Microstructural investigation of the initial oxidation of the FeCrAlRE alloy Kanthal AF in dry and wet O2 at 600 and 800°CShow others and affiliations
2010 (English)In: Journal of the Electrochemical Society, ISSN 0013-4651, E-ISSN 1945-7111, Vol. 157, no 6, p. C223-C230Article in journal (Refereed) Published
Abstract [en]
The FeCrAlRE (where RE is reactive element) alloy Kanthal AF was exposed isothermally at 600 and 800°C for 72 h in dry O2 and in O2 with 10 vol % H2O. The mass gains were 3–5 times higher at the higher temperature. The presence of water vapor increased the oxidation rate at 800°C, while no significant effect was observed at 600°C. A thin two-layered oxide formed at 600°C: an outer (Fe,Cr)2O3 corundum-type oxide, containing some Al, and an inner, probably amorphous, Al-rich oxide. At 800°C a two-layered oxide formed in both environments. The inner layer consisted of inward grown a-Al2O3. In dry O2 the originally formed outward grown g-Al2O3 had transformed to a-Al2O3 after 72 h. Water vapor stabilized the outward grown g-Al2O3 and hence no transformation occurred after 72 h in humid environment. RE-rich oxide particles with varying composition (Y, Zr, and Ti) were distributed in the base oxide at both temperatures and in both environments. The RE-rich particles were separated from the alloy substrate by a layer of Al-rich oxide. At 800°C the Y-rich RE particles were surrounded by thick oxide patches in both dry and humid O2.
Place, publisher, year, edition, pages
The electrochemical society , 2010. Vol. 157, no 6, p. C223-C230
Keywords [sv]
FeCrAl-legering, högtemperaturoxidation, transmissionselektronmikroskopi
National Category
Manufacturing, Surface and Joining Technology
Research subject
Research Profiles 2009-2020, Steel Forming and Surface Engineering
Identifiers
URN: urn:nbn:se:du-4669DOI: 10.1149/1.3391447ISI: 000277260200050Scopus ID: 2-s2.0-77958558527OAI: oai:dalea.du.se:4669DiVA, id: diva2:520189
2010-04-282010-04-282021-11-12Bibliographically approved