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dc.contributor.advisorChairperson, Graduate Committee: Paul E. Gannonen
dc.contributor.authorMartin, Joshua Danielen
dc.date.accessioned2016-01-03T17:19:25Z
dc.date.available2016-01-03T17:19:25Z
dc.date.issued2014en
dc.identifier.urihttps://scholarworks.montana.edu/xmlui/handle/1/9360en
dc.description.abstractMicrobially induced corrosion (MIC) of steel due to the presence of sulfide is a leading cause of pit formation of carbon steel in fuel-seawater environments. While extensively studied, the exact causes of pitting corrosion in naval fuel tanks when exposed to MIC in the presence of fuel and seawater are not completely understood. This thesis focuses on the role that cold-rolling of carbon steel plays on corrosion while subjected to sulfidogenic, suboxic corrosive environments. Particularly, the effects of microscopic residual strain found within 1018 steel on the anodic dissolution of the metal is studied in different MIC sulfide environments using EBSD, AFM, FE-SEM, EDX, and electrochemistry. It is found that regions of increased plastic deformation of the crystalline lattice as a result of cold rolling correlate to an increase in anodic dissolution rates of 1018 steel coupons cut parallel to rolling direction. Image overlay provides a verification of the location of corrosion of samples to the same locations found in EBSD mapping taken prior to corrosion, ensuring the predictive value of EBSD analysis in establishing locations of accelerated corrosion. The effect of different corrosion environments on the corrosion rate of steel is measured through electrochemistry. Values obtained through these measurements are applied using mechanochemical theories to predict the localized dissolution rate of the steel due to strain using computational methods. Mechanochemical analysis of the strained areas results in predicted corrosion rates within an order of magnitude of the corrosion rates measured using AFM for the exposed time period at the same locations. Areas exhibiting increased corrosion rates occur in areas exhibiting increased strain as measured by EBSD analysis. Further electrochemical results show an increase in corrosion rates for suboxic sulfide rich systems containing low levels of oxygen, when compared to anaerobic sulfide environments. Variations in corrosion current density as a function of oxygen presence, as measured by electrochemistry, accurately predict variations in mechanochemical corrosion rates of strained areas well within an order of magnitude. Results from this study support the use of EBSD as a means to further the understanding of pitting corrosion as a function of material properties.en
dc.language.isoenen
dc.publisherMontana State University - Bozeman, College of Engineeringen
dc.subject.lcshBiodegradationen
dc.subject.lcshShipsen
dc.subject.lcshFuel tanksen
dc.subject.lcshSteel--Cold workingen
dc.subject.lcshElectrons--Backscatteringen
dc.titleBiocorrosion of 1018 steel in sulfide rich marine environments : a correlation between strain and corrosion using electron backscatter diffractionen
dc.typeThesisen
dc.rights.holderCopyright 2014 by Joshua Daniel Martinen
thesis.catalog.ckey2769773en
thesis.degree.committeemembersMembers, Graduate Committee: Recep Avci; Mark Wolfendenen
thesis.degree.departmentChemical & Biological Engineering.en
thesis.degree.genreThesisen
thesis.degree.nameMSen
thesis.format.extentfirstpage1en
thesis.format.extentlastpage159en


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