Effects of alloying elements upon austenite decomposition in high strength low alloy steels

dc.contributor.authorChen, Jhewn-Kuangen
dc.contributor.committeechairReynolds, William T. Jr.en
dc.contributor.committeememberHouska, Charles R.en
dc.contributor.committeememberDesu, Seshu B.en
dc.contributor.committeememberAning, Alexander O.en
dc.contributor.departmentMaterials Science and Engineeringen
dc.date.accessioned2014-03-14T21:47:15Zen
dc.date.adate2009-10-10en
dc.date.available2014-03-14T21:47:15Zen
dc.date.issued1992-10-03en
dc.date.rdate2009-10-10en
dc.date.sdate2009-10-10en
dc.description.abstractThe kinetics of austenite decomposition were studied in high purity Fe-0.1 C-0.4 Mn-0.3 Si-X (concentrations in weight percent, X represents 3 Ni, 1 Cr, or 0.5 Mo) steels at temperatures between 500 and 675°C. The transformation stasis phenomenon was found in the Fe-C-Mn-Si-Mo and Fe-C-Mn-Si-Ni alloys isothermally transformed at 650°C and 675°C but not in the Fe-C-Mn-Si and Fe-C-Mn-Si-Cr alloys at any of the temperatures investigated. The occurrence of transformation stasis was explained by synergistic interactions among alloying elements. The paraequilibrium model was applied to calculate the metastable fraction of ferrite in each alloy. This fraction was shown to coincide with cessation of transformation in the Mo alloy transformed at 600°C. Transformation stasis was found in both the Ni and the Mo alloys isothermally reacted at 650°C and 675°C. The interactions among Mn, Si, and Mo as well as interactions among Mn, Si, and Ni appear to decrease the threshold concentrations for occurrence of transformation stasis in Fe-C-Mn-Si systems. The segregation of Mn and Mo to the α/γ boundary assisted by Si was suggested to enhance the drag force and led to transformation stasis. In the Ni alloy, lower driving force for ferite formation by addition of Ni could be responsible for occurrence of transformation stasis.en
dc.description.degreeMaster of Scienceen
dc.format.extentix, 98 leavesen
dc.format.mediumBTDen
dc.format.mimetypeapplication/pdfen
dc.identifier.otheretd-10102009-020227en
dc.identifier.sourceurlhttp://scholar.lib.vt.edu/theses/available/etd-10102009-020227/en
dc.identifier.urihttp://hdl.handle.net/10919/45126en
dc.language.isoenen
dc.publisherVirginia Techen
dc.relation.haspartLD5655.V855_1992.C546.pdfen
dc.relation.isformatofOCLC# 28011490en
dc.rightsIn Copyrighten
dc.rights.urihttp://rightsstatements.org/vocab/InC/1.0/en
dc.subject.lccLD5655.V855 1992.C546en
dc.subject.lcshSteel alloysen
dc.subject.lcshSteel, High strengthen
dc.titleEffects of alloying elements upon austenite decomposition in high strength low alloy steelsen
dc.typeThesisen
dc.type.dcmitypeTexten
thesis.degree.disciplineMaterials Science and Engineeringen
thesis.degree.grantorVirginia Polytechnic Institute and State Universityen
thesis.degree.levelmastersen
thesis.degree.nameMaster of Scienceen

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