Breakdown of protective scales during the oxidation of thin foils of Fe–20Cr–5Al alloys at high temperatures
Autor: | F. H. Stott, N. Hiramatsu |
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Rok vydání: | 2000 |
Předmět: |
inorganic chemicals
Materials science Mechanical Engineering Alloy Metallurgy technology industry and agriculture Metals and Alloys chemistry.chemical_element Substrate (electronics) engineering.material equipment and supplies Condensed Matter Physics Chromia chemistry Mechanics of Materials Molybdenum Aluminium Transmission electron microscopy Materials Chemistry Ceramics and Composites engineering Lanthanum Layer (electronics) |
Zdroj: | Materials at High Temperatures. 17:93-99 |
ISSN: | 1878-6413 0960-3409 |
Popis: | The oxidation behaviour of alumina-forming Fe–20Cr–5Al and similar alloys containing small concentrations of lanthanum or lanthanum plus molybdenum in air at 1,150°C has been studied, with emphasis on thin (0.05 mm) specimens, where the aluminium reservoir in the substrate is soon depleted to a very low value. Oxidation of these alloys involves establishment and growth of protective alumina scales. However, once the residual aluminium concentration in the alloy drops below a critical level, a layer of chromia is able to develop and grow at the alumina–alloy substrate interface. Eventually, breakaway oxidation occurs and iron-rich oxides form and engulf the specimen.This paper presents some kinetics of oxidation of these alloys and discusses the growth and breakdown of the protective scales, drawing on the results of detailed examinations of the oxidized specimens using analytical scanning and transmission electron microscopy in cross section. It has been shown that lanthanum increases the time to ... |
Databáze: | OpenAIRE |
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