Understanding the effects of applied cathodic protection potential and environmental conditions on the rate of cathodic disbondment of coatings by means of local electrochemical measurements on a multi-electrode array

Mahdavi, Fariba; Forsyth, Maria; Tan, Yongjun

doi:10.1016/j.porgcoat.2016.10.020

Cited by 27 publications

(13 citation statements)

References 24 publications

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“…Such boxes were mostly subjected to less negative potentials, as shown in Table 1. Also, boxes 12A and 12B, where samples were protected by a potential of ‐1500 mV, provided the largest disbondment sizes, indicating that greater disbondment can be associated with lower potentials [ 3,25 ] and more aggressive soils. [ 19 ]…”

Section: Resultsmentioning

confidence: 99%

“…Such boxes were mostly subjected to less negative potentials, as shown in Table 1. Also, boxes 12A and 12B, where samples were protected by a potential of -1500 mV, provided the largest disbondment sizes, indicating that greater disbondment can be associated with lower potentials [3,25] and more aggressive soils. [19] According to Figure 5, holidays located at 0°provided the greater number of disbondment events, that is, 6 on the rural soil and 10 on the industrial one, with average values of 5.3 and 6.1 mm, respectively.…”

Section: Effect Of Holiday Distance From Anode On the 3lpe Disbondmentmentioning

confidence: 99%

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Long‐term cathodic disbondment tests in three‐layer polyethylene coatings

Freitas

Brasil

Leoni

et al. 2023

Materials & Corrosion

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Cathodic protection allied to a polymeric coating is one of the most employed techniques to protect buried steel pipelines against corrosion. Nevertheless, cathodic disbondment, a phenomenon associated with such protection in highperformance coatings such as (three-layer polyethylene [3LPE]), still concerns the oil and gas segment regarding pipeline integrity. The present work was part of a Program of Integrity Management and studied in field-like conditions the influence of cathodic potential, type of soil and coating system on the coating disbondment of buried pipelines for 450 days. The coating systems herein studied simulated the patching between aged (coal tar) and new coatings (3LPE), a standard procedure during damaged pipeline repair. Results pointed out that the combination between aged (coal tar) and new coatings (3LPE) in a pipe segment reduced coating disbondment when compared to the systems where 3LPE was the sole type of coating. Moreover, it was shown that more cathodic potentials (<−1100 mV) and the aggressiveness of the industrial soil herein tested induced disbondment diameters as high as 15.5 mm.

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Section: Resultsmentioning

confidence: 99%

Section: Effect Of Holiday Distance From Anode On the 3lpe Disbondmentmentioning

confidence: 99%

Long‐term cathodic disbondment tests in three‐layer polyethylene coatings

Freitas

Brasil

Leoni

et al. 2023

Materials & Corrosion

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“…2b) as can be deduced from the low frequency limit of the LEIS diagram which tends towards a negative polarization resistance. The LEIS technique is widespread analysis technique used for mapping coatings delamination [37] or disbondment [38] as well as the study of galvanic coupling using the latest developments in dynamic electrochemical impedance spectroscopy [39]. When performing fixed frequency mapping, it is possible to monitor the evolution of defect size over time, but a quantitative analysis at each position requires a complete impedance spectrum to be recorded at each point.…”

Section: From Global To Local Impedance Measurementsmentioning

confidence: 99%

Local electrochemical impedance spectroscopy: A window into heterogeneous interfaces

Gharbi

Ngo

Turmine

et al. 2020

Current Opinion in Electrochemistry

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The ability to probe surface reactivity on a local scale has led to new insight on the comprehension of the electrochemical reactivity in relation with the microstructure of the surface. Among the different techniques developed in recent years, local electrochemical impedance spectroscopy has the advantage of using a transient approach to locally characterize a stationary electrochemical system without the need to add any redox mediator in solution, which is a great advantage for the study of different systems. In this review, particular attention is paid to the different ways of measuring the local impedance, and the technique implementing a local current measurement in solution is deeply discussed. This local electrochemical impedance spectroscopy journey also encompasses a discussion about technical and experimental limitations.

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“…Despite extensive efforts, the complete elucidation of the influence remains elusive, and research is ongoing. [ 6,27–29 ]…”

Section: Introductionmentioning

confidence: 99%

“…Despite extensive efforts, the complete elucidation of the influence remains elusive, and research is ongoing. [6,[27][28][29] The starting point of this study was the observation that a commercial thermoset primer without a topcoat and as thin as 3 μm exhibited a superb resistance of more than 1000 h in a neutral SST. To identify the crucial parameters behind this excellent performance, a variety of coating variables (dry film thickness, polymeric matrix, substrate, pigments…) and accelerated laboratory corrosion tests have been employed, to elucidate the mode of action of thermoset primers without topcoats in a thickness range below 10 μm-a topic, which has gained up to now only little attention in the literature.…”

Section: Introductionmentioning

confidence: 99%

Thermoset thin film primers: Influence of substrate, layer thickness and wettability of additives in laboratory testing

Wiener

Strauß

Luckeneder

et al. 2023

Materials & Corrosion

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Steel sheets are often protected from corrosion using primers in combination with a top coat. However, the effectiveness of primers alone has not been extensively studied. Here, we use a selection of complementary corrosion tests for benchmarking the performance of thin-film primers across a set of varying engineering parameters such as thickness, wettability, and substrate. Five established tests were selected, covering all predominant mechanisms that may occur, namely tests for cathodic and anodic delamination and barrier protection. Electrochemical investigations, among others, were carried out to evaluate the corrosion behavior, while structural properties were analyzed using techniques such as SEM. A total of nine primer formulations were tested in a layer thickness range of 3-9 μm, on GI and ZM-coated steel. Both layer thickness and substrate strongly influence performance, and to a lesser degree the primer formulation. Further, hydrophobization has a beneficial effect on cathodic delamination, while white rust formation is enhanced due to pigment leaching limitations. This suggests that competing effects can be traced well using the combination of the suggested five tests.

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Understanding the effects of applied cathodic protection potential and environmental conditions on the rate of cathodic disbondment of coatings by means of local electrochemical measurements on a multi-electrode array

Cited by 27 publications

References 24 publications

Long‐term cathodic disbondment tests in three‐layer polyethylene coatings

Long‐term cathodic disbondment tests in three‐layer polyethylene coatings

Local electrochemical impedance spectroscopy: A window into heterogeneous interfaces

Thermoset thin film primers: Influence of substrate, layer thickness and wettability of additives in laboratory testing

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