Electrochemical Behavior Of Carbon Steel Research Articles

Study ability of protection effect of organic acids for multi-metallic anti-corrosion additive system in ethylene glycol-water coolants

In this work, the electrochemical behavior of carbon steel, brass, bronze and aluminum alloys in the presence of various important organic acids (sebacic acid (SbA), terephthalic (TPA), 2-ethylhexanoic (E2C6A), and octanoic (C8A)) and the effect that these have on the growth and protectiveness of the alloys have been investigated. The results show that the presence of organic acids in the coolant increases the protective effect of the system by forming a film on the surface of the alloys. The EIS impedance results demonstrate the formation of active and passive protective layers on the surface of the alloys. The results of surveying 04 types of organic acids for the protection of different alloy substrates show that TPA and SbA acid additives are more effective than C8A and E2C5A. The additive C8A not only did not inhibit corrosion but also promoted this process strongly, especially with aluminum alloys and the TPA has the best anti-corrosion effect for steel, followed by C1 copper alloy and aluminum.

Electrochemical Behavior of Steel Coated with Organosilicon Self-Organizing Layers

Methods have been developed for preliminary modification of the surface of structural metals with compositions based on organosilanes, including both solutions of individual organosilanes and two-component mixtures consisting of two organosilanes or an organosilane with an organic corrosion inhibitor. As a result of this modification, self-organized siloxane polymer/oligomer nanosized layers are formed on the metal surface. Such layers are capable of changing the physical and chemical properties of the metal surface, in particular its electrochemical behavior. In this work, the influence of organosilicon surface layers on the electrochemical behavior of carbon steel, especially on the anodic local dissolution of the metal, is studied in detail. Inhibition of metal dissolution by surface layers has been shown. It has been established that the greatest inhibitory effect is exhibited by two-component modifying compositions, namely, mixtures of vinylsilane with aminosilane and vinylsilane with benzotriazole. The mechanism of corrosion inhibition by surface nanolayers formed during surface modification with two-component mixtures is considered.

Electrochemical behaviour of carbon steel in sodium chloride solution by using thiophenol derivative inhibitor

The corrosion inhibition performance of thiophenol has been evaluated for carbon steel immersed in sodium chloride solution by weight loss method. As a results of weight loss method, it gives the corrosion rate and inhibition efficiency. The increase of corrosion inhibition efficiency with increase in concentration of thiophenol derivative inhibitor. When increase in concentration of inhibitor, the corrosion rate decreases. It is because of the higher concentration of inhibitor solution which arrest the active site of a carbon steel by the way of forming protective layer on the surface of carbon steel. The mechanistic aspects of corrosion inhibition has been assessed by electrochemical studies such as potentio dynamic polarisation studies and AC impedance spectra. The decrease of corrosion current and double layer capacitance value, increase in linear polarisation resistance values and impedance values obtained from electrochemical studies suggest that the formation of protective layer on the carbon steel surface. Surface analysis of polished, corroded and inhibitor carbon steel surface has been evaluated by SEM.

Electrochemical behavior of carbon steel with bentonite/sand in saline environment

AbstractCurrent designs for the geological disposal of high‐level radioactive waste in Japan use carbon steel overpack containers surrounded by a mixed bentonite/sand buffer material, which will be located in a purpose‐built repository deep underground. Though there are many suitable sites for a repository in Japan, the coastal areas are preferable from a logistical point of view. It is, therefore, important to evaluate the long‐term performance of the carbon steel overpack and the mixed bentonite/sand buffer material in the saline groundwaters of coastal areas. In the current study, the passivation behavior and initial corrosion rates of carbon steel with and without mixed bentonite/sand were tested as a function of the pH and salt concentration in representative saline groundwaters. The main findings indicate that the passivation of carbon steel encapsulated in a buffer material will be unlikely in a saline environment, even at high pH (12), and that the corrosion rate of carbon steel is more strongly affected by the presence of the buffer material than by the salt concentration.

The effect of superhydrophobic coating on the electrochemical behavior of carbon steel in chloride and hydrogen sulfide–chloride environments

The effect of superhydrophobic coating on the electrochemical behavior of carbon steel in chloride and hydrogen sulfide–chloride environments

Effect of Concentrations of Fe2+ and Fe3+ on the Corrosion Behavior of Carbon Steel in Cl− and SO42− Aqueous Environments

The concentration of metal ions in aqueous environments significantly affects the formation of corrosion products and further metal corrosion. In this paper, the electrochemical behavior of carbon steel in the presence of Fe2+ or Fe3+ concentration in Cl− and SO42− aqueous environments have been investigated using conventional electrochemical methods such as linear polarization and alternating current impedance spectroscopy. The morphology and composition of carbon steel corrosion products were studied using scanning electron microscopy and laser Raman spectroscopy. The effects of corrosion products and iron ions concentration on the corrosion of carbon steel were discussed. Corrosion products of carbon steel in aqueous environments were γ-FeOOH, γ-Fe2O3 and a small amount of α-Fe2O3. The addition of Fe2+ affected the cathode reaction of the electrode reaction, and promotes the formation of γ-FeOOH and Fe3O4. And with the increase of Fe2+ concentration in the solution, the anode process of electrode reaction was suppressed. The addition of Fe3+ promoted the formation of γ-Fe2O3 and Fe3O4. Fe3+ affected the ionization of water, causing the pH of the solution to drop. Fe3+ undergoes a redox reaction with the matrix. Addition of Fe3+ ions promoted the formation of FeOOH, an intermediate product, which reacts with the anode product Fe2+. These factors all accelerated the corrosion process.

Electrochemical behavior of carbon steel under a continuous kerosene flow in two different kind of sections

Electrochemical behavior of carbon steel under a continuous kerosene flow in two different kind of sections

The influence of the sandblasting as a surface mechanical attrition treatment on the electrochemical behavior of carbon steel in different pH solutions

This investigation aimed to study the influence of time of sandblasting, as a surface mechanical attrition treatment method, on the corrosion behavior of carbon steel in different solutions with different pHs. Optical microscopy, micro-hardness test, as well as Scanning Electrochemical Microscopy, were used to examine the affected area underneath the surface of the sandblasted specimens. The results of the electrochemical experiments showed significant improvement in corrosion resistance of the sandblasted specimens in the high alkaline solution. In neutral and acidic solutions, specimens sandblasted for 5 min showed superior corrosion resistance compared to the as-received and other specimens, sandblasted for longer period of time.

Galvanic effect of magnetite on the corrosion behavior of carbon steel in deaerated alkaline solutions under flowing conditions

The effect of magnetite on the corrosion of carbon steel was investigated in simulated secondary water of pressurized water reactors at 60°C by using the immersion and electrochemical tests. The corrosion rate of carbon steel was increased by the galvanic coupling with magnetite, and was more accelerated with increasing the area ratio of magnetite to carbon steel. From the electrochemical behavior of carbon steel and magnetite, it was verified that the corrosion of carbon steel is accelerated by a galvanic corrosion mechanism. This phenomenon is expected to be an acceleration factor on the corrosion of carbon steel piping.

Improved EIS Analysis of the Electrochemical Behaviour of Carbon Steel in Alkaline Solution

Steady-state polarization curves, X-ray photoelectron spectroscopy, and impedance spectroscopy were used to explore the electrochemical properties for carbon steel in alkaline electrolytes. The complex-capacitance representation allowed determination of a capacitance value at high frequency, from which the oxide film thickness could be estimated. These results are in good agreement with values obtained using the power-law model, providing a single mathematical model that is shown to apply in both the anodic and cathodic domains for the characterization of an oxide layer.

Effect of carbonation on the electrochemical behavior of corrosion resistance low alloy steel rebars in cement extract solution

In this paper, cyclic voltammetry technique, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and Mott-Schottky measurement combined with surface morphology observation were applied to investigate the electrochemical behavior of carbon steel (CS) and three Cr modified low alloy steels in the carbonated cement extract solution. Results show that pH plays an important role in the formation of passive films on steel rebars. In non carbonated cement extract solution, corrosion behaviors of CS and Cr modified steel vary slightly, and Cr addition brings down the amount of defects in passive film. In carbonated cement extract solution, pitting potential shifts negatively as pH value decreases. Polarization resistance declines and the density of the current carrier in the passive film increases. With Cr content increasing, corrosion current density declines; pitting potential, polarization resistance and passivation range are magnified. Besides, the effect of Cr is more significant in lower pH. The good-to-poor sequence of corrosion resistance is: 5Cr>3Cr>1.5Cr>CS, and 5Cr steel possesses the best corrosion resistance.

Development and protection evaluation of two new, advanced ceramic composite thermal spray coatings, Al2O3–40TiO2 and Cr3C2–20NiCr on carbon steel petroleum oil piping

Carbon steel is the most commonly used material in the petroleum industry owing to its high performance and relatively low cost compared with highly alloyed materials. The corrosion resistance of carbon steel in aqueous solutions is dependent on the surface layer created on carbon steel. This layer often consists of siderite (FeCO3) and cementite (Fe3C), but it is neither compact nor dense. To improve the carbon steel surface resistance against corrosion and wear, a compact and dense layer can be deposited onto the surface by thermal spray coating. In this research, Al2O3–40TiO2 and Cr3C2–20NiCr were deposited onto mechanical part surfaces by HVOF spray technique. The present study describes and compares the electrochemical behavior of carbon steel, Cr3C2–20NiCr and Al2O3–40TiO2 in 3.5% NaCl using open-circuit potential measurement (OCP) and electrochemical impedance microscopy (EIS) for 36 days. The tribological and mechanical properties are also investigated using a tribometer (pin-on-disc). The results indicate that these chemical composition coatings facilitated significant anti-corrosion and anti-wear improvement. However, the samples coated with Al2O3–40TiO2 exhibited the lowest corrosion rate. In terms of wear performance, both coated samples displayed similar behavior under different loads. Scanning electron microscopy (SEM) showed the distinctive microstructure of the HVOF-sprayed samples before and after corrosion and wear testing.

Effect of hydrodynamics and surface roughness on the electrochemical behaviour of carbon steel in CSG produced water

The influence of fluid flow, surface roughness and immersion time on the electrochemical behaviour of carbon steel in coal seam gas produced water under static and hydrodynamic conditions has been studied. The disc electrode surface morphology before and after the corrosion test was characterized using scanning electron microscopy (SEM). The corrosion product was examined using X-ray photoelectron spectroscopy (XPS) and X-ray diffractometry (XRD).The results show that the anodic current density increased with increasing surface roughness and consequently a decrease in corrosion surface resistance. Under dynamic flow conditions, the corrosion rate increased with increasing rotating speed due to the high mass transfer coefficient and formation of non-protective akaganeite β-FeO(OH) and goethite α-FeO(OH) corrosion scale at the electrode surface. The corrosion rate was lowest at 0rpm. The corrosion rate decreased in both static and dynamic conditions with increasing immersion time. The decrease in corrosion rate is attributed to the deposition of corrosion products on the electrode surface. SEM results revealed that the rougher surface exhibited a great tendency toward pitting corrosion.

Electrochemical Behavior of Carbon Steel in Acidic Medium Containing Cationic Inhibitor

Electrochemical behavior of carbon steel in 1 M acetic acid (CH3COOH) containing tetramethyl ammonium bromide (TMB) as the cationic inhibitor was investigated by potentiodynamic polarization technique and electrochemical impedance spectroscopy (EIS). The aim of this study is to evaluate the inhibition efficiency of cationic inhibitor for carbon steel corrosion. The electrochemical analysis revealed that inhibition efficiency significantly increased with the increasing of inhibitor concentration. Polarization study indicated that TMB acted as a mixed type inhibitor, which inhibited both cathodic and anodic reactions. The changes of impedance parameters by different inhibitor concentration showed a better protection due to formation of a thin film onto the steel surface. This study suggests that TMB is able to inhibit corrosion process of carbon steel in acidic medium with significant inhibition efficiency.

Electrochemical Behavior of Carbon Steel in a Synthetic Environment and Hydrocarbon on a System with Continuous Flow

This work studies the behavior AISI 1018 carbon steel in a buffered solution of chlorides with and without hydrocarbon in a continuous flow rate system. For techniques was designed a cell setup of a system continuous flow. The electrochemical techniques used polarization curves and electrochemical impedance spectroscopy. The polarization curves obtained indicated that both the anodic part and the cathodic suffer a significant change with the addition of hydrocarbon. The presence of hydrocarbon in the system increases currents in comparison to the system in absence of hydrocarbon. The EIS technique shows steel has a higher activity in the studied solution presented at low frequencies. The adsorption of corrosive agents prevents the formation and growth of a passive layer of corrosion products. The analysis with XPS showed that the presence of hydrocarbon in the system allows the deposition of several Cl- crystals on the metal surface.

Geobacter sulfurreducens: An iron reducing bacterium that can protect carbon steel against corrosion?

The effect of Geobacter sulfurreducens on the electrochemical behaviour of carbon steel in anaerobic phosphate solution is studied here. In natural environments, G. sulfurreducens is able to reduce Fe(III) to Fe(II) during the oxidation of acetate. High availability of Fe(II) promoted the formation of an iron (II) phosphate layer on the steel. It is assumed that this phosphate layer, formed only when bacteria were present, is responsible for maintaining the corrosion potential stable even after intrusion of air. In contrast, the corrosion potential in the abiotic experiments suffered an increase of 450mV after few hours of exposure to air.

Study on the Corrosion Electrochemical Behaviors of Carbon Steel in Eutrophic Fresh Water

The environment of fresh water has been changed greatly because of eutrophication, which made the corrosion behaviors of metals in this water become more and more complex. Presently, the study on the corrosion behaviors and mechanism of metals in eutrophic fresh water was very rare; therefore, we considered the research on this field was a very meaningful work. In this paper, the corrosion behaviors of carbon steel in eutrophic fresh water were studied by electrochemical methods, the influence of temperature, value of pH and dissolving oxygen content on the electrochemical corrosion behavior of carbon steel were investigated mostly.

Time-dependent electrochemical behavior of carbon steel in MEA-based CO2 capture process

Time-dependent electrochemical behavior of carbon steel was evaluated in CO2-loaded monoethanolamine (MEA) solutions in simulated carbon capture environments. Tests were conducted in 30wt.% MEA solution with different combinations of controlling factors (oxygen [O2], heat stable salts [HSS], flow and temperature) for 7 days. Corrosion behavior of carbon steel was evaluated by using electrochemical techniques (linear polarization resistance [LPR] and potentiodynamic polarization measurements), weight loss method and surface analytical techniques. Solution pH and ferrous/ferric ion concentration were also measured to monitor the change of water chemistry with time. The results showed that the corrosion rate of carbon steel decreased with time and then stabilized to very low values in the MEA/CO2 condition. XPS characterization revealed formation of a very thin protective FeCO3 layer on the surface, as well as adsorption of MEA. However, when O2 was present in the system, the corrosion rates remained at relatively high values, further increasing with flow. The presence of HSS resulted in a higher corrosion rate at the initial stage, but had a minimal effect on the corrosion rate for longer time exposure. Temperature had a slight effect on the corrosion rate because the solubility of CO2 and O2 decreases with increasing temperature.

Influence of surface roughness on the electrochemical behavior of carbon steel

The effect of the surface roughness of carbon steel on corrosion properties was investigated using electrochemical tests, and surface and Kelvin probe force microscopy (KPFM) analyses. The results of electrochemical tests show that the corrosion rate of carbon steel is increased as the surface roughness increases. It was estimated using KPFM measurement that the difference in the Volta potential between the peak and the valley increased with increasing surface roughness. As the peak has a lower potential than that of the valley, the peak acts as an anode. The surface roughness affects the Volta potential, and the Volta potential difference is inversely proportional to electron work function (EWF). The larger difference in Volta potential between the peak and valley on the rougher surface and the smaller EWF accelerated the micro-galvanic corrosion between them. The surface analyses reveal that corrosion initiated along the peak lines. The results from this study suggest that an increase of surface roughness leads to a decrease of the corrosion resistance.

Electrochemical Behavior of Carbon Steel in Neutral Chloride Solution Adding Amine-Carboxylate Based Corrosion Inhibitor

Studies have been carried out to investigate the inhibiting effect of organic corrosion inhibitor (OCI) on steel electrode in 1% NaCl solution using electrochemical techniques. The test results show that the commonly used inhibitors such as triethanolamine (TEA), dimethylethanolamine (AMA) and monofluorophosphate (MFP) as well as their complexes are efficient when used in the chloride solution, while an amine-carboxylate inhibitor (C12) prepared in lab bring an excellent inhibitive performance when added in the chloride solution. Based on the date of linear polarization resistance, the calculated lowest corrosion current of the steel electrode for 10d is about 0.32% of the initial current of the electrode in the chloride solution before adding C12 inhibitor.The date of potentiodynamic scanning curves also show that the inhibitor has self-repair ability even when the steel is localized corrosion attack. The Bode-phase diagram results suggest that the protective layer at the surface of steel becomes homogeneous and compact in the presence of chloride.