Application of Electrochemical Noise Measurements to Coated Systems

Eden, D. A.; Hoffman, Michael; Skerry, B. S.

doi:10.1021/bk-1986-0322.ch004

Cited by 17 publications

(8 citation statements)

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“…6' 7 Voltage and current noise mea surements have also been analyzed from corroding electrodes under open-circuit conditions. 8,1 This latter 0010-9312/91/0001 67/$3.00/0 approach is particularly suitable for the analysis and assessment of the corrosion resistance properties of organic coatings on steel substrates.t [0][1][2][3][4][5][6][7][8][9][10][11][12] In the present work, these two techniques have been applied simultaneously to four organic coatings of commercial quality to determine how effectively the two techniques distinguish their relative corrosion protection performance properties. A further aim has been to investigate whether laboratory-generated electrochemical data from continuous immersion tests can be related to similarly obtained data from equivalent, painted samples after 12 months exposure to a natural outdoor environment.…”

Section: Introductionmentioning

confidence: 99%

Assessing the Corrosion Resistance of Painted Steel by AC Impedance and Electrochemical Noise Techniques

Chen¹,

Skerry²

1991

CORROSION

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Four organic coatings of commercial grade (polyurethane, epoxy-polyamide, medium-quality and low-cost alkyds) with an expected range of corrosion protective properties were applied to steel substrates and immersed for up to 4,300 h in 0.6 M NaCl solution. These painted electrodes were assessed by AC impedance in the frequency range 60 kHz to 0.1/0.01 Hz and also by a statistical analysis of the voltage and current noise transients generated under freely corroding conditions. Good corrosion-resistant coatings were associated with stable paint-film AC resistance (R,) values and derived noise resistance (Re) values of the order of 108 to 1010 S2 •cm2. Associated capacitances were also stable in the range 10-10 F/cm2. Relatively poor corrosion protection occurred when the R, value decreased below -10 5 52 •cmz. Associated capacitance values in and above the luF/cm ,2 range suggested increased exposed electrode areas under delaminating paint and/or formation of corrosion pits. For significantly degraded paints, the R, values were somewhat higher than the equivalent Rf values because of charge-transfer and diffusion effects, which are not separated in the noise data. Immersion performance trends were consistent with results obtained from samples exposed for 12 months to an industrial atmosphere, suggesting that immersion testing may provide information relevant to atmospheric exposure conditions. In this respect, further work is necessary.

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Section: Introductionmentioning

confidence: 99%

Assessing the Corrosion Resistance of Painted Steel by AC Impedance and Electrochemical Noise Techniques

Chen¹,

Skerry²

1991

CORROSION

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“…32,33,[61][62][63][64] For polymer-coated metals, the current noise indicates changes in coating integrity, while the potential noise indicates passivity and the presence of electrolyte at the coating-metal interface. 22,65 A typical experimental setup is shown in Fig. 7(a), where the current noise is recorded between the two WEs (i.e.…”

Section: Electrochemical Noisementioning

confidence: 99%

“…However, the testing times for environmental exposure are long and may be impractical. 22 The tests also offer qualitative evaluation of the protective properties without providing quantitative information about the coating degradation and failure mechanism. 15 Alternatively, it is a common practice to rapidly assess and predict the damage and failure modes of coated samples by accelerated testing.…”

Section: Introductionmentioning

confidence: 99%

Surface electroanalytical approaches to organic polymeric coatings

Caldona

Smith

Wipf

2020

Polymer International

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Surface characterization techniques for organic polymeric coatings are numerous and diverse. Many of these techniques can provide physical information about how coating systems perform under certain environmental conditions, but they provide less mechanistic information on how they function as corrosion barriers. Since many coating failures are initiated from ionic diffusion through the coating and the subsequent reactivity at the coating-metal interface is mostly electrochemical in nature, the utility of electrochemical-based techniques is therefore more appropriate. This mini-review highlights five of the most commonly used electroanalytical techniques for the evaluation of corrosion protection properties for polymer coatings on metals: open circuit potential, electrochemical impedance spectroscopy, potentiodynamic polarization, electrochemical noise and scanning electrochemical microscopy. These techniques can perform their own unique approach of examining the protection performance of polymer coatings, but the elucidation of coating degradation and mechanism of corrosion at the coating-metal interface is their common objective.

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“…Solutions containing inhibitors [54][55][56][103][104][105][106] . Coatings [67][68][69][70][71][72][73][74][75][107][108][109][110] . H 2 S systems [111][112][113] .…”

Section: E Applications For Real-time Corrosion Monitoringmentioning

confidence: 99%