Case hardening vs. induction hardening -economical comparison in the heat treating of gears

With the introduction of SDF®1 hardening about ten years ago the induction hardening of complex shaped surfaces be- came possible. Especially for the production of gears and other toothed parts this method offers big benefits. With the SDF® process the energy is only required to heat the real hardened surface in a thin layer. This volume is very small compared with the complete volume of the hardened part, which is ne- cessary to heat and hold on temperature several hours in the classical carburizing process. The SDF® technology requires a high power density in the surface and very short heating times, to be prevent the heat in the surface from thermal flow into the not treated area. So the method is perfectly useful for integra- tion in line production with single part handling and low cycle times. Systems for process chain integration are available with up to 3 MW power.