Microstructural investigations of pure nickel exposed to KCl induced high temperature corrosion
Artikel i vetenskaplig tidskrift, 2015

Oxidation of 99.99% pure nickel was studied with and without 0.10 mg cm(-2) KCl(s) in an environment containing 5 vol.-% O-2, 40 vol.-% H2O and 55 vol.-% N-2 at 600 degrees C for up to 168 h. Oxide microstructure was investigated by X-ray diffraction (XRD), focused ion beam (FIB), broad ion beam (BIB) and SEM/ EDX. Oxidised nickel shows an approximately parabolic oxide growth rate. The oxide scale is dense with some pores at the oxide/metal interface. Adding small amounts of KCl does not result in a faster corrosion rate of nickel. However, the surface morphology changes and small oxide crusts were observed in the vicinity of former KCl particles. This is proposed to be the result of a NiCl2-KCl eutectic on top of the oxide scale formed above 514 degrees C. The oxide scale formed in the presence of KCl contains more and differently distributed voids than the scale formed without KCl.

600 degrees C

KCl

Nickel

Electron microscopy

High temperature corrosion

Författare

Torbjörn Jonsson

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

Andreas Slomian

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

T. N. Lomholt

Danmarks Tekniske Universitet (DTU)

S. Kiamehr

Danmarks Tekniske Universitet (DTU)

K. V. Dahl

Danmarks Tekniske Universitet (DTU)

Materials at High Temperatures

0960-3409 (ISSN)

Vol. 32 1-2 44-49

Ämneskategorier

Metallurgi och metalliska material

DOI

10.1179/0960340914z.00000000060

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Senast uppdaterat

2018-02-28