Abdulaziz Sindi, Hyeong Jin Kim, Igor A. Chaves, Jeom Kee Paik
In digital healthcare engineering (DHE) for aging monopile‐type offshore wind turbines, predictive health analysis is essential for robust future maintenance planning. This paper presents the development of a DHE module for the predictive health analysis of corroded monopile‐type offshore wind turbines, focusing on wind and rotor blade rotation effects. An empirical formula for predicting time‐variant corrosion wastage is derived from a statistical analysis of a decade‐long corrosion wastage database and applied to predict the corrosion depth of a 5 MW monopile‐type offshore wind turbine, serving as an illustrative example. Nonlinear finite element analyses using LS‐DYNA are performed on the corroded turbine tower under combined wind‐induced loads and rotor‐induced thrust forces. Two types of corrosion wastage, pitting, and uniform (general) corrosion, are considered. The health condition of the corroded tower is evaluated based on serviceability limit state and ultimate limit state criteria. The methodology developed in this paper will be integrated into the DHE system currently being developed by the authors for aging monopile‐type offshore wind turbines.
在针对老化单桩式海上风力涡轮机的数字保健工程（DHE）中，预测性健康分析对于制定稳健的未来维护计划至关重要。本文介绍了针对腐蚀单桩式海上风力涡轮机预测性健康分析的 DHE 模块的开发情况，重点关注风力和转子叶片旋转效应。通过对长达十年的腐蚀损耗数据库进行统计分析，得出了预测时变腐蚀损耗的经验公式，并将其应用于预测 5 兆瓦单桩式海上风力涡轮机的腐蚀深度，以此作为示例。使用 LS-DYNA 对腐蚀的涡轮机塔架进行了风致载荷和转子推力联合作用下的非线性有限元分析。分析中考虑了点蚀和均匀（一般）腐蚀两种类型的腐蚀损耗。腐蚀塔的健康状况根据适用性极限状态和极限状态标准进行评估。本文开发的方法将集成到作者目前正在开发的 DHE 系统中，用于老化的单桩式海上风力涡轮机。
{"title":"Effect of Corrosion Wastage on the Limit States of Monopile‐Type Offshore Wind Turbines Under Combined Wind and Rotor Blade Rotation","authors":"Abdulaziz Sindi, Hyeong Jin Kim, Igor A. Chaves, Jeom Kee Paik","doi":"10.1002/maco.202414378","DOIUrl":"https://doi.org/10.1002/maco.202414378","url":null,"abstract":"In digital healthcare engineering (DHE) for aging monopile‐type offshore wind turbines, predictive health analysis is essential for robust future maintenance planning. This paper presents the development of a DHE module for the predictive health analysis of corroded monopile‐type offshore wind turbines, focusing on wind and rotor blade rotation effects. An empirical formula for predicting time‐variant corrosion wastage is derived from a statistical analysis of a decade‐long corrosion wastage database and applied to predict the corrosion depth of a 5 MW monopile‐type offshore wind turbine, serving as an illustrative example. Nonlinear finite element analyses using LS‐DYNA are performed on the corroded turbine tower under combined wind‐induced loads and rotor‐induced thrust forces. Two types of corrosion wastage, pitting, and uniform (general) corrosion, are considered. The health condition of the corroded tower is evaluated based on serviceability limit state and ultimate limit state criteria. The methodology developed in this paper will be integrated into the DHE system currently being developed by the authors for aging monopile‐type offshore wind turbines.","PeriodicalId":18223,"journal":{"name":"Materials and Corrosion","volume":"16 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142180248","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Soroosh Hakimian, Abdel‐Hakim Bouzid, Lucas A. Hof
Bolted flanged joints play a critical role in offshore wind turbine tower structures, serving as integral components that connect various sections of the tower. This research study employs electrochemical techniques to investigate the effect of gap dimensions, which determine the crevice gap thickness and crevice depth, on corrosion behavior of 321 stainless steel flange sample plates in a 3.5 wt% NaCl solution at 50°C. Gaskets are used in this study to create gaps between two flange surfaces. A novel fixture is utilized to simulate the applied stress on the gasket, fluid flow within the fixture, and the geometric aspects of the gasket and flange. The findings reveal that increasing the gap thickness from 1.58 to 6.35 mm results in a rise in the general corrosion rate of the flange surface from 0.09 to 1.03 mm y−1, and crevice corrosion initiation time increases from 0.23 to 3.12 h. Furthermore, reducing the crevice depth (d) from 7.49 to 0 mm leads to a decrease in the general corrosion rate from 0.09 mm y−1 to 0.04 µm y−1, and cases with d = 3.81 and d = 0 mm show no observable crevice corrosion after potentiostatic tests.
螺栓法兰连接在海上风力涡轮机塔架结构中起着至关重要的作用，是连接塔架各部分的不可或缺的部件。本研究采用电化学技术来调查缝隙尺寸（决定缝隙厚度和缝隙深度）对 321 不锈钢法兰样板在 50°C 的 3.5 wt% 氯化钠溶液中的腐蚀行为的影响。本研究使用垫片在两个法兰表面之间形成缝隙。利用一种新型夹具来模拟垫片上的外加应力、夹具内的流体流动以及垫片和法兰的几何特性。研究结果表明，将缝隙厚度从 1.58 毫米增加到 6.35 毫米会导致法兰表面的总体腐蚀速率从 0.09 mm y-1 增加到 1.03 mm y-1，缝隙腐蚀开始时间从 0.23 小时增加到 3.12 小时。此外，将缝隙深度 (d) 从 7.49 mm 减小到 0 mm 会导致总体腐蚀速率从 0.09 mm y-1 降至 0.04 µm y-1，而 d = 3.81 和 d = 0 mm 的情况在恒电位测试后没有观察到缝隙腐蚀。
{"title":"Effect of gap size on flange face corrosion","authors":"Soroosh Hakimian, Abdel‐Hakim Bouzid, Lucas A. Hof","doi":"10.1002/maco.202414367","DOIUrl":"https://doi.org/10.1002/maco.202414367","url":null,"abstract":"Bolted flanged joints play a critical role in offshore wind turbine tower structures, serving as integral components that connect various sections of the tower. This research study employs electrochemical techniques to investigate the effect of gap dimensions, which determine the crevice gap thickness and crevice depth, on corrosion behavior of 321 stainless steel flange sample plates in a 3.5 wt% NaCl solution at 50°C. Gaskets are used in this study to create gaps between two flange surfaces. A novel fixture is utilized to simulate the applied stress on the gasket, fluid flow within the fixture, and the geometric aspects of the gasket and flange. The findings reveal that increasing the gap thickness from 1.58 to 6.35 mm results in a rise in the general corrosion rate of the flange surface from 0.09 to 1.03 mm y<jats:sup>−1</jats:sup>, and crevice corrosion initiation time increases from 0.23 to 3.12 h. Furthermore, reducing the crevice depth (<jats:italic>d</jats:italic>) from 7.49 to 0 mm leads to a decrease in the general corrosion rate from 0.09 mm y<jats:sup>−1</jats:sup> to 0.04 µm y<jats:sup>−1</jats:sup>, and cases with <jats:italic>d</jats:italic> = 3.81 and <jats:italic>d</jats:italic> = 0 mm show no observable crevice corrosion after potentiostatic tests.","PeriodicalId":18223,"journal":{"name":"Materials and Corrosion","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-04-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140602371","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ole Øystein Knudsen, Eystein Vada, Waldemar Krieger, Jan Bertram, Ivana Jevremovic, Håvard Wilson
Cathodic protection of various 6000 aluminium alloys and variants of EN AW‐5083 in seawater has been studied. The alloys were immersed in seawater and polarized to about −1.06 V versus Ag/AgCl for 1 year. The cathodic current density increased initially due to formation of a copper film on the surface, but the effect was temporary. After 200 days, the current demand for cathodic protection had stabilized on all the investigated alloys at 0 to about 20 mA/m2, depending on the Fe/Si ratio in the alloy. Depending on the content of noble intermetallic particles, the aluminium will corrode at a low and constant rate. Application of a coating on the aluminium will decrease the cathodic current demand for cathodic protection significantly. Coatings on submerged aluminium are very stable and not susceptible to degradation mechanisms like cathodic disbonding.
{"title":"Cathodic protection of aluminium in seawater","authors":"Ole Øystein Knudsen, Eystein Vada, Waldemar Krieger, Jan Bertram, Ivana Jevremovic, Håvard Wilson","doi":"10.1002/maco.202314229","DOIUrl":"https://doi.org/10.1002/maco.202314229","url":null,"abstract":"Cathodic protection of various 6000 aluminium alloys and variants of EN AW‐5083 in seawater has been studied. The alloys were immersed in seawater and polarized to about −1.06 V versus Ag/AgCl for 1 year. The cathodic current density increased initially due to formation of a copper film on the surface, but the effect was temporary. After 200 days, the current demand for cathodic protection had stabilized on all the investigated alloys at 0 to about 20 mA/m<jats:sup>2</jats:sup>, depending on the Fe/Si ratio in the alloy. Depending on the content of noble intermetallic particles, the aluminium will corrode at a low and constant rate. Application of a coating on the aluminium will decrease the cathodic current demand for cathodic protection significantly. Coatings on submerged aluminium are very stable and not susceptible to degradation mechanisms like cathodic disbonding.","PeriodicalId":18223,"journal":{"name":"Materials and Corrosion","volume":"43 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140312013","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Rob E. Melchers, Robert Jeffrey, Igor A. Chaves, Robert B. Petersen
Physical infrastructure in coastal and offshore locations often is constructed from mild and low alloy steels. These are prone to marine corrosion even with the application of protective coatings and cathodic protection. Particularly for high‐value assets such as energy facilities (wind farms, oil and gas production and subsea pipelines), the prediction of their safe and economic life is of much interest. Herein, a review is given of the modern development of models for the prediction of long‐term marine corrosion of steel exposed to various marine environments. These include immersion, tidal, splash and atmospheric zones and contact with sands and soils. The effects of temperature and water pollution are especially important, as is the ability of the steels or irons to form protective corrosion products. Comments are made also about other alloys such as copper‐nickels and aluminium. All show that corrosion, including pitting corrosion, develops with increased exposure time in a bimodal manner. The reasons for such behaviour are considered, together with the practical implications, important for containment structures such as pipelines, tanks and floating offshore energy platforms.
{"title":"Predicting corrosion for life estimation of ocean and coastal steel infrastructure","authors":"Rob E. Melchers, Robert Jeffrey, Igor A. Chaves, Robert B. Petersen","doi":"10.1002/maco.202314201","DOIUrl":"https://doi.org/10.1002/maco.202314201","url":null,"abstract":"Physical infrastructure in coastal and offshore locations often is constructed from mild and low alloy steels. These are prone to marine corrosion even with the application of protective coatings and cathodic protection. Particularly for high‐value assets such as energy facilities (wind farms, oil and gas production and subsea pipelines), the prediction of their safe and economic life is of much interest. Herein, a review is given of the modern development of models for the prediction of long‐term marine corrosion of steel exposed to various marine environments. These include immersion, tidal, splash and atmospheric zones and contact with sands and soils. The effects of temperature and water pollution are especially important, as is the ability of the steels or irons to form protective corrosion products. Comments are made also about other alloys such as copper‐nickels and aluminium. All show that corrosion, including pitting corrosion, develops with increased exposure time in a bimodal manner. The reasons for such behaviour are considered, together with the practical implications, important for containment structures such as pipelines, tanks and floating offshore energy platforms.","PeriodicalId":18223,"journal":{"name":"Materials and Corrosion","volume":"26 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140311943","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Michael Irmer, Daniel Kelm, Tom Marquardt, Andreas W. Momber, K. Eiben, Sascha Buchbach
The application of multilayer organic protective coating systems with conventional liquid spray methods is complex, time‐ and energy‐consuming, and it requires extensive technical equipment. An alternative to these methods is the application of thin, self‐adherent foil systems directly to the steel substrate. The corrosion protection performance of newly developed foil systems was tested for various combinations of foil materials and pressure‐sensitive adhesives (with and without corrosion inhibitors) and different surface preparation parameters by means of accelerated cyclic laboratory tests with simulated offshore conditions. The adhesion properties were determined by means of peel tests. The tests were designed, by means of statistical methods (design of experiments, analysis of variance). A foil system with the following factor combination was found to provide an optimum performance: Surface preparation grade: Sa 2½; roughness: Rz = 50–75 µm; abrasive material: high‐carbon steel grit; adhesive layer thickness: 200 g/m2; inhibitor material: calcium aluminum polyphosphate silicate hydrate; foil material: polyvinylchloride (160 µm) + poly(methyl methacrylate) (40 µm).
{"title":"The performance of a self‐adherent foil system for the corrosion protection of steel substrates for offshore wind tower structures","authors":"Michael Irmer, Daniel Kelm, Tom Marquardt, Andreas W. Momber, K. Eiben, Sascha Buchbach","doi":"10.1002/maco.202314218","DOIUrl":"https://doi.org/10.1002/maco.202314218","url":null,"abstract":"The application of multilayer organic protective coating systems with conventional liquid spray methods is complex, time‐ and energy‐consuming, and it requires extensive technical equipment. An alternative to these methods is the application of thin, self‐adherent foil systems directly to the steel substrate. The corrosion protection performance of newly developed foil systems was tested for various combinations of foil materials and pressure‐sensitive adhesives (with and without corrosion inhibitors) and different surface preparation parameters by means of accelerated cyclic laboratory tests with simulated offshore conditions. The adhesion properties were determined by means of peel tests. The tests were designed, by means of statistical methods (design of experiments, analysis of variance). A foil system with the following factor combination was found to provide an optimum performance: Surface preparation grade: Sa 2½; roughness: Rz = 50–75 µm; abrasive material: high‐carbon steel grit; adhesive layer thickness: 200 g/m<jats:sup>2</jats:sup>; inhibitor material: calcium aluminum polyphosphate silicate hydrate; foil material: polyvinylchloride (160 µm) + poly(methyl methacrylate) (40 µm).","PeriodicalId":18223,"journal":{"name":"Materials and Corrosion","volume":"96 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140150185","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Corrosion degradation significantly contributes to the deterioration of offshore structures and subsea installations, impacting the durability of technology equipment while potentially leading to structural failure and environmental pollution. This review primarily focuses on the various types of corrosion observed in offshore structures, the factors influencing corrosion, and the resulting degradation of mechanical properties following corrosion exposure. The study examines the deterioration patterns in tensile properties of offshore structures and subsea facilities, along with the assessment and analysis of corrosion in offshore steel bridges and submarine pipelines. Future research should include a comprehensive scientific investigation of corrosion mechanisms and the development of engineering predictive models to assess corrosion failure and extend the remaining life of offshore structures.
{"title":"Deterioration of marine offshore structures and subsea installations subjected to severely corrosive environment: A review","authors":"Ruilin Xia, Chen Jia, Yordan Garbatov","doi":"10.1002/maco.202314050","DOIUrl":"https://doi.org/10.1002/maco.202314050","url":null,"abstract":"Corrosion degradation significantly contributes to the deterioration of offshore structures and subsea installations, impacting the durability of technology equipment while potentially leading to structural failure and environmental pollution. This review primarily focuses on the various types of corrosion observed in offshore structures, the factors influencing corrosion, and the resulting degradation of mechanical properties following corrosion exposure. The study examines the deterioration patterns in tensile properties of offshore structures and subsea facilities, along with the assessment and analysis of corrosion in offshore steel bridges and submarine pipelines. Future research should include a comprehensive scientific investigation of corrosion mechanisms and the development of engineering predictive models to assess corrosion failure and extend the remaining life of offshore structures.","PeriodicalId":18223,"journal":{"name":"Materials and Corrosion","volume":"17 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139756849","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Akhil Varghese, Miguel Arana‐Catania, S. Mori, A. Encinas-Oropesa, Joy Sumner
Gas turbine superalloys experience hot corrosion, driven by factors including corrosive deposit flux, temperature, gas composition, and component material. The full mechanism still needs clarification and research often focuses on laboratory work. As such, there is interest in causal discovery to confirm the significance of factors and identify potential missing causal relationships or codependencies between these factors. The causal discovery algorithm fast causal inference (FCI) has been trialled on a small set of laboratory data, with the outputs evaluated for their significance to corrosion propagation, and compared to existing mechanistic understanding. FCI identified salt deposition flux as the most influential corrosion variable for this limited data set. However, HCl was the second most influential for pitting regions, compared to temperature for more uniformly corroding regions. Thus, FCI generated causal links aligned with literature from a randomised corrosion data set, while also identifying the presence of two different degradation modes in operation.
{"title":"Causal discovery to understand hot corrosion","authors":"Akhil Varghese, Miguel Arana‐Catania, S. Mori, A. Encinas-Oropesa, Joy Sumner","doi":"10.1002/maco.202314240","DOIUrl":"https://doi.org/10.1002/maco.202314240","url":null,"abstract":"Gas turbine superalloys experience hot corrosion, driven by factors including corrosive deposit flux, temperature, gas composition, and component material. The full mechanism still needs clarification and research often focuses on laboratory work. As such, there is interest in causal discovery to confirm the significance of factors and identify potential missing causal relationships or codependencies between these factors. The causal discovery algorithm fast causal inference (FCI) has been trialled on a small set of laboratory data, with the outputs evaluated for their significance to corrosion propagation, and compared to existing mechanistic understanding. FCI identified salt deposition flux as the most influential corrosion variable for this limited data set. However, HCl was the second most influential for pitting regions, compared to temperature for more uniformly corroding regions. Thus, FCI generated causal links aligned with literature from a randomised corrosion data set, while also identifying the presence of two different degradation modes in operation.","PeriodicalId":18223,"journal":{"name":"Materials and Corrosion","volume":"133 9","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139842993","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"EVENTS","authors":"","doi":"10.1002/maco.202470034","DOIUrl":"https://doi.org/10.1002/maco.202470034","url":null,"abstract":"","PeriodicalId":18223,"journal":{"name":"Materials and Corrosion","volume":"47 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139847844","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Carbonation‐induced corrosion of steel in concrete can allow for premature degradation of structures. Corrosion probes in health monitoring systems can assess concrete carbonation and steel corrosion rates. The electrochemical noise (EN) technique has advantages for corrosion sensing. Instrumented concrete columns were fitted with a carbonation chamber for accelerated testing. EN was assessed through statistical evaluation of noise time signatures, noise resistance, and spectral analysis. The mean noise potential for the electrodes showed electronegative potential and correspondingly high rms noise current, indicative of corrosion activation in carbonated concrete. The estimated corrosion rates obtained from the noise impedance were comparable to those resolved from the polarization resistance and noise resistance. The shot noise analysis indicated isolated spontaneous noise events associated with the activation of local steel anodes. The outcomes of the testing indicate that the placement of low‐cost sensors and passive EN measurements can be used to monitor the onset of carbonation‐induced corrosion of steel in concrete and provide estimates on corrosion rates.
混凝土中碳化引起的钢材腐蚀会导致结构过早退化。健康监测系统中的腐蚀探头可以评估混凝土碳化和钢材腐蚀率。电化学噪声（EN）技术在腐蚀传感方面具有优势。带仪器的混凝土柱安装了一个碳化室，用于加速测试。通过对噪声时间特征、噪声阻抗和频谱分析的统计评估，对 EN 进行了评估。电极的平均噪声电位显示出电负电位和相应的高均方根噪声电流，表明碳化混凝土中的腐蚀活化。噪声阻抗得出的估计腐蚀率与极化电阻和噪声阻抗得出的腐蚀率相当。射击噪声分析表明，孤立的自发噪声事件与局部钢阳极的活化有关。测试结果表明，放置低成本传感器和被动 EN 测量可用于监测混凝土中钢材碳化诱导腐蚀的开始，并提供腐蚀率估计值。
{"title":"Identification of carbonation‐induced corrosion of steel in concrete by electrochemical testing","authors":"Samanbar Permeh, K. Lau","doi":"10.1002/maco.202414272","DOIUrl":"https://doi.org/10.1002/maco.202414272","url":null,"abstract":"Carbonation‐induced corrosion of steel in concrete can allow for premature degradation of structures. Corrosion probes in health monitoring systems can assess concrete carbonation and steel corrosion rates. The electrochemical noise (EN) technique has advantages for corrosion sensing. Instrumented concrete columns were fitted with a carbonation chamber for accelerated testing. EN was assessed through statistical evaluation of noise time signatures, noise resistance, and spectral analysis. The mean noise potential for the electrodes showed electronegative potential and correspondingly high rms noise current, indicative of corrosion activation in carbonated concrete. The estimated corrosion rates obtained from the noise impedance were comparable to those resolved from the polarization resistance and noise resistance. The shot noise analysis indicated isolated spontaneous noise events associated with the activation of local steel anodes. The outcomes of the testing indicate that the placement of low‐cost sensors and passive EN measurements can be used to monitor the onset of carbonation‐induced corrosion of steel in concrete and provide estimates on corrosion rates.","PeriodicalId":18223,"journal":{"name":"Materials and Corrosion","volume":"37 9-10","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139853494","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Hélène Lotz, D. Neff, F. Mercier‐Bion, C. Bataillon, Nicolas Nuns, P. Dillmann
A two‐step corrosion experiment was performed on a ferritic steel (Armco) in a synthetic solution representing the Callovo–Oxfordian at 120°C. After the development of a carbonated corrosion product layer (CPL) during the first 15 days of the experimental step, corrosion front progression was investigated using 13C marked carbonate species during the second 15 days experimental step. CPL was characterized at each step, in terms of morphology (scanning electron microscopy), composition (energy‐dispersive spectroscopy), and structure (µ‐Raman). 13C corrosion product locations were analyzed by time‐of‐flight secondary ion mass spectrometry. Results evidenced that after a step of generalized corrosion, iron corrosion continues locally at the metal/CPL interface. These results suggest that although a protective siderite layer formed on the iron surface after 15 days, a local dissolution of the carbonate layer at the M/CPL interface occurred. A galvanic effect is developed between the bared surface (anode) and the covered one (cathode). This activates iron oxidation. The precipitation of carbonate corrosion products to the metal/CPL interface is possible by the diffusion of 13CO32− ions from the bulk through the siderite layer.
{"title":"13C isotopic labeling to decipher the iron corrosion mechanisms in a carbonated anoxic environment","authors":"Hélène Lotz, D. Neff, F. Mercier‐Bion, C. Bataillon, Nicolas Nuns, P. Dillmann","doi":"10.1002/maco.202314203","DOIUrl":"https://doi.org/10.1002/maco.202314203","url":null,"abstract":"A two‐step corrosion experiment was performed on a ferritic steel (Armco) in a synthetic solution representing the Callovo–Oxfordian at 120°C. After the development of a carbonated corrosion product layer (CPL) during the first 15 days of the experimental step, corrosion front progression was investigated using 13C marked carbonate species during the second 15 days experimental step. CPL was characterized at each step, in terms of morphology (scanning electron microscopy), composition (energy‐dispersive spectroscopy), and structure (µ‐Raman). 13C corrosion product locations were analyzed by time‐of‐flight secondary ion mass spectrometry. Results evidenced that after a step of generalized corrosion, iron corrosion continues locally at the metal/CPL interface. These results suggest that although a protective siderite layer formed on the iron surface after 15 days, a local dissolution of the carbonate layer at the M/CPL interface occurred. A galvanic effect is developed between the bared surface (anode) and the covered one (cathode). This activates iron oxidation. The precipitation of carbonate corrosion products to the metal/CPL interface is possible by the diffusion of 13CO32− ions from the bulk through the siderite layer.","PeriodicalId":18223,"journal":{"name":"Materials and Corrosion","volume":"2 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139860651","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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