著者

佐藤 教男

出版者

社団法人 日本金属学会

雑誌

日本金属学会会報 (ISSN:00214426)

巻号頁・発行日

vol.7, no.10, pp.617-631, 1968 (Released:2011-09-13)

参考文献数

84

被引用文献数

11 5

著者

佐藤 教男

出版者

社団法人 日本金属学会

雑誌

日本金属学会会報 (ISSN:00214426)

巻号頁・発行日

vol.12, no.10, pp.661-669, 1973-10-20 (Released:2011-08-10)

参考文献数

17

被引用文献数

1 1

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.

著者

野田 哲二 工藤 清勝 佐藤 教男

出版者

公益社団法人 日本金属学会

雑誌

日本金属学会誌 (ISSN:00214876)

巻号頁・発行日

vol.37, no.9, pp.951-957, 1973

被引用文献数

11

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The anodic passivation film formed on iron in neutral borate-buffer solution has been studied by using ellipsometric, electrochemical, and gravimetrical techniques. The film can be dissolved from its outer surface by applying a cathodic current in borate-buffer solution at pH 6.35 in which the reductive dissolution,<BR>(This article is not displayable. Please see full text pdf.) <BR>\oindentproceeds at 100 per cent current efficiency. Ellipsometric measurements carried out during the galvanostatic-cathodic reduction of the film in this solution reveals that the film consists of two layers, an inner layer with the optical constant 3.0&minus;0.5<I>i</I> and an outer layer with the constant 1.8&minus;0.1<I>i</I>. It is also shown that the density of the inner layer is in agreement with that of &gamma;-Fe<SUB>2</SUB>O<SUB>3</SUB>.<BR>The inner layer thickness increases linearly with the passivating potential, and the potential extrapolated at zero thickness of the inner layer corresponds to the equilibrium potential of the anodic formation of &gamma;-Fe<SUB>2</SUB>O<SUB>3</SUB>,<BR>(This article is not displayable. Please see full text pdf.) <BR>\oindentThe outer layer, however, is not directly related to the anode potential. <BR>Thermo-gravimetrical measurements indicate that the film contains some amount of water which is concentrated in the outer layer. The average composition of the outer layer is estimated as Fe(OH)<SUB>3</SUB>.<BR>A film model is proposed in which the inner layer of anhydrous &gamma;-Fe<SUB>2</SUB>O<SUB>3</SUB> is the cause of the potential drop in the film producing a field intensity of 5.6&times;10<SUP>6</SUP> V/cm and the outer layer of hydrous ferric oxide depends on the solution environment and passivation process.

著者

野田 哲二 工藤 清勝 佐藤 教男

出版者

公益社団法人 日本金属学会

雑誌

日本金属学会誌 (ISSN:00214876)

巻号頁・発行日

vol.37, no.9, pp.951-957, 1973 (Released:2008-04-04)

参考文献数

22

被引用文献数

18 11

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The anodic passivation film formed on iron in neutral borate-buffer solution has been studied by using ellipsometric, electrochemical, and gravimetrical techniques. The film can be dissolved from its outer surface by applying a cathodic current in borate-buffer solution at pH 6.35 in which the reductive dissolution,(This article is not displayable. Please see full text pdf.) \ oindentproceeds at 100 per cent current efficiency. Ellipsometric measurements carried out during the galvanostatic-cathodic reduction of the film in this solution reveals that the film consists of two layers, an inner layer with the optical constant 3.0−0.5i and an outer layer with the constant 1.8−0.1i. It is also shown that the density of the inner layer is in agreement with that of γ-Fe2O3.The inner layer thickness increases linearly with the passivating potential, and the potential extrapolated at zero thickness of the inner layer corresponds to the equilibrium potential of the anodic formation of γ-Fe2O3,(This article is not displayable. Please see full text pdf.) \ oindentThe outer layer, however, is not directly related to the anode potential. Thermo-gravimetrical measurements indicate that the film contains some amount of water which is concentrated in the outer layer. The average composition of the outer layer is estimated as Fe(OH)3.A film model is proposed in which the inner layer of anhydrous γ-Fe2O3 is the cause of the potential drop in the film producing a field intensity of 5.6×106 V/cm and the outer layer of hydrous ferric oxide depends on the solution environment and passivation process.

著者

佐藤 教男

出版者

Japan Society of Corrosion Engineering

雑誌

Zairyo-to-Kankyo (ISSN:09170480)

巻号頁・発行日

vol.44, no.3, pp.183-191, 1995-03-15 (Released:2009-11-25)

参考文献数

19

被引用文献数

2 2

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The electrode potential, which plays an important role in corrosion, may be defined by either the electronic or the ionic energy level in the electrode. The electronic electrode potential corresponds to the real potential of electron, i.e. the real free energy for electron transfer from the point at the outer potential of aqueous solution to the point inside the electrode, which is found to be a linear function of the electrode interfacial potential difference. Under equilibrium condition, the electronic potential represents the Fremi level of equilibrium redox electron in the solution for electron transfer electrodes, and the hypothetical Fermi level associated with ion transfer equilibrium for ion transfer electrodes. With localized corrosion, the corrosion potential at the cathode site is more positive than that at the anode site. This corrosion potential difference does not correspond to any local difference in the Fermi level inside the corroding metal, but to the difference in the electrode interfacial potential difference at the two sites.