Corrosion Of Low Carbon Steel Research Articles

Permeating hydrogen generated from the elemental sulfur corrosion of low carbon steel

Permeating hydrogen generated from the elemental sulfur corrosion of low carbon steel was investigated using a double cell system and its effect on the mechanical properties of steel was also discussed. Results show that elemental sulfur corrosion of low carbon steel is accompanied by significant hydrogen permeation, e.g., permeating hydrogen current reaches 12.3 μA/cm2 in CO2-containing environment at 80 °C. The hydrogen permeation process are greatly affected by the structure and composition of the corrosion product, the environmental temperature and gas composition. This permeating hydrogen enhances the brittleness of the low carbon steel and tends to cause hydrogen-induced cracking.

Corrosion of low carbon steel by bacteria, study of its effect on physical properties (fatigue)

درس دور التاكل البايولوجي الحاصل بفعل البكتريا المؤكسدة للكبريت Thiobacillus وتأثيرها في الصفات الفيزيائية للصلب المنخفض الكربون ( ٠.١١ %) . وقد ركز البحث على دراسة مقاومة الكلال Fatigue لاهميتها في thiooxidansقياس تحمل المواد. استحصلت البكتريا من عيون المياه الكبريتية في حمام العليل (شمال العراق). وقد عزلت هذه البكتريا على وسط الثايوسلفات الصلب ، ثم اخذ منها عينات ولقح بها وسط الاملاح المعدنية فى دورق زجاجي

Inhibitory behavior of new ionic liquids against low carbon steel corrosion in a 1 M HCl solution

Inhibitory behavior of new ionic liquids against low carbon steel corrosion in a 1 M HCl solution

MD and DFT computational simulations of Caffeoylquinic derivatives as a bio-corrosion inhibitor from quince extract with experimental investigation of corrosion protection on mild steel in 1M H2SO4

The inhibition performance of Quince Extract (Q.E.) at concentrations of 0–1200 ppm on the low carbon steel corrosion in the corrosive media of sulfuric acid (H2SO4) was evaluated by using conventional electrochemical methods (potentiodynamic polarization and impedance spectroscopy). Based on the results, Q.E. displays a mixed-type behavior as an inhibitor. The inhibition efficiency of Q.E. increased with its concentration in the acid solution .The highest performance was observed at the maximum tested concentration (1200 ppm). Using polarization and EIS results, the highest inhibition efficiency of Q.E. was estimated to be 94.5% and 90.7%, respectively. Structural units and functional groups of Q.E. were detected by Fourier transform infrared spectroscopy. This spectroscopy confirmed that the extract contains nitrogen atoms, oxygen atoms, and aromatic rings that are known to have corrosion inhibition effects. The morphology of the specimen's surface after exposure to H2SO4 with and without Q.E. was examined by SEM and AFM techniques. This examination showed substantially lower surface degradation in the low-carbon steel specimens exposed to the acid in the presence of Q.E. The Langmuir isotherm approach was utilized to explain the adsorption of Q.E. onto the low-carbon steel surface. The Gibbs free energy calculated based on this approach (-21.05 kJ-mol−1) confirmed that the Q.E. adsorption onto the steel surface is supposed to involve more physisorption. In addition to the results of molecular simulation and computational chemistry, such as molecular dynamics simulation (MD), density functional theory (DFT), and Monte Carlo for all Caffeoylquinic acid derivatives confirmed that amino acid of quince extracts in an acidic medium (1 M sulfuric acid) adsorbed on compact and energetic iron surfaces mainly surfaces with miller index (110), which are inclined to corrosion and electrochemical reactions, takes place spontaneously.

Effect of Cathodic Protection Potential Fluctuations on the Corrosion of Low-Carbon Steels and Hydrogen Absorption by the Metal in Chloride Solutions with Nearly Neutral pH.

Considerable fluctuations in the cathodic protection potential under the impact of stray currents lead to the occurrence of local corrosion on steel structures operated in soils and seawater. The potential fluctuations induced by both alternating and direct current sources can be simulated by cycling a square potential step. This paper covers the impact of sign-alternating cyclic polarization (SACP) on the general and local corrosion of carbon steel in 3.5% NaCl solution containing a borate buffer (pH 6.7) and without it. A decrease in the cathodic half-period potential (Ec) of SACP inhibited the general corrosion and accelerates the local corrosion of steel in both solutions, which was associated with an increase in the amount of hydrogen in the metal. Increasing the duration of the SACP cathodic half-period increased the pit density and total area at less negative Ec values. At more negative Ec values, an increase in the duration of cathodic polarization reduced the intensity of steel local corrosion in the unbuffered chloride solution. This effect is explained by blocking of the pit nucleation centers on the metal surface by a layer of steel dissolution products formed in the near-electrode electrolyte layer with a high pH. The combined body of data shows that hydrogen absorption by the metal determines the corrosion behavior of carbon steel under the impact of SACP in chloride solutions, which should be taken into account in the development of models of the corrosion of steel structures under the action of stray currents.

Corrosion of Low Carbon Steel in Chloride Containing Environment

This research aims to investigate the corrosion of low-carbon steel in a chloride-containing environment. The investigation started by preparing and studying the surface condition of the specimens. The mechanical properties, microstructures and chemical compositions were also comparatively investigated between standard and corroded specimens. The results showed that the surface of the corroded samples was rough and peeling, different from the standard specimens, which were relatively smooth and non-corrosive. The average ultimate tensile strength and average yield strength of normal specimens were higher than those of corroded specimens at 5.39% and 2.32%, respectively. The corrosion products developed on the surface of corroded specimens caused a high-stress concentration area. The specimen is more prone to cracks and breaks when subjected to tensile stress. The surface of the normal specimen was composed of iron, oxygen, carbon, and silicon. In contrast, the surface of the corroded specimen contained the same elements as the normal specimen except chlorine which was detected. The film layer of the corroded specimen was cracked in contrast with the normal specimen, where the film still covered the metal substrate. The chemical composition analysis found that the corroded specimen's film layer contained chlorine, which is not detected in the film layer of the normal specimen. This is because the film layer of hot-rolled steel remains porous even passing the hot-rolling process. These pores allow chloride ions to diffuse and react with the film layer and the metal substrate. This makes the film layer of the corroded specimen thicker and initiates cracks. When stable alpha-iron-oxyhydroxide is formed on the steel surface, it can help to suppress corrosion.

Inhibition of low carbon steel corrosion by a cationic gemini surfactant in 10wt.% H2SO4 and 15wt.% HCl under static condition and hydrodynamic flow

The corrosion inhibition potentials of a cationic gemini surfactant (CGS) on low carbon (LC) steel in highly corrosive environment of 10 wt.% H2SO4 and 15 wt.% HCl (which imitates oil well acidic environment) at elevated temperatures was studied using potentiodynamic polarization (PDP), gravimetric, and surface (XPS, SEM and EDX) analyses. Unprecedented inhibition efficiencies (IE) of 92.2% and 92.5% were repeatedly obtained at CGS concentrations of as low as 0.25 ppm and 1 ppm in 15 wt.% HCl and 10 wt.% H2SO4 at 25 °C by gravimetry, respectively. Higher inhibition efficiencies were obtained at elevated CGS concentrations. The inhibitor act as a mixed type based on the PDP data. The adsorption of CGS on the steel surface further supports a stronger tendency for he CGS adsorption onto the steel surface, thereby establishing an effective protective mechanism of the steel. The CGS performance was enhanced under hydrodynamic condition than static condition in 15 wt.% HCl while the opposite was the case in 10 wt.% H2SO4. Density Functional Theory (DFT) calculations and Monte-Carlo (MC) dynamics simulations supported the experimental findings of the CGS inhibition potentials for steel surface in the studied media. This study showcases the high potential of employing CGS for effective control of the corrosion, even at low dosage, in industrial applications involving the use of highly reactive acids at higher temperatures where economically viable operations are necessary.

Mechanism of Corrosion of Low-Carbon Steel in 1 M Solutions of Hydrochloric Acid Saturated with Oxygen

Mechanism of Corrosion of Low-Carbon Steel in 1 M Solutions of Hydrochloric Acid Saturated with Oxygen

4-(3-Amino-4-mehoxy-5-methylphenyl)-1-oxo-1H-phthalaz-2-yl] acetic acid hydrazide and its synergetic effect with KI as a novel inhibitor for low carbon steel corrosion in 0.5 M H2SO4

We report the synthesis of novel [4-(3-amino-4-mehoxy-5-methyl phenyl)-1-oxo-1H-phthalaz-2-yl] acetic acid hydrazide (APPH), followed by its characterization using X-ray diffraction (XRD), Fourier transforms infrared (FT-IR) spectroscopy, 1H-NMR spectroscopy, and LC/MS. Further, the inhibition effect of the varying concentration of APPH on the corrosion of low steel (LCS) in 0.5 M H2SO4 was investigated by weight loss and electrochemical measurements at 30 °C. The percentage inhibition efficacy of APPH increased with concentration and reached about 84% at 0.5 mM at 30 °C, also rising to 88% after 6 h of exposure. According to the polarization measurements, the investigated APPH works as a mixed-type inhibitor. Furthermore, the synergistic corrosion inhibition mechanism APPH showed that the inhibition efficiency maximizes with increasing inhibitor concentration, and the maximum value was 83% at 0.5 mM APPH. The adsorption of APPH on the LCS surface is more fitting to the Langmuir isotherm model. The free energy value (–ΔG° ads) was 33.3 kJ mol−1. Quantum chemical calculation was applied to APPH and acted as excellent support for the experimental data.

Optimization, kinetics, and electrochemical investigations for green corrosion inhibition of low-carbon steel in 1 M HCl by a blend of onion-garlic leaves wastes

An aqueous extract of onion and garlic leaf extract (OGLE) blend was employed to retard low-carbon steel (LCS) corrosion in 1 M HCl for the first time. The corrosion inhibition ability of OGLE has been tested via weight loss and electrochemical techniques. Firstly, onion and garlic leaf extracts are separately tested at 30 °C using a Doehlert experimental design to find the optimum concentration of each extract. Secondly, a full-factorial design is used to evaluate the corrosion rate at different blend concentrations and temperatures. Experimental results revealed that the OGLE blend can be considered a good green inhibitor. At 300 ppm OGLE and 60 °C, the maximum blend corrosion inhibition efficacy was 96.65 %. The Langmuir adsorption isotherm demonstrates that OGLE adsorbed with negative heat of adsorption, suggesting a stable monolayer developed spontaneously on LCS. According to electrochemical experiments, when OGLE is present, corrosion current densities are greatly reduced.

Performance of cross-linked polymers as a potential anticorrosive coating for low carbon steel in acidic condition: Experimental and computational studies

• Polyethylenimine (PEI) with three different epoxies were evaluated as potential corrosion inhibitors. • The corrosion resistance performances of PEIs were revealed with several electrochemical tests. • SEM and AFM show extraordinary surface adsorption performances by PEIs. • Linear PEI showed better corrosion protection as compared to branched PEI. Polyethylenimine (branched and linear) cross-linked coatings were studied for Low Carbon Steel (LCS) corrosion protection in 2 M sulfuric acid corrosive media. Three epoxies namely 4,4′-methoxy (N,N-diglycidyl anisole) (ER1), 4,4′-methylene (N,N-diglycidyl aniline) (ER2), and Diglycidyl 1,2-cyclohexanedicarboxylate (ER3) have been used to produce different cross-linked coating materials with polyethylenimine branched (PEIB) and polyethylenimine linear (PEIL). Our aim was to investigate and find the best surface protective materials among the studied crosslinked polymers. Weight-loss, potentiodynamic polarization techniques including electrochemical impedance spectroscopy were used to conclude the corrosion inhibition behavior of the cross-linked polymeric coatings in 2 M H 2 SO 4 solution. Electrochemical analysis suggested that the sample PEIL-ER3 (cross-linked polymer) has better corrosion inhibition performance as compared to the other studied samples. After assessment of the electrochemical investigation, the inhibitory action of PEIB-ER1, PEIB-ER2, PEIB-ER3, PEIL-ER1, PEIL-ER2, and PEIL-ER3 at 303 K was found to be approximately 68%, 79%, 89%, 72%, 84%, and 92%, respectively. Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM) revealed that the substrate coated with PEIL-ER3 showed less corroded surfaces as compared to the substrates coated with the other studied samples. Fourier Transform Infrared Spectroscopy-Attenuated Total Reflection (FTIR-ATR) investigated the surface characterization of the LCS. The obtained results verify the surface adsorption of the LCS by the studied cross-linked polymer materials.

Effect of scale formation and CP potentials on AC-induced pitting corrosion of low carbon steels

Effect of scale formation and CP potentials on AC-induced pitting corrosion of low carbon steels

Investigation of African mangosteen leaves extract as an environment-friendly inhibitor for low carbon steel in 0.5 M H2SO4

The African mangosteen plant species comprises a variety of bioactive molecules. In the following research, phytochemicals have been screened with Shinoda test, Benedict's test, etc., for ethanolic African mangosteen leaves extract (AMLE). The inhibition efficacy of AMLE for low carbon steel corrosion in 0.5 M H2SO4 was assessed by mass-loss, polarization, and electrochemical impedance spectroscopic (EIS) approach. Corrosion studies were performed for various inhibitor concentrations and differing temperatures. The inhibition performance of AMLE on low carbon steel rises with concentration rise. Potentiodynamic polarization results revealed that AMLE bind to the surface of low carbon steel, as they hinder corrosion spots from the bulk media, and the maximum inhibition performance (ηw) was 96.14% for 1.5 g/L concentration. Electrochemical impedance spectroscopy (EIS), the maximum inhibition performance (ηw) was 95.57% attributed to AMLE adsorption on the low carbon steel surface. Findings reported from electrochemical and chemical research are well in agreement. The AMLE inhibition activity is stated by the adsorption process on low carbon steel and complies with Langmuir isotherm. The values of ΔGadso were estimated to be between −30.27 to −33.06 kJ mol−1, indicating that the inhibition effect is exothermic and spontaneous. Furthermore, the determined thermodynamic parameters suggest that the adsorption process is intuitive. Scanning electron microscope (SEM), Fourier-transform infrared (FT-IR) spectroscopy, and atomic force microscopic technique (AFM) were employed to examine the surface analysis of the low carbon steel samples.

Investigation of Q235 low-carbon steel corrosion under simulated ballast water tank conditions

Investigation of Q235 low-carbon steel corrosion under simulated ballast water tank conditions

Inhibition effect of cow bone soot on low carbon steel corrosion in artificial concrete pore environment

Abstract The corrosion inhibition of cow bone soot (BAS) at 5%, 10%, 15% and 20% weight on low carbon steel (LCS) in artificial concrete pore solution was evaluated with potentiodynamic polarization and current-time displacement. BAS visibly decreased the corrosion rate of LCS from 7.31 x 102 mm/y at 0% BAS to 1.45 x 102 mm/y at 20% BAS concentration. Maximum inhibition performance of 80.18% was obtained at 20% BAS concentration. The inhibition mechanism of BAS was determined to be anodic type. Cathodic reduction of the polarization plot was significant due to decrease in O2 adsorption. Plot of current versus time shows BAS reduces the thermodynamic tendency of LCS to corrode.

Corrosion inhibition of steel by selected homologues of the class 3-alkyl-5-amino-1H-1,2,4-triazoles in acidic media

The use of hydrochloric acid in the treatment of the bottomhole formation zone leads to the significant corrosion of metals, as well as hydrogen and chloride stress cracking of pump compressor pipes. In order to solve this problem, corrosion inhibitors are added to a hydrochloric acid solution. This article presents the results of a study of the anticorrosive activity of a number of derivatives of the class of 3-alkyl-5-amino-1H-1,2,4-triazole under the conditions of hydrochloric acid corrosion of low-carbon steel. During the study, selected 3-alkyl-5-amino-1H-1,2,4-triazoles were synthesized. Their structure was confirmed and proved using NMR spectroscopy and HPLC/MS spectrometry. Regularities of the anticorrosive ction of the investigated compounds have been established using polarization electrochemical studies and gravimetric direct corrosion tests. Corrosion rates, inhibition coefficients and degrees of protection have been calculated for all inhibitors. The probable mechanism of the inhibitory action of the studied compounds has been substantiated using quantum chemical calculations based on the density functional theory using the Gaussian program. It was shown that the structure of the alkyl substituents has the greatest effect on the inhibitory activity of the studied compounds. The mechanism was proposed for the adsorption of the inhibitor, which explained the increase in protective properties with an increase in the length of the alkyl substituent. The high hydrophobicity of the aliphatic fragment, not involved in the chemisorption process, additionally prevents the acid solution from contacting the metal surface, while the heterocyclic moiety ensures the sorption of the inhibitor on the metal surface. As a result, it was shown that derivatives of the homologous series of 3-alkyl-5-aminotriazole are suitable as inhibitors of acid corrosion of ST-3 steel. The minimum length of a hydrocarbon radical at which significant inhibitory activity was observed is 7 carbon atoms. Protection degrees of 65–85% were achieved when 3-heptyl-5-amino-1H-1,2,4-triazole additives at a concentration of at least 2 g/L were added to the hydrochloric acid solution.

Особенности коррозии и ингибиторной защиты сталей в растворах кислот, содержащих соли железа (III). Обзор

A critical analysis of literature data on corrosion of steels in solutions of mineral acids containing Fe(III) salts and the possibility of inhibitory protection of steels in these environments has been carried out. The accumulation of Fe(III) salts in acid solutions during their operation at metallurgical, oil and gas enterprises, objects of housing and communal services is a result of dissolution of mineral deposits, scale, thermal scale, and rust containing Fe (III) compounds in them. In addition, additional oxidation of Fe(II) salts in acid solutions to Fe(III) compounds is possible. The effect of the redox potential, determined by the ratio of the content of Fe(III) and Fe(II) cations in them, as well as mobility of Fe(III) cations, on the corrosivity of the systems under consideration was examined. The reasons for the accelerating and retarding action of Fe(III) salts on corrosion of steels in acidic media were analyzed. Modern concepts of the mechanism of corrosion of steels in these environments are discussed. The low efficiency of the inhibitory protection of steels in mineral acids containing Fe(III) salts is demonstrated. It is noted that it is possible to increase the protective effect of some corrosion inhibitors (CI) in these environments by reducing their overall aggressiveness. It can be achieved by introducing H3PO4 into them, which is capable of binding Fe(III) into strong complexes that have a lower oxidizing capacity than Fe(III) aqua complexes and mobility in an aggressive environment. The CI used in an aggressive environment must be effective in slowing down not only the cathodic reduction of protons and anodic ionization of iron, but also significantly suppress reduction of Fe(III) cations, which is realized with the diffusion control. These requirements are met by composite CI based on triazoles, which in H2SO4 + H3PO4 and HCl + H3PO4 solutions containing Fe(III) salts are effective in slowing down the corrosion of low-carbon steel.

Comparison of the Inhibition Effect of Cedrus Atlantica and Azadirachta Indica on Low Carbon Steel Corrosion: Data and Statistical Analysis

Comparative study of the corrosion inhibition effect of specific concentrations of cedrus atlantica (CA) and azadirachta indica (AI) oil distillates was performed on low carbon steel in 3M of C6H7O8by coupon analysis. Data obtained showed both distillates performed adequately at all concentrations assessed with principal inhibition value of 94.31% and 99.59%. The performance of CA oil distillate was concentration dependent compared to AI distillate which showed limited variation with respect to concentration. Statistical computation by analysis of variance shows inspection time and inhibitor concentration influences the inhibition performance of both compounds. The margin of error values shows the performance values of both compounds above 70% inhibition efficiency is 100% (+0%). Results from standard deviation shows the inhibition efficiency data varied positively with respect inspection time.

Inhibitive performance of 4-Methoxyphenethylamine on low-carbon steel in 1 M hydrochloric acid: Kinetics, theoretical, and mathematical views

The current study looked at the inhibition performance of 4-Methoxyphenethylamine (MPTA) in 1 M HCl. Besides the experimental investigation, a theoretical and mathematical attempt to correlate some chemical characteristics and inhibitor efficacy was also made. The inhibiting effect was investigated by potentiodynamic polarization, electrochemical impedance spectroscopy, and weight loss techniques. Corrosion rate was evaluated as function of time, MPTA concentration, and temperature. The results show that MPTA suppressed both cathodic and anodic processes of low-carbon steel corrosion in acidic solutionby adsorption on the surface, which followed a Langmuir adsorption isotherm. Maximum corrosion inhibition efficiency was 91% at 30 °C and 200 ppm. Kinetics studies revealed that the corrosion reaction was behaved according to the first order mechanism. Mathematical studies showed a high correlation coefficient was obtained between predicated and experimental corrosion rate. The 6-311G (d, p) base set and Density Functional Theory (DFT) were employed. MPTA's inhibitory capabilities were discovered to be connected to the charge on the nitrogen atom as well as the total of the net charges of the six atoms in the cyclic ring. MPTA was studied in a three states, ground state (1), oxygen protonated state (2), nitrogen protonated state (3). Physical characteristics such as dipole moment, hardness, ionization energy, and softness of MPTA and its protonated states were computed. Theoretical order of inhibitor efficiency was 2 > 3 > 1. It is concerned with an experimental, theoretical, and mathematical explanations between electronic and structural characteristics of MPTA and its inhibitor efficiency.

Novel gossypol–indole modification as a green corrosion inhibitor for low–carbon steel in aggressive alkaline–saline solution

The corrosion of low–carbon steel in aggressive alkaline–saline environments is a very large problem. Protecting low–carbon steel from corrosion in aggressive alkaline–saline solutions using green inhibitors is a very important task in industry. However, there are no studies related to low–carbon steel corrosion in aggressive alkaline–saline environments. Green type corrosion inhibitors are an interesting topic of research. However, currently, the studied type inhibitors are not efficient at low concentrations, and there are no studies on them in aggressive alkaline–saline environments in regard to steel corrosion. In this research work, a novel gossypol–indole modification (GIM) is introduced as a green corrosion inhibitor for low–carbon steel in an aggressive alkaline–saline environment. This inhibitor is a large, highly planar structural molecule that is more water soluble than other inhibitors. Its inhibition behavior is stable at high temperatures, and it contains a large number of electron–rich heteroatoms. All of these properties make it an excellent corrosion inhibitor. The inhibition performance of the novel gossypol–indole modification for low–carbon steel in 1 M NaOH + 1 M NaCl is fully characterized by thermodynamic, gravimetric, electrochemical frequency modulation (EFM), potentiodynamic polarization (PDP), electrochemical impedance spectroscopy (EIS), density functional theory (DFT), molecular dynamics (MD) simulations, scanning electron microscopy (SEM) and energy dispersive X–ray spectrometry (EDX) methods. The results confirm that the novel gossypol–indole modification is an excellent inhibitor, with a maximum inhibition efficiency of 96.01% at 100 mg/L and 0.112 mM. The adsorption behavior follows the Langmuir isotherm. Electrochemical studies have indicated that this modified is a mixed–type corrosion inhibitor, and the theoretical investigations correlate well with the experimental results.