Remediation of Lost Compressive Residual Stresses in Carburized Steel Gears

Author:  Students: Mitchell Roux, Rui Zeng, Ryan Wilmes, and Keun Young Kim. Faculty Advisor: Kevin Trumble
Source:  Purdue University
Doc ID:  2016042
Year of Publication:  2016
Abstract:  
The formation of non-transformation products and grinder burn on heat-treated steel gears is a serious problem for John Deere. These defects reduce hardness, residual compressive stresses and fatigue life, increasing scrap costs. John Deere has suggested shot peening as a possible way to restore mechanical properties. Shot peening induces compressive residual stress into the gears, potentially undoing the damage caused by grinder burn. Residual stress, metallography and microhardness measurements were conducted on gear samples provided by John Deere in order to recommend whether or not John Deere should pursue the shot peening approach.