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study of the reactive-element effect in oxidation of fe-cr alloys using transverse section analytical electron microscopyThe role of trace additions of reactive elements like Y, Ce, Th, or Hf to Cr bearing alloys was studied by applying a new developed technique of transverse section analytical electron microscopy. This reactive-element effect improves the high temperature oxidation resistance of alloys by strongly reducing the high temperature oxidation rate and enhancing the adhesion of the oxide scale, however, the mechanisms for this important effect remain largely unknown. It is indicated that the presence of yttrium affects the oxidation of Fe-Cr-Y alloys in at least two ways. The reactive element alters the growth mechanism of the oxide scale as evidenced by the marked influence of the reactive element on the oxide scale microstructure. The present results also suggest that reactive-element intermetallic compounds, which internally oxidize in the metal during oxidation, act as sinks for excess vacancies thus inhibiting vacancy condensation at the scale-metal interface and possibly enhancing scale adhesion.
Document ID
19860000620
Document Type
Other
Authors
King, W. E.
(Argonne National Lab. United States)
Ethridge, E. C.
(NASA Marshall Space Flight Center Huntsville, AL, United States)
Date Acquired
August 12, 2013
Publication Date
May 1, 1985
Publication Information
Publication: NASA, Washington Microgravity Sci. and Appl. Program Tasks
Subject Category
ASTRONAUTICS (GENERAL)
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
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