Dissertations / Theses: 'Iron alloys'

1

Kloppers, Marius Jacques 1962. "Electrochemistry of iron-chromium alloys." Thesis, Massachusetts Institute of Technology, 1991. http://hdl.handle.net/1721.1/106706.

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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Materials Science and Engineering, 1991.
Vita.
Includes bibliographical references (leaves 307-314).
by Marius Jacques Kloppers.
Ph.D.

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2

Wang, Da-yung. "Simultaneous chrominizing-aluminizing of iron and iron-base alloys /." The Ohio State University, 1987. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487325740721186.

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3

Nuttall, Robert Horan. "Aqueous hydrogen sulphide corrosion of iron, iron/chromium and iron/nickel alloys." Thesis, Robert Gordon University, 1993. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.358471.

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4

Feng, Zhiyao. "The Lattice Parameter of Gamma Iron and Iron-Chromium Alloys." Case Western Reserve University School of Graduate Studies / OhioLINK, 2015. http://rave.ohiolink.edu/etdc/view?acc_num=case1429138602.

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5

Bramhall, M. D. "The toughness of iron manganese alloys." Thesis, Sheffield Hallam University, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.234820.

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6

Baumgaertner, Manfred E. "The electrodeposition of palladium-iron alloys." Thesis, Loughborough University, 1999. https://dspace.lboro.ac.uk/2134/7058.

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The main subject of the thesis is the investigation of palladium-iron alloy electrodeposition from aqueous solutions in general. Palladium-iron alloy deposits could be in principle a substitute for nickel or nickel-palladium deposits to avoid metal dermatitis. Nickel contact dermatitis is an especially sensitive allergy caused by decorative or functional use of nickel: it needs to be avoided in a number of applications. Electrochemical and chemical experiments have been carried out on several solutions with variable pH, salts and metal complexes to design a chemical and electrochemical stable electrolyte for palladium-iron alloy electrodeposition. Electrochemical measurements, physical and chemical analysis techniques, mechanical, optical, chemical and electrochemical measurements methods as well as different corrosion tests were used to describe the electrochemical processes and the properties of the palladium-iron deposits. Investigations have shown that from ammoniacal electrolytes electrodeposition in a wide range of composition is possible (pH = 7.5 - 10.5). Electrolyte consists of palladiurn as Pd(NH3)4CI2 and iron as iron(ill)-citrate. Composition of the deposited alloys depends mainly on the ratio of the metal ions in the electrolyte, while the effect of current density and electrolyte temperature is slight. Current efficiency depends on iron concentration in the electrolyte and is a maximum of ca. 85 %. Palladium-iron alloys with a higher content of palladium (>80.-%) show cracks because of the high internal stress (tensile stress) of those layers. Alloys with smaller content of palladium (<20 wt. -%) are less sensitive to cracking. Wear resistance and corrosion resistance of the palladium-iron alloys are similar or sometimes better to palladium, palladium-silver, palladium-cobalt or palladium-nickel deposits. Hardness of the palladium-iron layers increases with increasing iron content from 200 to 600 VHN. Contact resistance is low in the range of 0.5 to 1.5 mfl and barrier layer properties are excellent for gold and copper diffusion during services up to 160 degrees Celsius for 240 hours.

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7

Man, H. C. "Laser glazing of iron boron alloys." Thesis, Imperial College London, 1985. http://hdl.handle.net/10044/1/37771.

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8

Ved, M. V., N. D. Sakhnenko, M. A. Glushkova, and A. V. Karakurkchi. "Nanostructured cobalt and iron electrodeposited alloys." Thesis, Springer Science+Business Media, Inc, 2014. http://repository.kpi.kharkov.ua/handle/KhPI-Press/22646.

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9

Leith, Steven D. "Electrodeposition of NiFe 3-D microstructures /." Thesis, Connect to this title online; UW restricted, 1998. http://hdl.handle.net/1773/9855.

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10

Dogo, Harun. "Point defect properties in iron chromium alloys." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2006. http://library.nps.navy.mil/uhtbin/hyperion/06Sep%5FDogo.pdf.

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Thesis (M.S. in Applied Physics)--Naval Postgraduate School, September 2006.
Thesis Advisor(s): Craig Smith, Xavier Maruyama. "September 2006." Includes bibliographical references (p. 57-59). Also available in print.

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11

Thang. "Permanent magnets based on iron-platinum alloys." [S.l. : Amsterdam : s.n.] ; Universiteit van Amsterdam [Host], 2003. http://dare.uva.nl/document/69891.

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12

Krupic, Vahid-Beg. "Metallurgy and magnetoelasticity of samarium-iron alloys." Thesis, University of Salford, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.335555.

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13

Bramhall, Michael D. "The impact toughness of iron manganese alloys." Thesis, Sheffield Hallam University, 1989. http://shura.shu.ac.uk/19392/.

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Fe-8Mn alloys may form the basis of a cryogenic steel similar to Fe-9Ni steels, but at a cost much more economical as manganese is cheaper than nickel. However, Fe-Mn alloys are susceptible to temper embrittlement through segregation of Mn, N and P to prior austenite grain boundaries. The present investigation shows that impact toughness can be improved by tempering to produce small amounts of reverted austenite into the structure. In quantifying the percentages of reverted austenite in these structures. X-ray and Mossbauer studies have shown that the phase analysis of these alloys varies from the surface of specimens into the bulk, and is thought to be due to deformation induced transformation of gamma→epsilon during sample preparation. It was concluded that bulk austenite and epsilon concentrations are best obtained after 2 minutes electro--polishing. Additions of 0.1%Ti and 0.1%Al to 'pure' alloys, in order to getter nitrogen, have been found to improve impact properties by reducing intergranular embrittlement. These additions also lead to a 'massive ferrite' structure not previously found in alloys of this manganese level. This is thought to be due to the lower interstitial levels in solid solution favouring formation of massive ferrite rather than lath martensite at a higher cooling rate and lower transformation temperature. A further considerable improvement in toughness has been achieved by water quenching rather than air cooling from the austenitisation temparature. Auger electron spectroscopy studies have shown that air cooling results in segregation of phosphorus and nitrogen to prior austenite grain boundaries. An addition of 0.5%Mo to these alloys was found not to be completely effective in reducing intergranular embrittlement. Commercially 'impure' alloys were found to exhibit inferior impact properties compared to 'pure' alloys. A further comparison with 9% nickel and 5% nickel steels has shown that pure Fe-8Mn alloys could be used as a low temperature steel down to ~ -100°C. A 'novel' heat treatment to an Fe-8Mn-G.2V alloy, consisting of a solution treatment followed by low temperature ageing has shown that vanadium carbide precipitation produces a significant reduction in grain size upon re-austenitisation due to particle pinning of grain boundaries.

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14

Geary, W. "Fatigue crack growth in iron silicon alloys." Thesis, Sheffield Hallam University, 1985. http://shura.shu.ac.uk/20609/.

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A technique for accurately monitoring fatigue crack growth at near threshold growth rates has been established. The characteristics of near threshold fatigue crack growth of a number of iron-silicon alloys has been quantitatively and qualitatively investigated. Relationships have been established relating the stress intensity factor, AK, and the fatigue crack growth rate da/dN. At fatigue crack growth rates approaching threshold the material has shown some microstructural sensitivity and this has been related to the stress intensity factor and the yield stress. A relationship has been shown to exist between the value of the threshold stress intensity factor and the inverse root of the grain size, d~2, for each of the alloys investigated. A model for near threshold fatigue crack growth has been proposed and includes the contributions made by grain size and crack tip plasticity. This work has also shown that fatigue crack closure plays an important role in the micromechanisms of fatigue crack growth near the threshold at low R ratio s. A number of mechanisms have been identified: crack closure due tothe presence of oxidation products on fracture surfaces in tests conducted in air, and closure due to the presence of fatigue fretting, facet contact and a contribution of mixed mode opening.

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15

Coleman, Andrew John. "Filiform corrosion of aluminium alloys and iron." Thesis, Swansea University, 2007. https://cronfa.swan.ac.uk/Record/cronfa42908.

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16

Wang, Haijuan. "Investigations on the Oxidation of Iron-chromium and Iron-vanadium Molten Alloys." Doctoral thesis, KTH, Materialens processvetenskap, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-12955.

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With the progress of high alloy steelmaking processes, it is essential to minimize the loss of valuable metals, like chromium and vanadium during the decarburization process, from both economic as well as environmental view points. One unique technique to realize this aim, used in the present work, is the decarburization of high alloy steel grades using oxygen with CO2 in order to reduce the partial pressure of oxygen. In the present work, the investigation on the oxidation of iron-chromium and iron-vanadium molten alloys under CO2-O2 mixtures was carried out and presented in this dissertation. For oxidation study on Fe-Cr molten alloy with CO2-O2 mixtures, on the basis of thermodynamic analysis, energy balance calculation and modeling results, experimental validation in laboratory was carried out, and later on, the oxidation kinetics of Fe-Cr and Fe-Cr-C melts under controlled partial pressure of oxygen was investigated. Thermodynamics calculation and energy balance estimation demonstrated that, it is possible to use CO2 or CO2-O2 mixtures as decarburizers during EAF process and high initial carbon contents in the steel can be adopted at the beginning in order to reduce the cost. A generic model has been developed to describe the overall process kinetics prevailing in metallurgical reactors containing liquid metal and gas bubbles. This model is general and can be extended further to consider any gas liquid reactions in any chemical engineering reactor, and especially the metallurgical ones, like AOD. In the present dissertation, the model is applied in predicting the evolution of Cr and C contents in a Fe-C-Cr melt during injection of different O2-CO2 mixtures. The related simulation results illustrated that CO2 is efficient in Cr retention. In order to verify the modeling results, 1kg induction furnace experiments were carried out in the present laboratory. The results indicated that the predictions of the model are in good agreement with the experimental results. Meanwhile, the experimental results indicated that the Cr-losses can be significantly lowered by replacing the oxygen with CO2 in the injected gas, specifically for Fe-Cr-C melts with carbon levels higher than about 0.8 mass%. Subsequently, the oxidation kinetics of Fe-Cr and Fe-Cr-C melts was investigated under different CO2-O2 mixtures. It is indicated that, the oxidation rate is controlled by the chemical reaction at the initial stage and the reaction rate can be expressed as at the Cr range of 11-21 mass% in the Fe-Cr melt. For oxidation study on Fe-V liquid alloy, the investigation of the oxidation kinetics was carried out under CO2-O2 mixtures, which is followed by the study on thermodynamic properties of vanadium containing slags. During oxidation of Fe-V melt, in the case of alloys with vanadium contents exceeding 10 mass%, there exists an incubation period before the chemical reactions prevail the process. In addition, the ‘incubation time’ increased with the increase of temperature and the vanadium content, whereas it decreased with the increase of oxygen partial pressure in the oxidant gas. High-temperature mass spectrometric method was used to determine the activity of the vanadium oxide in CaO-MgO-Al2O3-SiO2-V2O3 slags, whereas, the oxidation states of vanadium in the CaO-MgO-Al2O3-SiO2-VOxslag system was studied by XANES method. The results indicated that, higher basicities stabilize higher vanadium oxidation state, whereas, higher temperature stabilizes lower vanadium oxidation state. The present work, which was carried out within the ECO-STEELMAKING project funded by MISTRA via Jernkontoret is expected to lead to implementation of some modifications in high alloy steel production based on fundamental concepts towards more environment-friendly steel processing.

QC20100628

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17

Shollock, B. A. "Precipitation in rapidly solidified aluminium-chromium-iron alloys." Thesis, University of Oxford, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.238185.

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18

Hull, S. "Precipitation in aluminium based and iron based alloys." Thesis, University of Reading, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.370120.

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19

McCartney, N. S. "Helium ion irradiation effects in ferritic iron alloys." Thesis, University of Sussex, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.383584.

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20

CORTEZ, ORFELINDA AVALO. "SYNTHESIS AND CHARACTERIZATION OF NANOSTRUCTURED IRON-NICKEL ALLOYS." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2008. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=12975@1.

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PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO
COORDENAÇÃO DE APERFEIÇOAMENTO DO PESSOAL DE ENSINO SUPERIOR
CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO
Oxido de níquel e hematita nanoestruturadas foram sintetizadas a partir da decomposição térmica de nitrato de níquel hexahidratado e nitrato férrico nonahidratado respectivamente, na faixa de temperatura de 350-450°C com variações no tempo reacional. Os tamanhos de cristalito do NiO e Fe2O3 foram estimados a partir dos difractogramas de Difração de Raios-X (XRD) utilizando os software PowderCell e Topas. Foi observado que o tamanho de cristalito varia em função da temperatura de sínteses. O resultado mais significante foi observado nos cristalitos de NiO os quais aumentam de 31 nm (T=350°C, 3hr) a 98 nm (T=450°C, 5hr). Foram realizados estudos cinéticos da redução NiO e Fe2O3 por hidrogênio na faixa de temperatura de 250-600°C. Ligas ferroníquel nanoestruturadas com composições FexNi100-x (x = 25, 50, and 75 w%) têm sido preparadas com sucesso por decomposição térmica de nitratos (formação de óxidos) e posterior redução com hidrogênio a 700ºC (formação das ligas). As ligas Fe-Ni, caracterizadas por difração de raios-X mostraram tamanhos de cristalito da ordem de 25nm. A fase rica em Ni, liga Fe25Ni75, apresentou uma estrutura γ(FCC). A liga Fe50Ni50 apresentou a existência de uma estrutura tetragonal. A fase rica em Fe, liga Fe75Ni25, contém uma mistura de fases α(BCC) e γ(FCC). A coexistência das fases e atribuída à segregação de fases que acontece nestas ligas como resultado da difusão atômica. A partir dos resultados das medições magnéticas efetuadas a 300K, pode-se estabelecer que as ligas Fe-Ni nanoestruturadas tem um comportamento superparamagnético.
Nickel oxide and hematite nanostructured were successfully prepared by thermal decomposition from nickel nitrate hexahydrate and ferric nitrate nonahydrate in the temperature range of 350-450°C with variation of the time. The average crystallite sizes of NiO and Fe2O3 were estimated from X-ray diffraction (XRD) peaks using the PowderCell and Topas software. We observed that the crystallite size changes as a function of synthesis temperature. The significant result was the large size of the resulting NiO crystallites, which increased from 31nm (T=350°C, 3hr) to 98nm (T=450°C, 5hr). Kinetic studies of the reduction of NiO and Fe2O3 by hydrogen in the temperature range 250-600°C have been investigated. Nanostructured Fe-Ni alloys with compositions FexNi100-x (x = 25, 50, and 75 w%) have been successively prepared by thermal decomposition from mixtures of nitrates (formation of oxides) and reduction by hydrogen at 700ºC (formation of alloys). The Fe-Ni alloys, characterized by X-ray diffraction show crystallites sizes about 25nm. The Nirich phase, Fe25Ni75 alloys show the existence of γ(FCC) phase. The Fe50Ni50 alloy show the existence of tetragonal phase. The Fe-rich phase, Fe75Ni25 alloy, contain a mixture of α(BCC) and γ(FCC) phases. The coexistence of these phases is attributed to phase segregation occurring in these alloys as a result of enhanced atomic diffusion. It was inferred from results of magnetic measurements at 300K, that nanostructured Fe-Ni alloys were in a superparamagnetic state.

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21

Edmund, Eric. "The Elasticity of Iron Alloys at Extreme Conditions." Electronic Thesis or Diss., Sorbonne université, 2018. https://accesdistant.sorbonne-universite.fr/login?url=https://theses-intra.sorbonne-universite.fr/2018SORUS531.pdf.

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Depuis environ 40 ans, il existe un modèle séismologique fiable (appelé PREM pour Preliminary Reference Earth Model) qui rend compte des propriétés élastiques (vitesse de compression - Vp, vitese transverse - Vs, et masse volumique - ρ) du noyau terrestre, mais il n’existe pas de consensus clair sur la composition chimique qui peut correspondre à de telles propriété s aux températures et pressions souhaitées. Tandis que le fer a des propriétés élastiques qui sont proches de celles du noyau interne, le fer est trop lourd pour expliquer, à lui seul, la masse volumique du noyau terrestre. À la lumière de ces connaissances, et grâce à une série d’arguments cosmochimiques et géochimiques, le silicium comme impureté a été proposé pour expliquer la différence entre les propriétés du Fe seul et du modèle PREM. En utilisant une combinaison de diffraction des rayons-X en synchrotron et la technique acoustique picoseconde, ρ et Vp des alliages Fe-Si et Fe-Ni-Si ont été mesurés à des pressions dépassant 1 Mbar et 2000 K. Les données obtenues nous permettent une détermination précise des relations vitesse-masse volumique, des équations d’état P-V et P-V-T, ainsi que des rapports axiaux pour ces alliages. Ces résultats sont utilisés pour discuter des propriétés élastiques des alliages Fe-Si à haute pression – haute température pour fixer des contraintes sévères sur l’abondance de Si dans le noyau terrestre interne
For nearly 40 years, there has been a robust seismological model (PREM - Preliminary Reference Earth Model) which reports the elastic properties (compressional velocity - Vp, shear velocity - Vs, and density - ρ) of the Earth’s core, and yet there is still no clear consensus on the chemical composition which can match such properties at relevant pressures and temperatures. While iron has elastic properties which are close to those of the solid inner core, iron alone is too heavy to match the density of the inner core. In light of this, and based on a series of cosmochemical and geochemical arguments, Si has been proposed for many years in varying quantities as a material which could explain the difference in material properties between Fe and PREM. Using a combination of Synchrotron X-ray Diffraction and Picosecond Acoustics, ρ and Vp of Fe-Si and Fe-Ni-Si alloys have been measured to pressures and temperatures exceeding 1 Mbar and 2000 K. Obtained data allows an accurate determination of Velocity-Density relations, both P-V and P-V-T equations of state, and axial ratios of a variety of geophysically important Fe-Si and Fe-Ni-Si alloys. These results are used to discuss the elastic properties of Fe-Si alloys at high pressure - high temperature conditions to place tight constraints on Si abundance in the Earth’s inner core

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22

Johnsen, John LeRoy. "An investigation of selected properties of as-cast, V-Ti-Fe alloys /." Full text open access at:, 1985. http://content.ohsu.edu/u?/etd,87.

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23

Tapasa, Kanit. "Computer simulation of solute effects in model iron-copper and iron-carbon alloys." Thesis, University of Liverpool, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.426141.

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24

Kerkar, Moussa. "A structural investigation of the passive film on iron and iron/chromium alloys." Thesis, University of Warwick, 1989. http://wrap.warwick.ac.uk/106531/.

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The Electrochemical Polarisation, Photocurrent Spectroscopy and Extended X-ray Absorption Fine Structure (EXAFS) techniques have been used to study the passive film on pure iron and iron alloy samples containing up to 25% chromium. The material used in this work was prepared both as bulk and thin films. The bulk samples were passivated electro- chemically at various anodic potentials whereas the film ones were either fully converted into passive films by simple immersion in various solutions for one week or electrochemically at various anodic potentials. The Fe and Fe/Cr film samples used in the electrochemical passivation were deposited onto gold substrate and those passivated by immersion were deposited directly onto mylar. Polarisation curves for both the bulk and film materials were recorded. They suggest that the electrochemical behaviour of the two materials is similar. The wavelength and potential dependence of the photocurrent spectra were also recorded for the bulk and film samples of Fe and Fe/Cr alloys. The data were analysed to obtain the effective optical band gaps and flat band potentials of the passive films respectively. These results also show that the two materials are similar. Furthermore, the photocurrent data suggest that the passive film on Fe/Cr alloys consists of Fe(III) and Cr(III) phases. The fluorescence EXAFS above the Fe and Cr K-absorption edges of the passive film on Fe and Fe/Cr alloy films has been recorded both in-situ and en- situ. The spectra obtained in these studies were analysed to obtain average Fe-O and Fe-Fe separations as well as Cr-0 and Cr-Cr ones. These results together with a detailed examination of the XANES suggest that the passive film on iron in the absence of chromium is best described as a disordered 7—FeOOH-like structure and that on Fe/Cr alloys as well as on pure Fe passivated in chromate solution contains two simultaneous phases of disordered 7-FeOOHand Cr(OH)j. The structure of the chromium containing phase of the passive film was found to be independent of the source of chromium whether it was present in the alloy or it was incorporated from the passivating solution. The EXAFS data show also that the structure of the passive film is insensitive to drying. The results obtained in these studies have enabled the determination of the structure of the passive film on iron and iron/chromium alloys and the rôle played by chromium in improving the corrosion resistance of iron and its alloys has been identified. These conclusions are discussed in the light of other structural investigations of the passive film.

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25

Yiu, Yin-ling Elaine. "Corrosion resistance of iron-platinum dental magnets." Hong Kong : University of Hong Kong, 2002. http://sunzi.lib.hku.hk/hkuto/record.jsp?

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26

Mews, Paul Aaron. "Evaluation of zirconium-iron-rhenium alloys as surrogates for a technetium alloy waste form." Texas A&M University, 2007. http://hdl.handle.net/1969.1/85856.

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Stainless steel - zirconium alloys were developed by the US Department of Energy Laboratories as metallic waste forms for noble metal fission products. This thesis evaluates iron-zirconium-rhenium alloys to establish a technical basis for using metal waste form alloys for technetium-99 immobilization. Rhenium is used as a surrogate for Tc-99 since Tc is not naturally available and Re is metallurgically similar to Tc. The iron-zirconium system has two eutectic compositions, Fe-15 wt % Zr and Zr- 16 wt% Fe. Ten test samples were successfully cast in yttrium oxide crucibles at 1600°C, half near each eutectic composition, with Re amounts varying from 2.5 to 12.5 weight percent. A scanning electron microscope (SEM) with energy dispersive X-ray spectroscopy (EDS) capability was employed to determine the phase structure and phase composition of each sample. Iron rich samples were found to form up to three phases, with the rhenium content favoring the intermetallic phases: 1) an Fe solid solution phase, 2) an FeZr2-type intermetallic with 11 wt % or less Re, and 3) a second intermetallic with about 18 wt % Re. Zirconium rich samples formed as many as five distinct phases: 1) a Zr solid solution phase, 2) a Zr3Fe-type intermetallic with as much as 13 wt% Re, 3) a rhenium-zirconium intermetallic, 4) another Fe-Zr intermetallic with very little Re, and 5) a Fe-Re intermetallic. Potentiostatic and potentiodynamic electrochemical tests were performed using sulfuric acid to evaluate the corrosion resistance of each sample. These tests found that the zirconium rich samples were very corrosion resistant but became increasingly susceptible at higher rhenium concentrations. The iron rich samples were not very resistant to corrosion under the test conditions; there was no notable trend in corrosion behavior related to the introduction of rhenium.

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27

Gao, Wei. "Oxidation and crystallisation of amorphous alloys." Thesis, University of Oxford, 1988. http://ora.ox.ac.uk/objects/uuid:8a2a2323-24e2-4bdc-9b3e-4a22f9ec45ae.

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Amorphous alloys have a range of desirable ferromagnetic, electrical, mechanical and chemical properties. For instance, the application of Fe-based soft ferromagnetic amorphous alloys as transformer core materials can cut the transformer core losses to about 1/4, with considerable energy saving. However, during manufacture, heat treatment and in service, amorphous alloys may need to be exposed to moderately high temperatures for a period of time, with possible degradation caused by oxidation and crystallisation. There has been almost no previous study of oxidation behaviour and the relationship between oxidation and crystallisation in amorphous alloys. Eight important amorphous alloys and an industrial crystalline silicon steel have been studied in the present work; amorphous Fe78Si9Bl3, Fe40Ni40B20, Fe40Ni40P14B6, Co58NilOFe5SillB16, Fe32Ni36Crl4P12B6, Co66Fe4NilSil5B14, Co76Fe2Mn4Si6B12 and Ni78Si8B14, and crystalline Fe94Si6. A combination of thermogravimetry, optical and electron microscopy, electron probe microanalysis, X-ray diffractometry and differential scanning calorimetry has been used to investigate the oxidation and crystallisation kinetics, oxide structure and composition, oxidation and crystallisation mechanisms and the effect of crystallisation on the oxidation behaviour. The results show that the oxidation resistance at 350 C in air increases in the order Fe40Ni40- P14B6 < Fe94Si6 < Co66Fe4NilSil5B14 < Co58NilOFe5SillB16 < Co76MnFe2- Si6B12 < Fe40Ni40B20 < Si78Si9B13 < Ni78Si8B14 < Fe32Ni36Crl4P12B6. Most of the amorphous alloys obey a parabolic oxidation rate law, but the oxidation kinetics, oxide growth mechanism and resulting oxide structure change sharply when crystallisation takes place in the amorphous alloys. Amorphous Fe78Si9B13 and Fe40Ni40B20 have better oxidation resistance than the corresponding crystalline alloys, while amorphous Fe40Ni40P14B6 and Co58NilOFe5Sil1B16 have poorer oxidation resistance than the crystalline counterparts. Most of the crystalline alloys also obey a parabolic oxidation rate law, except for the crystalline Co based alloys and Fe40Ni40B20, which obey a logarithmic rate law. In most cases, the amorphous and crystalline alloys oxidise to form a fine-scale multiphase oxide scale, except for amorphous Fe40Ni40P14B6, which oxidises to form a whisker-like thick layer of Fe203- In general, ion diffusion through fast transport paths such as grain boundaries and dislocations is the rate controlling process for oxide growth. Different oxidation kinetics and oxide growth mechanisms in amorphous and crystalline alloys of the same composition are caused by micro-chemical segregation of the alloying elements during crystallisation.

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28

Yiu, Yin-ling Elaine, and 姚燕玲. "Corrosion resistance of iron-platinum dental magnets." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2002. http://hub.hku.hk/bib/B31954261.

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29

Poeppelman, Craig D. "Characterization of magnetostrictive iron-gallium alloys under dynamic conditions." Connect to resource, 2010. http://hdl.handle.net/1811/45012.

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30

Hale, Geoffrey Eric. "The structure and properties of iron-manganese-aluminium alloys." Thesis, University of Leeds, 1985. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.434965.

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31

Dungworth, David Barry. "Iron Age and Roman copper alloys from northern Britain." Thesis, Durham University, 1995. http://etheses.dur.ac.uk/1024/.

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32

Heritage, Neil. "Inverse photoemission from nickel and nickel-iron alloys and photoemission from magnesium-transition metal alloys." Thesis, University of Liverpool, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.333675.

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33

Iyer, Venkata Subramanian. "Diffusion induced grain boundary motion in the iron-zinc system /." The Ohio State University, 1986. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487265143145921.

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34

Edgemon, Glenn Leon. "The time-temperature-sensitization behavior of alloy 800 as determined by the electrochemical potentiokinetic reactivation test and the modified strauss test." Thesis, Georgia Institute of Technology, 1993. http://hdl.handle.net/1853/20034.

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Humphreys, Elen Siobhain. "Production and characterisation of rapidly solidified Al-V-Fe alloys." Thesis, University of Oxford, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.302070.

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Hosmani, Santosh S. "Nitriding of iron-based alloys : the role of excess nitrogen." Stuttgart Max-Planck-Inst. für Metallforschung, 2006. http://nbn-resolving.de/urn:nbn:de:bsz:93-opus-27675.

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37

Schacherl, Ralf Erich. "Growth kinetics and microstructure of gaseous nitrided iron chromium alloys." Stuttgart Max-Planck-Inst. für Metallforschung, 2004. http://deposit.d-nb.de/cgi-bin/dokserv?idn=972066217.

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38

Lazo, Johnny. "NUMERICAL SIMULATIONS OF MICROSTRUCTURAL EVOLUTION OF IRON ALLOYS UNDER IRRADIATION." Thesis, KTH, Reaktorfysik, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-138165.

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39

Shabestari, Saeed G. "Formation of iron-bearing intermetallics in aluminum-silicon casting alloys." Thesis, McGill University, 1994. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=28920.

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The formation of iron-bearing intermetallics in the 413 type of aluminum alloys was investigated comprehensively. Both synthetic and commercial 413 alloys were studied with iron concentrations in the range of 0.4-1.2 wt. % and manganese up to 0.5 wt.%. The effects of cooling rate during solidification and of melt chemistry on the morphology of iron intermetallic phases were determined. Image analysis was used to quantify the intermetallic size, volume fraction, and number, as a function of both melt chemistry and cooling rate. The total volume fraction of intermetallic compounds in these alloys was related to cooling rate by an exponential equation.
The kinetics of both dissolution of intermetallics on melting, and of re-formation on cooling of the liquid were investigated by means of quenching experiments. Quantitative evaluation of intermetallic size and number revealed that the change in volume fraction of intermetallics in the liquid state is controlled by nucleation.
The effect of settling time and the rate of gravity segregation of intermetallic compounds in a stagnant liquid metal were investigated. It was found that, in the absence of convection, settling obeys Stokes' law with the terminal velocity reached at very short times and very close to the melt surface.
Strontium was used to modify or eliminate the iron-intermetallics. (Abstract shortened by UMI.)

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40

Deards, Nicola. "Recrystallisation nucleation and microtexture development in aluminium-iron rolled alloys." Thesis, University of Cambridge, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.259602.

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41

Huang, Qianwen. "Electrodeposition of Amorphous Alloys: Nickel Cobalt Phosphorus and Iron Phosphorus." Case Western Reserve University School of Graduate Studies / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=case1465574470.

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Klymenko, D. "Iron in industry." Thesis, Сумський державний університет, 2013. http://essuir.sumdu.edu.ua/handle/123456789/33562.

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Steel is the world’s most important material. Steel production requires iron, steel scrap and flux. Iron production requires: iron ore, coal and limestone, dolomite. The iron ore is smelted to produce an impure metal called “hot metal” when liquid, or “pig iron” when solid. The hot metal is refined to remove impurities and to develop the desired composition. The liquid steel is continuously cast into semi-finished products which are processed into the desired shapes by rolling or forging. Iron is one of the most used metals, accounting 95% of world steel production. After oxygen, silicon and aluminium, iron is the fourth most plentiful element in Earth’s crust. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/33562

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Cisloiu, Roxana. "Computational modeling of hydrogen embrittlement of iron aluminides." Morgantown, W. Va. : [West Virginia University Libraries], 2001. http://etd.wvu.edu/templates/showETD.cfm?recnum=1910.

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Thesis (M.S.)--West Virginia University, 2001.
Title from document title page. Document formatted into pages; contains vii, 93 p. : ill. (some col.). Includes abstract. Includes bibliographical references (p. 71-75).

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Chen, Tzuyu. "Pitting and general corrosion characteristics of boride-strengthened nickel- and iron-based microcrystalline alloys /." The Ohio State University, 1986. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487264603219694.

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Armstrong, Derek C. "Influence of segregated impurities on the corrosion and oxidation of ferrous alloys." Thesis, University of Cambridge, 1991. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.239600.

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Eadie, Edward Norman. "Pattern of international trade in chromite and ferrochromium : an historical perspective /." Title page, table of contents and abstract only, 1997. http://web4.library.adelaide.edu.au/theses/09PH/09phe11.pdf.

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Verduzco, Martinez Jorge A. "Study of the fatigue behaviour of some Fe-based metallic glass wires." Thesis, University of Sheffield, 2000. http://etheses.whiterose.ac.uk/10241/.

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Fe78_C.,r xSiioBj2 and Fe77S. xCr-,S i7S. Bjs (with x values ranging from 0 to 8) glassy metallic alloys have been produced in the form of both wires and ribbons using the rotating water bath melt spinning process and chill block melt spinning process, respectively. It was found that the Fe77.5C.,r,, ,S ii. 5B15s eries had better amorphousw ire forming ability than the Fe7g_XCrXSiloBs1e2ri es. However, in ribbon form, both series showed good castability as amorphous alloys. Selected mechanical properties of the glassy samples have been compared with those of high tensile steel wire. Both thermal and mechanical properties were found to be composition-dependent, especially on the Cr content, with the Fe77.X5.C rrSi7.5B1s5e ries wires being thermally more stable and strongert han their Fe7gX. CrrSiloB12c ounterparts. A new bend type fatigue testing machine that uses two pulleys (DP) has been developed to perform tests on the basis of tension-compression loading cycles. The results have been compared with those obtained by using an existing single pulley (SP) machine that performs only tensile-tensile loading cycles. Although the DP machine can impose compressive to tensile bend stresses at different constant mean stress, it was observed that, for low stress ranges and large constant mean stresses the machine performed equivalent bend tests to those using the SP machine. The fatigue performance of amorphous wires was improved on substituting Fe by Cr and on decreasing the constant mean stress. The high tensile (HT) steel wire apparently had better fatigue performance than amorphous wires in terms of stress range; however, when the results were expressed in terms of strain range, the fatigue performance of amorphous wires was slightly better than HT steel wires, as had been demonstrated in previous studies. It was observed that, when the DP machine performed compressive to tensile bending stress cycles, the fracture surfaces differed from those observed in the SP machine. Under tensile to tensile conditions, the fracture surfaces observed for samples tested in the DP machine were similar to those tested in the SP machine. Fracture mechanics analysis of the results suggests that embrittlement is occurring ahead of growing fatigue cracks in these amorphous wires.

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Wolff, Ira M. "Ductility in high chromium super-ferritic alloys." Doctoral thesis, University of Cape Town, 1989. http://hdl.handle.net/11427/22200.

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Includes reprints of author's related articles.
Bibliography: pages 187-201.
The competition between microfracture and plastic flow has been studied in relation to the thermomechanical processing parameters and minor element chemistry of wrought super-ferritic alloys based on a composition of Fe-40wt% Cr. These alloys have been developed for corrosion-resistant applications, specifically by micro-alloying with platinum group metals to induce cathodic modification, but their use has been hampered by inadequate toughness at ambient temperatures. Brittle cleavage of the alloys is a consequence of the high resistance to plastic flow required to accommodate local stresses, such as those found ahead of a loaded crack. Once initiated, a crack propagates in a brittle manner with minimal ductility. The impact toughness therefore relies on the ability of the alloys to withstand crack initiation. The frequency of the crack initiation events is related to the distribution of secondary phases within the matrix and at the grain boundaries. A direct means of improving the toughness and the ductility is accordingly via annealing cycles and minor alloying additions to control the precipitation of second phases. The ductility is enhanced by raising the mobile dislocation density, and this may be achieved by pre-straining recrystallised material, or increasing the number of dislocation sources in the otherwise source-poor material. The generation of mobile dislocations by prismatic punching at second phase particles in response to local or tessellated stresses was found to increase the ductility and the impact toughness of the alloy. The addition of nickel also increases the brittle fracture resistance by promoting stress accommodation at the crack tip, a result which can, in principle, be explained on the basis of enhanced dislocation dynamics. The tendency of the alloys to form a stable recovered substructure was identified as a critical parameter for both the mechanical and corrosion properties. The low-angle dislocation sub-arrays contribute to overall strain-hardening, but destabilise the passivity of the alloys in acid media. In practice, rationalisation of the microstructural parameters has enabled the practicable fabrication of tough, corrosion-resistant alloys, suitable for commercial development.

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Kalcioglu, Ali Ferdi 1960. "Distribution of antimony between carbon-saturated iron and blast furnace slags." Thesis, The University of Arizona, 1989. http://hdl.handle.net/10150/277129.

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Understanding the effects of the process parameters on the distribution behaviour of antimony between metal and slag in the iron blast furnace is critical to develop a universal method of controlling temper embrittlement in commercially pure low alloy steels.

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Hu, Rong. "Irradiation effects on Fe-Cr alloys." Thesis, University of Oxford, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.560928.

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Ferritic chromium steels are important structural materials for future nuclear fission and fusion reactors due to their advantages over traditional austenitic steels, including low swelling rates, better thermal fatigue resistance, and lower thermal expansion coefficients. Radiation-induced segregation or depletion (RIS/RID) of solute atoms at grain boundaries is considered to be a potentially significant phenomenon for structural materials because of its potentially detrimental role in affecting microstructure and furthermore mechanical properties. However, the behaviour of Cr at grain boundaries in ferritic steels is not well understood. Both segregation and depletion of Cr at grain boundary under irradiation have been previously observed and no clear dependency on irradiation condition or alloy type has been presented. Furthermore, ferritic alloys are known to undergo hardening and embrittlement after thermal aging in the temperature range of 300-550DC and this phenomenon is related with a and a' phase separation occurring in the solid solution. However the low temperature a-a' miscibility gap in the currently used phase diagram is extrapolated from high temperature results and conflicts with many experimental observations. To understand the Cr behaviour at gram boundaries in ferritic steels under irradiation, a systematic approach combining SEM/EBSD, FIB specimen preparation and APT analysis has been developed and successfully applied to a Fe- 15.2at%Cr to investigate the effect of pre-irradiation chemistry, grain boundary misorientation, impurities, irradiation damage, irradiation depth, and other possible factors to get a better understanding of RIS/RID phenomena. Both low sigma boundaries and randomly selected high angle boundaries have been investigated in detail. Systematic differences between the behaviour of different classes of boundaries had been observed, and the operating mechanisms are also discussed in this thesis. The maximum separation method has been applied on APT data to study the C- enriched clusters and Cr-enriched clusters, which were not directly visible on the atom maps. The composition of the Cr-enriched clusters was consistent with a' phase and the irradiation was found to accelerate the nucleation rather than the growth of these clusters. Such results provided important information in re- determining the a-a' phase boundary.

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