Induction Hardening of Gears: Physical Subtleties and Practical Solutions

The induction hardening of gears provides a valuable combination of quality, efficiency, and single-piece flow to gear manufacturers and heat treatment practitioners. The fundamental physics of electromagnetic induction and the capabilities of modern gear hardening equipment promote the strengthening of gears while minimizing geometric distortion, energy consumption, and environmental impact. Leveraging computer simulation and real-world case studies, this paper illustrates how and why different induction hardening approaches (i.e. different processing methods, power supplies, and inductor styles) are used to harden gears of different size, shape, and application. Physical subtleties and process parameters unique to the induction hardening of gears are also presented, focusing particularly on their quality implications.