Pit morphology and its relation to microstructure of 850°C aged duplex stainless steel

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dc.contributor.authorMagnabosco R.
dc.contributor.authorAlonso-Falleiros N.
dc.date.accessioned2019-08-20T00:17:35Z
dc.date.available2019-08-20T00:17:35Z
dc.date.issued2005
dc.description.abstractThe relation between pit morphology and microstructure formed during 850°C isothermal aging of UNS S31803 duplex stainless steel (DSS) could be reached through the explanation of pit nucleation and growth during potentiodynamic polarization in 3.5 wt% sodium chloride (NaCl) aqueous solution. Aging times up to 10 min at 850°C led to sigma formation by direct precipitation from ferrite, resulting in Cr- and Mo-depleted ferrite, or secondary ferrite. Between 30 min and 5 h of aging, the ferrite suffered eutectoid decomposition, resulting in sigma phase and secondary austenite, also impoverished in Cr and Mo. Those Cr- and Mo-depleted zones around the sigma phase were preferential sites for the nucleation of pits. At those sites, the passive film breakdown was easier, as shown by the low pitting potential values found in aged samples. Pit growth occurred as selective corrosion of the metallic matrix surrounding the sigma phase, as a consequence of the lower corrosion resistance of the secondary ferrite and austenite phases found. The low passivation potential values indicated the difficulty in repassivation of the pits formed, probably related to the Cr and Mo depletion of the regions surrounding the sigma phase. © 2005, NACE International.
dc.description.firstpage130
dc.description.issuenumber2
dc.description.lastpage136
dc.description.volume61
dc.identifier.citationMAGNABOSCO, R.; Alonso-Falleiros, N.. Pit Morphology and Its Relation to Microstructure of 850°C Aged Duplex Stainless Steel. Corrosion (Houston, Tex.), v. 61, n. 2, p. 130, 2005.
dc.identifier.doi10.5006/1.3278167
dc.identifier.issn0010-9312
dc.identifier.urihttps://repositorio.fei.edu.br/handle/FEI/2265
dc.relation.ispartofCorrosion
dc.rightsAcesso Restrito
dc.subject.otherlanguageDuplex stainless steel
dc.subject.otherlanguagePit morphology
dc.subject.otherlanguagePotentiodynamic polarization
dc.subject.otherlanguageSigma phase
dc.subject.otherlanguageSodium chloride
dc.subject.otherlanguageUNS S31803
dc.titlePit morphology and its relation to microstructure of 850°C aged duplex stainless steel
dc.typeArtigo
fei.scopus.citations47
fei.scopus.eid2-s2.0-14844303359
fei.scopus.subjectDuplex stainless steel (DSS)
fei.scopus.subjectIsothermal aging
fei.scopus.subjectPit nucleation
fei.scopus.subjectSigma phase
fei.scopus.updated2024-12-01
fei.scopus.urlhttps://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=14844303359&origin=inward
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