Abstract
The Mixed-Conduction Model (MCM) has been adapted to
obtain the main kinetic and transport parameters for
passive film growth on nickelbased alloys in
high-temperature electrolytes. For the purpose, a
procedure for the calculation of these parameters from
electrochemical impedance spectroscopic data measured on
Ni-15% and Ni-20%Cr alloys in 0.1M Na2B4O7 at 300°C in a
wide potential range has been devised. The obtained sets
of parameters have been used to successfully predict the
steady-state current density versus potential dependence
for the two Ni-Cr alloys, as well as the thickness versus
time dependence for films grown on Alloy 600 at times
ranging between a few minutes and a few thousand hours.
The calculations are supported by results of previous XPS
measurements of film growth on Alloy 600 showing that the
barrier layer growing in the early stage consists of
Cr2O3
| Original language | English |
|---|---|
| Pages (from-to) | 7475-7483 |
| Journal | Electrochimica Acta |
| Volume | 52 |
| Issue number | 26 |
| DOIs | |
| Publication status | Published - 2007 |
| MoE publication type | A1 Journal article-refereed |
Keywords
- nickel-based alloys
- Oxide film growth
- High-temperature water
- Kinetic model