Microstructural Investigation of the Initial Oxidation of the FeCrAlRE Alloy Kanthal AF in Dry and Wet O-2 at 600 and 800 degrees C
Artikel i vetenskaplig tidskrift, 2010

The FeCrAlRE (where RE is reactive element) alloy Kanthal AF was exposed isothermally at 600 and 800 degrees C for 72 h in dry O-2 and in O-2 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 degrees C, while no significant effect was observed at 600 degrees C. A thin two-layered oxide formed at 600 degrees C: an outer (Fe, Cr)(2)O-3 corundum-type oxide, containing some Al, and an inner, probably amorphous, Al-rich oxide. At 800 degrees C a two-layered oxide formed in both environments. The inner layer consisted of inward grown alpha-Al2O3. In dry O-2 the originally formed outward grown gamma-Al2O3 had transformed to alpha-Al2O3 after 72 h. Water vapor stabilized the outward grown gamma-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 degrees C the Y-rich RE particles were surrounded by thick oxide patches in both dry and humid O-2. (C) 2010 The Electrochemical Society. [DOI: 10.1149/1.3391447] All rights reserved.

cyclic oxidation

alumina scales

oxide scales

water-vapor

40-percent h2o

fecraire alloys

high-temperature oxidation

growth

900 degrees-c

mg-incorporation

Författare

Sead Canovic

Chalmers, Teknisk fysik, Mikroskopi och mikroanalys

Josefin Engkvist

Högskolan i Dalarna

Fang Liu

Chalmers, Teknisk fysik, Mikroskopi och mikroanalys

Haiping Lai

Chalmers, Teknisk fysik, Mikroskopi och mikroanalys

Mikael Götlind

Chalmers, Kemi- och bioteknik, Oorganisk miljökemi

Kristina M Hellström

Chalmers, Kemi- och bioteknik, Oorganisk miljökemi

Jan-Erik Svensson

Chalmers, Kemi- och bioteknik, Oorganisk miljökemi

Lars-Gunnar Johansson

Chalmers, Kemi- och bioteknik, Oorganisk miljökemi

M. Olsson

Högskolan i Dalarna

Mats Halvarsson

Chalmers, Teknisk fysik, Mikroskopi och mikroanalys

Journal of the Electrochemical Society

0013-4651 (ISSN)

Vol. 157 6 C223-C230

DOI

10.1149/1.3391447

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Senast uppdaterat

2019-04-01