Gas Phase Initial Oxidation of Incoloy 800 Surfaces
- 238 Downloads
The surface oxidation of Incoloy 800 was studied using dilute O2 gas at temperatures of 300 °C. Samples with two differing grain sizes were studied using time-of flight secondary ion mass spectrometry (ToF–SIMS) and X-ray photoelectron spectroscopy (XPS) as primary analysis tools. A multi-layered oxide film was detected and was composed of an exterior gamma-Fe2O3 with a Cr2O3 layer at the oxide–metal interface also containing significant concentrations of NiCr2O4. Minor concentrations of another spinel oxide, NiFe2O4 were distributed throughout the film. The kinetics of oxidation growth was found to follow a direct logarithmic relationship for both grain sizes, suggesting that the oxide would be a suitably protective. Very small oxide nodules formed at later stages, particularly for the small grained samples. A protocol for assessment of XPS spectral envelopes is advanced. The method measures the percent residual intensities remaining after spectral subtraction of reference spectra and appears to be an effective means for screening of possible components.
KeywordsNickel alloy oxidation XPS SIMS Oxide growth kinetics Alloy 800
The assistance of Dr. H.Y. Nie and Mr. R. Davidson of Surface Science Western for SIMS and SEM measurements is appreciated. Dr. B. Payne is thanked for his advice on XPS measurements. The financial assistance of the Natural Sciences and Engineering Research Council of Canada (NSERC) and the CANDU Owners Group is also appreciated.
- 1.D. G. Hurst, Canada Enters the Nuclear Age: A Technical History of Atomic Energy of Canada Limited (McGill-Queen’s University Press, Canada, 1997), p. 279.Google Scholar
- 2.Incoloy Alloy 800H and HT Specification Sheet, Special Metals Corporation, http://www.specialmetals.com.
- 5.P. G. Stone, J. Orr, and J. G. Guest, Journal of the British Nuclear Energy Society 14, 15 (1975).Google Scholar
- 8.G. C. Wood and F. H. Stott, Materials Science and Technology 3, 519 (1987).Google Scholar
- 14.M. Yamawaki, M. Mito, and K. Masayoshi, Journal of the Japan Institute of Metals 18, 567 (1977).Google Scholar
- 24.CasaXPS Software, Version 2.3.15 (c) (Casa Software Ltd).Google Scholar
- 26.R. P. Gupta and S. K. Sen, Physical Review B10, 71 (1974).Google Scholar
- 28.B. P. Payne, P. Keech, and N. S. McIntyre, Corrosion Science (submitted).Google Scholar
- 34.J. S. Armijo, D. L. Douglass, and R. A. Huggins, Journal of the Electrochemical Society: Solid-State: Science and Technology 120, 825 (1973).Google Scholar