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Marine structures are constantly exposed to the corrosive effects of seawater, making effective corrosion protection crucial for their longevity and performance. Sacrificial anodes, commonly made of zinc, aluminum, or magnesium alloys, are widely employed to mitigate corrosion by sacrificing themselves to protect the steel structures. However, the selection and implementation of sacrificial anode materials present various challenges that need to be addressed. This paper explores the challenges associated with sacrificial anode materials for steel structures and provides potential solutions. To overcome these challenges, the paper proposes solutions such as using advanced alloy compositions, protective coatings, hybrid anode systems, and improved design considerations. Furthermore, the importance of monitoring techniques to assess the performance and remaining lifespan of sacrificial anodes is emphasized. Several case studies and experimental findings are discussed to illustrate the effectiveness and limitations of sacrificial anode materials based on zinc alloys, aluminum alloys, and magnesium alloys. The paper highlights the need for ongoing research and development efforts to address the evolving demands of corrosion protection in marine environments. [ABSTRACT FROM AUTHOR]

Corrosion affects the usefulness of metallic materials used in the construction of an effluent treatment plant (ETP). The present report investigates the corrosive and inhibitive properties of the chemicals present in the effluent of paper mill and distillery industries. Chemicals such as chloride, chlorophenols, phosphate, calcium, nitrite, and nitrate enhance corrosion, whereas the presence of sulfate, potassium, organic matter, and melanoidins (color) inhibits corrosion at an acidic pH level in distillery and paper mill effluents. A finding shows that pH level has an important role in increasing or decreasing the effect on corrosivity of effluents. [ABSTRACT FROM AUTHOR]

In recent decades of research, organic coatings have been considered the most effective and economical measure for corrosion protection of metals. However, defects in organic coatings created during the curing reaction provide corrosion channels for corrosive media, which in turn accelerate the failure of metallic materials. Functional nanomaterials are considered to be the key to solving this challenge. Metal organic frameworks (MOFs) materials, as an emerging nanomaterial, show great potential as a durable and efficient nano-corrosion filler in organic anti-corrosion coatings. Therefore, this paper reviews the application of MOFs materials as solid corrosion inhibitors, small molecule corrosion inhibitor vehicles and modified graphene oxide in anti-corrosion coatings and looks forward to the prospect of research on their application in engineering practice. [ABSTRACT FROM AUTHOR]

Magnesium alloy is one of the most promising automotive lightweight materials, but its poor corrosion resistance seriously hinders its practical application in automotive engines. Corrosion inhibitor technology has the characteristics of small dosage, simple operation, low cost, and does not affect the heat dissipation of metals. Therefore, adding high-efficiency long-term corrosion inhibitors to automotive engine coolants is the simplest, most practical and effective way to realize the application of magnesium alloy in automotive engines. This paper reviewed the corrosion and corrosion inhibition behaviors of magnesium alloy in ethylene glycol aqueous solution. The effects of temperature, galvanic effect, water content, and anionic and acidic oxides on the corrosion of magnesium alloy in automotive coolant were summarized. The research, advantages and disadvantages of inorganic, organics small-molecule, polymer, and composite corrosion inhibitors for inhibiting the corrosion of magnesium alloy in ethylene glycol aqueous solution were also summarized. The construction of inorganic-polymer corrosion inhibitor composite films was proposed to realize the application of magnesium alloy in engine, which further enriched the corrosion theories and anti-corrosion technologies of magnesium alloy. [ABSTRACT FROM AUTHOR]

The objective of this review is to create a body of knowledge on the theoretical and practical aspects of corrosion inhibition to prevent and/or to eliminate corrosion in natural environments such as water, air, and acids and in industrial facilities such as oil, natural gas, concrete, paints and coatings, electronics, and military equipment. Corrosion inhibitors (CIs) and volatile corrosion inhibitors (VCIs) are applied in diverse forms such as powders, pellets, aqueous, or solvent solutions and in impregnated papers; closed in pouches and sachets; and added to coatings. Natural CIs are extracted by water or organic solvents from suitable plants. They represent the advanced trends of corrosion management based on green chemistry. [ABSTRACT FROM AUTHOR]

The ammonia-hydrazine shutdown protection method is widely used in thermal power plants in China because of its good protective performance. However, the toxicity and safety of hydrazine have restricted its use in many power plants, and it is necessary to improve the shutdown protection techniques. In this paper, electrochemical impedance spectroscopy and potentiodynamic polarization curves were used to study the effect of hydrazine in water solutions of different pH values, adjusted with ammonia on the corrosion behavior of carbon steel. It was found that in the water solution without hydrazine, the corrosion resistance of a carbon steel electrode increased with raising the pH. When the pH value of water increased to 10.5, the impedance value of the carbon steel increased significantly, the corrosion current density decreased from 26.06 μA·cm−2 at pH 10.0 to 2.36 μA·cm−2, and the steel surface was passivated. Hydrazine had different effects on the electrochemical corrosion behavior of carbon steel in water solutions with various pH. When the pH of water was not higher than 10.0, hydrazine had a good corrosion inhibition effect on carbon steel. When the pH of water was not lower than 10.5, the addition of hydrazine inhibited the passivation of carbon steel and promoted the corrosion. The adsorption and substitutional oxidation of hydrazine in the anode region of carbon steel surface should be the reasons for the above phenomenon. [ABSTRACT FROM AUTHOR]

In this paper, the principle and application of atomic force microscopy (AFM) are reviewed and discussed in detail. Several scientific papers are used to find out data about AFM. The obtained scientific results are summarized to get a better understanding of the method and its application. The application of AFM for corrosion study is discussed in detail, and the possible conclusion is made based on the results of several articles. It is summarized that AFM is an important method to determine the surface phenomena of metal corrosion. [ABSTRACT FROM AUTHOR]

The corrosion mechanism of copper and copper alloy is reviewed. A number of scientific papers have been investigated to determine the corrosion mechanism and protection techniques of copper and copper alloy corrosion. Results have shown that copper can be corroded in an acidic or an alkaline environment, and oxide formation is the corrosion initiation process. The use of corrosion inhibitors is one of several ways of controlling metal corrosion. There are inorganic (toxic) and organic (green) corrosion inhibitors invented so far. Nowadays, environmental issue is a concern of several scientists in the world. From the results of recent scientific papers, green corrosion inhibitors can be used for copper corrosion protection and they are both economical and environmentally safe. Furthermore, future researches are needed to determine more efficient, environmentally friendly corrosion inhibitors for copper and copper alloys. [ABSTRACT FROM AUTHOR]

The operating environment of Navy aircraft varies to a good degree depending upon the squadron location, flight requirements, and other field and ground activities. All these conditions promote corrosion of one type or the other. The aircraft operations will also have influence on the type of corrosion. Thus, building an environment history that can monitor and track the damage development in many areas of the aircraft structure based on aircraft activities, operating environment, and service history data is crucial. The development of such environmental history builder has two main advantages: first, it provides a tool to treat corrosion as a structural issue, and second, it accounts for time variation of environmental factors such as relative humidity (RH) and temperature rather than average environmental data. This paper will demonstrate how the environmental history builder could be used, in conjunction with predictive models, to predict corrosion damage. [ABSTRACT FROM AUTHOR]

Phosphoric acid has been used in many industrial applications and can be in contact with a lot chemical and petrochemical equipment. Most of this equipment is made of steel alloys that may be damaged because of contact with acid. Corrosion inhibitors can be used for to protect steel alloys against several forms and various environments of corrosion. In this paper, the efficiency and applications of organic and inorganic inhibitors in different environments of phosphoric acid are investigated. More than 40 papers were collected and reviewed. Surveys of the stated works in phosphoric acid environments are documented. It was concluded that organic inhibitors performed as good corrosion inhibitors and are used widely. The use of inorganic inhibitors was limited. Most of studied inhibitors follow Langmuir’s adsorption isotherm, and the mechanism of the inhibition can be ascribed to the mixed effect on cathodic and anodic reactions. The synergistic effect was also addressed in the present work. [ABSTRACT FROM AUTHOR]

Anodic protection (AP) is one of the corrosion control methods that has been widely used in the manufacture, storage, and transport of sulfuric acid. The present paper gives a brief review of the history, some applications, and a case study of failure causes and remedial actions of AP in a sulfuric manufacturing plant. The AP system consists of a direct current source, cathodes, reference electrodes, and signal conditioning electronics. In a sulfuric manufacturing plant, for AP of 316L piping (as an anode), platinized titanium (Pt/Ti) and Hastelloy B-2 were used as reference and cathode electrodes, respectively. After seven years of operation of the AP system in the sulfuric acid plant, a section of the protected pipelines has severely corroded. The study of the system showed that the reference electrodes, which were titanium-electroplated with platinum, lost their stability in the acid with the loss of coating and caused overprotection. However, the system could not control the pipe's potential in the AP situation. In this condition, accelerated corrosion of the cathodes and pipes has also occurred. [ABSTRACT FROM AUTHOR]

Carbon capture and storage (CCS) technology is considered to be one of the key technologies to reduce CO2 emissions. This paper reviews the industry corrosion accidents of CCS transportation system, in which the pipeline corrosion risk is analyzed, and the pipeline corrosion theory is summarized. Also, the effect of impurities on gas phase properties is discussed. We analyze the corrosion mechanism of multicomponent impurities on metals in a supercritical CO2 environment from the aspects of corrosion rate and corrosion products. We also describe the mechanism of pitting and stress corrosion of metals in a supercritical CO2 environment. Besides, the formation mechanism of FeCO3 protective layer and the research status of corrosion resistant alloys in supercritical CO2 are reviewed and analyzed. Finally, a series of shortcomings and prospects of the current research are put forward. [ABSTRACT FROM AUTHOR]

This paper investigated optimization of corrosion inhibitory attributes of mixed cocoa pod-Ficus exasperata (CP-FE) extracts towards mild steel in 1.5 M HCl using central composite design. Potentiodynamic polarization, linear polarization resistance and electrochemical impedance spectroscopy measurements were used for the electrochemical study. The result revealed maximum inhibition efficiency of 91.52% at temperature, inhibitor concentration, time and acid concentration of 50 °C, 5 g/L, 144 h and 0.2 M, respectively with R2 value of 0.9429. Central composite design predicted optimum point of 70.37 °C, 3.81 g/L, 127.37 h and 0.22 M. Potentiodynamic polarization revealed extract to be mixed-type inhibitor with anodic prevalence. Electrochemical impedance spectroscopy showed that corrosion inhibition occurred via adsorption of CP-FE molecules on active sites of MS surface. Scanning electron microscopy images revealed protection of mild steel surface by adsorbed molecules of CP-FE extracts. Fourier transform infrared revealed presence of carboxyl (–COOH), unsaturated (–C-C–) and hydroxyl (–OH). Energy dispersive spectroscopy revealed presence of high iron composition on mild steel surface in the presence of mixed CP-FE extract proving its corrosion inhibition efficiency in 1.5 M HCl. Atomic adsorption spectroscopy revealed loss of Fe2+ into free HCl solution. Generally, extract from mixed CP-FE was found as effective corrosion inhibitor for mild steel in 1.5 M HCl solution. [ABSTRACT FROM AUTHOR]

This paper describes the study of electrodeposition process by cyclic voltammetry for Zn-Ni bimetallic coating on the X52 carbon steel substrate. Prior to the deposition at the bath temperatures of 25°C, 40°C, and 60°C, investigations were carried out to find the optimum potential range for zinc-nickel coatings with respect to the Ag/AgCl reference electrode. Scanning electron microscopy (SEM) coupled with energy dispersive X-ray (EDX) was used for surface morphology and elemental composition studies. The corrosion rate of the deposits was studied using the linear polarization resistance (LPR) method by immersing the samples (with and without coating) into 3.5% NaCl solution for 24 h. SEM and EDX results showed that the bath temperature has affected the formation of the microstructures and composition of coating. In addition, micro-cracks, nickel content, mobility of ions and compactness of microstructure increased by raising the bath temperature used for electrodeposition. The corrosion rate obtained from the LPR method can be correlated with the SEM/EDX analysis. The coating deposited at the temperature of 60°C including more content of nickel and micro-cracks led to lower corrosion resistance compared to the coating deposited at the bath solution temperatures of 25°C, 40°C, and non-coated X52 steel. Based on the results, the Zn-Ni coating deposited on the X52 steel substrate in the bath solution at 40°C presented the best performance due to more suitable achievements of microstructure compaction, composition, microcracks, and corrosion resistance observations. [ABSTRACT FROM AUTHOR]

Corrosion exposure study was conducted on the commercial nickel-based K411 superalloy in a simulated gas turbine operating environment (air + 2 vol% SO2) at 900 °C up to 2000 h. The corrosion behavior of the alloy was quantificationally analyzed from both morphological and chemical points with SEM, XRD, EDS, and EPMA. The results show that the formation of fine TiN inside the oxide layer can be strongly accelerated with the introduction of SO2. Sulfide is assumed as diffusion channels for gas molecules that accelerate internal nitridation. Large-volume variation caused by the TiN formation leads to a stress gradient, which induces Cr and Ni elements from inside to the surface of the alloy. The oxide scales release the compressive stresses generated by internal nitridation through forming protrusions on the surface, which is a potential risk for alloy failure. The corrosion behavior of K411 superalloy is controlled by a combination of oxidation, sulfidation, and internal nitridation whereby the relevant corrosion mechanism has been given. [ABSTRACT FROM AUTHOR]

This paper reports on the influence of heat treatment on the corrosion properties of CuAlMn alloy in 0.1%, 0.9% and 1.5% NaCl solution (pH = 7.4). Heat treatment of alloy samples was performed by samples annealing at 900°C for 30 min. Electrochemical methods of investigations included measuring the open circuit potential (Eoc) and linear and potentiodynamic polarisation. Optical microscopy, scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) were used to study the morphology and composition of the corroded surfaces, along with X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). Heat-treated samples have slightly more positive values of Eoc, slightly lower values of corrosion current density and higher values of polarisation resistance compared with the as-cast alloy. The microscopic analysis showed the rough surfaces due to corrosion processes. Increasing the electrolyte concentration leads to an increase in alloy surface damage. AFM and SEM examinations showed that the surface was covered with interlaced layers of corrosion products, as well as cracks and ducts formed by their dissolution. EDX and XPS analyses showed that corrosive products consist mainly of aluminium and manganese oxides and chlorides. Annealed CuAlMn alloy samples have significantly lower copper content compared with the as-cast CuAlMn alloy. [ABSTRACT FROM AUTHOR]

This manuscript has provided an overview of the development of TiNi alloys and their applications in biomedicine. The microstructures and properties of TiNi alloys are first introduced. The breakthroughs in the manufacturing and applications in biomedicine of TiNi alloys in recent years have been achieved by scientists and are presented in the present paper. It is well known that the properties of TiNi alloys are affected by the modification methods on the surface of bulk TiNi alloys. The main preparation technologies of TiNi alloy coatings are evaluated, with particular attention to several spray technologies. Then, the biocompatibility, strong anticorrosion and antiwear properties, and mechanism of TiNi alloys are also described in detail. Several advanced manufacturing processes of TiNi alloys are also briefly outlined such as selective laser melting and spark plasma sintering. The performance of TiNi alloy coatings prepared by thermal spraying techniques are fully qualified for medical applications. Thermal spraying techniques have great prospects in reducing the cost and improving the quality of TiNi alloy medical products. [ABSTRACT FROM AUTHOR]

In this paper, the plasma electrolytic oxidation (PEO) was used to improve the corrosion resistance of aluminum in 0.5 M HCl solution. Influence of many factors such as the composition of electrolytes, time and inorganic additives on the performance of PEO process have been investigated. The surface morphology of PEO films was inspected using SEM, EDX and XRD analysis. The electrochemical impedance spectroscopy (EIS) and polarization measurements were carried out to evaluate the corrosion resistance of aluminum. The hardness and reduced modulus of aluminum surface at different PEO process time were determined by nanoindenter measurements. The results showed that the best conditions for formation high efficient oxide layer on the aluminum surface during PEO process were carried out in 0.001 M NaOH electrolyte containing 9 × 10−5 M Na2WO4 for 5 min. The PEO process is able to inhibit uniform and pitting corrosion of aluminum in HCl solution. The surface morphology analysis showed that PEO process produce a highly resistant protective oxide layer, mainly composed of orthorhombic crystalline phase of α-Al2O3. This oxide characterized by its greater hardness. [ABSTRACT FROM AUTHOR]

In many industries and processes, heat exchangers are of vital importance as they are used to transfer heat from one fluid to another. These fluids can be corrosive to heat exchangers, which are usually made of metallic materials. This paper illustrates that corrosion is an important problem in the operation of heat exchangers in many environments, for which no straightforward answer exists. Corrosion failures of heat exchangers are common, and corrosion often involves high maintenance or repair costs. In this review, an overview is given of what is known on corrosion in heat exchangers. The different types of corrosion encountered in heat exchangers and the susceptible places in the devices are discussed first. This is combined with an overview of failure analyses for each type of corrosion. Next, the effect of heat transfer on corrosion and the influence of corrosion on the thermohydraulic performances are discussed. Finally, the prevention and control of corrosion is tackled. Prevention goes from general design considerations and operation guidelines to the use of cathodic and anodic protection. [ABSTRACT FROM AUTHOR]

This paper presents the results of a series of investigations that were performed on a reinforced concrete bridge structure exposed to marine environment in subtropical weather. Data were obtained by assessing the structural conditions using visual observations, nondestructive evaluations, and laboratory testing in order to define the cause and the level of concrete deterioration due to corrosion. In addition, a probabilistic methodology was used to compute the time of corrosion initiation focusing on reinforced concrete subjected to a similar chloride environment. The initial service life was predicted with a method that employed the use of statistical models of the governing parameters obtained from field data. Results show that this approach could be utilized for assessment of existing and new constructions and/or as a tool for decision-making process during the structural design phase. [ABSTRACT FROM AUTHOR]

In chloride environments, reinforcement stress limits, intended to control flexural cracking, are one of the most important requirements for service limit state (SLS) design. However, concrete damage at the steel-concrete interface between bending cracks, so called cover-controlled cracking, is always correlated to areas of severe steel reinforcement corrosion. Based on the assumption that cover-controlled cracking should be limited, a model has been developed to provide alternative reinforcement stress limits in marine exposure conditions such as concrete in sea water, including permanently submerged, spray zone and tidal/splash zone, as well as coastal constructions located within 1 km of the shoreline. In this paper, the new reinforcement stress limitation is compared to the Australian Standards AS3600 concrete building code and AS5100.5 concrete bridge code provisions. Analysis shows that the new model is very sensitive to the reinforcement percentage of the cross-section. As a result, the existing AS3600 and AS5100.5 code provisions are more conservative than the new limitation for lightly to normally reinforced concrete cross-section. In this case, crack width control governs the SLS design. However, for normally to heavily reinforced concrete cross-section, the new model provides more conservative results suggesting that cover-controlled cracking governs the SLS design. [ABSTRACT FROM AUTHOR]

The efficiency of industry depends upon the working conditions of the equipment and components used in the industrial process. The biggest problems faced by the industries are the problems of erosion and corrosion. The harmful effects of corrosion will lead to material loss, which results from the degradation of the equipment. The degradation of the equipment will cause the breakdown of the plant; moreover, it is a threat to the safety of people, and also from the point of conservation, it can cause the exploitation of available resources. The cost of replacing equipment increases the expense, and it can also result in the temporary shutdown of the plant. The protection of surfaces from the adverse effects of corrosion and erosion-corrosion is a matter of great concern in most industrial applications. Advancements in technology provides a wide range of techniques to overcome adverse conditions. The selection of appropriate technology must be from the viewpoint of their interaction with the environment. This review paper addresses the adverse effects of erosion-corrosion in the present scenario. [ABSTRACT FROM AUTHOR]

Traditionally, controlling corrosion has been managed by various methods like cathodic protection, process control, reduction of the metal impurity content and application of surface treatment techniques as well as incorporation of suitable alloys. However, the use of corrosion inhibitors has proven to be the easiest and cheapest method for corrosion protection and prevention in acidic media. These inhibitors slow down the corrosion rate and thus prevent economic losses due to metallic corrosion on industrial vessels, equipment or surfaces. Many researchers have recently focused on corrosion prevention methods using organic inhibitors for mild steel in acidic solutions to mimic industrial processes. This paper arranges for an overview of types of corrosion, corrosion process and mainly recent work done on the application of quinolone derivatives as corrosion inhibitors for different metals. [ABSTRACT FROM AUTHOR]

The aim of this paper was to evaluate the performance of two different modified zeolitic minerals as anticorrosion pigments in order to reduce or eliminate zinc phosphate in paints. In the first stage, the selected minerals were characterized and modified with cerium ions to obtain the anticorrosion pigments. Their inhibitive properties were evaluated by means of electrochemical techniques (corrosion potential measurements and polarization curves) employing a steel electrode immersed in the pigments suspensions. In the second stage, solvent-borne paints, with 30% by volume of the anticorrosion pigment, with respect of the total pigment content, were formulated. The performance of the resulting paints was assessed by accelerated (salt spray and humidity chambers) and electrochemical tests (corrosion potential measurements and electrochemical impedance spectroscopy) and compared with that of a control paint with 30% by volume of zinc phosphate. Results obtained in this research suggested that zeolites can be used as carriers for passivating ions in the manufacture of anticorrosion paints with at least reduced zinc phosphate content. [ABSTRACT FROM AUTHOR]

In order to achieve a full mechanistic understanding of stress corrosion cracking (SCC), the key operating mechanisms need to be identified but also quantified. In this study, we summarize and rationalize key findings from the last 15 years of high-resolution characterization of SCC in our group. A comprehensive characterization of a set of austenitic alloys with different Ni content and constant Cr level, tested under simulated pressurized water reactor (PWR) primary water conditions at various temperatures, has revealed evidence for at least two operating mechanisms: one diffusion-related and the other deformation-related. For their relevance to the nuclear industry, two additional alloys with increased Cr content were also studied (A800 and A690). Key precursors for SCC initiation and propagation are identified and their effect on alloy degradation discussed. A list of key materials' properties that ensure low SCC susceptibility is proposed. [ABSTRACT FROM AUTHOR]

It is common to observe that monotonic K1c (lab air) and K1scc (NaCl solution) decrease with increasing YS of an alloy. K1c is measured in lab air and K1scc in an aqueous solution such as NaCl. It is noted that K1c is not considered as a subcritical parameter while K1scc is. Interestingly, for a given alloy, both these parameters seem to be inter-related. That is, K1scc is linearly related to K1c, such that K1scc increases with increasing K1c. This may indicate that plasticity is affecting the K1scc behavior. This article looks into the conditions that affect K1scc for steels, Al-alloys, and Ti-alloys. This linear variation of K1scc with K1c seems to be independent of alloy YS, E, microstructure, and work hardening rate. This observation seems similar in all three systems of alloys. How these parameters are interrelated is analyzed and discussed in detail. [ABSTRACT FROM AUTHOR]

The paper summarizes the results obtained by authors concerning near-neutral stress corrosion cracking (SCC) phenomena on buried pipelines. Stress corrosion tests according to different methodologies and fatigue propagation tests were executed on traditional steel grades. Tests were performed also on specimens pre-corroded according to a procedure developed to produce localized attacks similar to those observed during failure analysis on pipelines, acting as preferential sites for crack nucleation. Electrochemical tests were carried out in order to evaluate the influence of environmental parameter on pit formation. The main role of continuous plastic deformations on nearneutral SCC is confirmed. The effect of pH, CO2, and bicarbonate concentrations on pitting formation is discussed. [ABSTRACT FROM AUTHOR]

Light-water reactor (LWR) fuel cladding shall retain the performance as the barrier for nuclear fuel materials and fission products in high-pressure and hightemperature coolant under irradiation conditions for long periods. The cladding also has to withstand temperature increase and severe loading under accidental conditions. As lessons learned from the accident at the Fukushima Daiichi nuclear power station, advanced cladding materials are being developed to enhance accident tolerance compared to conventional zirconium alloys. The present paper reviews the progress of the development and summarizes the subjects to be solved for enhanced accident-tolerant fuel cladding, focusing on performance degradation under various corrosive environmental conditions that should be considered in designing the LWR fuel. [ABSTRACT FROM AUTHOR]

The fundamental process of drilling within the oil and gas industry appears straightforward, entailing the creation of a borehole that connects to the underlying oil reservoir. An indispensable component in this operation is the mud formulation, playing a critical role in lubricating the drill bit and facilitating the efficient removal of cuttings. However, a notable challenge arises due to the machinery's predominantly metal composition, leading to corrosion concerns. Various strategies, including the application of corrosion inhibitors, have been introduced to address and manage this corrosion challenge. This review provides a comprehensive exploration of recent research endeavors focused on corrosion inhibitors in the context of offshore drilling operations. It aims to offer insights into the diverse types of corrosion commonly encountered during drilling activities in marine environments. Moreover, the review delves into an in-depth examination of various corrosion inhibitors utilized for mitigation, shedding light on their performance characteristics and limitations within the specific scope of drilling operations. By scrutinizing these corrosion inhibition strategies, the review contributes to a nuanced understanding of the evolving landscape in drilling technology and the measures taken to ensure the longevity and efficiency of drilling equipment. [ABSTRACT FROM AUTHOR]

The partitioning coefficient of the R12Na corrosion inhibitor is determined by relating its concentration in the water phase (CW) to the expected theoretical concentration (Ci,T) due to a re-concentration phenomenon after the mixing stage. Partition experiments were performed by varying the water cut in brine-kerosene mixtures, temperature, and the inhibitor concentration using NACE 1D182 brine as a water phase and ultraviolet-visible spectrophotometry. The partition results varied from 37.81 to 43.75 %, 36.68 to 61.23 %, and 40.29 to 56.47 % at 40 °C, 60 °C, and 80 °C, respectively, indicating that R12Na is a water soluble inhibitor and dispersible in the organic phase. Likewise, the partition results varied from 41.69 to 44.04 % in the presence of 20, 50, and 100 mg L−1 of the inhibitor, using a ratio of 80–20 vol% WP–OP and 60 °C. Furthermore, making the same considerations, the partition of different corrosion inhibitors reported in the literature was evaluated, supporting its determination, the latter is of great importance for dosing corrosion inhibitors in the oilfield industry. [ABSTRACT FROM AUTHOR]

In this study, in situ hybrid (Al3Ni + Al2O3)/Al composites were prepared successfully by the solid-state combustion via Al–NiO system. The effects of Al3Ni + Al2O3 on the corrosion features of composites were analyzed using potentiodynamic polarization, electrochemical impedance spectroscopy, and immersion corrosion in 3.5 wt% NaCl solution. The results show that with the increase of NiO addition, the corrosion resistance of composites is improved, and the corrosion resistance of 15 % NiO–Al composite is almost comparable to the Al matrix. The increased quantity and dispersive distribution of Al3Ni and Al2O3 particles can effectively prevent the occurrence of corrosion and the movement of free electrons. Besides, more fine Al2O3 particles distributed in grain boundaries can increase the impedance and hinder the electrochemical corrosion preferentially starting at the boundary. Also, in the composite with high NiO addition, a better and compact interface bonding can be formed due to reduction of large size Al3Ni particles and improvement in the dispersion of particles, thereby inhibiting interface damage. This study has advanced understanding of corrosion. [ABSTRACT FROM AUTHOR]

Stainless steels are used extensively in semiconductor manufacturing as chamber, structure component and gas delivery systems. The corrosion in the aggressive gas in the semiconductor manufacturing industry leads to particle release, contaminating wafers and limiting their application. Moisture content can accelerate the corrosion rate of stainless steel. In a high-temperature environment, the corrosion is determined by the synergistic effect of the vapour of the corrosion product and thermal ageing. To eliminate corrosion, lots of efforts have been performed and categorized into three aspects: (1) Material purification using innovating metallurgy techniques, especially vacuum induction melting (VIM) and vacuum arc remelting (VAR). The ultra-pure stainless steel minimizes the inclusion in stainless steel, suppressing the breakdown of the passive film. (2) Smoothing the surface by polishing; the polishing surface shows hydrophobic behaviour and decreases moisture absorption. (3) Applying surface and coating techniques against corrosion, including passivation treatment and electroplating/electroless Ni-based coating. Herein, the techniques mentioned above are reviewed, and the prospect and development of stainless steel in the semiconductor manufacturing industry are forecasted. [ABSTRACT FROM AUTHOR]

The effectiveness of 5-acetyl-4-(3-methoxyphenyl)-6-methyl-1-phenyl-3,4-dihydropyrimidin-2(1H)-one as a corrosion inhibitor for mild steel in acidic conditions was investigated herein through the experimental and theoretical approach. Experimental results demonstrated that this compound acts as a reliable corrosion inhibitor (η %) for mild steel in acidic environments, with its inhibition efficiency increasing as the inhibitor concentration rises. Adsorption behavior on the mild steel surface followed Langmuir and Temkin adsorption isotherms. Electrochemical polarization tests indicated that the compound exhibited a mixed corrosion type, and impedance spectroscopy revealed an increase in charge transfer resistance with higher inhibitor concentrations. Examination of the mild steel surface using SEM and Atomic Force Microscopy (AFM) confirmed the formation of a protective film. Wettability characteristics were assessed using the contact angle method. Frontier molecular orbital analysis revealed the HOMO and LUMO values for both the neutral and protonated forms of the compound. At 289 °C, the interaction energy for adsorption was found to be approximately −146.3006 kJ/mol for the neutral system and −135.8122 kJ/mol for the protonated system, while at 318 °C, the corresponding values were −140.6106 kJ/mol and −147.6022 kJ/mol. These findings collectively suggest the potential industrial utility of the investigated inhibitor as an effective corrosion inhibitor. [ABSTRACT FROM AUTHOR]

Effects of minor alloying elements (Si, Mn, and Al) on the corrosion resistance behaviors of stainless steel (SS) modified 310S used as a cathode current collector (CCC) material for molten carbonate fuel cells (MCFC) were examined in a mixture of 62 mol% Li2CO3–38 mol% K2CO3 at 650 °C by measuring the change in corrosion potential and the potentio-dynamic, potentio-static polarization responses. The corrosion potential of modified 310S gradually increased after 9 h of immersion due to an active to passive transition and that of SSs added with minor alloying elements drastically increased before 6 h of immersion due to the reactive alloys. Si, Mn, and Al addition to base SS led to a decrease in corrosion resistance due to the rapid corrosion rate at the cathode operation potential, −40 mV, of the MCFC. The steady state current densities of SSs added with minor alloying elements were higher than that of 310S and modified 310S. Addition of Si, Mn, and Al induced a decrease in corrosion resistance of CCC materials in molten carbonate fuel cell operating temperatures, 650 °C. [ABSTRACT FROM AUTHOR]

X-ray photoelectron spectroscopy (XPS) combined with Ar ion etching was used to analyse the surface film of pure Mg at different depth after immersion in 3.5 % NaCl solution for 10 min. The XPS spectra of specimen surface showed that the corrosion products are mainly made up of Mg(OH)2 and Mg2Cl(OH)3·xH2O. The formation process of Mg2Cl(OH)3 is the reaction of Mg(OH)2 and Cl− and H+ in weak acidic solutions. The XPS results indicated that the intensities of Mg2Cl(OH)3·xH2O decreased with the increase of etching time from 0 s to 4680 s. It is confirmed that the edge of Mg(OH)2 protrudes outward and then splits into Mg2Cl(OH)3 when Cl− attacks the Mg(OH)2 films, so the Mg2Cl(OH)3 attached to Mg(OH)2. Meanwhile, coupling the scanning electron microscope (SEM) and transmission electron microscopy (TEM) with the XPS to analyze the corrosion mechanism. Furthermore, the results displayed that the XPS combined with Ar ion etching is a good characterization method to understand the reaction of corrosion products. [ABSTRACT FROM AUTHOR]

For the prevention of steel rebar corrosion in cement pore solutions, new ionic liquids with an imidazole base were tested using the polarization and mass loss methods. The structure of the cations of imidazole base ionic fluids with various derivatives makes them good mixed-type inhibitors by adsorbing them on steel bars to suppress both anodic and cathode processes. The best performance efficiencies recorded by mass loss and polarization methods at 100 ppm were 97.4 and 96.1 %, respectively. These results will motivate numerous researchers to continue their arduous research to identify new ionic liquids' anti-corrosion properties in the field of concrete additives. [ABSTRACT FROM AUTHOR]

The corrosion behavior of GH3535 alloys in KCl–MgCl2 eutectic salts with or without magnesium (Mg) was investigated using the static immersion tests. The effect of purification treatment on the corrosion of GH3535 specimens was also evaluated by the different analysis. The KCl–MgCl2 salts purified with Mg and reducing service temperature can slow down the corrosion rate of GH3535 specimens. Infrared spectra results showed that purification treatment reduced the content of crystal water in the KCl–MgCl2 salts. The difference of hydrate content in KCl–MgCl2 salts and the diffusion rate of Cr in alloy are the main reasons for the change of GH3535 specimens corrosion rate. [ABSTRACT FROM AUTHOR]

The present paper deals with evaluation of corrosion behavior of electrodeposited nanocrystalline (Nc) NiCo, NiZn and NiCu alloys. Nc NiCo, NiZn and NiCu coating electrodes were electroplated from sulfate electrolyte on copper foil by the galvanostatic technique and ultrasound waves. The chemical composition, surface morphology and crystalline structure of the different alloys were studied using energy dispersive spectroscopy, scanning electron microscope and X-ray diffraction methods. The electrochemical behavior of the deposited material in 1.0 M KOH solutions was investigated. The electrochemical behavior of the coating electrodes in alkaline solutions was investigated by potentiodynamic polarization techniques and electrochemical impedance spectroscopy (EIS). Results showed that the alloying of nickel with Co causes an increase in the stability of Ni-alloy in alkaline solutions in comparison to Ni-Cu and Ni-Zn alloys. The corrosion resistance values of Ni-Zn coatings were lower compared to those of the other investigated alloy coatings due to preferential dissolution of Zn from the matrix. The experimental impedance data were fitted to theoretical data according to a proposed equivalent circuit model representing the electrode/electrolyte interface. [ABSTRACT FROM AUTHOR]

The degradation of materials due to erosion–corrosion occurs on the components that handle particle-laden corrosive slurry. The combined attack of mechanical erosion and corrosion shows increased material loss than the individual action of erosion and corrosion. The synergy accelerates material removal by eroding the corroded surface layer and corroding the surface due to the elimination of the passivating oxide layer by erosion. The synergism of erosion–corrosion is found to be more complex. Further, the coupled effect of mechanical erosion and electrochemical corrosion and the factors influencing erosion–corrosion still needs to be fully investigated. This review aims to provide a general and detailed summary of the interaction between erosion and corrosion of materials for the applications of pump impellers, pipelines for desalination, and oil and gas transportation. Importance is also given to the factors influencing erosion–corrosion, such as erodent particle properties (hardness, size, and shape), slurry properties (particle concentration, pH value, temperature), and flow characteristics (impingement angle, velocity). The various erosion models and the most used apparatus have also been reviewed. [ABSTRACT FROM AUTHOR]

Corrosion of metals is considered a global dilemma that is attracting an increasing number of researchers in the scientific community. One of the fundamental solutions against corrosion is using corrosion inhibitors. Corrosion inhibitors are the substances added to the medium or the metal to inhibit corrosion through different mechanisms, most commonly by the formation of a protective layer on the metal surface. Organic corrosion inhibitors constitute most of the known and used corrosion inhibitors, however, due to the toxicity and cost of synthesis, green replacements are needed. Green nanomaterials corrosion inhibitors provide a green and sustainable solution for corrosion. The low toxicity, availability, and cost-effectiveness of green nanoparticles made them a growing research field. This review article highlights the synthesis, use, and application of green nanomaterials in corrosion inhibition. Moreover, the article provides insight into the different types of green nanomaterials inhibitors and their common characterization techniques. [ABSTRACT FROM AUTHOR]

Two environmentally friendly inhibitors of imidazolium-based ionic liquids namely 3-benzyl-1-hexadecyl-1H-imidazol-3-ium chloride (IL-H), and 3-(4-chlorobenzyl)-1-hexadecyl-1H-imidazol-3-ium chloride (IL-Cl) were manufactured and their chemical structures were confirmed by spectra tools (FT-IR, and 1H NMR). The utilizing of these two new ionic liquids as green corrosion inhibitors for low carbon steel (LCS) in 1.0 M HCl under altered experimental conditions. Mass loss (ML), potentiodynamic polarization (PP), AC impedance spectroscopy (EIS) and surface morphology are take place in this study. The protection performance found to increase with increasing ionic liquid dose and temperature, reaching 92.9% and 95.1% for IL-H and IL-Cl at 120 ppm, respectively. Based on the PP records, the investigated ionic liquids behave as mixed-type inhibitors, influencing both anodic and cathodic responses. The inhibitory activity from these explored ionic liquids was stimulated by their adsorption on the effective surfaces of the steel surface in accordance with the Langmuir adsorption isotherm. The Density Functional Theory (DFT) method is used to analyze the relationship between quantum chemical calculations and the protection efficiency of ionic liquids. [ABSTRACT FROM AUTHOR]

This work presents a summary of environmental data from 3600 h of data collected during operations of a U.S. Coast Guard HC-130H aircraft performing its routine missions over a five-year period. The aircraft operated from multiple U.S. and deployed locations during the data collection period in the tropical and mid-latitudes at altitudes up to 8.5 km (28 kft). The aircraft collected pressure, temperature and humidity data during the period. No aerosol components were sampled (chlorides, sulfur dioxide, etc.). While there was no Time of Wetness sensor, the ISO 9223 definition is used for the present work as an estimator. These data are presented in the context of research into corrosion and environmental severity, or the potential conditions for it. About 40% of the data were collected while the aircraft was parked on the ground at various based and deployed locations. The purpose of this work is to present and summarize the flight data as an aid in providing some context for future research into environmental effects as they relate to both corrosion and environmentally assisted cracking (EAC) of aircraft structure, and perhaps for comparisons with existing or future datasets from aircraft having other missions. Prediction models need realistic, real-world inputs, such as those presented here. An example for the use of these data in corrosion prediction based on the ISO 9223 international standard is presented. Perhaps not surprisingly, these data show that, for this aircraft, conditions most favorable to corrosion occurred while the aircraft was on the ground. [ABSTRACT FROM AUTHOR]

The influence of iron sulfide on the rate of cathodic and anodic processes of steels with ferrite, perlite and ferrite perlite structure was shown. It was established that the hydrogenation and corrosion rate of steels with different structures depends not only its structure, but also the nature of sulfide-containing products of corrosion. The well-known scheme of the influence of hydrogen sulfide on the processes of corrosion and hydrogenation of steel was supplemented by reactions of formation iron sulfides. They can affect the rate of recombination of hydrogen atoms and, respectively, its molation and absorption by metals. [ABSTRACT FROM AUTHOR]

The effect of cysteine on the corrosion characteristics of Cu5Zn5Al1Sn alloy in 3.5 wt% NaCl solution has been studied by electrochemical and surface characterization techniques in various immersion times. The results of electrochemical impedance spectroscopy (EIS) revealed that the degradation of Cu5Zn5Al1Sn alloy occurred in 3.5 wt% NaCl and was aggravated with increasing immersion time. The results of inhibition efficiency calculated from EIS data showed that cysteine can act as an effective anti-corrosion substance, which was also proved by the less eroded morphology of the alloy surface observed on scanning electron microscopy (SEM). Furthermore, the elemental analysis of alloy surfaces was investigated by Raman, electron dispersion spectroscopy (EDS), and X-ray photoelectron spectroscopy (XPS), which confirmed the presence of S and N species. An adequate adsorption isotherm and inhibition mechanism was also suggested based on EIS results. [ABSTRACT FROM AUTHOR]

Graphene and its derivatives have attracted much interest as corrosion-resistant coatings for magnesium alloys since 2014, when the first reports appeared in the literature. The interest in the use of such carbonaceous compounds to protect magnesium and its alloys from corrosion relies on a set of attributes such as chemical inertness, and high surface area. To support the development of optimized graphene-based films it is imperative to expand the current knowledge toward a deeper understanding of corrosion mechanisms and their interaction with practical aspects related to coating deposition and morphology. In the present work, graphene-based coatings for magnesium alloys are reviewed. We explored the correlation between coating architecture, deposition methods and materials selection using the Ashby approach. The results of the materials selection process revealed that composite coatings consisting of an inorganic matrix obtained by plasma electrolytic oxidation of magnesium alloys and graphene oxide nanosheets as blocking agents can provide surfaces with high corrosion resistance in sodium chloride solution. For biomedical applications, composite coatings consisting of a mixture of organic matrices such as chitosan and graphene oxide as reinforcing particles are attractive candidates. The results are discussed based on coating architecture and its interplay with the corrosion properties. [ABSTRACT FROM AUTHOR]

The oil and gas industry worldwide is experiencing problems of vandalism and mechanical deterioration due to corrosion in its various pipeline transport systems, a drop in the price of hydrocarbons due to the COVID-19, limitation of maintenance processes. This article provides a contribution original to the knowledge and management of a pipeline transportation system (PTS), without an immediate high impact that would help reduce property loss due to corrosion, through the development of intelligent evaluation models that combine field data, laboratory, and cognitive knowledge in a case study in Mexico. The research is divided into Part 1: modeling, a Fuzzy expert system (FES) unified the knowledge of corrosion specialists and mechanical integrity studies (MIS) and identified evolutionary corrosion patterns with reliability of 0.9029. An artificial neural network (ANN) supported by statistics and metallography establishes test reliability of 0.9556 and determines the corrosion inhibition capacity (C) of Mexican hydrocarbon mixtures based on their properties compared to carbon steel. Part 2: analysis of the operational and economic risk of the PTS under corrosive effects, using Monte Carlo simulation (MCS) estimates various financial scenarios considering corrosive profiles of soils, supply, demand, and inflation. [ABSTRACT FROM AUTHOR]

The review article summarizes various ionic liquids (ILs) used as corrosion inhibitors reported in the literature during the preceding five years (2016–2020) for corrosion of carbon steel in acidic solutions. The ILs are a green and sustainable choice for corrosion inhibition as compared to natural extracts as corrosion inhibitors due to lack of stability which restricts their application at the industrial level. The review discusses the inhibition efficiency of the ILs as corrosion inhibitors; the evaluation techniques like weight-loss method, potentiodynamic polarization, electrochemical impedance spectroscopy, etc., used for determination of inhibition efficiency and plausible mechanism of inhibition, adsorption isotherms are discussed. The review affirms that ionic liquids serve as excellent green corrosion inhibitors for carbon steel dissolution in acidic media. Most of the reported inhibition efficiency values ranged between 80 to 90% at minute concentrations which is valuable. The scope for further improvements is given for the benefit of readers. [ABSTRACT FROM AUTHOR]

Our research on employing the cellular automata methodology to corrosion and passivation phenomena is reviewed. Examples of a peculiar pit development are found and presented. The diffusion rate in the corroding medium is argued and shown in the simulation results to affect mainly the characteristic length scale for the corrosion process. New data for the pitting corrosion development on a planar interface are presented and discussed. [ABSTRACT FROM AUTHOR]

Industrial crops and products have proved to be an excellent alternative to petro-based chemicals. Vegetable oils are rich in functional groups that can be transformed into monomers and polymers with applications such as biodiesel, lubricants, inks, coatings, and paints. This study describes the synthesis of rapeseed oil (RO)-based esteramide for the first time. The reaction was carried out by amidation of RO, producing diol fatty amide (N,N-bis(2-hydroxyethyl) RO fatty amide), followed by its esterification reaction with hippuric acid, resulting in RO-based hippurate amide (ROHA). Fourier-transform infrared spectroscopy and nuclear magnetic resonance confirmed the introduction of amide and ester moieties in ROHA. ROHA was further reinforced with silver nanoparticles (SNPs) to develop corrosion-protective nanocomposite coatings. ROHA/SNP coatings were scratch-resistant, impact-resistant, and flexible and showed good corrosion resistance performance toward 3.5 w/w% NaCl medium, with adequate corrosion protection efficiency, and antimicrobial behavior against Staphylococcus aureus, Chromobacterium violaceum, Escherichia coli, Pseudomonas aeruginosa, and Candida albicans. ROHA/SNP coatings can be safely used up to 250°C. [ABSTRACT FROM AUTHOR]