Medium-frequency induction heating typically operates between 1 kHz and 10 kHz, offering a greater heating depth suitable for through-heating or surface hardening of large workpieces; in contrast, high-frequency induction heating operates above 100 kHz with a shallower heating depth, making it ideal for the rapid heating or localized heat treatment of small components.
Technically, the lower frequency of medium-frequency induction heating allows for deeper electromagnetic field penetration and more uniform internal heating, making it common in processes requiring bulk heating, such as forging and casting. Conversely, the high frequency associated with high-frequency induction heating results in a pronounced skin effect that concentrates heat on the workpiece surface, making it suitable for components requiring surface hardening, such as gears and bearings.
Regarding energy consumption, medium-frequency equipment typically features higher power ratings but superior efficiency, making it well-suited for continuous production; while high-frequency equipment may have relatively higher energy consumption, its rapid response makes it ideal for precision processing. In terms of cost, high-frequency generators usually entail a higher initial investment due to their greater technical complexity.
Regarding industry standards, medium-frequency heating often complies with heavy-industry standards such as ISO 5826, whereas high-frequency systems must meet specific safety requirements for high-frequency equipment, such as those outlined in IEC 60519-1. Selection depends on a comprehensive assessment of workpiece dimensions, material properties (such as the influence of the Curie point in magnetic materials), and production cycle requirements. For instance, medium-frequency heating is commonly selected for hardening automotive crankshafts, whereas high-frequency heating is preferred for welding watch components.
