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Corrosion assessment of infrastructure assets in coastal seas
Abstract
The seas play an essential role for the peoples living on their coastal regions, since the marine infrastructure is located in the coasts. Seawater is a corrosive environment that affects infrastructure particularly in polluted seawater. Corrosion and pollution are pernicious chemical, physical processes that impair the quality of the environment and the durability of the marine structures and materials. They are aggravated by the discharge into the sea coast of municipal, industrial and agricultural effluents, which contain and produce toxic and highly corrosive components by biological and chemical degradation. Reinforced concrete and carbon steel are the main engineering materials used for the construction of marine installations and equipment but other metals and alloys: aluminium; copper, stainless steels are applied, too. Laboratory and field corrosion tests in seawater were carried out applying gravimetric, electrochemical and surface examination methods, based on American Society of Testing and Materials (ASTM) and National Association of Corrosion Engineers (NACE) standards. This work is the result of a cooperation between academic institutions in Mexico and Israel. The data generated advance the management of sea corrosion prevention and mitigation, and provide a guide for marine infrastructure maintenance and corrosion control. Several cases of corrosion in the sea coasts based on the authors experience and knowledge are presented.
... Ιn the impressed current density corrosion (ICDC) method, the reinforcing bars to be corroded and the stainless steel bars are connected to a power supply applying direct electric current before being immersed a 5% sodium chloride solution by weight of water ( Figure 5). The specific content of the NaCl solution represents the salinity of the Mediterranean basin, according to previous studies [28,29]. With the supply of electric current from the power supply, a closed electrical circuit is created, with the reinforcing steel bars to be corroded as the anode, the stainless bars as the cathode, and the sodium chloride solution as the electrolyte. ...
... It is worth mentioning that even In the impressed current density corrosion (ICDC) method, the reinforcing bars to be corroded and the stainless steel bars are connected to a power supply applying direct electric current before being immersed a 5% sodium chloride solution by weight of water ( Figure 5). The specific content of the NaCl solution represents the salinity of the Mediterranean basin, according to previous studies [28,29]. With the supply of electric current from the power supply, a closed electrical circuit is created, with the reinforcing steel bars to be corroded as the anode, the stainless bars as the cathode, and the sodium chloride solution as the electrolyte. ...
The mechanical behavior of corroded steel reinforcement under dynamic loadings is crucial for the entire structural response of reinforced concrete elements located in seismic regions. Taking into account the need to assess the structural integrity of existing building stock and the fact that the majority of the existing RC structures in Greece are constructed with the use of steel grades of S400 (equivalent to BSt 420s) and Tempcore B500c, the present study examines the dynamic behavior of rebars of different grades under low cycle fatigue (LCF) at a constant strain amplitude of ±2.5% and compares their performance through a quality material index. In the margin of the current research, the study also included two different grades of hybrid rebars, Tempcore B450 and dual-phase F (DPF). The outcomes demonstrated that single-phase S400 steel underwent mild degradation in its ductility, whereas its bearing capacity was significantly decreased due to corrosion. In contrast, B500c illustrated its superiority in terms of strength, yet recorded extremely limited service life, even in uncorroded conditions, raising questions about its reliability and the structural integrity of existing building stock. However, in corroded conditions, even if B500c corroded rebars showed higher mass loss values than the other examined grades, the degradation of their mechanical behavior due to corrosion was found to be minimal. Furthermore, dual-phase DPF rebars, with their homogeneous microstructure, appeared particularly promising with respect to Tempcore B450 if one considers the span of its service life compared to the extent of corrosion damage.
... Marine environments can be very challenging for metallic structural materials due to factors such as high salinity, water velocity, temperature, and biological activities [1][2][3][4][5]. The corrosion of alloys in seawater has serious effects on the reliability and service life of marine equipment, causing severe damage to structures, materials, equipment, port facilities, and ships, which is a major concern for scientists and engineers [6][7][8]. In addition to the adverse effects of chlorides and other halide ions naturally present in seawater, pollutants can also have a significant impact on the corrosion of metals. ...
... Corrosion and pollution are interrelated processes, as many pollutants produced by burning fossil fuels accelerate corrosion, and corrosion products such as rust, oxides, and salts pollute water. Both processes negatively affect the quality of the environment and the durability of marine structures and building materials [7,9]. Pollution also leads to climate change, which can alter environmental conditions and increase the risk of corrosion failures, altered precipitation patterns, and the corrosiveness of coastal regions, with added stresses on marine systems [9,10]. ...
The effect of temperature (from 288 to 308 K) and concentration of sulfide ions (up to 40 ppm) on the corrosion behavior of AISI 304L and AISI 316L stainless steels in seawater was studied with measurements of open-circuit potential, linear and potentiodynamic polarization, and electrochemical impedance spectroscopy. An increase in temperature and pollutant concentration negatively affects the corrosion stability of stainless steels at the open circuit (the resistance, compactness, and thickness of the surface layer decrease and the corrosion current increases), in the passive region (the passivation current increases, the depassivation potential decreases, and the passive potential region narrows), and in the transpassive potential region (the rate of metal dissolution increases). The occurrence of pitting corrosion on the surface of the samples was confirmed with optical microscopy and a non-contact 3D profilometer. A few large pits (depth 80–100 μm and width 100 μm) were formed on the surface of AISI 304L steel, while several smaller pits (depth 40–50 μm and width 50 μm) were formed on the surface of AISI 316L steel. With increasing temperature and sulfide ion concentration, the width, depth, and density of the pits increased on both steel samples. In the studied temperature and concentration range of sulfide ions, the AISI 316L steels exhibited higher corrosion resistance. Overall, the influence of sulfide ions on steel corrosion was more pronounced than the influence of temperature.
... The selected content of the NaCl solution better simulated the case in the regions of Mediterranean basin, where the hot climate results in a higher salinity of the seawater, in contrast to northern countries. Moreover, in the Mediterranean basin, the salinity of the sea increases during the summer periods due to the high temperatures recorded [18,19]. ...
... The protocol for the execution of the mechanical tests was elaborated; a cyclic horizontal displacement history, gradually increasing, with three complete cycles for each drift was imposed, similar to the strain histories followed The selected content of the NaCl solution better simulated the case in the regions of Mediterranean basin, where the hot climate results in a higher salinity of the seawater, in contrast to northern countries. Moreover, in the Mediterranean basin, the salinity of the sea increases during the summer periods due to the high temperatures recorded [18,19]. ...
The corrosion of steel reinforcement negatively influences the mechanical performance of reinforced concrete (RC) elements reducing both their strength capacity and ductility. Especially in seismic prone areas, the degradation of the cyclic behavior of corroded RC elements is more intense, limiting the service life of structures and leading to premature failures. In the present paper, in order to study the degraded behavior of the embedded (in concrete) steel reinforcement under cyclic loading, laboratory corrosion experiments were performed on embedded steel reinforcing bars. Thereafter, mechanical tests under dynamic loadings with gradually increased deformations were carried out. From the experimental study, hysteretic models of the non-linear behavior of steel bars were extracted in non-corroded and corroded conditions, in the case of both uniform and pitting corrosion. Based on the hysteretic models of steel bars, an analysis of the cyclic response of (non-corroded and corroded) RC columns was performed using the OpenSees code. The outcomes of the present study indicated the negative consequences of corrosion on the hysteretic behavior of steel reinforcing bars, demonstrating mainly the local reduction in their cross-section (pitting corrosion) combined with the loading history and buckling phenomena as the main factors which deviate the mechanical behavior of steel bars from the classic bilinear model of monotonic loading.
... values, as were OD and redox potential. Although oxygen-poor seawater inhibits diffusion-controlled corrosion, corrosion processes driven by the chloride ions, H 2 S and the metabolism bacteria such as SRB are favoured (Phull, 2010;Valdez et al., 2016). ...
Since 2011, massive strandings of Sargassum (brown alga) have significantly affected Caribbean islands causing major health, environmental and economic problems. Amongst them, the degradation of algae releases corrosive gases, hydrogen sulphide (H2S) and ammonia (NH3) which causes an accelerated corrosion of the metallic structures of these coastal areas. The aim of this study was to quantify the impact of Sargassum strandings on the corrosion of three types of steels (DC01 carbon steel, 304L and 316L stainless steels) immersed for up to 120 days at various sites in Martinique which were gradually impacted by Sargassum. A multidisciplinary approach was developed, incorporating: (i) surface analysis through macrophotography and corrosion product examination, (ii) weight loss measurements, and (iii) analysis of physicochemical parameters alongside microbial composition. As a result, in the presence of degraded Sargassum, an anaerobic, reducing and more acidic environment was correlated with high corrosion rates for all studied steels. When high density of Sargassum sp. was present, elemental sulphur was identified in the corrosion product layers of DC01 and 316L. Moreover, in this condition, sulphate-reducing bacteria (SRB) were observed in the surface biofilms of 304L coupons such as Desulfobulbus rhabdoformis. All these factors have highlighted the aggressiveness of the medium resulting from the presence of decomposing Sargassum, leading to increased corrosion rates. Our work provides new information on the importance of managing Sargassum strandings in order to avoid accelerated degradation of metallic structures in harbours and coastal zones.
... Additionally, quay walls and infrastructure are typically exposed to corrosion, which can severely impact infrastructure. Valdez et al. (2016) mentioned that corrosion and pollution are harmful processes that degrade the environmental quality and compromise the longevity of marine structures and materials. Therefore, to ensure the protection of people and areas surrounding ports, it is crucial that the existing quay walls remain structurally sound and continue to function effectively. ...
Background: Harbors provide shelter for vessels, whereas ports facilitate the docking of ships that transport passengers and cargo (Jellett 2024). The Port of Durban relies on steel sheet piles to protect quay walls from rising sea level and erosion. Understanding the corrosion rate is crucial for maintaining these structures. Objectives: This study aimed to assess the corrosion rates and estimate the remaining thickness of steel sheet pile walls at the Island View Berth 3 and Maydon Wharf Berth 12. Methods: Ultrasonic thickness (UT) gauges were employed to measure the remaining thickness of steel sheet piles. Corrosion rates were calculated using the formula icorr=(To−Ta)/t, where To is the original thickness, Ta is the actual thickness, and t is the exposure time in years. Additional laboratory analyses of chloride content and pH levels were conducted to evaluate the impact of the marine environment on corrosion. Results: At Island View Berth 3, the average corrosion rate was 0.0516 mm/year 28 years after installation. At Maydon Wharf Berth 12, the corrosion rates vary by zone: 0.0545 mm/year in the splash zone, 0.0485 mm/year in the tidal zone, 0.0345 mm/year in the low-water zone, and 0.0290 mm/year in the immersion zone, yielding an overall corrosion rate of 0.0466 mm/year. Conclusions: This study highlights the significant corrosion variability across different zones and emphasizes the need for a comprehensive maintenance plan to address deterioration. These findings provide essential insights for future design and preservation strategies of marine structures at the Port of Durban.
... The unique hydrographic characteristics of the Black Sea render it particularly susceptible to ocean acidification [17,18]. The increasing acidity of seawater accelerates the corrosion of ships, submarines, and other naval assets, necessitating more frequent and costly maintenance while potentially reducing the operational lifespan of these assets [19][20][21]. This additional financial burden strains the Navy's resources and can affect long-term planning. ...
Climate change poses a significant threat to European security, implicitly to Romania’s naval forces in the Black Sea. Rising sea levels, extreme weather events, and ocean acidification impact maritime operations, infrastructure, and personnel, with potential ramifications for regional stability. This paper explores the implications of climate change for the Romanian Navy and proposes "Green Defence" strategies to enhance resilience and sustainability. These strategies encompass energy efficiency, renewable energy integration, sustainable procurement, and the application of advanced functional materials in naval operations and infrastructure. By adopting a proactive and multifaceted approach, the Romanian Navy can adapt to the changing climate, ensuring operational effectiveness while minimizing environmental impact. This approach aligns with broader European security concerns and contributes to a more sustainable and resilient defence posture in the face of climate-related challenges.
... The same is true for other anthropogenic activities, such as deep-sea mining. Secondary impacts of CC, such as the corrosion of coastal infrastructure (e.g., wind turbines, dikes, coastal roads, bridges, naval bases, harbors), however, have been fairly well studied 116,117 . ...
... The most common tasks in ocean engineering include designing, constructing, and maintaining infrastructures [11]; underwater mapping [12], monitoring, and exploration [13]; identifying and exploring natural resources [1]; environmental monitoring and protection [14]; and developing sustainable energy sources [15]. Autonomous vehicles are expected to automate most of these tasks, thus reducing human intervention and increasing system reliability. ...
In ocean engineering, engineering principles are applied to the ocean domain. Advanced technology is facilitating efficient exploration of oceanic regions with minimal human intervention, and autonomous vehicles are increasingly used to automate various ocean engineering tasks. However, using fully autonomous vehicles raises ethical and legal concerns that must be properly regulated. Nowadays, the most common applications of autonomous vehicles in the ocean domain include infrastructure maintenance, underwater mapping, resource exploration, environmental monitoring, and various military operations such as mine warfare (MW) and intelligence, surveillance, and reconnaissance (ISR). This article explores the prevalent applications of autonomous vehicles in ocean engineering, analyzing existing regulations, liability and accountability issues, data privacy, cybersecurity challenges, and interoperability. Through a Strengths, Weaknesses, Opportunities, and Threats (SWOT) analysis, it was possible to better understand the current state of using autonomous vehicles in ocean engineering and develop a possible future strategy in the field. To make the usage of autonomous vehicles more reliable in ocean engineering, it is essential to advance them technologically and update the existing laws that deal with these kinds of applications.
... Corrosion of metal infrastructures in aquatic settings raises significant worries regarding environmental pollution, potential harm to aquatic ecosystems, degradation of infrastructure integrity, and substantial economic losses [1]. Metal abiotic deterioration is further accelerated by the involvement of biofouling and Microbiologically Influenced Corrosion (MIC), two mechanisms mediated by the biological activity of different organisms [2]. ...
Microbiologically Influenced Corrosion (MIC) is one of the main threats for marine infrastructures, leading to severe safety and environmental risks associated with structural failures and/or leakages of dangerous fluids, together with potential huge economic losses and reputational damage for the involved parts. For a safe design and a proper installation of infrastructure systems in contact with the seabed, a deep knowledge of the site-specific microbial community of the sediments should be beneficial. Therefore, in addition to the simple detection or the sole quantification of Sulphate-Reducing Bacteria (SRB), the whole characterization of the microbial members involved in MIC phenomena is desirable. In this study, 16S rRNA-based comparison between bacterial communities thriving in offshore and nearshore marine sediments was performed, with a focus on the main bacterial groups putatively responsible for MIC. The nearshore sediments were significantly enriched in bacterial members associated with human and organic compounds contamination belonging to the Bacteroidota, Desulfobacterota, and Firmicutes phyla, while the offshore sediments hosted Alphaproteobacteria, Nitrospinota, and Nitrospirota members, representative of a low anthropogenic impact. Quantitative PCR targeting the dsrA gene and detailed community analyses revealed that the nearshore sediments were significantly enriched in SRB mainly affiliated to the Desulfobulbus and Desulfosarcina genera potentially involved in biocorrosion, compared to the offshore ones. These results suggest that the bacterial community associated with the high concentration of organic compounds derived by an elevated anthropogenic impact is likely to favour MIC. Such observations highlight the importance of microbiological investigations as prevention strategy against MIC processes, aiming both at characterizing sites for the establishment of new infrastructures and at monitoring those already installed.
... Buildings located in extreme environments such as coastal and marine areas have the potential to experience corrosion. The presence of chloride ions contained in sea water can enter the pores in the concrete and react with the passive layer of the reinforcing steel, causing an oxidation reaction that causes corrosion of the reinforcing steel [1]. Reinforced concrete materials with good concrete mixture properties usually have corrosion resistance capacity [2]. ...
The degradation of concrete strength may occur due to extreme environmental factors such as sea or coastal areas. Those factors can decrease the durability level of concrete structure signified by the corrosion of reinforced concrete structure. The use of fly ash as a concrete mixture is expected to minimize corrosion in concrete structures. Since fly ash has small particles, it can fill small voids in concrete and minimize corrosive substances. The investigation parameters in this study employed two types of corrosion acceleration test modelling using a 15x15x15cm cube tested object with a concrete quality of 40 MPa. Meanwhile, fly ash involves classes F and C within the level of 20% as well as applied corrosion prediction by 10% and 20%. The addition of fly ash to the concrete mixture can reduce the mass loss of reinforced concrete. The maximum mass loss on a normal test object with a corrosion prediction of 20% was obtained at 18.22%, while a 20% corrosion prediction obtained the smallest value for the SCMFA-C test object at 17.04%. The 20% corrosion prediction obtained the largest distribution of 0.355 mm on the normal test object and the smallest distribution of 0.299 mm occurred on the SCMFA-F test object. Thus, the addition of fly ash to the concrete mixture can reduce the distribution of corrosion and mass loss in reinforced concrete.
... In order to avoid detrimental system failures effective corrosion management should be carried as a concerted effort (Schmitt et al., 2009). The pervasive effects of corrosion over the economy and the environment are elaborated in the literature (Batmani et al., 2017;Dohmann et al., 2021;Farmer et al., 1993;Hossen et al., 2023;Koch et al., 2016;Lawal et al., 2023;Michel & Angst, 2018;Olivo et al., 2016;Papavinasam, 2013;Schmitt et al., 2009;Slaughter & Stevens, 2015;Valdez et al., 2016). These effects motivate the corrosion control industry to constantly seek innovative solutions. ...
Corrosion, driven by chemical reactions, poses challenges in estimating its cost due to its impact across industries. Direct and indirect costs include structure replacement, shutdowns, maintenance, product losses, and safety hazards. Key studies highlight rising costs over time, with corrosion expenses estimated at 3.1% of the U.S. GDP in 1998. Current estimates suggest corrosion represents 3.5 to 5% of the global GDP, with potential reductions of up to 30% through advanced technologies. Environmental impacts are difficult to quantify, and efforts to replace harmful chemicals will require significant time and resources. Corrosion protection is crucial, especially in sectors like aviation and nuclear technology. Theoretical assessments of nanoparticles will evaluate their corrosion inhibitor potential, aiding in structural integrity management. To this end, theoretical comparisons of seven nanoparticles will be conducted, assessing the corrosion inhibitor potential of both unprotonated and protonated forms using Gaussian 9 and Gaussian View programs.
... Laboratory tests and field corrosion tests are used to determine the corrosion rate and assess the long-term viability of exposed metallic structures. Structures with excessive corrosion issues may benefit from a cathodic protection system compliant with the National Association of Corrosion Engineers (NACE) standard for impressed current cathodic protection of steel structures (NACE 2000) (Valdez, 2016). Most stainless steels (SS) are passivated (covered with a protective oxide film) due to dissolved oxygen in seawater. ...
... Studies on gas scavenging, cylinder untightening, and geometric parameters in internal combustion engines offer insights into engine operation and maintenance [13][14][15]. Explorations into maritime failures underscore the importance of proactive measures, innovative technologies, and a deep understanding of failure mechanisms in fortifying the maritime industry [16][17][18][19][20][21]. ...
The loss of steerage in maritime vessels often stems from main engine failures, as expounded in the present article. The focal incident involves a cascading engine breakdown initiated by a single exhaust valve fault. Subsequent consequences encompass the fragmentation of the second exhaust valve, structural damage to the engine components, including the head and piston, cracking of valve seats, and the inadvertent entry of cooling water into a cylinder. The ensuing plastic strain on the cylinder surface, coupled with valve fragments infiltrating the turbocharger, leads to additional, albeit minor, damage. Notably, the high degree of plastic strain obfuscates the original features of the cracked elements, necessitating the author to delineate a hypothetical cause and progression of the destruction process. In the conclusive remarks, the author underscored the paramount importance of continuous
engine operation monitoring and meticulous fault diagnosis to uphold the safety standards of maritime transport.
... Introduction As a direct result of industrialization and technical advancement, more than 90% of current construction equipment is made of CS [1]. CS is used in chemical processing, oil drilling and refining, pipelines, mining, construction and metalprocessing equipment, despite its low corrosion resistance [2][3][4]. It is widely used due to its high strength, durability and cost-effectiveness [5][6][7][8]. ...
In this study, gravimetric analysis was used to determine corrosion properties, i.e., WL and CR of welded and tempered UNS G10400 CS exposed to Sw. In order to determine optimal WL and CR, RSM approach was utilized to develop a prediction model. 20 runs of the experiment were used for statistical ANOVA. As response variables, the experimental design matrix included WL and CR. To optimize the results of GC method and develop a predictive regression model, CCD was utilized. By ANOVA, the generated models for WL and CR indicated a significant p-value (which is probability, under the null hypothesis assumption, of obtaining a result equal to or higher than the one observed) of < 0.0001. F-values and R 2 showed good statistical correlation between experimental and predicted values. Optimal conditions for WL and CR occurred at 25 °C(as-welded), with an ET of 17 days, and their optimum values were 0.744 g and 0.769 mm/year, respectively. Validation of optimized predicted results showed an UE of 1.6 and 2.9%, for WL and CR, respectively, which was below 5%. This revealed that the generated model adequately predicted CP of welded and tempered UNS G10400 CS in a Sw environment.
... In the last 50 years, many coastal regionsparticularly in the developed world, but increasingly globally have experienced significant economic decline as a result of deindustrialisation and globalisation pressures (Kim and Sumner 2019). Around the world, abandoned infrastructure can be found in these regions, rusting, corroding, and polluting coastal waters (Valdez et al. 2016), and serving as remnants of forgotten industries such as shipbuilding that were left behind with little institutional support as the global economy changed (Poulsen and Sornn-Friese 2011). This has led many coastal villages, towns, and cities to be described as 'left-behind places' (Corfe 2017;McDowell and Bonner-Thompson 2020;Telford 2022), that is, those places that are experiencing economic hardship, demographic shifts, community disruption, and loss of identityand are seen as hotbeds for political discontent (Rodríguez-Pose 2018). ...
The blue economy purportedly involves equitable and sustainable development across a range of ocean sectors spanning fisheries, aquaculture, tourism, shipping, seabed mining, oil and gas extraction, and renewable energy. Here, we argue that blue economy scholarship and policy gives insufficient attention to coastal regions – and the cities, towns, and villages within – that depend on these sectors. Rather than prioritising the profitability of corporations and expansion of industry, we advise actors to consider three transformative processes that are (re)shaping coastal regions. First, are techno-industrial processes for which we draw on the fourth industrial revolution literature, highlighting that coastal regions must adapt to rapidly changing technological innovations or risk facing decline. Second, are socio-cultural processes for which we draw on the left-behind places literature, which exemplifies spatial inequalities from declining and deindustrialised coastal regions. Third, are physical-environmental processes, highlighting geographically variable opportunities and challenges around natural resources, marine biodiversity, and climate change in coastal regions. We then promote place-based policymaking as a multi-level and participatory mode of managing these transformations. Finally, we present a blue economy research agenda to help navigate these transformative processes, and enable place-based solutions. The article intersects with broader literatures around ocean governance and sustainable transformations.
... Studies of biofilms on steel in the marine environment have revealed key roles in nutrient cycling, structural degradation processes, and microbiologically influenced corrosion (McBeth et al. 2011;Lee et al. 2013;Mugge et al. 2019b;Garrison and Field 2020). Carbon steel is a common material for construction of marine infrastructure including pipelines, steel pilings, moorings, and ship hulls (Church et al. 2009;McBeth et al. 2011;Valdez et al. 2016), due to its versatility, strength, and low cost. However, biofilm growth on steel causes biofouling that results in structural degradation with economic consequences (Lee et al. 2004;Bermont-Bouis et al. 2007;Zhang et al. 2019a). ...
The rapidly expanding built environment in the northern Gulf of Mexico includes thousands of
human built structures (e.g. platforms, shipwrecks) on the seabed. Primary-colonizing microbial
biofilms transform structures into artificial reefs capable of supporting biodiversity, yet little is
known about formation and recruitment of biofilms. Short-term seafloor experiments containing
steel surfaces were placed near six structures, including historic shipwrecks and modern decommissioned
energy platforms. Biofilms were analyzed for changes in phylogenetic composition,
richness, and diversity relative to proximity to the structures. The biofilm core microbiome was
primarily composed of iron-oxidizing Mariprofundus, sulfur-oxidizing Sulfurimonas, and biofilmforming
Rhodobacteraceae. Alpha diversity and richness significantly declined as a function of
distance from structures. This study explores how built structures influence marine biofilms and
contributes knowledge on how anthropogenic activity impacts microbiomes on the seabed.
... However, chloride erosion in marine environments poses severe threats to infrastructure, including corroding steel reinforcements, eroding concrete, environmental pollution, and increased maintenance and repair costs [11,12]. Understanding and quantifying CAC-CC is crucial for assessing the onset of steel corrosion and chloride ion diffusion properties [13]. ...
... Bio-weathering or biodeterioration is an important deterioration mechanism caused by microorganisms [26] that is clearly related to environmental conditions (materials types, building architectural properties, expositional parameters, and stone-conserving treatments [27][28][29][30]. In our case, this mechanism affected the fortress stones, which, in permanent contact with seawater, through the accumulating of microorganisms (fungi, bacteria, etc.) as attested previously in similar cases [31,32]. Their effects mostly occurred by anodic and cathodic electrochemical reactions and were promoted by the corrosive metabolites produced by the biofouling fauna [33]. ...
This paper investigates the marine effects that affect Qait Bey Fortress in Alexandria—Egypt. It presents the results of scientific studies and examinations to evaluate the deterioration conditions that affected archaeological buildings in the marine environment. In Alexandria, many monumental sites and stone buildings have suffered from many aggressive factors of deterioration (mechanical, chemical, and biological), which have caused great harmful appearances and threatened to eradicate them. These effects include the chemical actions resulting from seawater and marine aerosol and the mechanical actions of water waves. (Qait Bey Fortress), as a case study, was periodically investigated by many scientific techniques over five years to check its decay conditions and to define the most suitable conservation approaches and non-destructive methods for preservation. Different techniques and examinations were carried out to evaluate the current deterioration state of the fortress. For example, XRD analysis and PM investigation were used to study the mineralogical compositions, lithotype, and petrographic characteristics of the stone samples. SEM was used to investigate the morphological features of the same samples. AAS was also used for studying the chemical constituents of seawater samples. In addition, microbiological investigations were conducted to evaluate the colored hard crusts that affected the stone surfaces in the fortress. Our results proved that severe deterioration factors influenced the fortress by collaborating with chemical, mechanical, and biological mechanisms. These mechanisms caused several manifestations, such as abrasion and attrition, crystallizing of salt species, mortar desegregation, pitting and minerals’ honeycomb (Alveolar), color changes, in addition to the accumulation of black and colored biogenic hard crusts composed of numerous tightly adjoining pits of several centimeters. Crusts, such as yellow to bluish green, resulted from P. aeruginosa and granular appearance having brownish ting in the center resulted from P. clacis. In addition, other pigmented features resulted from Bacillus firmus and Bacillus atrophaeus. The presence of some black and dark color crusts was attributed to the growth of some fungal species, such as A. niger, A. phoenicis, Cladosporium cladosporioides, and Alternaria alternata.
... Epoxy resins and polyurethane based coatings, acting as artificial barriers to separate the steel from the corrosive environment, are some of the most commonly employed materials as corrosion protection systems with applicability in a wide range of marine transports and infrastructures (Verma, Khanna, & Bhattacharya, 2021). These protection systems may contain chemicals like binding agents, pigments, or colorants for, among others, naval traffic security reasons (Valdez et al., 2016). These organic components are susceptible to being released from the coatings upon contact with seawater through leaching or weathering processes or material losses. ...
Functional coatings provide durability to the bulk material and add other value-added properties which enhance the mechanical, electrical, optical and many other properties of the surface. The functional response of these coatings stems from the ambiance which can be made to sense in response to a sharp change in the temperature, pH, moisture, active ions, or mechanical stresses. Recently, there have been many efforts made to impart multi-functionality within a single coating i.e., to achieve hydrophobicity as well as antifouling characteristics which can for example be achieved by combining an appropriate material of the coating with a geometric nanopattern. Such coatings are poised to shape the future of transport, healthcare, and energy sector including marine, aeronautics, automobile, petrochemical, biomedical, electrical and electronic industries. This perspective sheds light on the design specifications and requirements to fabricate functional coatings and critically discusses the fabrication methods, working principles, and case studies to survey various applications with a particular focus on anticorrosion and self-cleaning applications.
... On the other hand, seawater has been widely accepted as a corrosive environment that exerts influence on infrastructure particularly those which are built in nearshore regions [9]. Nearshore geo-structures and infrastructures are mainly built of either steel or reinforced concrete as two fundamental materials in civil engineering. ...
Civil engineering assets and geo-structures continually deteriorate during their lifetime, particularly in harsh environments that may be contaminated with corrosive substances. However, efficient and constant structural health monitoring and accurate prediction of the service-life of these assets can help to ensure their safety, performance, and health conditions and enable proper maintenance and rehabilitation. Nowadays, many of the largest cities throughout the world are situated in coastal zones, leading to a dramatic increase in the construction of nearshore geo-structures/infrastructures which are vulnerable to corrosion attacks resulting from salinity contamination. Additionally, seawater intrusion can threaten the quality and the sustainability of fresh groundwater resources, which are a crucial resource in coastal areas. To address these issues, detection of salinity in soil utilizing a novel polymer optical fibre Bragg grating (POFBG) sensor was investigated in this research. Experiments were carried out at different soil water contents with different salinities to assess the sensor’s response in a representative soil environment. The sensitivity of the POFBG sensor to salinity concentrations in water and soil environment is estimated as 58 ± 2 pm/%. The average standard error value in salinity is calculated as 0.43% for the samples with different soil water contents. The results demonstrate that the sensor is a promising and practical tool for the measurement and monitoring with high precision of salinity contamination in soil.
... The deployment of coating in protecting the marine vessel and construction is common. This requirement is because of the nature of seawater that can corrode metallic structures leading to the failure of a system [7]. Thus, to reduce the cost of repairing and maintenance, an effective coating is a must. ...
Air pollution is an increasing prevalence of environmental diseases. Previously, hazardous air pollutants (HAPs) on the ozone layer, which primarily constitute volatile organic compounds (VOCs), have become a major public concern. As a result, the Environmental Protection Agency (EPA) has introduced a strict regulation on the limit of VOCs content for various daily products such as paints and solvents to reduce the risk. Hence, the study aims to develop an eco-friendly coating with low VOCs content per the imposed regulation by deploying the leaves extract of Moringa Oleifera (MOE) for marine vessel protection. The formulated coating was characterized by using optical, electrochemical, and morphological analysis to study the effectiveness of its barrier property against the aggressive solution of seawater. Additionally, measurement of its VOCs content was conducted following the ASTM D2369-03. The results obtained suggested that the incorporation of 1 wt.% of MOE of C2 increased the resistivity of coating in reducing the penetration of ionic electrolytes up to 91.2% while exhibiting the traits of low VOCs content category at a value of 198 g/L.
... Biofouling is a complex, dynamic, and a lengthy procedure involving a variety of biological mechanisms that are not fully comprehended [6]. Mollusc bivalves, particularly mussels, are a common and a troublesome fouling element to assemblies related to ship's sea chests and pipework [8,9]. These species have shown to be dominant in coastal Atlantic areas [10][11][12]. ...
Wind energy is expected to play a significant role in meeting emission targets over the next 20 years. Offshore wind turbines in deep water (>150 m) must be developed due to resource quality, environmental, and activity constraints. Floating offshore wind turbines (FOWT) will be the best technology for reaching these targets. The dynamic submarine electrical cable (DSEC) is a key component of FOWT. Its electric insulation system is intended to withstand a maximum conductor temperature of 90 °C. However, biofouling growth, particularly mussels, can modify the heat transfer around the cable and thus its maximum conductor temperature, as well as temperature fluctuation, affecting the fatigue lifetime. In our work we estimate the effective thermal conductivity of mussels of various ages, as well as the heat transfer coefficient of the water around them. The results revealed that the effective thermal conductivity of juvenile mussels is lower than that of mix (both juvenile and adult) and only adult mussels. This variation in effective thermal conductivity with mussel age is related to the water porosity of the mussel’s layer. Then, the thermal effect of the resulting global thermal resistance can lead the DSEC conductor wire to either overheat (colonized by juvenile and mixed mussels) or cool down (colonized by adult mussels). Numerical simulations are used to quantify this effect.
... Corrosion of seawater pipes is a significant concern for vessel operators, and both biofouling organisms and some biofouling treatments can increase corrosion (Carvalho, 2018;Grandison et al., 2011;Loto, 2017;Valdez et al., 2016). Pipe materials are selected to minimise corrosion and some materials must be used to reach certain safety and vessel class standards that dictate insurance and operational classification (DNV, 2021). ...
Invasive non-native species are a major threat to global biodiversity. For at least 15 million years coastal Antarctica has been poorly connected to nearby temperate ecosystems due to physical and physiological barriers. Yet, Antarctica is experiencing significant environmental change and becoming increasingly exposed to ship-borne human activity that crosses the physical barriers. These factors may facilitate the establishment of non-native marine species. This doctoral research adds insight into the risk of non-native marine species being transported to Antarctica via ships’ hulls and internal seawater systems, with particular focus on pathways of introduction and species found within those pathways. To begin my research, I assessed the current knowledge of non-native marine species in the Antarctic region: the physical and physiological factors that resist establishment of non-native marine species; changes to resistance under climate change; the role of legislation in limiting marine introductions; and the effect of increasing human activity on vectors and pathways of introduction. Evidence of non-native marine species was limited: up to 2019 just four marine non-native and one cryptogenic species that were likely introduced anthropogenically had been reported free-living in Antarctica or in the sub-Antarctica islands, but no established populations have been reported. An additional six species had been observed in pathways to Antarctica that are potentially at risk of becoming invasive. I estimated there may be approximately 180 vessels and 500+ voyages in Antarctic waters annually. However, these estimates are necessarily speculative because relevant data are not recorded comprehensively. In response to the scarcity of data on ship movements into the Southern Ocean, I obtained data on ship activity in the Southern Ocean from 2014-2018 inclusive and developed a ship traffic network for Antarctic-going vessels. I analysed the ship movements and conducted a spatially-explicit assessment of introduction risk for non-native marine species in all Antarctic waters. I found that vessels connect Antarctica via an extensive network of ship activity to all global regions, and especially South Atlantic and European ports. Ship visits were more than seven times higher to the Antarctic Peninsula and the South Shetland Islands than elsewhere around Antarctica. I found that, while the five recognised ‘Antarctic Gateway cities’ are important last ports of call, an additional 53 ports had vessels directly departing to Antarctica from 2014-2018. I identified ports outside Antarctica where biosecurity interventions could be most effective and the most vulnerable Antarctic locations where monitoring programmes for high-risk invaders should be established. Biofouling communities within the major pathway to Antarctica from Europe via the South Atlantic, identified in the network analysis, became my next focus. I obtained biofouling samples from the polar research vessel RRS James Clark Ross and found that niche (protected) areas of the hull represent significantly greater colonisation (species richness) and propagule pressure (individual abundance) than exposed areas of the hull. The composition of the biological communities did not differ among exposed and niche areas, but did change significantly among the three surveys conducted. Only six species were found on the ship’s hull in Antarctica, but they included a known invasive bryozoan, Tricellaria inopinata, and barnacles that have no counterparts in Antarctica. While the role of hull fouling is recognised as a globally important vector for introductions of non-native marine species, the role of a vessel’s internal pipework has been overlooked. I conducted the first comprehensive study of biofouling macrofauna living inside an Antarctic vessel’s internal seawater systems, finding breeding communities of Jassa marmorata (Amphipoda) and mytilid mussels throughout the internal pipework system. I found fouling communities that occluded ~9-17% of a pipe’s cross-sectional area, increasing running costs for ships. Since ships are constantly pumping their water through their pipework, they are likely to be releasing propagules at all stages of their voyages, including in polar regions. Before I started my research, Antarctic operators and policy-makers were unaware of the total number of vessels that visit Antarctica. Now, I have provided comprehensive insight into the most traversed routes to Antarctica and identified Antarctic locations that are the most likely recipient locations for non-native marine species. I found that non-native species from temperate regions can survive passages through polar areas and that sheltered sections of the hull and internal systems are especially important sites for both propagule and colonisation pressure. Together, these results demonstrate that Antarctica is well connected to worldwide marine ecosystems and that biofouling on ships poses an important and growing introduction risk to Antarctica.
... Industrial discharges, pesticide residues, and leakage from organotin-treated chemicals into freshwater, according to Paredes et al. (2017), resulted in a high detection of TBT in river channels flowing to Mexico City. According to Valdez et al. (2016), domestic primary sewage sludge effluents can contribute to coastal TBT pollution. TBT has a No Observed Effective Level (NOEL) of less than 1 ng/L, according to WHO, and TBT levels in all locations identified exceed the WHO recommended threshold. ...
Sri Lanka’s Western-Southern coastal area, home to more than 40% of the country’s population and the commercial capital city of Colombo, receives the most attention. Fisheries, tourism, hotel and restaurant, commercials, and administrations are among the government and non-government enterprises established in the area, demonstrating localization that impacts people’s lifestyles. This study aimed to identify point sources of coastal water pollution in the west-south coastal belt using the standard physico-chemical and microbiological methods, for 65 sampling sites from Negombo to Mirissa. The study area was divided into 11 land segments based on the environment type. 6 land segments and 5 land segments were used to cover the Western province and Southern province respectively. Each parameter was compared by province. Temperature and pH fluctuated less over the coastal belt between Negombo and Mirissa. The average temperature was 28.89 ±1.5 °C, and the pH ranged from 7.41 ± 1.5 to 9.64 ± 1.6. Electrical Conductivity (EC) and Dissolved Oxygen (DO) displayed dynamic changes, with average values of 40.88 ± 16.90 mS/cm and 7.66 ± 2.78 mg/L, respectively. The chemical limiting factor of the study areas was nitrogen. Nitrate was 0.01 mg/dm³ for almost all sampling locations and the highest Nitrite was 2.94 ± 0.8 μg/dm³. The highest Ammonia was 62.18 ±6.1μg/dm³, and Total Phosphorus (TP) was ranged from 92.41 ± 6.4 to 421 ±7.2μg/dm³. The Chemical Oxygen Demand (COD) was recorded between 112.5 ± 8.7 and 7318 ± 8.9 mg/dm³ and the maximum oil and grease concentration of 192.34 ± 7.6 mg/dm³. Unsurprisingly, fecal coliform was found in practically all of the coastal waterways, indicating fecal contamination, and the discovery of Salmonella sp. pathogenic bacteria from the Dehiwala canal and Rathmalana sampling locations drew additional attention. The highest level of Tributyltin (TBT) pollution was found in the Dikkovita fishery harbor (241 ± 4 ng/L), with TBT levels ranging from 51 ± 2 to 158 ± 2 ng/L in the remaining locations. The findings revealed that the study area has begun to decline due to anthropogenic activities and that there is less care for environmental friendliness as development stories progress.
... The dataset consists of distress images of road infrastructure provided by East Nippon Expressway Company Limited. The distress we focused on is corrosion, which is well-known distress [7], [8]. The classes of degradation levels are "A", "B" and "C", where "A" represents the most degraded state. ...
... Severity of deterioration in structures depends on geographical location and its functional utility like structures nearer to the sea-shore are more prone to corrosion and spalling e.g. harbors, shipyards and bridges [3], whereas structures which undergo cyclic loading or subjected to fatigue stress lead to microscopic to structural cracks e.g. beams, girders and tall buildings [4]. ...
To ensure the safety and the usefulness of civil structures, it is fundamental to visually inspect and survey its physical and functional condition. Current techniques in condition and safety assessment of large concrete structures are performed physically promoting to subjective and unreliable outcomes, costly and time-consuming data collection, and safety issues. This paper presents a study on less time consuming and less expensive alternative to the present methods of preliminary assessment for the detection of damages in structures. Henceforth, the focus is set on various vision-based methods for different parameters like cracks, corrosion and spalling which cause damage and deterioration of structures. Thus, a study is made on the current achievements and drawbacks of existing methods as well as open research difficulties are outlined to help both the structural engineers and the computer science researchers in setting a motivation for future research.
Metals in coastal regions are threatened by corrosion, underscoring the need for precise detection and monitoring methods. Traditional methods often faces limitations in terms of accuracy and applicability under diverse conditions. This study introduces the Corrosion Severity Index (CSI), an innovative spectral index for assessing corrosion in steel and iron structures. Several iron samples were placed in a salt spray chamber to generate different degrees of corrosion. The samples were analysed using hyperspectral cameras covering the visible near-infrared (VNIR) to the shortwave infrared (SWIR) spectrum. A Scale-Invariant Feature Transform (SIFT) registration algorithm was employed to generate the full spectral signatures from 400 nm to 1700 nm for each pixel. The CSI combines four spectral bands (457.50 nm, 791.91 nm, 1305.08 nm, and 1442.60 nm) where a pixel value close to 0 represents the absence of corrosion, whereas a higher value indicates greater severity of corrosion. Based on the average CSI values, samples are classified into Grade A, B, C, or D which indicates the degree of corrosion. CSI demonstrates its ability to detect early-stage corrosion and has been evaluated for robustness across a variety of steel and iron samples in different environmental conditions. In addition, the performance of the CSI is validated by comparing it with the previously published Corrosion Index (CI). CSI demonstrates a higher accurate ability to detect corrosion products and identify the degree of corrosion with a simplified approach. This index allows a balance between accuracy, low computational demands, and usability, providing an optimal solution for early diagnosis and proactive management of corrosion in coastal infrastructures.
Climate change poses a significant threat to European security, implicitly to Romania's naval forces in the Black Sea. Rising sea levels, extreme weather events, and ocean acidification impact maritime operations, infrastructure, and personnel, with potential ramifications for regional stability. This paper explores the implications of climate change for the Romanian Navy and proposes "Green Defence" strategies to enhance resilience and sustainability. These strategies encompass energy efficiency, renewable energy integration, sustainable procurement, and the application of advanced functional materials in naval operations and infrastructure. By adopting a proactive and multifaceted approach, the Romanian Navy can adapt to the changing climate, ensuring operational effectiveness while minimizing environmental impact. This approach aligns with broader European security concerns and contributes to a more sustainable and resilient defence posture in the face of climate-related challenges.
Due to the deepening levels of port automation and intelligence, the degree of equipment automation and the complexity of maintenance operations have increased substantially. Consequently, the evolution of intelligent technology has led to significant shifts in the types and quantities of issues encountered during the actual operation of equipment compared to historical contexts. The prevailing understanding of equipment maintenance systems might restrict ports’ capacity to handle emergencies and exacerbate operational risks. This paper employs bibliometric methods to analyze the current state of cooperation, key focus areas, and emerging trends in port equipment maintenance. Additionally, the study conducts a critical analysis and systematic investigation based on the bibliometric results. The findings indicate that intelligent technology introduces novel methodologies for port equipment maintenance. Nevertheless, multiple challenges remain in applying intelligent technologies, such as data integration, fault tracking, and real-time diagnosis. The paper emphasizes that future research should concentrate on enhancing data fusion capabilities, improving fault management effectiveness, and refining maintenance decision-making processes to elevate the intelligence of port equipment.
Nanozirconium vanadate (nZV) was synthesized and encapsulated in calcium alginate as a novel composite material to be used as an eco-friendly and novel self-healing coating. Physicochemical characterizations of the synthesized nanozirconium vanadate, and nanozirconium vanadate/alginate composite microcapsules (nZV@A) were conducted to confirm size and sphericity (129.95 µm ± 12.8, 0.82 ± 0.094), elemental composition, and microcapsule cross sectional analysis. The self-healing mechanism of nZV@A is initiated by an ion-exchange process that transforms the microcapsules from a stiff state to gel-like due to Ca2+/Na+ competition at alginate guluronic junction of the microcapsules, enabling the release of nZV leading to the formation of protective barriers and zirconium oxide films, effectively preventing corrosion and simultaneously facilitating the formation of pentavalent hydrates of vanadium, for self-healing. Electrochemical analysis and self-healing tests were examined in 3.5 wt% of NaCl solution at room temperature to investigate the protective capability of the novel ZV-CA/EP coating compared with the blank epoxy coating for steel substrates. The coating of the zirconium vanadate composite showed excellent barrier protection as well as remarkable self-healing capabilities.
Physics-based multi-scale corrosion simulation plays a vital role in predicting the evolution of pitting corrosion on large civil infrastructure such as miter gates, contributing to a model-informed structural health monitoring (SHM) strategy for risk-based asset health management. The physics-based analysis, however, may not accurately reflect the underlying true physics due to various uncertainty sources and needs to be updated using Bayesian inference methods based on observations to make the prediction closer to field observations. However, traditional Bayesian inference requires the evaluation of a likelihood function, which is often unavailable due to the complex model architecture and various surrogate models used in the analysis. Therefore, likelihood-free inference approaches are required for the updating of the multi-scale corrosion simulation models. This paper meets this need by proposing a conditional invertible neural network (cINN)-based Bayesian model updating method for an existing corrosion simulation model. We first train an cINN model based on simulated observations generated from a high-fidelity forward corrosion analysis model. A convolutional neural network (CNN)-based feature extraction algorithm is then employed to extract key features from corrosion images. After that, the extracted corrosion features from CNN is used as inputs of the cINN model to directly obtain posterior distributions of uncertain corrosion model parameters without evaluating the likelihood function. The results show that the proposed cINN-based model updating approach can provide more accurate inference results with a reduced computational cost in comparison to the classical approximate Bayesian computation (ABC) approach.
The main purpose of this work was to study the microstructure evolution and surface properties of rolled 5B70 aluminum alloy during ultrasonic impact treatment (UIT). The microstructural features of the surface deformed layer were characterized by OM and EBSD. The result indicated that UIT could transform the linear microstructure to a plastic flow feature and the deformation evolution characteristics of lamellar size gradient (LSG), which is characterized by gradient deformation from the grain boundary to the interior in the linear structure of each layer. The newly formed fine grains and the refined long gradient structure were formed due to the continuous dynamic recrystallization (CDRX), which is caused by the high strains. Surface roughness and hardness were consistent with the variation trend of geometrically necessary dislocations (GND) density. When the UIT coverage reaches 400%, the surface roughness performs best, and the UIT surface hardness is about 53.9 MPa higher than the base material.
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.
The passive film of reinforcing steel in marine concrete is damaged by the infiltration of chloride and sulfate ions. Layered double hydroxide (LDH) can adsorb anions and release interlayer ions to form passive films due to its ion exchange property. A Mg-Al-NO3 layered double hydroxide/montmorillonite (LDH/Mnt) composite inhibitor was prepared by layer-by-layer self-assembly (LBL) of LDH and Mnt. The structure and morphology of the LDH/Mnt composites were characterized by X-ray diffraction (XRD), laser Raman spectroscopy, N2-adsorption/desorption measurements, and transmission electron microscopy (TEM). The LDH/Mnt composites, as inhibitors of chloride ions and sulfate ions, exhibited high slow-release efficiency. The mass ratio of LDH and Mnt affected the curing capacity of the synthesized composites, and the optimum mass ratio was LDH/Mnt = 1:1 for which slow-release efficiency reached 94.16%.
Ports play a significant role in the economic and social activities of the areas they serve. However, the adverse effects of the harsh and highly corrosive environments that ports operate in, along with phenomena related to the climate crisis and insufficient maintenance practices, increase port infrastructure's susceptibility to rapid degradation. This degradation can be aesthetic, functional, or structural and often leads to loss of serviceability at either a component (local and national) level or a global level. Moreover, many port structures have reached the limit of their lifetime, thus introducing the concept of extending their lifespan as a financially attractive alternative to constructing new facilities. Therefore, port operators pursue monitoring the structural integrity of the structures through an inspection plan aiming to reduce their maintenance and rehabilitation costs and ensure the safety of both the port infrastructure itself and human lives. Optimising monitoring approaches to enable damage detection and condition assessment can be achieved through the employment of Non-Destructive Testing (NDT) and Remote Sensing (RS) techniques. The current surge of using Unmanned Aerial Vehicles (UAVs) for both RS and NDT monitoring practices has proved promising since UAVs provide improved accessibility, increased inspection speed, and reduced safety hazards. The present paper is focused on investigating and evaluating the recent advances in UAV-driven port infrastructure monitoring. For this purpose, a comprehensive review of UAVs applications combined with NDT Infrared Thermography (IRT) and Ground Penetrating Radar (GPR) or RS Close Range Photogrammetry (CRP) and Light Detection and Ranging (LiDAR) is carried out to assess the potential and the limitations of the UAV-based monitoring approaches. This research provides valuable information on enhancing management strategies by upgrading port monitoring practices.
The objective of the present study was to introduce a cost‐effective and environmentally friendly coating to improve the corrosion resistance of the structures located in salt water. The coating solution, based on amorphous aluminum phosphate composition, was synthesized by sol–gel process and applied to AISI 304 stainless steel by dip coating technique. X‐ray diffraction, scanning electron microscopy, and energy dispersive X‐ray spectroscopy analyses were employed to investigate the phase composition and morphology of the coating. Corrosion behavior of the uncoated and coated samples was investigated using standard salt spray test, potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS) in 3.5 wt.% NaCl solution. Salt spray test results for the bare substrate revealed a corrosion rate of six‐time greater than that of the coated surface after 168 hr exposure time. Electrochemical test results declared that the amorphous AlPO 4 coating decreased the corrosion current density of the AISI 304 stainless steel by 10 orders of magnitude. Furthermore, according to the corresponding EIS measurements, the coated surface exhibited a superior anti‐corrosion performance than uncoated sample. Overall, the results declared that the amorphous AlPO 4 coating could be a good choice for surface protection of stainless steel against electrochemical corrosion in salty environments.
In order to design and develop new marine structural materials with a balance of strength-toughness-corrosion resistance, in this work, the synergistic effects of Al and Ti on the microstructure, mechanical and corrosion resistance properties of CoCrFeNi(Al0.3Ti0.2)x high-entropy alloys were systematically investigated. With the addition of Al and Ti, the L12-γ' phase formed in the alloys significantly improves the mechanical properties, but excessive addition will lead to the formation of Al-Ti-rich B2 phase structure, which reduces the ductility of the alloy. For the corrosion resistance of the alloys in 3.5 wt.% NaCl solution, the increase of Al and Ti contents improves the stability of the passive film, while effectively reduces the corrosion current density and passivation current density of the alloys. However, the precipitation with a large number of strengthening phases aggravates the segregation of elements, resulting in a decrease in the pitting corrosion resistance and the resistance to the pit propagation of the alloy. In addition, compared with conventional structural alloys, the L12-strengthened dual-phase CoCrFeNiAl0.15Ti0.1 high-entropy alloy possesses an excellent balance of strength-toughness-corrosion resistance. This work also provides guidance for the future development of high-performance high-entropy alloy systems for marine engineering.
Anti-corrosion coatings are of great significance for marine equipment and engineering on account of the harsh marine environment. Vinyl ester resin is widely used as a resin material for anti-corrosion coating because of its excellent hardness and protective performance. However, the intrinsic brittleness of vinyl ester resin causes the resulting coating film with poor toughness. In this study, the tung oil-based toughen modifier (TOAMA) with a long carbon chain and annular structure is firstly prepared by Diels-Alder reaction of tung oleic acid and maleic anhydride under solvent-free conditions, and then used as a reactive toughening agent to synthesize toughened vinyl ester resin. The characterization results of Fourier transform infrared and hydrogen nuclear magnetic resonance spectroscopies reveal the successful synthesis of the TOAMA-toughened vinyl ester resin. Furthermore, the toughened vinyl ester resin is used in the anti-corrosion coatings, and the properties of the related cured coating films including thermostability, mechanical performance and corrosion resistance are systematically studied. The related results display that TOAMA can effectively toughen vinyl ester resin, and the toughened vinyl ester resin prepared with the optimized TOAMA content can effectively improve the mechanical properties including mechanical strength, elongation at break and fracture toughness, and achieve favorable thermal stability and excellent corrosion resistance of the cured coating films. Grafting tung oil-based toughening modifier TOAMA into the backbone of vinyl ester resin effectively provides a significant promising method to toughen vinyl ester resin, which is beneficial to the application of vinyl ester resin in the marine anti-corrosion coating field.
Salinity, temperature, humidity and illumination are main factors in determining the corrosion tendency of metallic materials under tropical marine atmosphere environment. In this paper, the weight loss, corrosion products, corrosion morphologies and electrochemical properties of S355 steel under simulated tropical marine atmosphere conditions were investigated. Different corrosion rules can be concluded under different atmospheric corrosion factors. The corrosion rate reaches maximum when the salinity content is 1.75%. S355 steel is easy to be corroded between 30 and 35 °C. The critical humidity of the S355 steel corrosion is 75%. The moisture condensing and illumination realizes dynamic balance at 70 W/m2, suggesting a lowest corrosion rate. In addition, the corrosion morphologies caused by salinity and illumination reveal uniform corrosion, while the corrosion morphologies caused by humidity and temperature show localized pitting corrosion. We believe the findings of this research will support the understanding of tropical marine atmospheric corrosion of metallic materials.
The main aim of this chapter is to monitor the cracking and damage assessment in steel-reinforced concrete (steel-RC) and glass fibre polymer-reinforced concrete (GFRP-RC) beams along with varying percentages of tension reinforcement ratio. Beam specimens measuring (150 × 230 × 2100) mm were tested using a four-point bending flexural test using a universal testing machine together with an AE monitoring system. Acoustic emission (AE) has been applied for the early monitoring of steel-RC and GFRP-RC structures using AE parameters such as cumulative AE hits, average frequency, rise angle, amplitude, duration and AE XY plots to evaluate the micro and macro cracking in the steel-RC and GFRP-RC beams specimens. The most popular applications of AE signal in structural health monitoring are specified on crack monitoring, quantifying the degree of damage, and crack classification. In this research, the results indicated that the average frequency and rise angle parameter of AE signal are applied to classify the types of cracks (flexural or shear cracks) that occur in steel-RC and GFRP-RC beams along with varying percentages of tension reinforcement ratio subjected to flexural loading. As a result of these findings, the AE approach may be used to examine crack monitoring and crack classification in steel and GFRP-RC beams with different percentages of tension reinforcement ratios.
Marine services and industry have emerged as one of the most significant pillars of global economic growth. Corrosion of materials, on the other hand, is still the most important issue for marine structures and equipment. Corrosion is a major contributor to the degradation of marine and offshore structures. It has an effect on the life of process equipment, and might lead to structural failure, leakage, product degradation, contamination, and even death. It is important to investigate the mechanisms of material corrosion in the marine environment, as well as corrosion prevention methods, in order to make effective use of marine resources. Various mitigation techniques, like the utilization of coatings, cathodic protection, and corrosion allowance are utilized to protect offshore structures against corrosion. In general, the marine environment has a significant impact on the protection of offshore structures. Therefore, the objective of this paper is to give an overview about corrosion of marine structures, how it happens and some of the current prevention techniques.
This review highlights the most important advances in the development and manufacture of advanced hybrid polymer-inorganic layered anticorrosion coatings for marine applications. These newly hybrid anticorrosion systems are gaining importance with the premise to improve the efficiency of the widely employed pure organic coatings, while widening the available types of polymeric materials employed. These could give rise to innovative high protective coatings with improved characteristics (mechanical strength, conductivity, biodegradability) or secondary functionalities (self-healing, anti-fouling). Through this document, four aspects are mainly overviewed, first, the use of 2D-layered inorganic fillers in coatings based on a barrier-type protection anticorrosion mechanism, with a special focus on graphene and its derivatives. Second, different modification strategies are presented, including covalent and non-covalent, always aiming to increase the compatibility between filler and matrix that would give as a result more efficient systems, due to 2D-layered fillers biggest drawback, their tendency to agglomerate. Third, different multi-functionalizing opportunities that graphene and its derivatives have to offer when introduced to these systems are reviewed, presenting some of the latest works reported in the past 2 to 3 years, while reviewing alternative layered structures such as natural clays or layered double hydroxides with their modifications. Fourth, different possibilities for multifunctioning these systems and their compatibility with graphene-like fillers are discussed. Finally, the conclusions and future perspectives on graphene-based anticorrosion nanocomposites are presented.
This is the second of two volumes that together provide an integrated picture of the Montenegrin Adriatic coast, presenting the natural components of the system as well as the chemical composition and chemical processes in the extended area.
This book covers all aspects of marine chemistry such as the hydrographic and oceanographic characteristics of seawater, the toxicity of heavy metals in the marine environment, the quality of marinas and maritime areas, and the legal regime for protecting the marine environment from pollution.
Given the breadth and depth of its coverage, the book offers an invaluable source of information for researchers, students and environmental managers alike.
In this work, fracture monitoring of steel and GFRP bars reinforced concrete beams in flexure is investigated by using non‐destructive acoustic emission (AE) and digital image correlation (DIC) techniques. The combined methodology provides complementary information from 'the ear' aided by the AE and from 'the eye' aided by the DIC. AE waveform parameters of the number of AE hits and their amplitudes, cumulative signal strength (CSS), average frequency, and rise‐time successfully pick‐up the divergent cracking initiation and fracture progression in steel‐reinforced concrete (RC) and GFRP‐RC beams. AE‐XY plots and longitudinal strain profiles obtained from DIC give an early, online, and real‐time representation of progressive AE activity and strains inside concrete much before it is visible to the naked eye. AE in conjunction with DIC was able to efficaciously depict the micro‐and‐macro cracks evolution and their advancement in steel‐RC and GFRP‐RC at various stages of loading Moreover, DIC identified critical damage areas as a function of loading periods, while AE was capable of monitoring the damage process and revealed changes in the overall behavior. It is successfully demonstrated that combined AE and DIC monitoring can enhance non‐destructive monitoring skills in RC structures involving widely different steel and GFRP bars as reinforcements and depict efficaciously their fracture/cracking behavior.
The performance of a volatile corrosion inhibitor (VCI) on steel via colloid formation through its reaction with Ca and Mg ions in seawater was studied. The physical and chemical properties of seawater, with and without the VCI at different concentrations, were determined. The VCI's effciency was assessed, and its suitability for the steel system in seawater was indicated at an optimal concentration of 0.05%.
The hydraulic infrastructure is constituted by the assets of two central elements: water supply and energy generation facilities. This study deals with the durability of the structures and their engineering materials. Four vital parts of this infrastructure were selected: dams, canals, aqueducts and hydroelectric stations, which are built of two basic materials; steel and concrete. The global climate change and warming and the greenhouse – gas emissions (all interrelated complex phenomena) affect these construction materials and structures, mainly by their extreme events such as torrential rains and flooding, dry and wet seasons, high and low humidity and solar radiation. This study presents a general global approach to the climate influence on the durability of those materials and structures and concludes with a description of a particular region: a section of the 'Great American Desert' on the Mexico–USA border.
In the present study, the overall economic impact of hull fouling on a mid-sized naval surface ship (Arleigh Burke-class destroyer DDG-51) has been analyzed. A range of costs associated with hull fouling was examined, including expenditures for fuel, hull coatings, hull coating application and removal, and hull cleaning. The results indicate that the primary cost associated with fouling is due to increased fuel consumption attributable to increased frictional drag. The costs related to hull cleaning and painting are much lower than the fuel costs. The overall cost associated with hull fouling for the Navy's present coating, cleaning, and fouling level is estimated to be 1B over 15 years. The results of this study provide guidance as to the amount of money that can be reasonably spent for research, development, acquisition, and implementation of new technologies or management strategies to combat hull fouling.
Background: Corrosion is a crucial worldwide problem that strongly affects natural and industrial environments, in particular affecting land, sea and air transportation vehicles: Cars, trucks, buses, merchant ships, and aircraft. This study describes a corrosion protection technology, based on chemical conversion coatings (CCC), to prevent, avoid or minimize corrosion event. Phosphating, a particular CCC was applied. Methods: Carbon steel pieces were phosphate by immersion in a solution containing phosphoric acid (PA, H 3 PO 4), zinc sulphate, hydrogen peroxide as an oxidant and a Zr salt, a sealing agent. The characteristics of the phosphate layer was determined by Scanning Electron Microscope (SEM), Energy Dispersive X-Ray Spectroscopy (EDS) and Raman Spectroscopy. The phosphate steel was painted with an industrial epoxy paint. Its corrosion resistance was determined by potentiodynamic polarization and by exposure in a saline chamber following the practice recommended in American Society for Testing and Materials (ASTM). Results: The steel specimens were weighed before and after immersion in the phosphating solution, after different immersion times. The weight increases resulting from the formation of the phosphate layer were recorded and are expressed in mg/cm 2. The corrosion rates were calculated using the Tafel slopes based on the Stern-Geary equation. The current density i in A/cm 2 units were converted into corrosion rate in mm/y units, applying the Faraday equation. Conclusion: Phosphating is a useful pretreatment, based on a phosphoric acid solution containing additional components to improve the protective capabilities of coating systems that are applied to steel in order to improve its corrosion resistance.
Biofilm control remains a challenge to food safety. A well-studied non-fouling coating involves codeposition of polytetrafluoroethylene (PTFE) during electroless plating. This coating has been reported to reduce foulant build-up during pasteurization, but opportunities remain in demonstrating its efficacy in inhibiting biofilm formation. Herein, the initial adhesion, biofilm formation, and removal kinetics of Bacillus cereus on Ni-PTFE-modified stainless steel (SS) are characterized. Coatings lowered the surface energy of SS and reduced biofilm formation by > 2 log CFU cm−2.Characterization of the kinetics of biofilm removal during cleaning demonstrated improved cleanability on the Ni-PTFE coated steel. There was no evidence of biofilm after cleaning by either solution on the Ni-PTFE coated steel, whereas more than 3 log and 1 log CFU cm−2 of bacteria remained on the native steel after cleaning with water and an alkaline cleaner, respectively. This work demonstrates the potential application of Ni-PTFE non-fouling coatings on SS to improve food safety by reducing biofilm formation and improving the cleaning efficiency of food processing equipment.
The corrosion of naval aluminum alloy UNS A95052 was investigated by exposing specimens in seawater at two ports-Ensenada on the Pacific Ocean, Mexico, and Ashdod on the Mediterranean Sea, Israel. Corrosion rates were calculated from weight loss and electrochemical parameters were measured in laboratory simulation tests. The alloy displays adequate corrosion resistance to both seawaters.
Liquefied natural gas (LNG) is transported from continent to continent in cryogenic sea vessels to maritime ports and regasification plants (RPs). Corrosion protection and control technologies are applied, which include correct selection of materials, coatings and linings, and cathodic protection (CP). LNG storage structures are constructed from corrosion-resistant engineering materials such as stainless steel (SS), Ni-alloys, reinforced concrete, aluminum alloys, and reinforced plastics. To maintain a continuous and effective operation, a diversified assembly of equipment is employed in RPs, including LNG storage tanks with special insulation, pumps, heat exchangers, screen filters for seawater, pipes of varying sizes for both operational processes, and LNG and NG transmission lines. The corrosive characteristic of NG requires the selection of CRAs (corrosion-resistant alloys) that will ensure long service life that is free of corrosion. They include martensitic, austenitic, and duplex SS, precipitation-hardened steel, and acid-resistant Ni-alloys.
The Gulf of Mexico (GOM) is a strategic, vast region that is home to numerous marine structures. Duplex and austenitic stainless steels (SS) are potential materials for critical components in offshore drilling, production, service, and oil storage platforms. In this investigation, the corrosion behavior of three SS in GOM seawater were studied by applying electrochemical, mechanical, and biological test methods.
Recent instances of bioinvasion, such as the emergence of the zebra mussel in the American Great Lakes, generated a demand among marine biologists and ecologists for groundbreaking new references that detail how organisms colonize hard substrates, and how to prevent damaging biomass concentrations. Marine Biofouling: Colonization Processes and Defenses is the English language version of a comprehensive work by eminent Russian scientist Alexander I. Railkin, who details the causes of vast biomass concentrations on submerged hard substrates. He also delivers a quantitative description of colonization processes and provides detailed models for preventing biofouling. This volume expounds on many topics rarely discussed in the frame of one book: types of hard substrate communities; comparison of hard and soft substrate communities; harm caused by micro- and macrofoulers; larval taxes and drift; mechanisms of settlement and attachment of microorganisms, invertebrates, ascidians and macroalgae; the impact of currents; protection from epibionts; industrial biofouling protection; successions on hard substrates; and the recovery of disturbed communities or the self-assembly of communities. The text includes much Russian-language research translated for the first time. Through a thorough examination of substrate organisms and an exploration of preventive methods, this monograph prepares those concerned with marine biology to help protect the self-purifying organisms that keep marine ecosystems healthy and productive.
Corrosion is a crucial worldwide problem that strongly affects the oil and gas industry. Natural gas (NG) is a source of energy used in industrial, residential, commercial, and electric applications. The abundance of NG in many countries augurs a profitable situation for the vast energy industry. NG is considered friendlier to the environment and has lesser greenhouse gas emissions compared with other fossil fuels. In the last years, shale gas is increasingly exploited in the USA and in Europe, using a hydraulic fracturing (fracking) technique for releasing gas from the bedrock by injection of saline water, acidic chemicals, and sand to the wells. Various critical sectors of the NG industry infrastructure suffer from several types of corrosion: steel casings of production wells and their drilling equipment, gas-conveying pipelines including pumps and valves, plants for regasification of liquefied NG, and municipal networks of NG distribution to the consumers. Practical technologies that minimize or prevent corrosion include selection of corrosion-resistant engineering materials, cathodic protection, use of corrosion inhibitors, and application of external and internal paints, coatings, and linings. Typical cases of corrosion management in the NG industry are presented based on the authors’ experience and knowledge.
Corrosion is a crucial worldwide problem that strongly affects the oil and gas industry. Natural gas (NG) is a source of energy used in industrial, residential, commercial, and electric applications. The abundance of NG in many countries augurs a profitable situation for the vast energy industry. NG is considered friendlier to the environment and has lesser greenhouse gas emissions compared with other fossil fuels. In the last years, shale gas is increasingly exploited in the USA and in Europe, using a hydraulic fracturing (fracking) technique for releasing gas from the bedrock by injection of saline water, acidic chemicals, and sand to the wells. Various critical sectors of the NG industry infrastructure suffer from several types of corrosion: steel casings of production wells and their drilling equipment, gas-conveying pipelines including pumps and valves, plants for regasification of liquefied NG, and municipal networks of NG distribution to the consumers. Practical technologies that minimize or prevent corrosion include selection of corrosion-resistant engineering materials, cathodic protection, use of corrosion inhibitors, and application of external and internal paints, coatings, and linings. Typical cases of corrosion management in the NG industry are presented based on the authors’ experience and knowledge.
Marine biofouling can be defined as the undesirable accumulation of microorganisms, algae and animals on structures submerged in seawater. From the dawn of navigation, marine biofouling has been a major problem for shipping in such areas as reduced speed, higher fuel consumption and increased corrosion. It also affects industries using off-shore structures such as oil and gas production and aquaculture. Growing concerns about the environmental impact of antifouling coatings has led to major new research to develop more environmentally-friendly alternatives. Advances in marine antifouling coatings and technologies summaries this wealth of research and its practical implications. This book is divided into four sub-sections which discuss: marine fouling organisms and their impact, testing and development of antifouling coatings, developments in chemically-active marine antifouling technologies, and new surface approaches to the control of marine biofouling. It provides an authoritative overview of the recent advances in understanding the biology of fouling organisms, the latest developments on antifouling screening techniques both in the field and in the laboratory, research on safer active compounds and the progress on nontoxic coatings with tailor-made surface properties. With its distinguished editors and international team of contributors, Advances in marine antifouling coatings and technologies is a standard reference for manufacturers of marine antifouling solutions, the shipping industry, oil and gas producers, aquaculture and other industries using offshore structures, and academics researching this important area.
Water pollution is often thought to cause accelerated corrosion of steels, particularly in harbors where levels of oxygenation of the waters may be low and where there may be industrial and shipping wastes. Harbors and coastal regions may also be prone to nutrient pollution from sewage or agricultural run-off. Offshore oilfields also are known to provide sources of nutrient pollution. There are some anecdotal observations but there appear to have been no systematic field or laboratory studies. Recent field observations have been reported on the effect of nutrient-based pollution on the corrosion of mild steel corrosion coupons. These are interpreted in terms of the phenomenological model previously described in the literature for the corrosion of mild steel under marine immersion conditions. A selection of field data previously reported in the corrosion literature is then considered and shown to have characteristics not inconsistent with nutrient-based water pollution. The effect of dissolved oxygen concentration is noted also.
The present article provides an overview of the effect of hydrogen sulphide (H2S) on corrosion in polluted waters, including sea, river, brackish, geothermal and sewage waters. H2S is a weak, reducing acid which originates from sulphide minerals by natural acidification and/or from sulphur – bearing, decaying organic matter by bacterial action. Human and industrial activities increase the generation of corrosive gases, dissolved in water: CO2, H2S and NH3. Carbon steel, stainless steel, aluminium alloys and copper base alloys are corroded by H2S, producing metallic, non-stable sulphide films. The H2S content in various waters, the electrode potential pH (Pourbaix) diagrams for Fe and Cu in H2S containing systems, and the electrochemical and corrosion performance of steel in oxygen depleted, H2S polluted waters, which indicate active corrosion behaviour, are presented and discussed.
According to most pundits on the topic, climate change will have a serious impact on many aspects of our life on the planet. At the onset it is not obvious how most of the predicted changes will take their toll on the integrity of the equipment and systems presently in use. This paper will examine three aspects of climate change that may alter the corrosive behaviour of the environment and increase the risk of corrosion failures: changes in precipitation patterns, corrosivity of coastal regions, and increased stresses on marine systems.
Corrosion affects both fixed and mobile marine installations and equipment made from two basic engineering materials: steel and reinforced concrete. Typical cases of corrosion appear in the retaining walls of marine ports and in the floating docks of shipyards. This situation has been aggravated in recent decades by the discharge of municipal, industrial, and agricultural effluents which contain and/or produce by biological and chemical decomposition, toxic and highly corrosive components. The corrosive substances include hydrogen sulphide (H2S), oxygen (O2), carbon dioxide (CO2), ammonia (NH3) and heavy metals. In this brief review, contaminated ports are described and typical cases of marine corrosion and methods of corrosion prevention and protection are discussed.
Charney School of Marine Sciences, Maritime Civilization
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Polución y corrosión en ríos contaminados. Paper presented at: III Congreso de Ingeniería Civil
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The future of the oceans: acid test
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La acidificación del océano y los arrecifes del Pacifico Mexicano
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Preservation of the infrastructure in the Gulf of Mexico
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13:65-80.
Potomac Institute for Policy Studies. Chapter 1, The need for improved corrosion control
- R Hummel
Corrosión de metales y degradación de materiales [Metals corrosion and materials degradation
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y degradación de materiales [Metals corrosion and materials degradation]. Mexico: Universidad Autónoma de Baja
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Alternative futures for corrosion and degradation research. Potomac Institute for Policy Studies. Chapter 1, The need for improved corrosion control
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Relationship of corrosion with climate change
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