Defect-dependent nitride surface layer development upon nitriding of Fe–1 at.% Mo alloy
| Autor: | Sai Ramudu Meka, T. Woehrle, H. Selg, I. Bernstein, Thomas Waldenmaier, R. E. Schacherl, E. J. Mittemeijer, Ewald Bischoff |
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| Rok vydání: | 2013 |
| Předmět: | |
| Zdroj: | Philosophical Magazine. 93:2133-2160 |
| ISSN: | 1478-6443 1478-6435 |
| DOI: | 10.1080/14786435.2013.765983 |
| Popis: | Upon nitriding of binary Fe–1 at.% Mo alloy in a NH3/H2 gas mixture under conditions (thermodynamically) allowing γ′-Fe4N1– x compound layer growth (nitriding potential: 0.7 atm−1/2 at 753 K (480 °C) – 823 K (550 °C)), a strong dependency of the morphology of the formed compound layer on the defect density of the specimen was observed. Nitriding of cold-rolled Fe–1 at.% Mo specimens leads to the formation of a closed compound layer of approximately constant thickness, comparable to nitriding of pure iron. Within the compound layer, that is, in the near-surface region, Mo nitrides are present. The growth of the compound layer could be described by a modified parabolic growth law leading to an activation energy comparable to literature data for the activation energy of growth of a γ′-Fe4N1− x layer on pure iron. Upon low temperature nitriding (i.e. ⩽793 K (520 °C)) of recrystallized Fe–1 at.% Mo specimens, an irregular, ‘needle-like’ morphology of γ′-Fe4N1− x nucleated at the surface occurs. This γ′ iron ni... |
| Databáze: | OpenAIRE |
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