Die Kinetik der Entstehung und des Wachstums von Lochfraßstellen auf passiven Eisenelektroden

Engell, Hans‐Jürgen; Stolica, N.

doi:10.1524/zpch.1959.20.3_4.113

Cited by 135 publications

(12 citation statements)

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“…The thickness of the passive film might be measured in nanometers or some tens of nanometers, whereas a would be several tenths of a nanometer so that L/a would have the magnitude of several tens of nanometers. Equation which agrees with many experimental results (15,18,19). This implies that the pit initiation potential becomes more positive than the thermodynamically estimated potential for the halide formation on the surface of the metal by an order of magnitude of 1V.…”

Section: Discussionsupporting

confidence: 90%

“…On the other hand, in the case where the dissolution reaction rate through the halide nuclei can be assumed for hemispherical pitting corrosion (15,16) If the specific resistance of the halide is designated by Rx, then In the case where the halide nuclei have a very high ionic conductivity, so that the potential difference through the halide nuclei is substantially determined by the potential of the metal and is almost constant through the progress of the irreversible change, i.e.…”

Section: J'i=--n'iv'i-~mentioning

confidence: 99%

“…(Other values as low as 950~ have been reported (11)(12)(13). Consequently, we selected ferrous sulfide (FeS) as a melting point lowering solute, primarily because of the availability of considerable data on the Na~S-FeS system (12,14,15), although in retrospect another alkali sulfide might have been preferable. Consequently, we selected ferrous sulfide (FeS) as a melting point lowering solute, primarily because of the availability of considerable data on the Na~S-FeS system (12,14,15), although in retrospect another alkali sulfide might have been preferable.…”

Section: Experimental Systemmentioning

confidence: 99%

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Halide Nuclei Theory of Pit Initiation in Passive Metals

Okada

1984

J. Electrochem. Soc.

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A kinetic approach is used to test the theory of pit initiation in passive metals in contact with a solution containing aggressive ions. A new process, hemispherical halide nuclei formation at the surfac.e of the passive film and inward growth under restricted conditions, is introduced. The possibility of nuclei growth is discussed, taking into account the irreversible thermodynamic stability of the system. The direction of the irreversible change of a system consisting of the metal substrate, the passive filml the halide nuclei, and the solution is determined using the general evolution criterion of irreversible thermodynamics proposed by Glansdorff and Priogogine. A critical radius of the halide nucleus r* is deduced. This radius must be surpassed for growth and pitting to take place. The present theory explains the nature of the pit initiation processes, especially some characteristic values of the pitting phenomenon, such as the critical pitting potential and the induction period of pit nucleation. ABSTRACTPolarization behavior of the Ni-200 electrode in 75% Na2S-25% FeS at 1000~ under H2-0.32% H2S at 1 atm is linear over an overpotential range of -600 -< W -< 600 mV and is consistent with resistance polarization in the electrolyte. Similar polarization behavior of the 304 stainless steel electrode and of the Ni-200 electrode in 85% NasS-15% NiS suggests that the charge transfer mechanism is a sulfide/polysulfide exchange reaction. Nonelectrodic dissolution of nickel in the 75% Na2S-25%

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Section: Discussionsupporting

confidence: 90%

Section: J'i=--n'iv'i-~mentioning

confidence: 99%

Section: Experimental Systemmentioning

confidence: 99%

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Halide Nuclei Theory of Pit Initiation in Passive Metals

Okada

1984

J. Electrochem. Soc.

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“…Although the recent work of Engell and Stolica (19) on the effect of CI' ions on iron passivated anodically in sulfuric acid, is strikingly similar to the present work on the relative effects of CI' and SO4" ions on aluminum, there exists another powerful means of destroying the protective action of oxide film on iron, i.e,, reductive dissolution (20)(21)(22); this reaction must be carefully considered in relation to any film breakdown phenomena on iron. In solutions having pH values below 7.0 it may well be that the relationship between impurity substitution, including departure from stoichiometry, and the reductive dissolution characteristics of a substituted iron oxide film governs the choice between localized film breakdown and pitting, on one hand, and passivity on the other.…”

Section: Ions On Aluminum 31supporting

confidence: 70%

The Specific Effects of Chloride and Sulfate Ions on Oxide Covered Aluminum

Heine

Keir

Pryor

1965

J. Electrochem. Soc.

112

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The distribution of a-c resistance throughout the thickness of oxide film on aluminum specimens, conditioned by pre-exposure to 1.0N solutions of sodium chloride and sulfate, has been determined by an electrical method. This method involves measurement of series capacitance and dielectric loss of the oxide covered aluminum as the surface films thin slowly in a slightly alkaline, passivating, sodium chromate solution. Results show that chloride ions become included at certain selected locations in the oxide film, create additional current carriers, and lower the ionic resistance of the film. Sulfate ions do not appear to become included in aluminum oxide films under these conditions and do not lower the film resistance. Aluminum oxide films containing chloride ions dissolve more rapidly in the chromate solution than similar untreated films or films that have been treated in sodium sulfate solution. These observations are held to throw new light on the well defined tendency of oxide covered aluminum to pit severely in nearly neutral sodium chloriae solutions. ) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 131.215.225.9 Downloaded on 2015-05-25 to IP Vol. 112, No. 1 EFFECTS OF CHLORIDE IONS ON ALUMINUM ) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 131.215.225.9 Downloaded on 2015-05-25 to IP ) unless CC License in place (see abstract). ecsdl.org/site/terms_use address. Redistribution subject to ECS terms of use (see 131.215.225.9 Downloaded on 2015-05-25 to IP

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“…This relationship between the creases exponentially as the chloride concentracritical pitting potential and halide ion concentration decreases. As noted above, Okada has used tion is consistent with the experimental results of two independent approaches to derive these exseveral research groups [18][19][20] Such data will be crucial in corrosion models that et al [21]. These investigators assume that will be used to predict container life.…”

Section: Aqueous-phase Corrosionmentioning

confidence: 99%