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dc.contributor.advisorDe Moor, Emmanuel
dc.contributor.authorFroman, Jarred
dc.date.accessioned2017-03-01T17:05:22Z
dc.date.available2018-02-28T04:18:44Z
dc.date.submitted2017
dc.identifierT 8234
dc.identifier.urihttp://hdl.handle.net/11124/170691
dc.descriptionIncludes bibliographical references.
dc.description2017 Spring
dc.description.abstractThe effects of copper content on the wear and rolling contact fatigue (RCF), specifically rolling sliding contact fatigue (RSCF), of hypereutectoid rail steels were evaluated. Steel from three heats of head hardened, hypereutectoid rails with copper levels of 0.07, 0.38, and 0.85 wt pct were selected for the study. All of the material was industrially produced through electric arc steelmaking at EVRAZ, Pueblo. Wear behavior was evaluated through the use of twin disc testing for the three hypereutectoid rail steels. The samples were measured at specific intervals. A high wear rate was observed during the first 1,000 cycles after which a linear steady state wear rate was observed. A small decrease in the steady state wear rate was observed with increasing copper content and increasing strength. Preliminary RSCF testing was performed using the 0.38 wt pct Cu rail steel and an intermediate hardness rail steel to evaluate two RCF testing methods reviewed in literature, a fully lubricated method and a dry-lubricated method where dry cycles were used to initiate damage and the lubrication was added to propagate the cracks through a hydrostatic mechanism. In both cases the 0.38 Cu hypereutectoid material outperformed the intermediate hardness rail steel. The fully lubricated method was chosen for the primary RSCF testing. The primary RSCF testing was performed with the three hypereutectoid rail steels and an intermediate hardness steel as a reference. A longer RSCF life was observed for the hypereutectoid rail than the intermediate hardness, as well as an increase in RSCF life with increasing copper content within the hypereutectoid steels. Atom probe tomography was used to investigate the location of the copper within the hypereutectoid rail steels, and clusters of higher copper concentration within the ferrite at the ferrite/cementite interface were observed.
dc.languageEnglish
dc.language.isoeng
dc.publisherColorado School of Mines. Arthur Lakes Library
dc.rightsCopyright of the original work is retained by the author.
dc.subjectRail
dc.subjectWear
dc.subjectRolling contact fatigue
dc.subjectCopper
dc.titleEffects of copper on wear and rolling-sliding contact fatigue of rail steels
dc.typeThesis
dc.rights.accessEmbargo Expires: 02/28/2018
dcterms.embargo.terms2018-02-28
dcterms.embargo.expires2018-02-28
dc.contributor.committeememberMatlock, David K.
dc.contributor.committeememberCryderman, Robert
thesis.degree.nameMaster of Science (M.S.)
thesis.degree.levelMasters
thesis.degree.disciplineMetallurgical and Materials Engineering
thesis.degree.grantorColorado School of Mines


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