Properties of Alumina/Chromia Scales in N2-Containing Low Oxygen Activity Environment Investigated by Experiment and Theory
Artikel i vetenskaplig tidskrift, 2017

The FeCrAl alloy Kanthal APMT™ was exposed to N2–5%H2 at 900 °C. Trace oxygen in the gases supplied an oxygen activity which was sufficient to render alumina and chromia thermodynamically stable. The exposures revealed that the oxide scale was penetrated by nitrogen exclusively at chromia domains. Microscopic analyses of the oxide scale did not reveal micro-cracks that could serve as points-of-entry for nitrogen. Instead it is suggested that nitrogen is transported through a dense chromia layer. Density functional theory was employed to investigate decisive nitrogen surface chemistry and transport properties in chromia and alumina. The study was used to validate that the complex redox chemistry of Cr3+ as opposed to Al3+ is a sufficient discriminating factor between alumina and chromia, facilitating N2 dissociation and mobility of N in chromia.

Chromia

Transport properties of the oxide

Metastable phases

Alumina

Nitridation

Författare

Christine Geers

Chalmers, Kemi och kemiteknik, Energi och material, Oorganisk miljökemi

Vedad Babic

Chalmers, Kemi och kemiteknik, Energi och material, Oorganisk miljökemi

Nooshin Mortazavi Seyedeh

Chalmers, Fysik, Materialens mikrostruktur

Mats Halvarsson

Chalmers, Fysik, Materialens mikrostruktur

Bo Jönsson

Chalmers, Kemi och kemiteknik, Energi och material, Oorganisk miljökemi

Lars-Gunnar Johansson

Chalmers, Kemi och kemiteknik, Energi och material, Oorganisk miljökemi

Itai Panas

Chalmers, Kemi och kemiteknik, Energi och material, Oorganisk miljökemi

Jan-Erik Svensson

Chalmers, Kemi och kemiteknik, Energi och material, Oorganisk miljökemi

Oxidation of Metals

0030-770X (ISSN) 1573-4889 (eISSN)

Vol. 87 3-4 321-332

Ämneskategorier

Oorganisk kemi

Materialkemi

Annan materialteknik

Teoretisk kemi

Korrosionsteknik

Drivkrafter

Hållbar utveckling

Innovation och entreprenörskap

Styrkeområden

Nanovetenskap och nanoteknik

Building Futures

Energi

Materialvetenskap

Infrastruktur

C3SE (Chalmers Centre for Computational Science and Engineering)

Chalmers materialanalyslaboratorium

DOI

10.1007/s11085-016-9703-3

Mer information

Senast uppdaterat

2018-11-01