Show simple item record

dc.contributor.advisorEvitts, Richard W.en_US
dc.contributor.advisorPhoenix, Aaron V.en_US
dc.creatorEtor, Aniekanen_US
dc.date.accessioned2009-11-25T12:58:49Zen_US
dc.date.accessioned2013-01-04T05:09:13Z
dc.date.available2011-01-13T08:00:00Zen_US
dc.date.available2013-01-04T05:09:13Z
dc.date.created2009-11en_US
dc.date.issued2009-11en_US
dc.date.submittedNovember 2009en_US
dc.identifier.urihttp://hdl.handle.net/10388/etd-11252009-125849en_US
dc.description.abstractCrevice corrosion is a form of galvanic corrosion that occurs when a metal is exposed to different environments. This occurs when the oxygen within the crevice gets depleted, thus acting as the anodic site for metal dissolution reaction. The anodic site thus encourages the migration of Cl- ions into the crevice leading to the development of an aggressive local solution. The acidic conditions present in the crevice reaches a critical crevice solution composition and results in the loss of stability of the passive film which further leads to a rapid breakdown of these films on the metal thus indicating the onset of active corrosion. In this research, it is hypothesized that the onset of crevice corrosion can be detected by measuring the galvanic coupling current between electrodes in a crevice and an external metal surface composed of the same material as the electrodes. To prove this hypothesis an engineered crevice was designed to measure IR controlled crevice currents along the crevice length of AISI 304 stainless steel immersed in a 0.5 M solution and a 1 M NaCl solution. Varying crevice openings were used to determine the effect of crevice gap (G) on the initiation of crevice corrosion and the position of the accelerated attack within the crevice. Multiplexed corrosion potential measurement and galvanic corrosion measurement techniques were used to measure the change in the open circuit potential (OCP) and the galvanic current for the four channels along the crevice length of the galvanic couple. The results obtained from the MGC test for the 100 µm crevice width immersed in 0.5 M NaCl solution showed good results with high anodic current at approximately 1 cm from the crevice mouth. This finding was in close agreement with the peak pH value observed at the position closest to the crevice mouth in the work of Alavi and Cottis (1987) and the model prediction of Kennell et al. 2009. However, for test samples with crevice width ≥ 200 µm, there was no initiation of crevice corrosion and the results obtained were discarded. The Linear polarization resistance scan and Potentiodynamic polarization scan carried out along the crevice to measure the polarization resistance, Rp , and to obtain the region of passivity along an AISI 304 SS crevice did not yield good results. Low corrosion rate in the range of 0.06 mm/yr was calculated for the AISI 304 stainless steel crevice.en_US
dc.language.isoen_USen_US
dc.subjectCrevice corrosionen_US
dc.subjectElectrochemistryen_US
dc.subjectMeasurementen_US
dc.subjectStainless Steelen_US
dc.titleElectrochemical neasurement of crevice corrosion of type AISI 304 stainless steelen_US
thesis.degree.departmentChemical Engineeringen_US
thesis.degree.disciplineChemical Engineeringen_US
thesis.degree.grantorUniversity of Saskatchewanen_US
thesis.degree.levelMastersen_US
thesis.degree.nameMaster of Science (M.Sc.)en_US
dc.type.materialtexten_US
dc.type.genreThesisen_US
dc.contributor.committeeMemberHill, Gordon A.en_US
dc.contributor.committeeMemberN.Oguocha, Ikechukwukaen_US
dc.contributor.committeeMemberBurgess, Ianen_US


Files in this item

Thumbnail

This item appears in the following Collection(s)

Show simple item record