Gear Contour Hardening by Micropulse® Induction Heating System 970971
Contour hardening of small gears, such as automotive transmission gears, is beneficial due to the higher strength characteristics and lower distortion. In the past, conventional induction hardening was not used due to its inability to produce a contour case pattern. However, carburizing also has inherent problems such as abnormal carburized layer, distortion due to high temperatures and long heating time, and retained austenite.
The Micropulse system, using both high and low frequencies, has been developed to alleviate some of the problems with traditional induction hardening. This Micropulse process makes it possible to produce a contour hardened pattern on a variety of gearing. This process is very rapid, as final heat time normally does not exceed 0.250 seconds.
The advantages to the Micropulse process include: high hardness, fine microstructure, high residual compressive stress, and low distortion. In addition to these benefits the process is environmentally friendly, energy efficient and easily adaptable to in-line processing.