Surface Reaction and Transport in Oxides Formed on FeCrAl Alloys in High Temperature Nitridation Environments
Paper in proceedings, 2017

An extended experimental study on corrosion of commercial FeCrAl alloys in predominantly N-2 atmosphere at high temperatures raises fundamental questions concerning nitrogen permeation through oxide scale components, each commonly perceived to constitute a robust barrier. State-of-the-art microscopy combined with DFT calculations is employed to unravel the underlying mechanisms for how chromia nodules support nitrogen dissociation and subsequently act windows for internal nitridation. A similar analysis addressed the role of yttria nodules shown to exhibit apparent expulsion of nitrogen, while favoring rapid alumina growth underneath the nodules. In this case, as for the slowly growing bare alpha alumina scale, the origin for the protection towards nitrogen permeation was identified as the inability to satisfy the necessary conditions for N-2 dissociation.

Surface reaction

DFT

growth

scales

Oxide transport properties

Author

Christine Geers

Chalmers, Chemistry and Chemical Engineering, Energy and Material, Environmental Inorganic Chemistry

Vedad Babic

Chalmers, Chemistry and Chemical Engineering, Energy and Material, Environmental Inorganic Chemistry

Lars-Gunnar Johansson

Chalmers, Chemistry and Chemical Engineering, Energy and Material, Environmental Inorganic Chemistry

Itai Panas

Chalmers, Chemistry and Chemical Engineering, Energy and Material, Environmental Inorganic Chemistry

Tms 2017 146th Annual Meeting & Exhibition Supplemental Proceedings

2367-1181 (ISSN)

387-392

Subject Categories

Metallurgy and Metallic Materials

DOI

10.1007/978-3-319-51493-2_36

ISBN

978-3-319-51493-2

More information

Created

1/24/2018