Corrosion Rate Of Metal Research Articles

Fabrication of an intelligent anti-corrosion silane film using a MoO42− loaded Micro/mesoporous ZIF67-MOF/multi-walled-CNT/APTES core-shell nano-container

The design of smart coatings for corrosion protection aims has become one of the most interesting hotspots for contemporary corrosion researchers. For this purpose, scientists mostly grabbed on the utilization of carriers with control-release capability, and carbonaceous materials are the most well-known celebrities among all. In this work, the multi-walled carbon nanotube (CNT) surface was decorated with ZIF67 crystals, and then MoO42− ions (Mo) were loaded into the constructed nano-carrier. Eventually, the synthesized particles' were covered by (3-Aminopropyl) triethoxysilane (APTES) amino silane for better dispersion in the silane matrix. The silanized and un-modified nano-hybrids were precisely explored by different characteristic methods to prove their successful synthesis. Also, the inductively coupled plasma (ICP) measurements demonstrated around 49 ppm, 18 ppm, and 0.02 ppm Co ions in the acidic, neutral, and alkaline conditions, respectively. The Electrochemical Impedance Spectroscopy (EIS) and polarization records in the solution phase revealed that CNT-ZIF67-Mo nano-hybrids successfully declined the corrosion rate of metal up to 91% and 84%, respectively. Thereupon, to design a self-healable anti-corrosion system, CNT-ZIF67-Mo particles at 0.15 wt% were incorporated into the silane-based hybrid coating. The EIS explorations carried out on the scratched composites proved that the total resistance was tripled and self-healing activity with a 69% index was visualized after the inclusion of APTES/CNT-ZIF67-Mo nanoparticles. Also, the EIS investigations over the intact composites declared that the silane coating resistance was increased from 23156 Ω.cm2 to 200169 Ω.cm2 and water uptake was around 73% upon the incorporation of APTES/CNT-ZIF67-Mo nanoparticles.

Growth Inhibition of Sulfate-Reducing Bacteria during Gas and Oil Production Using Novel Schiff Base Diquaternary Biocides: Synthesis, Antimicrobial, and Toxicological Assessment.

Upstream crude oil production equipment is always exposed to destruction damagingly which is caused by sulfate-reducing bacterium (SRB) activities that produce H2S gas, which leads to increased metal corrosion (bio-fouling) rates and inflicts effective infrastructure damage. Hence, oil and gas reservoirs must be injected with biocides and inhibitors which still offer the foremost protection against harmful microbial activity. However, because of the economic and environmental risks associated with biocides, the oil and gas sectors improve better methods for their usage. This work describes the synthesis and evaluation of the biological activities as the cytotoxicity and antimicrobial properties of a series of diquaternary cationic biocides that were studied during the inhibition of microbial biofilms. The prepared diquaternary compound was synthesized by coupling vanillin and 4-aminoantipyrene to achieve the corresponding Schiff base, followed by a quaternization reaction using 1,6-bromohexane, 1,8-bromooctane, and 1,12-bromododecane. The increase of their alkyl chain length from 6 to 12 methylene groups increased the obtained antimicrobial activity and cytotoxicity. Antimicrobial efficacies of Q1-3 against various biofilm-forming microorganisms, including bacteria and fungi, were examined utilizing the diameter of inhibition zone procedures. The results revealed that cytotoxic efficacies of Q1-3 were significantly associated mainly with maximum surface excess and interfacial characteristics. The cytotoxic efficiencies of Q1-3 biocides demonstrated promising results due to their comparatively higher efficacies against SRB. Q3 exhibited the highest cytotoxic biocide against the gram +ve, gram -ve, and SRB species according to the inhibition zone diameter test. The toxicity of the studied microorganisms depended on the nature and type of the target microorganism and the hydrophobicity of the biocide molecules. Cytotoxicity assessment and antimicrobial activity displayed increased activity by the increase in their alkyl chain length.

Influence of Metal Cation and Temperature on Localized Corrosion Behavior of Steels in Aqueous Environments

Steels are abundantly used in many areas because of their good formability and low price. Steels suffer from corrosion in aqueous environments with chloride ions. Corrosion of steels is also a serious problem for long-term usage of steel structures such as bridges and buildings. There are many studies focused on chloride ions. There are reports that metal cations have a tendency to inhibit the corrosion of steels in a chloride aqueous environment by forming a layer on the steel.The other important factor for corrosion of steels in an aqueous environment is temperature. The corrosion rate of metal in cold regions is expected to slow because of low temperature. A recent study on atmospheric exposure tests carried out in different places in Hokkaido, it has elucidated that the corrosion rate in the cold region is the same as in the warm region.However, it is not fully elucidated that temperature, especially below freezing point, and metal cations on corrosion behavior and distribution of active dissolution site. The purpose of this study is to investigate the influence of temperature and metal cations on thecorrosion behavior of steels.Steel sheets of 15 x 20 mm and 20 x 20 mm were used as specimens. Three solutions of 0.1 mM ZnCl2, 0.5 mM ZnCl2 and 1.0 mM ZnCl2 were used for examination of the effect of metal cations, and 20 mass % NaCl solution was used for examination of effect of temperature. After the tests, the morphology of specimens was examined by optical microscope and scanning electron microscope.After the wet/dry corrosion tests used 10 mL solutions droplets, corrosion products were formed on the specimens. The corrosion processes under NaCl and MgCl2 were similar. Yellow corrosion products were firstly observed in the solution during the wet period. In the case of under ZnCl2, after the formation of oxide layer on the specimens the corrosion proceeded in localized areas. The color of almost half area of the exposed surface was light, which might indicate less corrosion occurred in the area. The initial corrosion stage of steel preferred to form a brown area in the center of the droplet. There are no similar corrosion products thatcan be observed in comparison to the samples under MgCl2 and NaCl solutions.A lot of corrosion products and localized corroded areas were formed on specimens after being immersed at 273 K, while less corrosion products and homogenously corroded surface were observed on specimens after being immersed at 293K.The results indicated that corrosion morphology and preferentially corroded area were changed with the kind of metal cation and temperature.

Effects of oyster as macrofouling organism on corrosion mechanisms of a high-strength low-alloy steel

Adhered oysters can cause complex corrosion of fouled steel structures, with localized crevice corrosion being the most severe. A crevice corrosion model of steel caused by oysters is proposed, showing that oyster secretions can penetrate into the oyster/steel interface and act as a stabilizer of the rust layer, enabling tight attachment and thereby slowing the metal corrosion rate. In contrast, oxygen concentration cells, enriched Cl-, anaerobic bacteria, the presence of organic free radicals and oxidative cross-linking during the curing process of oyster secretions act as localized corrosion accelerators facilitating the crevice corrosion process in the oyster/steel gap.

Experimental and theoretical insights into two fluorine-containing imidazoline Schiff base inhibitors for carbon steels in hydrochloric acid solution

In this article, two fluorine-containing imidazoline Schiff base derivatives have been synthesized for corrosion inhibition of carbon steels, namely, (E)-N-(3-(1H-imidazol-1-yl)propyl)-1-(4-fluorophenyl)methanimine (FIM1) and (E)-N-(3-(1H-imidazol-1-yl)propyl)-1-(4-(trifluoromethyl)phenyl)methanimine (FIM2). The structures of the two synthesized compounds are confirmed by 1H and 13C NMR. The corrosion inhibition performance of the two corrosion inhibitors is tested by weight loss, electrochemical experiment, surface analysis and theoretical calculation. The weight loss and electrochemical experiments show that both imidazole derivatives inhibitors reduce the metal corrosion rate, while the inhibition efficiency values of FIM1 and FIM2 reach 91.17 % and 93.99% with the concentration of 2 mM. Surface analysis experiments are carried out to analyze the morphology and composition of carbon steel surface immersed in HCl solution without and with corrosion inhibitors. Finally, the results of quantum chemical calculation and molecular dynamics simulation confirm the experimental results theoretically. The fluorine-containing imidazoline Schiff bases corrosion inhibitors exhibit more adsorption sites, which provides a unique insight for designing new kinds of corrosion inhibitors with robust protection efficiency even at high temperatures.

The Importance of Electrochemically Active Surface Area in the Corrosion Behavior of Additively Manufactured 316L Stainless Steel

Surfaces of additively manufactured (AM) stainless steel (SS) by fusing metallic powders are known to be much rougher than those produced by conventionally fabrication methods. The measured surface roughness (Sa or Sq) can range from a few to tens of microns depending on the build angle. Recent studies have shown that the large surface roughness associated with printing conditions makes the AM SS surfaces susceptible to localized corrosion and open-circuit corrosion [1, 2]. Sa or Sq have also long been used to characterize the corrosion behavior of traditionally manufactured metals [3]. However, the open-circuit corrosion rate of the traditional metals has been mainly studied in the submicron-scale surface roughness, and some results have showed that changes in the roughness of hundreds of nanometers or more have little effect on the change in the corrosion rate [4]. In addition, when applied to AM materials, no consistent correlation between the pitting breakdown potential (Eb) and surface roughness has been observed.In this study, the dependence of the corrosion behavior on the electrochemically active surface area of AM 316L SS, defined as the total area of the curvilinear surface that is exposed to the electrolyte, has been explored. The localized corrosion susceptibility was evaluated under full immersion in 3.5 wt% NaCl solution through potentiodynamic polarization for testing articles with different surface roughness. While no correlation to Sa or Sq was displayed, the Eb values showed a clear statistical trend with respect to the electrochemically active surface area: the lager the active surface area, the smaller the Eb. The observed correlation fits well with a previously reported stochastic pitting model on metal surfaces [5]. In addition, by normalizing linear polarization resistance and electrochemical impedance spectra with the electrochemically active surface area, it can be confirmed that the as-printed surface roughness of AM 316L SS did not have a significant effect on the change of the open-circuit corrosion phenomenon under static immersion conditions. Our results suggest that electrochemically active surface area is an appropriate parameter to characterize the corrosion behavior of AM metal surfaces.This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

(Digital Presentation) Investigation of the Hexylamine Adsorption on Platinum By Potentiostatic and Potentiodynamic Methods

Adsorption is one of the electrochemical process stages often. The adsorption of polar organic molecules (surfactants) on metal electrodes is of significant interest. In particular, the surfactant adsorption affects the exchange current value and determines the metal corrosion rate. Therefore, the explanation of the adsorption mechanism is the most important problem in the investigation of the electrochemical kinetics.The kinetics of the Fe2+ and Fe3+ oxidation-reduction reaction on a platinum electrode in 1 M HClO4 was investigated by potentiodynamic and chronoamperometric methods in the presence of hexylamine as a surfactant. The main kinetic characteristics of the reaction (exchange current density, transfer coefficient, diffusion coefficients of iron ions) have been determined.The dependence of the exchange current density on the hexylamine concentration is analyzed. The surface coverage with a surfactant was estimated at various hexylamine concentrations. It was shown that the hexylamine adsorption on platinum is described by the Dhar-Flory-Huggins adsorption isotherm. The values of the adsorption constant and the adsorption free energy are obtained. These values are close to the corresponding values for the hexylamine adsorption on mild steel in hydrochloric acid. Consequently, the objective laws for the hexylamine adsorption depend low on the acid type and the electrode nature. This indicates the physical adsorption of the surfactant.It is possible that adsorption occurs due to the hydrophobic interaction of the surfactant molecules with polar water molecules. Then, the displacement of surfactant molecules to the interface takes place regardless of the nature of the acid and the metal contacting with the solution. The latter assumption requires further investigations of the surfactant adsorption on various metals.

Tafel-Piontelli model for the prediction of uniform corrosion rate of active metals in strongly acidic environments

Corrosion represents a threatening and expensive problem for every industrial sector. To address this issue, several predictive models were developed and categorized in empirical, semiempirical and mechanistic, according to their underlying hypotheses, their representation of major physicochemical phenomena, and their applicability limits. In this work, a mechanistic model strongly based on the theory of kinetics of electrochemical corrosion is presented and validated. The model, called Tafel-Piontelli, was firstly proposed in 2017 as a tool for the calculation of the corrosion rate of active metals in acidic environments, characterized by hydrogen evolution as the dominant cathodic process. Starting from its initial version, the base-equation of the model has been revised and the theoretical architecture improved. The model was validated according to the experimental data collected for a variety of strong acids in a wide range of temperature and pH sets. The kinetic parameters of the equation, such as the cathodic Tafel slope and the hydrogen evolution exchange current density, were determined via cathodic potentiodynamic polarization tests (Tafel extrapolation method), while the iron ion activity and the corrosion rate were determined from mass loss tests and application of the Faraday law. The results show a remarkable improvement in the representation of the iron ion activity and of its exponential dependence on pH and temperature with respect to the original formulation. Additionally, the estimated corrosion rates accurately capture the dynamics observed in the empirical data, thus confirming the validity of the model.

Analysis of corrosion behaviour of carbon steel in a Qatari GTL plant process water

Internal Corrosion in tubing, piping, and process system is a huge challenge to the oil and gas facilities. Severe corrosion problems in the carbon steel pipelines are caused by the high corrosive produced water, leading to significant threats to the humans’ safety, and operation quality, and causing economic losses. In this study, the effect of the process water from the Qatar Shell GTL plant on the corrosion of SAE-1040 carbon steel was studied by using electrochemical measurements. The electrochemical measurement was performed utilizing electrical impendence spectroscopy (EIS) and Potentiodynamic polarization techniques. The corrosion behavior of the metal was tested at a variety of temperatures between 293K and 333K and different immersed times up to 3 h. It is reported that the corrosion rate of the carbon steel metal increased as the immersed period and the temperature increased. The behavior was attributed to the presence of cracks, holes, and pitting observed on the corroded steel surface as the immersion time and temperature increased. Scanning Electron Microscopic (SEM), X-ray Diffraction (XRD), Energy-dispersive X-ray (EDX), and X-ray Photoelectron Spectroscopy (XPS) tests were employed to study the surface of the corroded metal samples. The analysis of the corrosion products confirmed the formation of iron oxide (Fe2O3) as the main corrosion product.

A review on application of marine algae as green corrosion inhibitors in acid medium

AbstractCorrosion is significant and continuous issue that causes serious problem on environment, properties, our lives and leads to economic losses. So, prevention of corrosion requires more attention. Metal corrosion inhibitors, both inorganic and synthetic, are used to prevent and slow down corrosion, although these inhibitors are hazardous. Thus, green corrosion inhibitors which both environmentally and economically are likely the solution to this problem. A lot of research has been done to discover good corrosion inhibitors from natural sources. Marine algae is one of the most valuable sources of natural marine products because of its ability to survive in the dynamic environment of the ocean and considered a natural source for corrosion inhibition. In this review, various species of marine algae are discussed as green corrosion inhibitors in terms of secondary metabolites, mechanism of inhibition, and methodologies used to evaluate the corrosion rate of different metals in acidic media.

Extracellular Polymeric Substances and Biocorrosion/Biofouling: Recent Advances and Future Perspectives.

Microbial cells secrete extracellular polymeric substances (EPS) to adhere to material surfaces, if they get in contact with solid materials such as metals. After phase equilibrium, microorganisms can adhere firmly to the metal surfaces causing metal dissolution and corrosion. Attachment and adhesion of microorganisms via EPS increase the possibility and the rate of metal corrosion. Many components of EPS are electrochemical and redox active, making them closely related to metal corrosion. Functional groups in EPS have specific adsorption ability, causing them to play a key role in biocorrosion. This review emphasizes EPS properties related to metal corrosion and protection and the underlying microbially influenced corrosion (MIC) mechanisms. Future perspectives regarding a comprehensive study of MIC mechanisms and green methodologies for corrosion protection are provided.

Dependence of corrosion activity of aquatic-petroleum mixtures on characteristics of aquatic environments

The processes of metal corrosion in water-oil mixtures depending on the level of water mineralization, reaction of the environment, and ratio between the volumes of oil and aqueous solutions at temperatures of 20 oC and 80 oC were studied. It is shown that the corrosiveness of the medium against metals becomes higher with increasing level of water mineralization and acidic content with decreasing pH of the medium and increasing temperature. The corrosion rate of metals is significantly reduced in the presence of oil. Increase in the oil content in water-oil mixtures has little effect on the corrosion rate of metals. Increase in the hardness of water in the presence of acetic acid does not reduce the corrosion rate of metals and, in some cases, there is an increase in the corrosion activity of water with increasing hardness.

Monitoring corrosion rates with ER-probes – a critical assessment based on experiments and numerical modelling

ABSTRACT Electrical resistance (ER) probes are a technique used to monitor the corrosion rate (CR) of metals in a wide range of applications and industries. However, limited data comparing CR measured with ER-probes, weight loss and electrochemical methods is available. The aim of this work is to provide data regarding the reliability of CR measurements with ER-probes by comparison with LPR, EIS and weight loss measurements and to provide suggestions for designing ER-probes depending on the expected corrosion mechanism and CR. To evaluate the ER-probes reliability in CR measurements, both uniform and localised corrosion in four different environments were studied. CRs obtained with ER-probes showed good agreement with weight loss and electrochemical measurements. Numerical models were used to optimise ER-probe geometry regarding the expected corrosion type and CR, and to study the effect of Joule heating. Design charts were proposed to support ER-probes design concerning the expected CR in certain applications.

The influence of grain size and triple junctions on corrosion behavior of nanocrystalline Ni and Ni-W alloy

The present study attempts to rationalize the higher corrosion rates of nanocrystalline passivating metals in ∼3.5 wt% NaCl environment when grain size approaches below 10 nm. A simple model is proposed correlating the grain size with corrosion current utilizing the contribution from triple junctions. The higher corrosion rate below critical grain size was attributed to the presence of a high volume fraction of triple junctions demonstrating inverse Hall-Petch type (corrosion) relation. The relationship proposed reveals the application window of nanocrystalline metals demanding improved corrosion resistance.

The effect of oxygen-containing species on corrosion behavior of Ta (1 1 0) surface: A DFT study with an experimental verification

Adsorption of oxygen-containing species on the surface of tantalum (Ta) electrode significantly affects its electrochemical corrosion behavior. Density-functional theory (DFT) is employed to investigate the adsorption energies, structural properties and electronic structures of atomic oxygen (O) and molecular water (H2O) on Ta (110) surface. The adsorption behavior of H2O at room temperature is also studied based on ab initio molecular dynamics (AIMD). We find the passivation of Ta metal is mainly attributed to the strong adsorption of oxygen atoms. Thermodynamic results show that bulk Ta2O5 is easily formed at room temperature, which is the fundamental reason for the spontaneous passivation of Ta (110) surface. The formation of an oxygen monolayer (1.00 ML) on Ta (110) surface dramatically increases the work function, making the equilibrium potential of Ta electrode move in the positive direction, thus slowing down the corrosion rate of Ta metal. However, the adsorption of H2O causes a negative work function change, which promotes its anodic dissolution. The electrochemical impedance spectra (EIS) of tantalum foil in three different NH4F-methanol electrolytes (pure, 0.01 M water and oxygen saturated) shows that the charge transfer resistance increases in the sequence RH2O < Rpure < Roxygen, which can be well explained by the results of DFT calculations.

Multiscale characterization of seawater pipe erosion of B10 copper\u2013nickel alloy welded joints

In seawater pipeline, the welding joint is a non-uniform structure composed of welding seam, base metal and heat affected zone. It has inhomogeneity in chemical composition, organizational structure, residual stress, etc. As local defects and high turbulence accelerate corrosion, the welding joint is often the weakest link in pipeline corrosion. Herein, the electrochemical corrosion behavior of B10 alloy welded joint in flowing seawater is studied from macroscopic and submicroscopic viewpoints using AC impedance, linear polarization, array electrode and morphological characterization. The results reveal that the corrosion rate of weld metal (WM), base metal (BM) and heat-affected zone (HAZ) decreased with the increase of time. Combined with SEM and EDS analysis, it can be seen that the increase in time led to the decomposition and accumulation of corrosion products, which gradually enhanced the corrosion resistance of welded joints. At the submicroscopic scale, WM acts as a cathode to mitigate corrosion during the later stages of high flow rate.

One-step electrodeposition of Janus chitosan coating for metallic implants with anti-corrosion properties

Hydrophilic-hydrophobic Janus chitosan coating was facilely fabricated by one-step electrodeposition in HCl/ethanol solvent. The face of chitosan coating attached to the electrode demonstrates a compact structure while the other face away from the electrode demonstrates a porous structure, which endows the chitosan coating asymmetric wettability. The concentration of ethanol has a profound effect on the structure and wettability of the chitosan coating and pioneer work on the corrosion resistance of the chitosan coating on metallic implants was carried out. The growth kinetics of the Janus chitosan coating reveals that the coating grows faster and contains more pores in the presence of ethanol. The anticorrosion properties of the Janus chitosan coating were investigated on common metal implants titanium and 316 L stainless steel. The results show that the Janus chitosan coating obtained with 10 wt% ethanol electrolyte has the best anti-corrosion ability due to its compactness and hydrophobic surface. The corrosion rates of the Janus chitosan coating were reduced to 3.94 × 10−4 mm/yr and 1.77 × 10−2 mm/yr, respectively, significantly improved as comparison to the bare metal corrosion rates (1.46 ×10−3 mm/yr for bare titanium and 3.00 ×10−1 mm/yr for bare stainless steel). The present work provides a simple way to prepare Janus chitosan coating and demonstrates its great potential in implant anticorrosion.

In situ growth of corrosion resistant Mg-Fe layered double hydroxide film on Q235 steel

HypothesisIn situ grown layered double hydroxide (LDH) is commonly used one of the anticorrosion ways for metal materials; Due to the dense growth of LDH on the metal surface, its special layered structure can effectively delay the corrosion rate of metal. MethodsIn this study, we use a hydrothermal method to successfully grow Mg-Fe LDH film on steel substrates based on self-supplied Fe3+ ions. The films were characterized by X-ray diffraction, scanning electron microscopy, and X-ray energy dispersive spectrometry. The potential corrosion resistance of the obtained Mg-Fe LDH film was confirmed using electrochemical impedance spectroscopy and polarization curves. FindingsAfter systematic adjustment and parameter optimization, it was found that Mg-Fe LDH film exhibited the best growth morphology and comprehensive performance with an initial pH value of 10, Mg2+/urea ratio of 1:4 and reaction time of 12 h. The SEM and electrochemical results further demonstrated that Mg-Fe LDH film play a good protection effect on carbon steel surface. This study provides an important reference for the processing of anticorrosion LDHs film.

Utilization of Natural Extracts as Corrosion Inhibitors in the Seawater Environment

Infrastructures in coastal area are mostly made of metal which is susceptible to corrosion due to direct contact with the seawater. The Seawater greatly affects the corrosion rate of metals because it contains chloride ions which can penetrate metal surface. The process of corrosion can be inhibited or slowed by decreasing the corrosion rate in one way, namely the addition of corrosion inhibitors derived from natural materials containing tannin compounds. This study proposed organic corrosion inhibitors which were derived from natural material extracts (coffee leaves and catappa leaves), the effect of time variations on the efficiency of organic inhibitors was investigated, and the efficiency of each inhibitor organic was compared. The corrosion rate with and without inhibitors was analysed by using the method of weight loss. The results showed that the corrosion rate can be reduced by adding the natural ingredients extract. The addition of 2% concentration coffee leaves extract resulted in the lowest corrosion rate with the addition of 0.00226 mmpy. The addition of catappa leaves extract concentration as much as 2% yield the lowest corrosion rate with the addition of 0.0012 mmpy. The highest efficiency of inhibition system was obtained by using 2% catappa leaves extract at 14 days soaking time at 69.23%, and the lowest by using 1% coffee leaves extract.

Expired streptomycin as corrosion inhibitor for carbon steel in acetic acid - sodium acetate buffer solution

Corrosion inhibition of carbon steel in buffer acid solutions by expired streptomycin was studied by weight loss method, linear polarization, electrochemical impedance spectroscopy, as well as scanning electron microscopy. It was found that streptomycin reduces the metal corrosion rate, and the inhibition efficiency increases proportionally with the drug content. A high efficiency has been obtained for 10–3 M amount of inhibitor. Tafel polarization results indicate that the drug is active especially on the cathodic side and less on the anodic dissolution of iron reaction, acting as a mixed type corrosion inhibitor. The double layer capacitance of the metal - buffer solution interface, polarization resistance and film formation on the carbon steel surface have been emphasized by electrochemical impedance measurements. The scanning electron micrographs of the carbon steel samples in blank solutions have revealed a severe corrosion on the samples surface, while in the presence of the expired drug, the surface has remained almost unaffected. Electrochemical behavior of streptomycin has been also investigated by cyclic voltammetry.