Systematic analysis of induction coil failures

Frequency selection not only affects the performance of the induction system but it also has a significant effect on coil life. Choice of an improper frequency is the most common mistake made by developers and users of induction heating processes. Numerous factors affecting frequency g`t4tion for surface (case) hardening, tempering, and stress relieving are discussed in Ref. 1. Frequency selection and the detrimental effect on coil life of choosing an improper frequency for induction through-heating applications (including through hardening, annealing, normalizing, and heating prior to hot and warm forming, for example) is the topic of this column and two others in the 'Systematic analysis of induction coil failures' series.