High-Frequency Heat-Treatment of Gears-Equipment and Processes

AFTER relating a few of the difficulties encountered in the development of high-frequency induction heating for gear teeth, Mr. Redmond discusses some of the equipment and processes now being used, such as the manually indexed turntable.

He explains why preheating the gear is necessary before R.F. power is applied and presents data showing the time required to preheat a gear to the desired temperature for induction surface hardening at various power densities.

To find out the limitations of the process as far as small teeth are concerned, he also gives the results of R.F. induction hardening a 16-pitch helical gear. This gear was preheated and hardened with 300- kc power.