Fj. Perez et al., Study of the corrosion of different alloys in molten carbonate salts by electrochemical impedance spectroscopy, B S ESP CER, 39(3), 2000, pp. 323-328
Citations number
6
Categorie Soggetti
Material Science & Engineering
Journal title
BOLETIN DE LA SOCIEDAD ESPANOLA DE CERAMICA Y VIDRIO
In the present work the corrosion behavior of different alloys (AISI 304, A
ISI 430 and TiAl6V) in molten carbonates at 650EC are compared. By using th
e Electrochemical Impedance Technique different corrosion parameters such a
s the corrosion rate and the oxyde concentration and others features of the
different layers of corrosion products are "in situ" determined. Take into
account, the corrosion product characterization by X-ray Diffraction (XRD)
, Scanning Electron Microscopy (SEM) and Electrochemical impedance Spectros
copy (EIS) a corrosion mechanism for every tested alloy is proposed. In all
cases, the corrosion mechanisms during the first hours are similar to a hi
gh temperature oxidation mechanism. When the equilibrium is established, th
e lithiation began by the formation of different double-layers on the surfa
ce of Li-metal oxydes. At the end of the corrosion process, one or two inne
r layers of metallic oxydes and one or two outer layers of Li-metal oxydes
were formed. The corrosion mechanisms of the stainless steels (AISI 304 ans
AISI 310S) are a function of their chromium contents. TiAl6V alloy showed
the best behavior against the corrosion of molten carbonates by the formati
on of a protective layer of mixed Li-Ti oxydes.