Online frequency adjustment for energy optimization of induction hardening processes

It is frequently necessary to harden multiple points on a component. The hardness specification may, in many cases, be variable, and the boundary conditions often diverse. The relevant sectors of the component are in many cases more deeply hardened, to enhance strength and vibration-fatigue properties, with simultaneous retention of ductile properties in the core, in order to reduce the danger of fracture of the heat-treated component in service. In other cases, the hardening process is intended more to provide protection against elevated surface loadings and against abrasive erosion of material. Both of these applications are illustrated on the basis of a component in the context of this article, and the requirements made on the inductive hardening process discussed. The authors consciously raise the question of the limits of technical feasibility.