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Advanced Techniques for the Measure of Microstructure and Residual Stress in Components Subject to Rolling Fatigue

James Thomas, Jonathan Mohan, Stephen Kendrish, Robert M. Fix
American Stress Technologies, Inc.

Demands on loaded, rotating components, e.g., bearings, shafts & gears continue to escalate. Modern manufacturing strategies require improvements in traditional measurements and process control tools.

Traditionally residual stress examination in bearings was accomplished with depth profiles obtained using X-Ray diffraction (XRD) and electrochemical layer removal. More recently Barkhausen Noise Analysis (BNA) has proven itself in the evaluation of microstructure as well as surface residual stress in ferromagnetic materials. Traditional BN analysis parameters have been used for fixed measurement depths, usually near the surface.

An examination on a set of as-hardened and ground bearing rings manufactured with variations in processing was made by AST. The Barkhausen signal was analyzed to yield information about a range of depths. XRD & BNA depth profiles were gathered and they correlate well. This allows a calibration of the BN signal to the residual stress. It is proposed that BNA can be used for quick, non-destructive assessment of residual stress depth profiles.

Reference:
Thomas, James, et.al.: “Advanced Techniques for the Measure of Microstructure and Residual Stress in Components Subject to Rolling Fatigue” SAE Int. J. Mater. Manuf. 2(1): 206-210, 2009

This study has been published in the second volume of the SAE International Journal of Material and Manufacturing in 2009, which is available on line at http://www.saejournals.org and here with the SAE permission:

SAE Paper 2009-01-0421 ©2009 SAE International. This paper is posted on this website with permission from SAE International. As a user of this website, you are permitted to view this paper on-line, and print one copy of this paper at no cost for your use only. This paper may not be copied, distributed or forwarded to others without permission from SAE.