Oxide reduction and diffusion in Fe-Cr alloy honeycombs
| Autor: | Joe K. Cochran, S.S. Kim, T. H. Sanders, Jason H. Nadler |
|---|---|
| Rok vydání: | 2004 |
| Předmět: |
business.product_category
Hydrogen Chemistry Diffusion Reducing atmosphere Alloy Kinetics Metallurgy Oxide General Physics and Astronomy chemistry.chemical_element engineering.material Metal chemistry.chemical_compound Chemical engineering visual_art engineering visual_art.visual_art_medium Die (manufacturing) business |
| Zdroj: | Journal de Physique IV. 120:47-54 |
| ISSN: | 1764-7177 1155-4339 |
| DOI: | 10.1051/jp4:2004120004 |
| Popis: | The goal of this study is to develop practices for evaluating and predicting the microstructural evolution of directly reduced iron-chromium alloys. This fundamental knowledge is being applied to a process developed at the Georgia Institute of Technology to fabricate metal honeycomb extrusions. A paste composed of oxide powders, binders and lubricants is extruded through a die of the desired cross-section and subsequently reduced to metal with hydrogen. The effects of time, temperature and composition on the extent of reduction and diffusion in reducing Fe2O3-Cr2O3 powder mixtures is investigated. The thermodynamics and kinetics of Fe2O3-Cr2O3 reduction are evaluated in terms of the free energy of formation as well as reducing species. The kinetics of the microstructural changes are evaluated through diffusion measurements. A thermodynamic model for Fe2O3-Cr2O3 was developed and used to determine the maximum amount of Cr2O3 that would reduce when in contact with iron as a function of the $\frac{P_{H_{2}}}{P_{H_{2}O}}$ ratio . Diffusion studies consisted of Fe-Cr2O3 couples held at temperature in a reducing atmosphere. Cr diffusion in Fe showed a concentration dependence for the geometries investigated. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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