The influence of elemental partitioning on hardness in a 12% chromium dual-phase steel

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dc.contributor.advisorShaw, Martinen_ZA
dc.contributor.authorPhilcox, Ann Een_ZA
dc.date.accessioned2016-10-20T03:32:30Z
dc.date.available2016-10-20T03:32:30Z
dc.date.issued1990en_ZA
dc.descriptionBibliography: pages 96-102.en_ZA
dc.description.abstractDuring the annealing treatment in the production of dual phase steels, partitfoning of alloying elements can occur depending on competitive solubility in the ferrite and austenite for the specific partitioning species. An investigation of the partitioning of substitutional elements was considered paramount in understanding certain anomalies that had been identified by previous researchers in various studies of a dualphase 12% Chromium steel, designated 3CR12. These anomalies concerned observed increases in bulk hardness that could not be attributed to changes in the volume fraction of martensite produced after exposure to a range of temperatures within the dual phase field. Subsequent experiments revealed an unexpected increase in the microhardness of the martensite phase prOduced by heat treatment in the temperature range of interest. In this thesis conventional analytical measurements using Energy dispersive X-ray analysis facilities attached to a Scanning Electron microscope have been utilised to determine the compositions of the two phases in the alloy. A range of temperatures in the dual phase region have been investigated at holding durations of 1, 4 and 20 hours. It was found that partitioning of substitutional elements was occurring, however no changes were observed as a function of holding time. Further empirical data was obtained using dilatometric methods. This strongly suggested that interstitial concentrations were increasing as a function of annealing time and clarified the anomalies observed during previous studies on 3CR12. Further study includes that of substitutional element partitioning in the prior states of the commercially produced hot-rolled and annealed 3CR12 alloy. These include the as cast slab and the hot-rolled slab, as well as the final hot-rolled and annealed slab. Segregation was found to occur in the as cast slab. Subsequent investigation showed the presence of δ-ferrite in the final processing stages of the hot-rolled and annealed product.en_ZA
dc.identifier.apacitationPhilcox, A. E. (1990). <i>The influence of elemental partitioning on hardness in a 12% chromium dual-phase steel</i>. (Thesis). University of Cape Town ,Faculty of Engineering & the Built Environment ,Centre for Materials Engineering. Retrieved from http://hdl.handle.net/11427/22213en_ZA
dc.identifier.chicagocitationPhilcox, Ann E. <i>"The influence of elemental partitioning on hardness in a 12% chromium dual-phase steel."</i> Thesis., University of Cape Town ,Faculty of Engineering & the Built Environment ,Centre for Materials Engineering, 1990. http://hdl.handle.net/11427/22213en_ZA
dc.identifier.citationPhilcox, A. 1990. The influence of elemental partitioning on hardness in a 12% chromium dual-phase steel. University of Cape Town.en_ZA
dc.identifier.ris TY - Thesis / Dissertation AU - Philcox, Ann E AB - During the annealing treatment in the production of dual phase steels, partitfoning of alloying elements can occur depending on competitive solubility in the ferrite and austenite for the specific partitioning species. An investigation of the partitioning of substitutional elements was considered paramount in understanding certain anomalies that had been identified by previous researchers in various studies of a dualphase 12% Chromium steel, designated 3CR12. These anomalies concerned observed increases in bulk hardness that could not be attributed to changes in the volume fraction of martensite produced after exposure to a range of temperatures within the dual phase field. Subsequent experiments revealed an unexpected increase in the microhardness of the martensite phase prOduced by heat treatment in the temperature range of interest. In this thesis conventional analytical measurements using Energy dispersive X-ray analysis facilities attached to a Scanning Electron microscope have been utilised to determine the compositions of the two phases in the alloy. A range of temperatures in the dual phase region have been investigated at holding durations of 1, 4 and 20 hours. It was found that partitioning of substitutional elements was occurring, however no changes were observed as a function of holding time. Further empirical data was obtained using dilatometric methods. This strongly suggested that interstitial concentrations were increasing as a function of annealing time and clarified the anomalies observed during previous studies on 3CR12. Further study includes that of substitutional element partitioning in the prior states of the commercially produced hot-rolled and annealed 3CR12 alloy. These include the as cast slab and the hot-rolled slab, as well as the final hot-rolled and annealed slab. Segregation was found to occur in the as cast slab. Subsequent investigation showed the presence of δ-ferrite in the final processing stages of the hot-rolled and annealed product. DA - 1990 DB - OpenUCT DP - University of Cape Town LK - https://open.uct.ac.za PB - University of Cape Town PY - 1990 T1 - The influence of elemental partitioning on hardness in a 12% chromium dual-phase steel TI - The influence of elemental partitioning on hardness in a 12% chromium dual-phase steel UR - http://hdl.handle.net/11427/22213 ER - en_ZA
dc.identifier.urihttp://hdl.handle.net/11427/22213
dc.identifier.vancouvercitationPhilcox AE. The influence of elemental partitioning on hardness in a 12% chromium dual-phase steel. [Thesis]. University of Cape Town ,Faculty of Engineering & the Built Environment ,Centre for Materials Engineering, 1990 [cited yyyy month dd]. Available from: http://hdl.handle.net/11427/22213en_ZA
dc.language.isoengen_ZA
dc.publisher.departmentCentre for Materials Engineeringen_ZA
dc.publisher.facultyFaculty of Engineering and the Built Environment
dc.publisher.institutionUniversity of Cape Town
dc.subject.otherSteel - Testingen_ZA
dc.subject.otherMaterials Engineeringen_ZA
dc.titleThe influence of elemental partitioning on hardness in a 12% chromium dual-phase steelen_ZA
dc.typeMaster Thesis
dc.type.qualificationlevelMasters
dc.type.qualificationnameMSc (Eng)en_ZA
uct.type.filetypeText
uct.type.filetypeImage
uct.type.publicationResearchen_ZA
uct.type.resourceThesisen_ZA
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