Abstract
Voltammetric and electrochemical impedance spectroscopic measurements in
combination with ex situ surface analysis are used to characterise the
passive state of Fe–18% Cr in molten NaOH at 470 °C. The areas of
corrosion, passivity and transpassivity are derived from experimental
voltammetric data and thermodynamic considerations. Impedance
measurements in a wide potential range are performed to study the
conductivity mechanism of the anodic layers formed. The surface
composition of the passive film is estimated by X-ray photoelectron
spectroscopy and its in-depth composition by Auger electron
spectroscopy. A transfer function based on a tentative kinetic model is
proposed to describe the impedance spectra. The parameters of the
transfer function are determined by best-fit calculation and some of the
kinetic and transport parameters characterising the film growth process
are estimated.
Original language | English |
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Pages (from-to) | 162-175 |
Journal | Applied Surface Science |
Volume | 249 |
Issue number | 1-4 |
DOIs | |
Publication status | Published - 2005 |
MoE publication type | A1 Journal article-refereed |
Keywords
- stainless steel
- molten hydroxide
- passive film
- electrochemical impedance spectroscopy
- surface analysis
- kinetic model
- surface treatment
- X-ray photoelectron spectroscopy