著者

佐藤 教男

出版者

Japan Society of Corrosion Engineering

雑誌

防食技術 (ISSN:00109355)

巻号頁・発行日

vol.39, no.9, pp.495-511, 1990-09-15 (Released:2009-10-30)

参考文献数

55

被引用文献数

4 3

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A review is given of some simplified concepts that will contribute to a better understanding of corrosion fundamentals. The corrosion process involves not only electrochemical reactions but also acid-base reactions, and it is the acid-base nature that diversifies the corrosion phenomena. Anions either catalyze or inhibit the anodic metal dissolution, and the passivation will result from the hydroxide-catalyzed mechanism of metal dissolution. Corrosion precipitates frequently control the selective mass transport in corrosion processes. Anion-selective precipitates accelerate and cation-selective precipitates decelerate corrosion propagation. A bipolar precipitate film, if anodically polarized, undergoes deprotonation and turns into a passive film. The electrochemical stability of passivated metals is determined by the electron energy band structure of the passive film. The passive film of n-type semiconducting oxides appears electrochemically more stable than the passive film of p-type semiconducting oxides.