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Yongjun Tan - One of the best experts on this subject based on the ideXlab platform.
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Characterising Localised Corrosion inhibition by means of parameters measured by an electrochemically integrated multielectrode array
Corrosion Engineering Science and Technology, 2013Co-Authors: Yongjun Tan, T. LiuAbstract:Electrochemical parameters including maximum anodic current density, total anodic current density, the number of anodic sites and the Localised Corrosion intensity index have been extracted from galvanic current distribution maps that were acquired using an electrochemically integrated multielectrode array, namely, the wire beam electrode. Experiments have been carried out to demonstrate the application of these new electrochemical parameters for characterising Localised Corrosion inhibition of metals. A typical Corrosion inhibitor, potassium dichromate, was found to affect Localised Corrosion processes in various ways, for instance in sodium chloride solutions, it was found to inhibit Localised Corrosion of aluminium alloy AA 2024-T3 by suppressing galvanic Corrosion activities occurring over the alloy surface, whereas it was found to control Localised Corrosion of AA 1100 by creating a large number of minor anodes distributing randomly over the metal surface.
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Quantifying the efficiency and understanding the mechanism of Localised Corrosion inhibition using the wire beam electrode
Materials and Corrosion, 2012Co-Authors: Yongjun Tan, Naing Naing AungAbstract:Parameters extracted from the wire beam electrode (WBE) galvanic current maps have been used in conjunction with electrochemical noise patterns to directly quantify the degree of Localised Corrosion inhibition provided by inhibitors and to understand the mechanism of Localised Corrosion inhibition. The behaviour of two traditional Localised Corrosion inhibitors has been assessed by their effects on the maximum anodic current density (imax), total anodic current density (itot), the number of anodic sites (Na) and the Localised Corrosion intensity index (LCII). Typical experiments are presented to illustrate the application of these parameters in providing useful information on the efficiency and mechanism of Localised Corrosion inhibition.
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An overview of Localised Corrosion inhibitor evaluation
2012Co-Authors: Yongjun Tan, Bruce Hinton, Maria ForsythAbstract:The use of Corrosion inhibitors is a flexible and economical option for Localised corro-sion control. Unfortunately some high performance traditional inhibitors are toxic or environmentally unacceptable. Various new approaches of designing environmentally friendly “greener” inhibitors have been reported in the literature; however the perfor-mance of inhibitors in preventing Localised forms of Corrosion are often not sufficiently evaluated. An obstacle in new inhibitor evaluation is technological difficulties associ-ated with the assessment of Localised Corrosion. It is a challenging task to design effective experiments that are able to assess not only the tendency, but also the rates and the distribution of Localised Corrosion. This paper provides an overview of some recent progress in methodologies for evaluating Localised Corrosion inhibitors.
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Evaluating Localised Corrosion intensity using the wire beam electrode
Corrosion Science, 2012Co-Authors: Yongjun Tan, Naing Naing Aung, Tie LiuAbstract:The intensity of Localised Corrosion of steel in the Evans solution has been evaluated by means of an electrochemically integrated multi-electrode array namely the wire beam electrode. A new parameter namely the Localised Corrosion intensity index (LCII) has been employed to quantify the degree of localisation of Corrosion and the effect of pH alteration on the intensity of Localised Corrosion. A major variation in the LCII has been found to indicate a change in Corrosion mechanism. In a typical experiment, the LCII dropped dramatically from approximately 1 to 0.02 when a pH modifier was added to the Evans solution, leading to the change of Corrosion mechanism from highly Localised pitting Corrosion to general or uniform Corrosion.
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Organic molecules showing the characteristics of Localised Corrosion aggravation and inhibition
Corrosion Science, 2011Co-Authors: Yongjun Tan, Mauro Mocerino, Tristan PatersonAbstract:Abstract The behaviour of imidazoline and an acid functionalised resorcinarene as steel Corrosion inhibitors in carbon dioxide (CO 2 )-saturated brine solutions has been studied using an electrochemically integrated multi-electrode array namely the wire beam electrode (WBE). Both imidazoline and resorcinarene acid provided excellent inhibition to general CO 2 Corrosion; however imidazoline was found to aggravate Localised Corrosion by creating a small number of major anodes that focused on a small area of the WBE surface, leading to highly concentrated anodic dissolution. The resorcinarene acid showed distinctively different behaviour by generating a large number of minor anodes randomly distributing over the WBE surface, leading to insignificant general anodic dissolution. These results indicate that resorcinarene acid provided effective Localised Corrosion inhibition by promoting a random distribution of insignificant anodic currents.
Tie Liu - One of the best experts on this subject based on the ideXlab platform.
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Evaluating Localised Corrosion intensity using the wire beam electrode
Corrosion Science, 2012Co-Authors: Yongjun Tan, Naing Naing Aung, Tie LiuAbstract:The intensity of Localised Corrosion of steel in the Evans solution has been evaluated by means of an electrochemically integrated multi-electrode array namely the wire beam electrode. A new parameter namely the Localised Corrosion intensity index (LCII) has been employed to quantify the degree of localisation of Corrosion and the effect of pH alteration on the intensity of Localised Corrosion. A major variation in the LCII has been found to indicate a change in Corrosion mechanism. In a typical experiment, the LCII dropped dramatically from approximately 1 to 0.02 when a pH modifier was added to the Evans solution, leading to the change of Corrosion mechanism from highly Localised pitting Corrosion to general or uniform Corrosion.
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Novel Corrosion experiments using the wire beam electrode. (I) Studying electrochemical noise signatures from Localised Corrosion processes
Corrosion Science, 2006Co-Authors: Yongjun Tan, Naing Naing Aung, Tie LiuAbstract:Abstract This series of papers presents four novel experiments that were designed to study Localised Corrosion phenomena using an electrochemically integrated multi-electrode array namely the wire beam electrode (WBE). This present paper reports a WBE based experimental method that has been employed, for the first time, to study electrochemical noise patterns (called noise signatures) from Localised Corrosion processes. The objective of this work is to demonstrate the applicability of the WBE for investigating the origin of spontaneous electrode potential/current fluctuations and their effects on electrochemical processes. The key strategy of this work is to apply the WBE in a novel experimental set-up to simultaneously measure electrode potential noise and WBE current distribution maps––an approach that allows the direct comparison and correlation of electrochemical noise and Corrosion events. Preliminary experiments have been carried out using a classic pitting Corrosion system: stainless steel in a solution containing FeCl 3 . A large number of anodic sites were found to exist on WBE surface at the very beginning of its exposure to the Corrosion environment. Correlation between characteristic patterns in electrode potential noise and Corrosion behaviour has been observed. More specifically, the characteristic sharp peaks in potential noise data (called noise signature I ) were found to correlate with the sudden disappearance of single unstable anode in WBE current distribution maps. The characteristic noise pattern of quick potential changes followed by partial or no recovery (called noise signature II ) was found to correspond with the massive disappearance of minor anodes in WBE current distribution maps. This result suggests that, in the Corrosion system under study, electrode noise activities were associated with the disappearance of minor anodic sites, which lead to the eventual disappearance of most anodic sites. Localised Corrosion was the result of the accelerated anodic dissolution of a small number of remaining anodic sites. The characteristics features in electrochemical noise and in WBE maps were reproducible.
Naing Naing Aung - One of the best experts on this subject based on the ideXlab platform.
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Quantifying the efficiency and understanding the mechanism of Localised Corrosion inhibition using the wire beam electrode
Materials and Corrosion, 2012Co-Authors: Yongjun Tan, Naing Naing AungAbstract:Parameters extracted from the wire beam electrode (WBE) galvanic current maps have been used in conjunction with electrochemical noise patterns to directly quantify the degree of Localised Corrosion inhibition provided by inhibitors and to understand the mechanism of Localised Corrosion inhibition. The behaviour of two traditional Localised Corrosion inhibitors has been assessed by their effects on the maximum anodic current density (imax), total anodic current density (itot), the number of anodic sites (Na) and the Localised Corrosion intensity index (LCII). Typical experiments are presented to illustrate the application of these parameters in providing useful information on the efficiency and mechanism of Localised Corrosion inhibition.
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Evaluating Localised Corrosion intensity using the wire beam electrode
Corrosion Science, 2012Co-Authors: Yongjun Tan, Naing Naing Aung, Tie LiuAbstract:The intensity of Localised Corrosion of steel in the Evans solution has been evaluated by means of an electrochemically integrated multi-electrode array namely the wire beam electrode. A new parameter namely the Localised Corrosion intensity index (LCII) has been employed to quantify the degree of localisation of Corrosion and the effect of pH alteration on the intensity of Localised Corrosion. A major variation in the LCII has been found to indicate a change in Corrosion mechanism. In a typical experiment, the LCII dropped dramatically from approximately 1 to 0.02 when a pH modifier was added to the Evans solution, leading to the change of Corrosion mechanism from highly Localised pitting Corrosion to general or uniform Corrosion.
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Monitoring Localised Corrosion in inhibited solutions using wire beam electrode–noise signatures method
Corrosion Engineering Science and Technology, 2006Co-Authors: Naing Naing Aung, Yongjun TanAbstract:Abstract The objective of this work is to determine the nature of Localised Corrosion in inhibited solutions by establishing possible relationships between characteristic features in electrochemical noise and Corrosion processes using an electrochemically integrated multielectrode system, namely the wire beam electrode (WBE) in combination with noise signatures method. Experiments have been carried out to simultaneously measure electrode potential noise and WBE current distribution maps from stainless steel (SS316L) WBE exposed to inhibited solutions containing 6%FeCl3 solution with inorganic inhibitors including 2 wt-% sodium chromate (Na2CrO4), cerium chloride (CeCl3) and lanthanum chloride (LaCl3). Characteristic electrochemical noise signatures were found to correlate with characteristic changes in WBE current distribution maps that show Corrosion rates distributions and the degree of Localised Corrosion. A new concept namely localisation parameter (LP) has been proposed to identify the degree of inhi...
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monitoring Localised Corrosion in inhibited solutions using wire beam electrode noise signatures method
Corrosion Engineering Science and Technology, 2006Co-Authors: Naing Naing Aung, Yongjun TanAbstract:Abstract The objective of this work is to determine the nature of Localised Corrosion in inhibited solutions by establishing possible relationships between characteristic features in electrochemical noise and Corrosion processes using an electrochemically integrated multielectrode system, namely the wire beam electrode (WBE) in combination with noise signatures method. Experiments have been carried out to simultaneously measure electrode potential noise and WBE current distribution maps from stainless steel (SS316L) WBE exposed to inhibited solutions containing 6%FeCl3 solution with inorganic inhibitors including 2 wt-% sodium chromate (Na2CrO4), cerium chloride (CeCl3) and lanthanum chloride (LaCl3). Characteristic electrochemical noise signatures were found to correlate with characteristic changes in WBE current distribution maps that show Corrosion rates distributions and the degree of Localised Corrosion. A new concept namely localisation parameter (LP) has been proposed to identify the degree of inhi...
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Novel Corrosion experiments using the wire beam electrode. (I) Studying electrochemical noise signatures from Localised Corrosion processes
Corrosion Science, 2006Co-Authors: Yongjun Tan, Naing Naing Aung, Tie LiuAbstract:Abstract This series of papers presents four novel experiments that were designed to study Localised Corrosion phenomena using an electrochemically integrated multi-electrode array namely the wire beam electrode (WBE). This present paper reports a WBE based experimental method that has been employed, for the first time, to study electrochemical noise patterns (called noise signatures) from Localised Corrosion processes. The objective of this work is to demonstrate the applicability of the WBE for investigating the origin of spontaneous electrode potential/current fluctuations and their effects on electrochemical processes. The key strategy of this work is to apply the WBE in a novel experimental set-up to simultaneously measure electrode potential noise and WBE current distribution maps––an approach that allows the direct comparison and correlation of electrochemical noise and Corrosion events. Preliminary experiments have been carried out using a classic pitting Corrosion system: stainless steel in a solution containing FeCl 3 . A large number of anodic sites were found to exist on WBE surface at the very beginning of its exposure to the Corrosion environment. Correlation between characteristic patterns in electrode potential noise and Corrosion behaviour has been observed. More specifically, the characteristic sharp peaks in potential noise data (called noise signature I ) were found to correlate with the sudden disappearance of single unstable anode in WBE current distribution maps. The characteristic noise pattern of quick potential changes followed by partial or no recovery (called noise signature II ) was found to correspond with the massive disappearance of minor anodes in WBE current distribution maps. This result suggests that, in the Corrosion system under study, electrode noise activities were associated with the disappearance of minor anodic sites, which lead to the eventual disappearance of most anodic sites. Localised Corrosion was the result of the accelerated anodic dissolution of a small number of remaining anodic sites. The characteristics features in electrochemical noise and in WBE maps were reproducible.
F J Perez - One of the best experts on this subject based on the ideXlab platform.
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sinergistic effect of ion implantation as a surface modification technique to improve Localised Corrosion of aisi 304 austenitic stainless steel
Surface & Coatings Technology, 2005Co-Authors: L Martinez, C Gomez, F J PerezAbstract:Abstract Ion implantation allows the formation of special alloys capable of slowing down the Corrosion process at the metal surface without alteration or sacrifice of the bulk properties. In this work, the effect on the Corrosion behaviour of silicon, nitrogen and argon ion implantation on AISI 304 is discussed where a 1×10 15 ions/cm 2 implantation dose at 80 keV was used. Silicon and nitrogen, as alloying elements, are known to improve the Localised Corrosion resistance of austenitic stainless steels in chloride media. Their effect as implanted elements has met different degrees of success depending on the implantation conditions. Argon implantation was also carried out to confirm whether the modifications produced on the materials behaviour are mainly due to the chemical effect of the implanted element or to the physical changes produced during the implantation process. Additionally, a multiple Si+N implantation was performed in the same conditions in order to find the response of this combination in the Corrosion resistance of AISI 304. Theoretical simulations using TRIM96 computer code have been performed to estimate the depth profiles of the implanted elements. The Corrosion measurements were carried out in NaCl solution by using Electrochemical Impedance Spectroscopy (EIS). The experimental results show that an improvement on the Corrosion behaviour of AISI 304 could be achieved in these conditions.
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Sinergistic effect of ion implantation as a surface modification technique to improve Localised Corrosion of AISI 304 austenitic stainless steel
Surface and Coatings Technology, 2005Co-Authors: L Martinez, C Gomez, F J PerezAbstract:Abstract Ion implantation allows the formation of special alloys capable of slowing down the Corrosion process at the metal surface without alteration or sacrifice of the bulk properties. In this work, the effect on the Corrosion behaviour of silicon, nitrogen and argon ion implantation on AISI 304 is discussed where a 1×10 15 ions/cm 2 implantation dose at 80 keV was used. Silicon and nitrogen, as alloying elements, are known to improve the Localised Corrosion resistance of austenitic stainless steels in chloride media. Their effect as implanted elements has met different degrees of success depending on the implantation conditions. Argon implantation was also carried out to confirm whether the modifications produced on the materials behaviour are mainly due to the chemical effect of the implanted element or to the physical changes produced during the implantation process. Additionally, a multiple Si+N implantation was performed in the same conditions in order to find the response of this combination in the Corrosion resistance of AISI 304. Theoretical simulations using TRIM96 computer code have been performed to estimate the depth profiles of the implanted elements. The Corrosion measurements were carried out in NaCl solution by using Electrochemical Impedance Spectroscopy (EIS). The experimental results show that an improvement on the Corrosion behaviour of AISI 304 could be achieved in these conditions.
Anne Neville - One of the best experts on this subject based on the ideXlab platform.
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Influence of a small velocity variation on the evolution of the Corrosion products and Corrosion behaviour of super 13Cr SS in a geothermal CO2 containing environment
Corrosion Science, 2021Co-Authors: Xiaoqi Yue, Anne Neville, Lei Zhang, Yong HuaAbstract:Abstract The general and Localised Corrosion of super 13Cr SS under various CO2 partial pressures (pCO2) in the static conditions and rotated speeds of 188 rpm at 200 °C were evaluated. The results show that super 13Cr SS exhibits lower Localised Corrosion risk at 188 rpm compared to the static conditions. The small velocity retards the Localised Corrosion through the formation of uniform Corrosion product scales, which mainly comprises nanocrystalline FeCr2O4 at 2.7 bar pCO2. A double-layered film consists of an inner layer of Cr(OH)3/undissolved austenite and an outer crystalline FeCO3 layer was observed at 28.5 bar pCO2.
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Performance evaluation of an imidazoline Corrosion inhibitor in a CO2-saturated environment with emphasis on Localised Corrosion
Corrosion Science, 2020Co-Authors: Amir Shamsa, Richard Barker, Yong Hua, Evgeny Barmatov, Trevor Hughes, Anne NevilleAbstract:Abstract The ability of an imidazoline inhibitor to provide Corrosion protection to X65 carbon steel in a CO2-saturated sodium chloride (NaCl) solution at 80oC was evaluated. The performance of the inhibitor was investigated with respect to both generalised and Localised Corrosion behaviour using in-situ electrochemical measurements, ex-situ scanning electron microscopy (SEM) and non-contact surface profilometry. We demonstrate that the optimum inhibitor concentration required to minimise generalised Corrosion is significantly lower than that required to minimise Localised Corrosion. This highlights the importance of systematic, post-test topographical measurements in the selection and optimisation of inhibitor dosage.
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effect of temperature on the critical water content for general and Localised Corrosion of x65 carbon steel in the transport of supercritical co2
International Journal of Greenhouse Gas Control, 2014Co-Authors: Richard Barker, Anne NevilleAbstract:Abstract An assessment of both the general and Localised Corrosion behaviour of X65 carbon steel in water-containing CO 2 environments representative of CO 2 transport in Carbon Capture and Storage (CCS) applications is presented. Autoclave experiments were conducted at a pressure of 80 bar and temperatures of 35 °C and 50 °C in environments where the CO 2 phase was either saturated or under-saturated with water. Such an approach enabled identification of the minimum water content for each system, below which no general or Localised attack was observed. At 50 °C in the water-saturated environment, material dissolution was Localised, with approximately only 10% of the surface showing signs of attack after 48 h immersion. In water-saturated tests at 35 °C after 48 h, almost the entire carbon steel surface showed signs of Corrosion and regions of more significant Localised attack were also visible. Iron carbonate (FeCO 3 ) was shown to precipitate onto the steel surface in both experiments, and appeared to offer better protection to the substrate at higher temperature due to the formation of a more extensive layer. In under-saturated tests at 50 °C, no Corrosion was observed at a water content below 1600 ppm, whilst small level of Corrosion were recorded with 300 ppm of water present at 35 °C. The results reflect that temperature drops within the system can promote Corrosion at lower water concentrations (on a molar basis) and that Localised Corrosion is a fundamental consideration in such systems.
