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dc.contributor.advisorJacobs, Laurence
dc.contributor.advisorKim, Jin-Yeon
dc.contributor.advisorQu, Jianmin
dc.contributor.authorGeibel, Timm Dennis
dc.date.accessioned2018-08-27T13:27:19Z
dc.date.available2018-08-27T13:27:19Z
dc.date.created2017-12
dc.date.issued2017-08-15
dc.date.submittedDecember 2017
dc.identifier.urihttp://hdl.handle.net/1853/60407
dc.description.abstractAustenitic stainless steels have a wide range of applications in the energy industry due to their high temperature performance and high corrosion resistance. Type 304 SS, is a widely used stainless steel, but is susceptible to sensitization, the formation of chromium carbide precipitates along the grain boundaries, causing chromium depletion when exposed to a certain temperature, ultimately leading to intergranular stress corrosion cracking (IGSCC). Sensitization preferably tends to occur in the heat affected zone (HAZ) of welds where heat is induced for a certain amount of time during welding. IGSCC is a main cause of the cracking in boiling water reactor piping systems and therefore is of great concern. Nonlinear ultrasound is a nondestructive evaluation method measuring the change of harmonic frequencies over propagation distance quantified by the nonlinearity parameter, β. The research evaluates the changes of microstructure caused by cold work (cold rolling) using two nonlinear ultrasound methods, Rayleigh and longitudinal waves. Moreover it shows the sensitivity of nonlinear ultrasound to sensitization and combines sensitization and cold rolling, then is compared with previous work [20] [6] [17] that investigated just the isolated effect of sensitization, or cold work. The results show that (1) cold work causes significant variations in the nonlinearity parameter which can be attributed to the formation of dislocations and twins as a consequence of the plastic deformation and phase transformation and that (2) cold work has large influences on the sensitization behavior of 304 SS.
dc.format.mimetypeapplication/pdf
dc.language.isoen_US
dc.publisherGeorgia Institute of Technology
dc.subjectNondestructive evaluation
dc.subjectRayleigh waves
dc.subjectLongitudinal waves
dc.subjectEPR
dc.subjectSensitization
dc.subjectCold work
dc.subjectCold rolling
dc.titleNonlinear ultrasonic measurement on cold rolled and sensitized 304 austenitic stainless steel
dc.typeThesis
dc.description.degreeM.S.
dc.contributor.departmentCivil and Environmental Engineering
thesis.degree.levelMasters
dc.date.updated2018-08-27T13:27:19Z


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