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dc.contributor.authorSchwenger, Nicholas
dc.contributor.otherQueen's University (Kingston, Ont.). Theses (Queen's University (Kingston, Ont.))en
dc.date.accessioned2019-07-30T20:44:28Z
dc.date.available2019-07-30T20:44:28Z
dc.identifier.urihttp://hdl.handle.net/1974/26443
dc.description.abstractThe objective of this thesis is two-fold: to study the relationship between microstructural parameters and the work hardening and back-stress that develops in dual-phase (DP) steels using an in-plane shear test, and to use tools such as micro-computed X-ray tomography and scanning electron micrography (SEM) to examine the potential effect of damage on back-stress at higher pre-strains. Five microstructural variants were prepared using various thermo-mechanical processing methods and inter-critical (IC) annealing. These variants were then subjected to uniaxial tension until failure to measure work-hardening behaviour, and to forward-reverse in-plane shear tests to measure the back-stresses at varying shear pre-strains. The high-volume fraction of martensite in the DP steel microstructures meant that all variants exhibited continuous yielding in both uniaxial tension and in in-plane shear. Microstructures with uniform distributions of martensite particles exhibited the most uniform elongation, while higher strengths were observed when a mixture of large and small martensite particles was present. Similarly, the highest back-stress was observed in microstructures with mixtures of large and small martensite particles. In all microstructures, back-stress initially increased with increasing shear pre-strain. At higher shear pre-strains the rate of increase decreased until a plateau was reached. Historically, this saturation can be attributed to void damage in the microstructure, the annihilation of GNDs around the hard martensite particles, and plastic deformation of the martensite. When examined with micro-CT imaging, no voids could be resolved in the deformed samples of the microstructures; hence, SEM imaging was conducted. While some voids were observed in all the microstructures, they were too few and too small to fully account for the saturation of the back-stress at high pre-strains. Furthermore, plastic deformation of martensite particles was not observed.en_US
dc.language.isoenen_US
dc.relation.ispartofseriesCanadian thesesen
dc.rightsQueen's University's Thesis/Dissertation Non-Exclusive License for Deposit to QSpace and Library and Archives Canadaen
dc.rightsProQuest PhD and Master's Theses International Dissemination Agreementen
dc.rightsIntellectual Property Guidelines at Queen's Universityen
dc.rightsCopying and Preserving Your Thesisen
dc.rightsThis publication is made available by the authority of the copyright owner solely for the purpose of private study and research and may not be copied or reproduced except as permitted by the copyright laws without written authority from the copyright owner.en
dc.subjectBack-stressen_US
dc.subjectdual-phaseen_US
dc.subjectsteelen_US
dc.subjectmartensiteen_US
dc.subjectstrainen_US
dc.subjectstressen_US
dc.subjectdamageen_US
dc.subjectmicrostructureen_US
dc.subjectshearen_US
dc.titleStudy of Back-Stress and Void Damage in Dual Phase Steels Subjected to In-Plane Shearen_US
dc.typethesisen
dc.description.degreeMaster of Applied Scienceen_US
dc.contributor.supervisorPilkey, Keith
dc.contributor.departmentMechanical and Materials Engineeringen_US


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