A stochastic analysis of potential fluctuation during passive film breakdown and repair on iron

Hashimoto, M.; Miyajima, Shumpei; Murata, Tetsuhito

doi:10.1016/0010-938x(92)90053-6

Cited by 66 publications

(21 citation statements)

References 25 publications

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“…Models of corrosion behavior based on current transients in the passive region point to a stochastic process where pits emerge, grow, and die Electrochemical and Solid-State Letters, 5 ͑11͒ B33-B36 ͑2002͒ B34 in a random manner. [16][17][18][19] Corrosion models have traditionally been based on total sample current measurements without knowledge of position of individual sites that can be deduced from SECM. While the above system warrants further study than given in this paper, this work provides an introduction into the potential for SECM study of corrosion dynamics and the potential problems that can be encountered.…”

Section: Resultsmentioning

confidence: 99%

Scanning Electrochemical Microscopy Study of Corrosion Dynamics on Type 304 Stainless Steel

Lister¹,

Pinhero²

2002

Electrochem. Solid-State Lett.

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Scanning electrochemical microscopy was utilized to study dynamics of corrosion on type 304 SS. The I Ϫ /I 3 Ϫ redox couple was used in the substrate generation/tip collection mode to determine active sites. Scanning the sample sequentially revealed that the electrochemical activity ͑where I 3Ϫ was detected͒ was localized and dynamic in nature. Subsequent microscopy indicated pitting occurred at many of the sites where electrochemical activity was detected. Currently, the technique is limited by the time required to raster a single probe through the scan area. In future studies, parallel ͑multielectrode͒ image acquisition is proposed to address this issue.The investigation of localized electrochemical reactions on metal surfaces is of great fundamental interest to corrosion science. Traditionally, corrosion is studied by accelerated tests using an external electric field and possibly followed by postmortem analysis of the surface to determine material loss and morphology. These techniques provide insight into corrosion rates and morphological changes at surfaces, but do not offer much detail about the localized dynamics of corrosion processes. This type of information is of interest to a fundamental understanding of corrosion processes. Recently, in situ probes ͓scanning tunneling microscopy, atomic force microscopy, and scanning electrochemical microscopy ͑STM, AFM, and SECM͔͒, have been developed for allowing real-time study of surface reactions at interfaces. 1-3 In terms of studying pitting corrosion, the SECM appears most suitable due to its ability to analyze larger areas of the sample than other in situ methods and can be tuned for chemical specificity. Large area measurements are important because the microstructure of most samples of interest are heterogeneous with multiple phases present. In addition, larger areas provide more statistically defensible results, a problem that high resolution techniques have when studying complex surfaces.In recent years, several SECM studies have probed local electrochemical activities of metal surfaces using redox molecules. [3][4][5][6][7][8][9] These papers show that only a small fraction of the surface was electrochemically active, localized to point sites on the surface. While the reason for this heterogeneous activity has not been determined, it was suggested that electrons tunnel through the oxide layer via areas that have either a thinner oxide layer or are more metallike ͑conductive͒. 4,7,9 Correlation of local electrochemical activity with areas of oxide breakdown has been made is some cases, thus suggesting that SECM could be used as a predictive tool to determine where corrosion might occur. In certain cases, a dynamic change in surface reactivity was observed with a variation in potential. The dynamics appear to be a delicate balance between oxide thickening and increased potential drop across the oxide which promotes electron transfer to redox species. 4 In this study, local electrochemical activity of type 304 SS was probed using the I Ϫ /I 3 Ϫ redox probe...

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Section: Resultsmentioning

confidence: 99%

Scanning Electrochemical Microscopy Study of Corrosion Dynamics on Type 304 Stainless Steel

Lister¹,

Pinhero²

2002

Electrochem. Solid-State Lett.

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“…Among the existing methods, the electrochemical noise signatures analysis has been employed to play a critical role in electrode noise origination [12,13] the stochastic nature of localized corrosion including pitting corrosion [14][15][16][17]19] and crevice corrosion [18,19] and various mathematical models in understanding electrode potential and current fluctuations [20,21], however, the exact origination process of electrochemical noise has not yet been clearly identified. The wire beam electrode (WBE) has been developed into an electrochemical sensor for monitoring various localized corrosion processes and it can measure the dispersion of current signals from the different electrodes and the degree of variations in the electrochemical properties among the electrodes [22][23][24][25].…”

Section: Introductionmentioning

confidence: 99%

Monitoring pitting‐crevice corrosion using the WBE‐noise signatures method

Aung¹,

Tan

2006

Materials & Corrosion

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An electrochemically integrated multi-electrode array namely the wire beam electrode (WBE) and noise signatures analysis have been applied in novel combinations to study crevice corrosion behaviour in the presence of pits. Characteristic electrochemical noise signatures were found to correlate with characteristic changes in WBE current distribution maps, which indicate corrosion rates distributions, corrosion patterns and the degree of pitting and crevice corrosion. Specifically, two characteristic noise patterns were observed: (i) the characteristic noise pattern of quick potential changes towards more negative direction with no recovery (termed noise signature I) was found to correspond with the initiation and stabilization of the anode inside crevice; and (ii) the characteristic noise pattern of the cyclic potential oscillation at a constant frequency (termed noise signature II) was found to correspond with the stable anodic dissolution in the occluded cavity site in WBE current distribution maps. A new parameter namely the localization parameter (LP) has been proposed to describe the degree of localization. The LP for crevice corrosion was found to be low compared to that for pitting corrosion.

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“…The potential noise peak caused by pitting corrosion often possesses the features of reducing quickly and recovering slowly. Current noise peak has the features of rising or reducing quickly and recovering slowly [21,22] . The potential decreases and current rises slowly with time of co-doped TiO 2 fi lms, which indicate that uniform corrosion is occurred in SBF.…”

Section: Methodsmentioning

confidence: 99%

Effects of C, N-codoped on the corrosion resistance of TiO2 films prepared by plasma surface alloying and thermal oxidation duplex process

Wang

Liu

et al. 2011

J. Wuhan Univ. Technol.-Mat. Sci. Edit.

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C, N-codoped TiO 2 films have been deposited onto stainless steel substrates using plasma surface alloying and thermal oxidation duplex process. Composition analysis shows that the films shield the substrates entirely. The TiO 2 films are anatase in structure as characterized by X-ray diffraction. The electrochemical measurements show that the equilibrium corrosion potential positively shifts from -0.275 eV for bare stainless steel to -0.267 eV for C, N-codoped TiO 2 coated stainless steel, and the corrosion current density decreases from 1.3×10 -5 A/cm 2 to 4.1×10 -6 A/cm 2 . The corrosion resistance obtained by electrochemistry noise also reveals that the C, N-codoped TiO 2 fi lms provide good protection for stainless steel against corrosion in stimulated body fl uid. The above results indicate that C, N-codoped TiO 2 fi lms deposited by plasma surface alloying and thermal oxidation duplex process are effective in protecting stainless steel from corrosion.

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A stochastic analysis of potential fluctuation during passive film breakdown and repair on iron

Cited by 66 publications

References 25 publications

Scanning Electrochemical Microscopy Study of Corrosion Dynamics on Type 304 Stainless Steel

Scanning Electrochemical Microscopy Study of Corrosion Dynamics on Type 304 Stainless Steel

Monitoring pitting‐crevice corrosion using the WBE‐noise signatures method

Effects of C, N-codoped on the corrosion resistance of TiO2 films prepared by plasma surface alloying and thermal oxidation duplex process

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