In Situ ESEM Investigation of KCl-Induced Corrosion of a FeCrAl and a Model FeNiCrAl Alloy in Lab Air at 450 degrees C
Journal article, 2015
The very early stages of KCl-induced corrosion of a FeCrAl and a FeNiCrAl alloy in an 0211420 environment were studied using in-situ Environmental Scanning Electron Microscopy (ESEM). The samples were KCl contaminated and then exposed to lab air at a total pressure of 4.8 Ton at 450 degrees C. After exposure, the samples were analyzed using SEM-EDX, FIB and STEM-EDX. For both alloys, fast oxide growth occurred at the KCl particles. Far away from the KCl particles, a thin base oxide formed with potassium chromate nodules on top. The base oxide was layered, consisting of iron-chromium oxide on top and alumina in the bottom part. The FeCrAl alloy suffered internal oxidation while the FeNiCrAl did not. Both alloys formed sub-scale chlorides. A mechanism is proposed for the reaction of KCl on the surface and for the formation of different surface features at the KCl particles.
rmany
v56
high-temperature corrosion
dry o-2
oxide scale
sanicro 28
p801
initial-stages
water-vapor
superheater materials
Materials Science
kanthal af
Electrochemistry
biomass
oxidation
Author
Nooshin Mortazavi Seyedeh
Chalmers, Applied Physics, Materials Microstructure
Luciana Intiso
Chalmers, Applied Physics, Materials Microstructure
Niklas Israelsson
Chalmers University of Technology
Lars-Gunnar Johansson
Chalmers University of Technology
Mats Halvarsson
Chalmers, Applied Physics, Materials Microstructure
Journal of the Electrochemical Society
0013-4651 (ISSN)
Vol. 162 14 C744-C753Subject Categories (SSIF 2011)
Metallurgy and Metallic Materials
Areas of Advance
Materials Science
DOI
10.1149/2.0581514jes