Thermochemical surface engineer heat treatments are effective in improving the performance of various gears made of ferrous alloys. The cost of machining typical gears during the manufacturing process often exceeds 55 percent of total cost, especially when there is significant grinding after carburizing the gears. Therefore, improvements in the manufacturing of gears that can lead to a reduction in machining are valuable.

Nitriding produces high hardness and compressive stresses in many low-alloy steels used for gears. It is a nearly distortion-free process, which allows for the treating of finished components, thus minimizing costs. The complex nature of the stresses at the contact area of rotating gears leads to contact fatigue and sliding friction. Nitriding is superior to other surface engineering techniques in resisting wear at gear f lanks. When a high-strength alloy steel suitable for nitriding is used, a nitrided surface layer withstands high contact Herztian stress (contact stress) at gear flanks better than a deeper carburized layer in many instances.

Read more:  Ion Nitriding of Ferrous and Titanium Alloys for Gear Applications by Edward Rolinski, Tekin Damirgi, and Mikel S. Woods