Dresden 2006 – scientific programme

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MM: Metall- und Materialphysik

MM 25: Poster Session

MM 25.7: Poster

Wednesday, March 29, 2006, 15:30–17:30, P4

Experimental Residual Stress Analysis of Hertzian Loaded Machine Parts — •Jürgen Gegner — SKF GmbH, Material Physics, Ernst-Sachs-Str. 5, D-97424 Schweinfurt, Germany

X-ray diffraction measurement represents an established testing tool for material response or residual life and failure analysis of machine elements that are highly loaded under Hertzian-contact fatigue conditions. The modified industrial-suited technique is described in detail and its application illustrated considering rolling bearings as example. Apart from the residual stress depth profiles, which could simpler be determined by the mechanical hole-drilling method, the martensite {211} line broadening characterizes material aging of hardened steels. Under rolling contact, the loaded volume in the edge zone sustains continuous constitutional changes, such as microstructure transformation (e.g. retained austenite decay) or carbide dissolution, caused by energy dissipation. By means of the X-ray diffraction technique, alterations of residual stresses and line broadening can be detected. For quantitative evaluation of these measured distance curves, calibration data, which permit comparison with the statistical parameters of the Weibull failure frequency distribution in the form of the L10 life equivalent, is available for ball and roller bearings.