Abstract
Corrosion kinetics of a stainless steel in nitric acid at elevated temperature has been investigated with special emphasis placed on its correlation with reduction rate of Cr (VI) in the solution. Extra High Purity (EHP) stainless steel, which is immune to intergranular corrosion in trans-passive potential range in nitric acid solution, has been employed to examine the dominant factor of corrosion rate. The results indicate that dissolution amount of the alloy agrees well with the stoichiometric value of dissolution based on the reduction amount of Cr (VI). This fact means that the dissolution kinetics of the stainless steel is simply dominated by reduction rate of Cr (VI) in the boiling nitric acid including Cr(VI). Reduction rate constant of Cr (VI) follows the identical Arrhenius equation including all the data with and without boiling, although oxidation rate constant of Cr (III) to Cr (VI) is strongly affected by boiling. A dominant factor of corrosion rate has been cleared based on the reduction rate constant of Cr (VI) and the oxidation rate constant of Cr (III).
Original language | English |
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Pages (from-to) | 302-306 |
Number of pages | 5 |
Journal | Zairyo to Kankyo/ Corrosion Engineering |
Volume | 65 |
Issue number | 7 |
DOIs | |
Publication status | Published - 2016 |
Keywords
- Chromium
- Corrosion
- Nitric acid
- Nuclear fuel reprocessing
- Oxidation reaction
- Oxidizing cations
- Reduction reaction
ASJC Scopus subject areas
- Surfaces, Coatings and Films
- Metals and Alloys
- Electrochemistry
- Materials Chemistry