Steam Oxidation of Zirconium–Yttrium Alloys from 500–$$1100\,^{\circ }\text {C}$$
Autor: | Brent J. Heuser, Peter A. Mouche |
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Rok vydání: | 2018 |
Předmět: |
010302 applied physics
Zirconium Materials science Hydrogen Hydride 020209 energy Metals and Alloys Analytical chemistry chemistry.chemical_element 02 engineering and technology Yttrium 01 natural sciences Inorganic Chemistry Minimal effect chemistry 0103 physical sciences 0202 electrical engineering electronic engineering information engineering Materials Chemistry Synchrotron diffraction Exponent Solid solution |
Zdroj: | Oxidation of Metals. 91:259-277 |
ISSN: | 1573-4889 0030-770X |
Popis: | The steam oxidation kinetics, oxide formation, and hydrogen uptake of nuclear-grade Zr with 0.01–12 wt% yttrium were studied. Metallography and diffraction of the as-received material showed yttrium remained trapped in solid solution in concentrations up to 2 wt%; therefore, steam oxidation focused on 0.01–1 wt% Y samples. Thermogravimetric analysis was performed in a steam–argon environment at $$500\,^{\circ }\text {C}, 700\,^{\circ }\text {C}, 900\,^{\circ }\text {C}$$ , and $$1100\,^{\circ }\text {C}$$ at atmospheric pressure. At $$500\,^{\circ }\text {C}$$ and $$700\,^{\circ }\text {C}$$ , increasing the yttrium concentration increased the total weight gain by up to 300% and caused an increase the oxidation power-law exponent. At $$900\,^{\circ }\text {C}$$ , increasing the yttrium concentration caused a much smaller increase in the weight gain, and resulted in a decrease in the oxidation power-law exponent. At the highest temperature, $$1100\,^{\circ }\text {C}$$ , increasing the yttrium concentration had a minimal effect on the kinetics. Transmission synchrotron diffraction and cross-sectional optical microscopy showed significant hydrogen uptake at $$500\,^{\circ }\text {C}$$ and $$700\,^{\circ }\text {C}$$ through the formation of $$\delta$$ and $$\gamma$$ zirconium hydrides. The volume of these two hydride phases increased with increasing yttrium concentration. This hydrogen uptake appears to be linked to the increase in the steam oxidation power-law exponent observed at $$500\,^{\circ }\text {C}$$ and $$700\,^{\circ }\text {C}$$ . |
Databáze: | OpenAIRE |
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