contactless inductors, split-return inductors, butterfly inductors, and inductors for heating internal surfaces. It discusses the current density distribution and the skin effect, the proximity effect, and crack-propagation specifics. The article also describes selected properties of copper alloys, the electromagnetic edge effect of coil copper turn, and the effect of magnetic flux concentrators on coil life. It also reviews the importance of having appropriate and reliable electrical contacts.

This article is a compilation of best practices, materials, and techniques for the design and manufacture of modern induction forge coils. It presents the basics of induction coil design along with various design considerations, namely, copper tube selection, water flow considerations, and brazing and fabricating the copper coil winding for heating billets, bars, and slabs. The article describes refractory selection criteria and the methods of mounting and securing the induction coil winding, and presents general refractory installation guidelines for induction heating applications. It provides information on curing, form removal, dryout, and coil refractory seasoning. Wear rails that are designed to prevent damage to the coil refractory and subsequent coil winding are also discussed. The article concludes with a discussion on preventive maintenance practices for induction forging coils.

This article provides information on single-shot and scanning, the two types of induction heat treating processes that are based on whether the induction coil is moving relative to the part during the heating process. It describes the effect of the frequency of induction heating current on the induction coil and process design, and the control of heating in different areas of the inductor part. The article reviews three main tools for adjustment of coil design and fabrication: coupling gap, coil copper profile, and magnetic flux controllers. It examines the method of holding a part and presenting it to the inductor during the initial inductor design. The article provides information on coil leads/busswork and contacts that mechanically and electrically connect the induction coil head to the power supply. It concludes with a discussion on flux and oxide removal, leak and flow checking, silver plating, and electrical parameter measurement.

Induction heating has many different applications, such as melting, heating stock for forging, and heat treating. This article begins with a discussion on the types of power supplies, namely, solid-state power supplies and oscillator tubes. It provides information on system elements, including cooling systems, power supplies, heat stations, work handling fixtures, induction or work coils, and quench systems. The article discusses the influence of system elements on induction heat treating system design. It also deals with the general theory, types, and applications of induction coils.

This article begins with a discussion on the energy sources used for thermal forming. These include electric induction coil, gas flame, plasma torch, and laser beam. The article discusses the mechanisms of forming and different modes of deformation. It describes the effect of process and material parameters on forming and the effect of metallurgical changes on mechanical property and microstructure of stainless steel. The article concludes with information on the applications of thermal forming.

Magnetic flux controllers are materials other than the copper coil that are used in induction systems to alter the flow of the magnetic field. This article describes the effects of magnetic flux controllers on common coil styles, namely, outer diameter coils, inner diameter coils, and linear coils. It provides information on the role of magnetic flux controllers for whole-body and local area mass-heating applications, continuous induction tube welding, seam-annealing inductors, and various induction melting systems, namely, channel-type, crucible-type, and cold crucible systems. The article also describes the benefits of the flux controllers for induction heat treating processes such as single-shot and scanning.

The historical use of induction heating relating to glass melting gives some insight into its use in today's glass manufacturing industry. A patent search on induction heating provides historical information about how induction heating was used in the glass melting industry, from both a direct fired or a susceptor/container approach. This article provides review of historical patents, following an introduction to conductivity in glass and electrical heating. The purpose is to show that induction heating has been and is being used in the glass melting industry.

This article discusses the principle, coil design, types and operation of a vacuum induction furnace. It describes the operation parameters that should be considered during the functioning of the induction furnace.

High-frequency (HF) welding is a welding process in which the heat source used to melt the joining surfaces is obtained from HF alternating current (ac) resistance heating. This article discusses the advantages and disadvantages and applications of HF welding. It describes the equipment used for HF welding and the safety aspects to be considered during welding. The article concludes with a discussion on inspection and quality control.