Study of the failure of a duplex stainless steel valve

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URI: https://hdl.handle.net/11556/3043
ISSN: 1350-6307
DOI: 10.1016/j.engfailanal.2008.09.006
Publication date
2009-07
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Abstract
A study has been performed to determine the reason for the failure of a group of duplex stainless steel valves after 15 years in service. Chemical analysis did not agree with the required quality. Metallographic analysis revealed some small pits with corrosive products inside which were blamed to be the origin of long cracks and consequently of the failure. Pitting and cracks progressed along the ferrite-austenite interface where carbides and brittle phases are precipitated. This precipitation drags a significant content of chromium whose percentage in the surrounding matrix is depleted losing its pitting resistance being attacked by the circulating fluid. The use of a steel with higher pitting resistance and avoid working in the temperature range where both carbides and brittle phases are formed is recommended.
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Brittle phases , Duplex stainless steel , Pitting corrosion , General Materials Science , General Engineering
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journal article
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Atxaga , G & Irisarri , A M 2009 , ' Study of the failure of a duplex stainless steel valve ' , Engineering Failure Analysis , vol. 16 , no. 5 , pp. 1412-1419 . https://doi.org/10.1016/j.engfailanal.2008.09.006