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Electrochemical reduction and re‐oxidation behavior of α, β, and γ‐iron oxy‐hydroxide films on electrodes
Author(s) -
Sugae Kiyonobu,
Kamimura Takayuki,
Asakura Ryo,
Doi Takashi,
Miyuki Hideaki,
Kudo Takeo
Publication year - 2019
Publication title -
materials and corrosion
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.487
H-Index - 55
eISSN - 1521-4176
pISSN - 0947-5117
DOI - 10.1002/maco.201810342
Subject(s) - corrosion , electrochemistry , rust (programming language) , cathodic protection , electrode , hydroxide , materials science , chloride , inorganic chemistry , anaerobic corrosion , redox , metallurgy , chemistry , computer science , programming language
To clarify the effect of rust on the corrosion of steel exposed to an atmosphere containing chloride, the electrochemical reduction and re‐oxidation behavior of α, β, and γ‐FeOOH is studied. Films are formed on gold electrodes and are electrochemically reduced at several potentials, thus simulating the corrosion potential under wet and dry conditions. The current flowing through the β‐FeOOH is the highest among the three films. The β‐FeOOH is reduced to Fe 3−δ O 4 at a noble potential of less than −300 mV, relative to a standard hydrogen electrode (SHE) and is reductively dissolved to Fe 2+ at a noble potential of less than −100 mV (SHE). The formed Fe 3−δ O 4 is not reformed to β‐FeOOH during re‐oxidation. It is found that the β‐FeOOH plays an important role in the cathodic reaction, acting as an oxidant, and can significantly affect the corrosion of steel in the atmosphere.