High-temperature oxidation/corrosion of iron-based superalloysThe oxidation and sulfidation of several novel iron-base superalloys were evaluated in high-temperature cyclic tests. The experimental austenitic alloys examined were modifications of NASAUT-4GA which were developed for Stirling-engine application. The weight gains and resulting surface scales were measured and analyzed. Mixed oxide scales were found to form on all specimens exposed above 871 C. The build-up of these scales led to a depletion of Mn and Cr in a zone adjacent to the oxides. In addition, the initial oxidation of the Fe-rich alloy was inhibited by a thin but tenacious Si layer which formed at the interface between oxides and the parent layer. Sulfidation tests using Na2SO4 coatings resulted in the formation of a protective spinel and alpha-Fe2O3 phases. Preferential attack of the carbide phase by hydrogen was not observed after 350 h at 871 C.
Document ID
19880022802
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Lemkey, F. D. (United Technologies Research Center East Hartford, CT, United States)
Smeggil, J. G. (United Technologies Research Center East Hartford, CT, United States)
Bailey, R. S. (United Technologies Research Center East Hartford, CT, United States)
Schuster, J. C. (Wien, Universitaet Vienna, Austria)
Nowotny, H. (Connecticut, University Storrs, United States)
Date Acquired
August 13, 2013
Publication Date
January 1, 1987
Subject Category
Metallic Materials
Meeting Information
Meeting: Alternate alloying for environmental resistance