Corrosion Prevention Research Articles

Mono and bilayer coatings of alkanethiol and silane on copper: Prevents corrosion and regulate bacterial adhesion

Self-assembling molecules (SAMs) provide a flexible system for surface modification of materials by forming films of molecular thickness. SAMs protect materials from corrosion and modify surface properties such as adhesion, adsorption and wetting due to their molecular composition and orientation. In this investigation, polished copper specimens were dip coated to form SAMs of alkanethiol and silane to study bacterial adhesion as well as for corrosion prevention. The SAM coated specimens were exposed to the log phase cultures of Pseudomonas aeruginosa (aerobic bacteria) and Desulfovibrio vulgaris (anaerobic bacteria) for 12, 24 and 48 hrs, to monitor cell adhesion and biofilm thickness by microscopy. The results showed that alkanethiols SAM promoted adhesion and biofilm formation. The biofilm thickness ranged from 10 to 38 µm for Pseudomonas and 9 – 25 µm for Desulfovibrio sp. Among the SAM coatings tested, octadecyl-trichlorosilane (ODTCS), alkane-thiol and ODTCS (bilayer SAM) showed no bacterial adhesion, however, solitary alkane-thiol SAM showed significant bacterial adhesion. The high hydrophobicity (contact angle ∼140°), antibacterial and anti-biofilm property of the ODTCS coating could have regulated bacterial adhesion. The constant climate test results showed that silane SAM prevented copper corrosion up to ∼160 days (3480 hrs), while the alkanethiol coating could protect up to 10 days (240 hrs). Confocal laser scanning microscopic images of the silane coated copper specimens showed initiation of the corrosion after 160 days of exposure, while at the end of 200 days significant copper corrosion was observed. Surface modification leads to specific biochemical interactions that regulate bacterial adhesion and prevent biofilm formation and corrosion of copper.

Synthesis of hexagonal boron nitride nanocoatings for corrosion prevention of iron substrates

Iron and its alloys have applications in diverse fields such as civil infrastructure, aerospace, and defense. Corrosion of these alloys in saline environments is a significant concern that causes huge environmental losses. The current study explores pulsed laser deposition technique to synthesize hexagonal boron nitride (hBN) films as protective coatings, directly on iron (Fe), to mitigate the corrosion. Microstructural, mechanical, wetting, and corrosion properties of hBN-coated Fe substrates were investigated at different deposition temperatures (25–800 °C) and varying thicknesses (35–115 nm). Raman spectra and transmission electron microscopy confirmed the presence of hBN in as-deposited films. Crystallinity and surface roughness of hBN coatings increased as deposition temperature increased. Electrochemical studies performed in 3.5 wt% NaCl solution showed that the 115 nm thick hBN coatings deposited at 600 °C resulted in lower corrosion rates and has ~6-fold higher corrosion resistance than bare Fe. Also, the corrosion rates decreased with an increase in hBN coating thickness. Overall results suggest that hBN nanocoatings reduced the corrosion activity and can potentially serve as a corrosion-resistant barrier coatings in saline environments.

Development of an eco-friendly waterborne polyurethane/catecholamine/sol-gel composite coating for achieving long-lasting corrosion protection on Mg alloy AZ31

One of the most effective strategies for Mg alloys corrosion prevention is to isolate the Mg alloys surface from the corrosive environment by applying a coating to the surface. Waterborne polyurethane (WBPU) has received widespread attention in recent years due to its advantages of sustainability and low toxicity. However, when Mg alloys contact with WBPU, hydrogen evolution reaction (HER) occurs simultaneously, which cannot provide corresponding protective effects and cause coating delamination. To solve this problem, sol-gel based thin pretreatment coatings were applied to isolate the contact between the substrate and the WBPU layer. Additionally, the mussel inspired catecholamine was used to modify the sol-gel coating, and its effects on the overall corrosion resistance and adhesion strength were studied. The research in this paper showed that the sol-gel modified by catecholamine not only improved the corrosion resistance, but also enhanced the adhesion between the WBPU layer and the pretreatment sol-gel layer. The adhesion was increased from 1.74 MPa to 2.75 MPa. According to the EIS results, the sample immersed in aqueous 3.5 wt% NaCl for 120 days showed that the anti-corrosion performance of the coating has been improved by more than two orders of magnitude (Rct from 4.9 × 104 Ω·cm2 increased to 1.7 × 107 Ω·cm2).

Cathodic Protection Online Monitoring Using a Low Power Wide Area Network Communication System

Cathodic protection is a corrosion control and prevention system that is applied to underground pipe structures by providing an electric charge to the structure to be protected. An online monitoring system for cathodic protection is urgently needed to save costs and ensure operator safety in the field in the care of the protected structure. This study aimed to evaluate cathodic protection online monitoring using a low power wide area network (LPWAN) communication system. Cathodic protection online monitoring in this study was applied using LPWAN with a radio frequency of 433 MHz. In this work, the type of communication with wireless technology has been chosen with low power consumption and can accommodate the distance between test stations in the distribution pipeline. From the results of testing the cathodic protection online monitoring system, it can be seen that measurement data that has been done manually can be replaced in real-time and monitored remotely. This system is highly recommended for areas that have so far not been covered by manual measurements, for example, remote areas prone to flooding, swamps, and interference areas that require denser data information to make handling easier to do early.

Dual-purpose corrosion and kinetic hydrate inhibitors based on 3-acrylamidopropyl trimethyl ammonium copolymers

Corrosion inhibitors (CIs) are cost-effective and efficient solutions to mitigate the corrosion and to protect the relevant assets in the oil & gas sector. The corrosion inhibitors have however the potential to dramatically impair the effectiveness of the kinetic hydrate inhibitor (KHIs) because of compatibility issues. Creating a copolymer with both CI and KHI qualities for a sour environment is a challenge. This study proposes a new copolymer with CI and KHI moieties: 3-acrylamidopropyl trimethyl ammonium chloride (AMPTMA) block copolymers with acryloyl and acrylamide type comonomers. The corrosion studies were carried out utilizing high-pressure high temperature (HPHT) rotating cage autoclave and electrochemical measurements under different laboratory (standard 3.5 wt% NaCl brine) and field simulated conditions. These copolymers provided corrosion inhibition efficiency of up to 90%, owing to their strong adsorption on the carbon steel surface. The type of comonomer used in copolymers appears to play a significant role in corrosion prevention and adsorption capabilities on the metal surface. Additionally, one of the copolymers demonstrated the effectiveness as KHI by holding a subcooling of 5.6 °C at 96 bar in a sour (H2S) environment. These findings provide evidence that AMPTMA based copolymers have the potential to work as dual-purpose inhibitors (KHCI) to mitigate corrosion and gas hydrate formation.

Natural Polyphenols and the Corrosion Protection of Steel: Recent Advances and Future Perspectives for Green and Promising Strategies

Corrosion is recognized as an unavoidable phenomenon and steel, particularly carbon steel, is strongly susceptible to corrosion. Corrosion damages cause serious material, energy, and economic losses as well as negative impacts on the environment. As a result, research interest has been focused on the development of effective corrosion prevention strategies. However, some of the most commonly used corrosion inhibitors, such as chromates and pyridines, are harmful to human and environmental health. Polyphenols are natural, non-toxic, and biodegradable compounds from plant sources or agricultural by-products. Polyphenols’ chelating capacity has been acknowledged since the 1990s, and tannins, in particular, have been widely exploited as green rust converters in phosphoric acid-based formulations to recover rusty steel. Polyphenolic compounds have recently been investigated as a method of corrosion prevention. This review overviews not only the polyphenolic rust converters, but also the application of green anticorrosive coatings containing polyphenols. Moreover, polyphenols were discussed as an active component in corrosion-inhibiting primers to also promote strong adhesion between the steel surface and the topcoat layer. Finally, an overview of the use of polyphenolic additives in coatings as sustainable systems to improve corrosion resistance is provided.

Prevention of marine corrosion with graphene-based polymer coatings

Prevention of marine corrosion with graphene-based polymer coatings

Polysulfide Anticorrosion Sealants and Corrosion Preventive Compounds (Literature Review)

Polysulfide Anticorrosion Sealants and Corrosion Preventive Compounds (Literature Review)

Corrosion prevention and control using in situ phase layers formation via application of the complexing‐type inhibitors

AbstractA set of organic ligands of different natures has been investigated as complexing‐type corrosion inhibitors for the protection of low carbon steel in an acidic medium. The inhibitive mechanism implying the formation of phase protective layers on the metal surface as a result of the complexation process of added organic ligands with the metal cations is being discussed. The results of the investigation of the influence of pH and temperature conditions on the phase layers formation dynamics have been presented. A range of practical aspects of the application of organic ligands as complexing‐type inhibitors for the formation of ultrathin coatings have been discussed. The stability constant of the metal–ligand complex and its solubility have been proposed as the basis of a predictive model for analytical assessment of their potential protective efficiency.

Studying the Tribological Properties of Coffee Oil-Loaded Water-Based Green Lubricant

Lubrication is the primary solution to reduce friction and wear. However, conventional lubricants cause pollution when not properly disposed of or due to accidental leaks. Therefore, environmentally friendly lubricating fluids are welcome in any application where they can meet the performance requirements. This study suggests using coffee oil produced from spent coffee grounds to improve the lubricity of water-based lubricating fluid. Bis(2-hydroxyethyl)ammonium oleate protic ionic liquid facilitates the dispersion of coffee oil in water. Kinematic viscosity, wettability, corrosion prevention, and lubricity tests were performed to evaluate the tribological properties provided by these additives. It was observed that a higher amount of coffee oil could be dispersed with the introduction of a higher amount of protic ionic liquid. In this study, ten wt.% of coffee oil was successfully dispersed using one wt.% of protic ionic liquid. Introducing additives increased dispersions’ viscosity, improved wettability, provided protection against corrosion, and reduced wear and friction. It was proposed that polar molecules of protic ionic liquid were responsible for most of the improvement, while coffee oil contributed by increasing viscosity. Further studies could be directed toward determining rational concentration to meet each particular application’s requirements.

Modeling the Effects of Electromagnetic Interference from Multi-Wire Traction Networks on Pipelines

The 25 kV traction network creates highly intensive electromagnetic fields. These fields affect the long conductive structures located near railway lines and can induce voltage, posing a danger for maintenance personnel. Typical examples of such structures are pipelines, which are used to transport liquid and gaseous products. In addition to compromising electrical safety, the induced voltage can result in dangerous densities of corrosion currents in pipe insulation defects. Therefore, the determination of the induced voltage and current in the pipes is undoubtedly relevant. An analysis of existing literature on the electromagnetic compatibility of traction networks and pipelines indicates that important aspects regarding the effects of traction networks and high-voltage power lines on extended conductive structures have been addressed. However, these works do not present a unified method to determine the induced voltage on parts of the structures and the current flowing through the pipeline. Such a method could be based on a technology that models the operation of electric power systems in phase coordinates. This paper presents the development of a method and the results of the studies aimed at modeling the voltage induced by complex traction networks. The developed digital models make it possible to adequately determine the induced voltage created by multi-wire traction networks and the current flowing through the pipes. Using these models, one can make an informed decision regarding the appropriate measure to ensure the safety of personnel working on these structures, as well as the development of corrosion prevention methods and measures.

Experimental and Numerical Investigation into the Effect of Water Uptake on the Capacitance of an Organic Coating.

Water uptake by organic coating systems used for corrosion prevention on airframes is one of the principal contributors to the loss of barrier properties of the coating. We used equivalent circuit analyses of electrochemical impedance spectroscopy (EIS) data to track changes in coating layer capacitance for a two-layer coating system consisting of an epoxy primer and polyurethane topcoat immersed in NaCl solutions with different concentrations and temperatures. The capacitance curve exhibited two different response regions, consistent with the "two-stage kinetics" mechanisms for water uptake by the polymers. We tested several numerical diffusion models of water sorption and found the most successful to be one that varied the diffusion coefficient as a function of polymer type and immersion time and accounted for physical aging processes in the polymer. We employed the Brasher mixing law along with the water sorption model to estimate the coating capacitance as a function of water uptake. The predicted capacitance of the coating was found to be consistent with the capacitance obtained from the EIS data, which is consistent with theories that water uptake occurs via initial rapid transport followed by a much slower aging process. Thus, both these water uptake processes need to be considered when making EIS measurements to assess the state of a coating system.

Film-forming amine product as an alternative to carbohydrazide oxygen scavenger in high pressure boilers

Hydrazine has been largely replaced by carbohydrazide (CHZ) as an oxygen scavenger due to safety and health concerns and CHZ is now used in Saline Water Conversion Corporation (SWCC) high pressure boilers. However, the operational problem of phosphate hide-out has become a continuous challenge for the plant operators. Advances in boiler water treatment have shown that effective corrosion control and prevention of scaling can be achieved by using a mixture of film-forming and alkalizing amines and polycarboxylates [Film Forming Amine Product (FFAP)]. With the use of FFAP, carbohydrazide/ammonia treatment of make-up water and phosphate treatment in the drum will not be required. A uniform FFAP formulation was used throughout the test.The evaluation study was carried out at a boiler of the Yanbu Phase 1 Desalination and Power Plant (Mitsubishi) generating 60 MWh, with make-up water of 15 t h−1 producing 330 t h−1 steam at a pressure of 67 barg and temperature of 480 °C.The trial provided evidence that FFAP was a good alternative to use of an oxygen scavenger. Changeover from CHZ to FFAP without phosphate addition in the drum was done initially by dosing FFAP from both hydrazine tank and phosphate tank so that pH was maintained to the required values in both feed water and drum water. With the optimal dose rate (0.6 ppm) maintaining FFAP in the range of 0.3–1.0 ppm in feed water, all the key parameters (pH, ammonia and specific conductivity) were within the specified boiler design limits. The average corrosion rates on the water side were low for both CHZ and FFAP treatment (0.009 ± 0.001 mm y−1), however FFAP treated coupons showed much lower corrosion rates compared to CHZ in the steam side (0.0006 ± 0.0003 mm y−1 cf. 0.0075 ± 0.0006 mm y−1).

HD-SiO2/SiO2 Sol@PDMS Superhydrophobic Coating with Good Durability and Anti-Corrosion for Protection of Al Sheets.

Superhydrophobic coatings with excellent water-repellent properties imply a wide range of application areas. However, improvements are needed in terms of stability and complex processing procedures. In the present study, a superhydrophobic coating on Al sheets was prepared by mixing hexadecyltrimethoxysilane (HDTMS)-modified SiO2 nanoparticles and acid-catalyzed silica sols (HD-SiO2/SiO2 Sol) with polydimethylsiloxane (PDMS) binder. The HD-SiO2 nanoparticles and acid-catalyzed silica sol (SiO2 sol) form a binary graded micro-nanostructure, providing excellent superhydrophobicity (Water Contact Angle = 158.5°, Sliding angle = 0°). Superhydrophobic coatings with excellent water-repellent properties have potential for corrosion prevention. However the commonly used organic resins have poor chemical and mechanical properties. In the present study, the results of outdoor exposure for 30 days, immersion in acid and alkaline solutions for 24 h, grit abrasion, and water impact experiments, respectively, showed that the prepared superhydrophobic coating has good wear resistance. The integrated superhydrophobic coating on the Al sheets exhibited good corrosion inhibition with an efficiency (η) of 98.9%, which is much higher than that of the uncoated sheets. The present study provides a promising approach for producing stable superhydrophobic coatings at a low cost, with the potential to supplant conventional organic resin anti-corrosion coatings.

Corrosion prevention for PEO-coated Mg by phosphate-based sealing treatment with added cation

There is no research on sealing treatments for PEO-coated Mg with phosphate sealing solutions containing different cations. In this work, four different cations are added to the phosphate solution for sealing treatment of PEO-coated Mg. The PEO coatings sealed with solutions containing Ca2+ and Mn2+ achieve the best corrosion resistance, since their dense deposition layers can seal the micropores and resist the erosion of the corrosive medium. The physical model and chemical equation used to deposit the formation of the sealing reaction are established by the experiment. They can predict the sealing effects when adding different cations to the phosphate solution. Comparing with other researches which are largely restricted to investigating the effect of phosphate-based sealing treatment on the corrosion resistance improvement of PEO coatings, conclusions here provide better guidance for formulating sealing methods to the PEO coating.

Adsorption of 2-Mercapto-1-methylimidazole on the (√3 × 22) Reconstructed and (1 × 1) Phases of an Ordered Au(111) Electrode under Potential Control

The self-assembled monolayers (SAMs) of organosulfur compounds bearing an imidazole (Im) functional group can form hydrogen bonds with others and tailor specific interfacial structures used for CO2 reduction, biosensing, and corrosion prevention. The current study employed cyclic voltammetry and in situ scanning tunneling microscopy (STM) to address the adsorption and structure of 2-mercapto-1-methylimidazole (MMI) on the reconstructed and unreconstructed Au(111) electrodes as a function of potential. The adsorbed MMI molecule assumed the unprotonated form, allowing its S- and N-ends to bind with the Au electrode at a positive potential. Molecular resolution STM images showed an ordered Au(111)–(√21 × √21)R10.9°–MMI structure. The Au–N bond could weaken and be broken at a negative potential, leading to a disordered MMI adlayer. This restructuring event was coupled with the protonation of the Im group. These processes resulted in a sharp peak, which shifted negatively by 60 mV with an increase of 1 pH unit. MMI admolecules were desorbed at a more negative potential to unveil a pitted Au surface, resulting from etching of MMI adsorption. This feature supports the S–Au–S motif for MMI adsorbed to the Au(111) electrode, irrespective of the initial Au surface structure. The effect of MMI as an additive to the deposition bath of Ni was also explored.

Corrosion inhibition study of 6061 aluminium alloy in the presence of ethyl 5-methyl-1-(4-nitrophenyl)-1H-1,2,3-triazole-4-carboxylate (NTE) in hydrochloric acid

The inhibitory effect of an ethyl 5-methyl-1-(4-nitrophenyl)-1H-1,2,3-triazole-4-carboxylate (NTE) was investigated on the corrosion of Al (AA6061) alloy at different temperatures (303–333 K) by Electrochemical impedance spectroscopy (EIS), Potentiodynamic polarization (PDP), and weight loss techniques. It was found that NTE molecules protect the aluminium against corrosion and its ability increases with increasing concentrations, and temperature resulting in better inhibitory performance. At all concentrations and temperature ranges, NTE exhibited mixed inhibitor action and complied with the Langmuir isotherm. At 100 ppm and 333 K, NTE demonstrated the highest inhibition efficiency (94%). The EIS results and the PDP results had a good level of concordance. A suitable mechanism for the corrosion prevention of AA6061 alloy was proposed. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) were used to confirm the adsorption of an inhibitor onto the aluminium alloy surface. The electrochemical results were validated by morphological examination, which demonstrated that NTE prevents uniform corrosion of aluminium alloy in acid chloride solutions. The activation energy and thermodynamic parameters were computed, and the results were discussed.

Failure analysis of the sewage pipeline on a shale gas platform

The wall thickness of the sewage pipeline on a shale gas platform is seriously reduced. In order to explore the specific reasons for the pipeline failure, this paper carried out analysis by means of macroscopic inspection, mechanical property test, chemical composition analysis of base metal and corrosion product analysis. The analysis results show that the site of this pipeline corroded most seriously is at 5 o ′clock and 12 o ′clock near the outlet, and the corrosion of liquid accumulation containing CO2 is the main reason for the serious failure of the inner wall of this pipeline. This paper explores the specific reasons for the failure of the sewage pipeline on a shale gas platform, and provides a reference for the corrosion prevention of the sewage pipeline.

Graphene-Assembled Film-Based Reconfigurable Filtering Antenna with Enhanced Corrosion-Resistance

Corrosion-resistance is the key to improve the reliability and service lifespan of highly integrated reconfigurable filtering antennae. However, the conventional methodology for corrosion prevention cannot achieve desired effects, due to the limited intrinsic corrosion-resistance capacity of traditional metal-based devices. Here, we developed a reconfigurable filtering antenna based on graphene assembled film (GAF), featuring significant corrosion-resistance enhancement. The GAF-based antenna exhibits comparable electrical performance when compared with a copper-based antenna, and can flexibly switch between two working modes, including ultra-wideband (UWB, 2.8–11 GHz) and narrowband filtering (NBF, 3.23–3.77 GHz). To further demonstrate the of the corrosion-resistance of GAF, a salt spray corrosion test found that the GAF-based antenna exhibits steady electrical properties after corrosion for over 336 h, while the copper-based antenna shows rapid performance degradation. The simulated and experimental results are in agreement, indicating that the proposed GAF reconfigurable filtering antenna can be applied to broader application prospects in communication systems, especially in severe environments.

Assessment of corrosion prevention methods for steel reinforcement embedded in concrete exposed to a natural marine environment

Corrosion of the steel reinforcement is a serious problem that lessens the durability of concrete structures. Numerous research studies focus on the improvement of the concrete matrix and the protection of the reinforcing bars against corrosion. Fly ash and silica fume have been used for the former and inhibitors for the latter; nevertheless, corrosion is a very complex multifactorial phenomenon because the deterioration mechanisms involved in a simulated-marine environment differ from those involved in a natural environment. Despite these facts most corrosion studies have been carried out in a laboratory under accelerated conditions and using non-destructive testing. In this research, the effects of the water-cementitious materials ratio, fly ash, and a calcium nitrite-based corrosion inhibitor, as well as their interactions, were investigated as methods to prevent the corrosion of reinforcing steel in concrete containing silica fume. Specimens were exposed to a natural marine environment for seven years and the corrosive activity was monitored annually using electrochemical techniques. At the end of the exposure period, the specimens were visually inspected, autopsied and the chloride concentrations at the steel–concrete interfaces were estimated. The steel bars were extracted and their mass losses and pitting depths evaluated and finally tested for tension. The results show the underlying performance of fly ash, alone or in combination with CNI, improves the concrete matrix and is an effective corrosion prevention method.