Using polarization curve scanning, electrochemical impedance spectroscopy, macroscopic morphology observation, scanning electron microscope, X‐ray diffraction (XRD), and energy dispersive spectroscopy (EDS), the corrosion regulars of connectors were investigated. A galvanic corrosion simulation model of aluminum‐titanium rivets was established by electrochemical experimental parameters as boundary conditions. The results showed that the galvanic couple connection accelerated the corrosion significantly. XRD and EDS results show that the main corrosion products are Al2O3, Al(OH)3. The corrosion potential of riveted parts decreased from the riveting point to both sides, ranging from −0.664 to −0.655 V. The corrosion current density decreases along both sides, and the corrosion current density at the most edge is 0.0113 A/m2. The results of numerical simulation indicate that the model effectively predicted the galvanic corrosion behavior of aluminum‐titanium rivets.
利用极化曲线扫描、电化学阻抗光谱、宏观形貌观察、扫描电子显微镜、X 射线衍射（XRD）和能量色散光谱（EDS）研究了连接器的腐蚀规律。以电化学实验参数为边界条件，建立了铝钛铆钉的电化学腐蚀模拟模型。结果表明，电偶连接明显加速了腐蚀。铆接部件的腐蚀电位从铆接点向两侧下降，从-0.664 V 到-0.655 V；腐蚀电流密度沿两侧减小，最边缘处的腐蚀电流密度为 0.0113 A/m2。数值模拟结果表明，该模型有效地预测了铝钛铆钉的电化学腐蚀行为。
{"title":"Exploring the galvanic corrosion behavior of 6061 aluminum alloy: TA1 titanium alloy based on finite element simulation","authors":"Xinyang Li, Junkai Zhang, Lei Li, Wenjia Wang, Guocheng Xu, Zhonglin Hou","doi":"10.1002/maco.202414469","DOIUrl":"https://doi.org/10.1002/maco.202414469","url":null,"abstract":"Using polarization curve scanning, electrochemical impedance spectroscopy, macroscopic morphology observation, scanning electron microscope, X‐ray diffraction (XRD), and energy dispersive spectroscopy (EDS), the corrosion regulars of connectors were investigated. A galvanic corrosion simulation model of aluminum‐titanium rivets was established by electrochemical experimental parameters as boundary conditions. The results showed that the galvanic couple connection accelerated the corrosion significantly. XRD and EDS results show that the main corrosion products are Al<jats:sub>2</jats:sub>O<jats:sub>3,</jats:sub> Al(OH)<jats:sub>3</jats:sub>. The corrosion potential of riveted parts decreased from the riveting point to both sides, ranging from −0.664 to −0.655 V. The corrosion current density decreases along both sides, and the corrosion current density at the most edge is 0.0113 A/m<jats:sup>2</jats:sup>. The results of numerical simulation indicate that the model effectively predicted the galvanic corrosion behavior of aluminum‐titanium rivets.","PeriodicalId":18223,"journal":{"name":"Materials and Corrosion","volume":"111 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142180252","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}
The hot dip aluminized ASTM 1035 steels (Al‐coated steel) underwent anodic oxidization, and various thicknesses of Al2O3 coating were applied to the surface of the Al‐coated steels (Al–Al2O3‐coated steel). The corrosion resistance of the Al–Al2O3‐coated steel was investigated using potentiodynamic tests, electrochemical impedance spectroscopy tests and measurement of galvanic current density in a bimetallic cell. It was found that the anodic oxidation resulted in the formation of a porous Al2O3 coating on the surface of the Al‐coated steel, improving both its corrosion resistance and galvanic corrosion resistance when coupled with carbon fiber reinforced nylon 6 composite (Cf/PA6). Silane treatment effectively sealed the pores within the Al2O3 coating, resulting in improved corrosion protection for Al–Al2O3‐coated steel due to the exceptional insulation, impermeability and hydrophobic properties of silane coating. Compared to the Al‐coated steel/carbon fiber reinforced polymer (CFRP) couple and Al–Al2O3‐coated steel/CFRP couple, stable galvanic current density decreased by approximately 75% and 45%, respectively.
{"title":"Corrosion protection investigations of oxide‐silane composite coating on hot dip aluminized steel","authors":"Zhong‐Xia Liu, Lei Shi, Ai‐Yun Jiang, Jian‐Xiu Liu, Bao‐Feng Zhang, Ya‐Jun Zhou, Guo‐Peng Zhang","doi":"10.1002/maco.202414506","DOIUrl":"https://doi.org/10.1002/maco.202414506","url":null,"abstract":"The hot dip aluminized ASTM 1035 steels (Al‐coated steel) underwent anodic oxidization, and various thicknesses of Al<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub> coating were applied to the surface of the Al‐coated steels (Al–Al<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub>‐coated steel). The corrosion resistance of the Al–Al<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub>‐coated steel was investigated using potentiodynamic tests, electrochemical impedance spectroscopy tests and measurement of galvanic current density in a bimetallic cell. It was found that the anodic oxidation resulted in the formation of a porous Al<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub> coating on the surface of the Al‐coated steel, improving both its corrosion resistance and galvanic corrosion resistance when coupled with carbon fiber reinforced nylon 6 composite (C<jats:sub>f</jats:sub>/PA6). Silane treatment effectively sealed the pores within the Al<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub> coating, resulting in improved corrosion protection for Al–Al<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub>‐coated steel due to the exceptional insulation, impermeability and hydrophobic properties of silane coating. Compared to the Al‐coated steel/carbon fiber reinforced polymer (CFRP) couple and Al–Al<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub>‐coated steel/CFRP couple, stable galvanic current density decreased by approximately 75% and 45%, respectively.","PeriodicalId":18223,"journal":{"name":"Materials and Corrosion","volume":"31 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-08-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142180254","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}
Kateřina Kolomá, Václava Havlová, Anna Pecková, Šárka Šachlová, Vlastislav Kašpar, Diana Tkachenok, Alžběta Danielisová, Drahomíra Malyková, Helena Březinová, Ludmila Barčáková, Saqib Mukhtar, Richard Bureš, Jan Stoulil
This work focuses on archaeological analogues as a way of obtaining long‐term data for assessing the lifetime of a spent nuclear fuel canister. An analysis of the environment around the excavated artefacts is presented, followed by geochemical modelling of the likely corrosion products and subsequent comparison with real phases in the corrosion layer estimated by X‐ray diffraction. A total of 16 archaeological sites with fine clay soils and the potential for long‐term flooding were evaluated. Although the soil pore solution contained high levels of silicates, no such phases with iron in the corrosion products were confirmed. Carbonate corrosion products, typical of bentonite environments, were also not observed. Although oxygen access is very limited in the environments of all sites, even low concentrations shifted the equilibrium of corrosion products formed in favour of (hydroxy)oxides.
这项工作的重点是通过考古模拟来获取评估乏核燃料罐寿命的长期数据。对出土文物周围的环境进行了分析，随后对可能的腐蚀产物进行了地球化学建模，并与通过 X 射线衍射估算的腐蚀层中的实际相进行了比较。共对 16 个考古遗址进行了评估，这些遗址的土壤为细粘土，有可能长期被水淹没。虽然土壤孔隙溶液中含有大量硅酸盐，但没有在腐蚀产物中发现铁相。也没有观察到膨润土环境中典型的碳酸盐腐蚀产物。虽然在所有地点的环境中氧气的获取都非常有限，但即使是低浓度的氧气也会使形成的腐蚀产物的平衡向（羟基）氧化物倾斜。
{"title":"Archaeological analogues for the lifetime prediction of the canister for spent nuclear fuel in the deep geological repository: Part I. Composition of pore water and corrosion products","authors":"Kateřina Kolomá, Václava Havlová, Anna Pecková, Šárka Šachlová, Vlastislav Kašpar, Diana Tkachenok, Alžběta Danielisová, Drahomíra Malyková, Helena Březinová, Ludmila Barčáková, Saqib Mukhtar, Richard Bureš, Jan Stoulil","doi":"10.1002/maco.202414516","DOIUrl":"https://doi.org/10.1002/maco.202414516","url":null,"abstract":"This work focuses on archaeological analogues as a way of obtaining long‐term data for assessing the lifetime of a spent nuclear fuel canister. An analysis of the environment around the excavated artefacts is presented, followed by geochemical modelling of the likely corrosion products and subsequent comparison with real phases in the corrosion layer estimated by X‐ray diffraction. A total of 16 archaeological sites with fine clay soils and the potential for long‐term flooding were evaluated. Although the soil pore solution contained high levels of silicates, no such phases with iron in the corrosion products were confirmed. Carbonate corrosion products, typical of bentonite environments, were also not observed. Although oxygen access is very limited in the environments of all sites, even low concentrations shifted the equilibrium of corrosion products formed in favour of (hydroxy)oxides.","PeriodicalId":18223,"journal":{"name":"Materials and Corrosion","volume":"41 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141784166","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}
Isehaq Al‐Nafai, Katarzyna Rzeszutek, Stuart Lyon, Christopher Jones, Douglas Beaumont
Novel sacrificial zinc‐rich organic coatings, with varying additions of aluminium, were prepared and tested for anticorrosion performance. Electrochemical measurements (potential vs. time and electrochemical impedance spectroscopy) were carried out to investigate cathodic protection and barrier performance while neutral salt spray and immersion experiments tested long‐term performance. Analytical scanning electron microscopy and X‐ray diffraction were used to characterize coatings before and after testing. Formulations containing aluminium significantly outperformed the standard 100% zinc‐rich coating with the greatest improvement occurring at 10%–15% aluminium by volume in the dry film. This improvement was caused by the dispersal of aluminium between zinc particles, which improved packing and enabled greater efficiency in zinc consumption resulting in extended galvanic protection times for steel substrates. The expected zinc corrosion product (basic zinc chloride, simonkolleite) was present within the coating as well as a Zn–Al layered doubled hydroxide. The latter's presence demonstrates that dissolution of aluminium contributed to the longevity of the galvanic action. The new Zn–Al formulations are extremely promising alternatives to standard zinc‐rich epoxy coatings, significantly reducing zinc loading and increasing the sacrificial lifetime.
制备并测试了不同铝添加量的新型牺牲性富锌有机涂层的防腐性能。电化学测量（电位与时间的关系和电化学阻抗光谱）用于研究阴极保护和阻挡性能，而中性盐雾和浸泡实验则用于测试长期性能。分析扫描电子显微镜和 X 射线衍射被用来描述测试前后涂层的特征。含铝配方的性能明显优于标准的 100% 富锌涂层，干膜中铝的体积分数为 10%-15%时，性能改善最大。这种改进是由于铝分散在锌颗粒之间，从而改善了填料，提高了锌的消耗效率，延长了钢基材的电化学保护时间。涂层中出现了预期的锌腐蚀产物（碱式氯化锌，simonkolleite）以及锌铝层状双氢氧化物。后者的存在表明，铝的溶解有助于延长电化学作用的寿命。新型锌-铝配方是标准富锌环氧涂层的极有前途的替代品，可显著降低锌负荷并延长牺牲寿命。
{"title":"How aluminium additions improve the performance of zinc‐rich organic coatings","authors":"Isehaq Al‐Nafai, Katarzyna Rzeszutek, Stuart Lyon, Christopher Jones, Douglas Beaumont","doi":"10.1002/maco.202414529","DOIUrl":"https://doi.org/10.1002/maco.202414529","url":null,"abstract":"Novel sacrificial zinc‐rich organic coatings, with varying additions of aluminium, were prepared and tested for anticorrosion performance. Electrochemical measurements (potential vs. time and electrochemical impedance spectroscopy) were carried out to investigate cathodic protection and barrier performance while neutral salt spray and immersion experiments tested long‐term performance. Analytical scanning electron microscopy and X‐ray diffraction were used to characterize coatings before and after testing. Formulations containing aluminium significantly outperformed the standard 100% zinc‐rich coating with the greatest improvement occurring at 10%–15% aluminium by volume in the dry film. This improvement was caused by the dispersal of aluminium between zinc particles, which improved packing and enabled greater efficiency in zinc consumption resulting in extended galvanic protection times for steel substrates. The expected zinc corrosion product (basic zinc chloride, simonkolleite) was present within the coating as well as a Zn–Al layered doubled hydroxide. The latter's presence demonstrates that dissolution of aluminium contributed to the longevity of the galvanic action. The new Zn–Al formulations are extremely promising alternatives to standard zinc‐rich epoxy coatings, significantly reducing zinc loading and increasing the sacrificial lifetime.","PeriodicalId":18223,"journal":{"name":"Materials and Corrosion","volume":"6 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141743162","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 Schneider, Ulrike Langklotz, Laurence Kühne, Claudia Kutzer‐Schulze
Mechanical grinding creates mechanical as well as thermal stress in treated material and the so‐called Beilby layer is formed. The present work investigates the influence of abrasive coarse grain size on the thickness and electrochemical behavior of the native oxide layer formed after the grinding process by using cyclovoltammetry. The difference in the native oxide layer thickness amounts to Δd ≈ 0.5 nm under the surface conditions investigated. Additionally, an experimental design is introduced and tested, which allows the operando measuring of the temperature of the material during the grinding process. Estimates result in a thermal stress Δσ between 0.8 and 1.3 MPa depending on the chosen grinding parameters and influence the subsequently formed oxide layer thickness.
{"title":"Influence of mechanical grinding on the formation of native passive layers on aluminum alloys","authors":"Michael Schneider, Ulrike Langklotz, Laurence Kühne, Claudia Kutzer‐Schulze","doi":"10.1002/maco.202414503","DOIUrl":"https://doi.org/10.1002/maco.202414503","url":null,"abstract":"Mechanical grinding creates mechanical as well as thermal stress in treated material and the so‐called Beilby layer is formed. The present work investigates the influence of abrasive coarse grain size on the thickness and electrochemical behavior of the native oxide layer formed after the grinding process by using cyclovoltammetry. The difference in the native oxide layer thickness amounts to Δ<jats:italic>d</jats:italic> ≈ 0.5 nm under the surface conditions investigated. Additionally, an experimental design is introduced and tested, which allows the <jats:italic>operando</jats:italic> measuring of the temperature of the material during the grinding process. Estimates result in a thermal stress Δ<jats:italic>σ</jats:italic> between 0.8 and 1.3 MPa depending on the chosen grinding parameters and influence the subsequently formed oxide layer thickness.","PeriodicalId":18223,"journal":{"name":"Materials and Corrosion","volume":"65 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141743160","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}
Saqib Mukhtar, Richard Bureš, M. Lhotka, A. Danielisová, Drahomíra Malyková, Helena Březinová, Ludmila Barčáková, Šárka Šachlová, Vlastislav Kašpar, Václava Havlová, Jiří Němeček, J. Stoulil
This work focused on evaluating the evolution of the corrosion product layer and associated corrosion rates on archeological artifacts from 16 sites. Sites with clay soils and maximum waterlogging (pond bottoms and wetlands) were monitored. The corrosion products were evaluated by X‐ray imaging, X‐ray diffraction, scanning electron microscope, Brunauer–Emmett–Teller, and nanoindentation. Two stages of corrosion attack with slightly different mechanisms were observed. Corrosion rates observed at sites with continuous flooding show average corrosion rates of 0.4–1 μm.a−1. These values demonstrate a minimum service life of the container outer case of 15 × 103 years, which is several times longer than the required lifetime of the outer case.
{"title":"Archeological analogs for the lifetime prediction of the canister for spent nuclear fuel in the deep geological repository: Part II. Evolution of the corrosion rate over time","authors":"Saqib Mukhtar, Richard Bureš, M. Lhotka, A. Danielisová, Drahomíra Malyková, Helena Březinová, Ludmila Barčáková, Šárka Šachlová, Vlastislav Kašpar, Václava Havlová, Jiří Němeček, J. Stoulil","doi":"10.1002/maco.202414521","DOIUrl":"https://doi.org/10.1002/maco.202414521","url":null,"abstract":"This work focused on evaluating the evolution of the corrosion product layer and associated corrosion rates on archeological artifacts from 16 sites. Sites with clay soils and maximum waterlogging (pond bottoms and wetlands) were monitored. The corrosion products were evaluated by X‐ray imaging, X‐ray diffraction, scanning electron microscope, Brunauer–Emmett–Teller, and nanoindentation. Two stages of corrosion attack with slightly different mechanisms were observed. Corrosion rates observed at sites with continuous flooding show average corrosion rates of 0.4–1 μm.a−1. These values demonstrate a minimum service life of the container outer case of 15 × 103 years, which is several times longer than the required lifetime of the outer case.","PeriodicalId":18223,"journal":{"name":"Materials and Corrosion","volume":"2 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141645941","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}
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