Failure of a Dampening PinCombination of dynamic service load and increased notch effect because of surface roughness
Andreas Neidel, Susanne Riesenbeck, Thomas Ullrich; und Jörg Völker, Berlin
ABSTRACT As revealed by an inspection of hot gas path components, a dampening pin for stage 4 moving blades of an industrial gas turbine for power plant applications had broken in the summer of 2003. The failure mode of the fractured pin is high cycle fatigue. The root cause of the failure is probably a combination of the dynamic service load and an increased notch effect caused by an increased surface roughness of the pin. In the case of the notch-sensitive material Udimet 720, this is detrimental to the fatigue limit. The measured surface roughness of the failed part is out of specification and traceable to the use of non-OEM (Original Equipment Manufacturer) components. High temperature corrosion did not seem to have played a significant role in the failure mechanism.
Publication Source: Materialprüfung, ISSN: 0025-5300
Issue: 2004-4, pp -
Publisher: Carl Hanser Verlag München
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