Steel In Acid Research Articles

Insight into the corrosion inhibition of novel macromolecular epoxy resin as highly efficient inhibitor for carbon steel in acidic mediums: Synthesis, characterization, electrochemical techniques, AFM/UV–Visible and computational investigations

The present work aimed to investigate the corrosion behaviour of carbon steel (CS) in hydrochloric acid and sulfuric acid solutions (1 M HCl and 0.5 M H2SO4) in the presence of new macromolecular epoxy resin synthesized namely N2.N4.N6-tris(2-(oxiran-2-yl methoxy) ethyl)-N2.N4.N6-tris(oxiran-2-yl methyl)-2.4.6-triamine-1.3.5-triazine (ERT). This corrosion protection activity was detected by utilizing various methods including electrochemical impedance spectroscopy (EIS), polarisation curve (PC) measurements, atomic force microscope (AFM) analysis, global quantum chemical descriptors computations (GQCDs) and molecular dynamics (MDs) simulation. The corrosive solutions after corrosion tests have been identified by UV–visible. The obtained results, indicating that the compound as mixed type inhibitor significantly reduced the corrosion rate of CS due to the formation of a stable protective film on the metal surface. As confirmed by EIS, AFM and theoretical studies, chemically adsorbed ERT molecule is a better corrosion inhibitor with higher corrosion efficacy of about 95.5% in HCl and 98% in H2SO4 at room temperature. Langmuir isotherm model is the most acceptable one to describe the ERT molecules adsorption on the surface of CS. Protection mechanisms were supported by GQCDs, Fukui functions, dual local descriptors, radial distribution function and MDs simulation. These theoretical calculations support the results obtained experimentally to qualify ERT as a very effective inhibitor against the corrosion of CS in both acidic media.

The use of 4-methylbenzenesulfonate ionic liquid derivatives as environmentally friendly corrosion inhibitors for mild steel in hydrochloric acid

SYNOPSIS The effectiveness of two synthesized ionic liquids, 1-(benzyloxy)-1-oxopropan-2-aminium 4-methylbenzenesulfonate (1-BOPAMS) and 4-(benzyloxy)-4-oxobutan-1-aminium 4-methylbenzenesulfonate (4-BOBAMS), were evaluated for mild steel corrosion inhibition in 1.0 M hydro-chloric acid solution, using electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP), and gravimetric techniques. Organic moieties responsible for the adsorption process on mild steel surface were investigated using Fourier transform infrared spectroscopy (FTIR). Gravimetric analysis revealed that the inhibition efficiency of 1-BOPAMS and 4-BOBAMS increased with concentration, with maximum inhibition values of 90.32% and 97.91%, respectively, at the highest concentration of the inhibitors. Gibbs free energy (nG°ads) values indicated a strong interaction between the mild steel surface and the molecules of the ionic liquids, and that the adsorption process was spontaneous. These values also show that the inhibitive nature of ionic liquids against mild steel corrosion is caused by a mixedtype of adsorption film formed on the steel surface. The Langmuir adsorption isotherm was used to describe the adsorption of ionic liquid molecules onto the mild steel surface. Polarization curves showed that 1-BOPAMS and 4-BOBAMS have a similar effect on both the anodic and cathodic half-reactions, indicating that they prevent the dissolution of mild steel through both physical and chemical process. Nyquist plots were defined by incomplete semicircle capacitive loops, showing that the charge transfer mechanism controls the corrosion of mild steel in acidic solution. Keywords: corrosion inhibition, ionic liquids, mild steel, adsorption isotherm.

Degradation of a schiff-base corrosion inhibitor by hydrolysis, and its effects on the inhibition efficiency for steel in hydrochloric acid

A Schiff base, known in the literature as a corrosion inhibitor for steel in acidic solution, is shown to hydrolyse in aqueous solution. It appears that the imine group present in this class of molecules is an unstable linkage and the hydrolysis reaction is both acid-catalysed and base-catalysed and is the reverse of the condensation reaction required to synthesize the Schiff base. Measurement of the rate of corrosion of carbon steel in 1 M hydrochloric acid shows that the Schiff base, and its hydrolysis products have similar inhibition efficiency when at similar molar concentration. This suggests that the inhibition imparted by Schiff base may be entirely due to the products of its hydrolysis under acid conditions. We also report here that a derivative of the Schiff base obtained by reduction shows higher corrosion inhibition efficiency and is not degraded by hydrolysis and provides a much more efficient corrosion inhibitor in 1 M HCl solution relative to the Schiff base itself.

Evaluation of 2-Mercaptobenzimidazole Derivatives as Corrosion Inhibitors for Mild Steel in Hydrochloric Acid

This research aimed to develop a better understanding of the corrosion inhibition of the mild steel in acidic medium by new organic molecules. For this purpose, two new compounds namely, 2,3-dihydrobenzo[4,5]imidazo[2,1-b]thiazole (2-BIT) and 3,4-dihydro-2H-benzo[4,5]imidazo[2,1-b]thiazole (3-BIT) were synthesized and evaluated for mild steel (MS) corrosion in HCl. Analyses were carried out using weight loss measurements, electrochemical techniques, and scanning electron microscope (SEM). The adsorption of inhibitors onto the steel surface follows the Langmuir adsorption model. Generally, results showed that the corrosion inhibition efficiency of the investigated molecules was found to increase with increased concentration of inhibitors. Electrochemical tests, i.e., electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PDP) techniques, showed that the addition of our investigated inhibitors decreases the dissolution of the metal and generally act as mixed-type inhibitors. In addition, the influence of temperature (from 303 to 333 K) on the corrosion inhibition was studied, and the results demonstrated that with an increase in temperature, the inhibition efficiency decrease. SEM results confirmed that the inhibition process is due to a protective film that prevents corrosion. Similarly, the results showed that the inhibitory efficiencies reach 93% at 5 × 10−3 M in the case of inhibitor 3-BIT. These results revealed that this compound could effectively control and reduce the corrosion rate of mild steel in the corrosion test solution.

Novel Green Corrosion Inhibitor for Mild Steel in Sulfuric Acid

Salix leaves water extract was studied for the corrosion inhibition of mild steel in H2SO4 at different temperatures. Energy dispersive spectroscopy (EDX), Gas Chromatography Mass spectrometry (GC–MS), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) were used in our investigation. By applying different techniques as potentiodynamic polarization and electrochemical impedance to detect the effect of the Salix active ingredients onto the mild steel in acidic medium, it was confirmed that the corrosion process was inhibited. Salix water extract acts by decreasing the available cathodic and anodic reaction area. The adsorption isotherm has revealed that the inhibitor adsorbed on the metal surface obeys Langmuir and Temkin isotherm.

Corrosion Inhibition and Adsorption Properties of <i>Commelina benghalensis</i> Leaves Extract on Mild Steel in 1M H<sub>2</sub>SO<sub>4</sub> Solution

The corrosion inhibition of mild steel in 1M sulphuric acid solution by the ethanol extract of Commelina benghalensis (C. B) leaves was determined using gravimetric technique. Phytochemical analysis was carried out on the extract and the effect of extract concentration, temperature, immersion time and acid concentration on the corrosion process was determined. The corrosion inhibition efficiency of the extract increased with increase in the concentration of the extract and decreased with increase in temperature. Increase in temperature also increased the corrosion rate of mild steel in 1M sulphuric acid in the absence and presence of different concentrations of the extract. The adsorption of the plant extract obeyed Langmuir and Freundlich adsorption isotherms. The process of physical adsorption was proposed for the extract from the trends of inhibition efficiency with temperature and from calculated values of Gibbs free energy, activation energy and enthalpy of adsorption. Gibbs free energy values for the reactions were less than 20kJ/mol, indicating physical adsorption process and were also found to be negative, indicating that the adsorption process was spontaneous. The corrosion inhibition efficiency (% IE) of the plant extract was attributed to the phytochemical constituents (alkaloids, flavonoids, tannins, saponins, phenolics, steroids and cardiac glycosides) present in them. The results showed that Commelina benghalensis can serve as a good corrosion inhibitor of mild steel in acid medium, since it reached a corrosion inhibition efficiency (% IE) of 91.91% at 2.0g/L extract concentration.

Corrosion Inhibition Efficiency of Terminalia Catappa Leaves Extracts on Stainless Steel in Hydrochloric Acid

Corrosion inhibition potential of Terminalia catappa leaves extract was investigated using Grade 304 austenitic stainless steel in 1.0 M HCl solution with a view to finding natural, eco-friendly, low-cost and readily available corrosion inhibitor. The corrosion inhibitory characteristics of the extract were investigated by utilizing gravimetric measurements and microstructural surface changes obtained from scanning electron microscopy (SEM). This study was carried out in the absence and presence of Terminalia catappa inhibitor (0.01-0.09 g/ml) and temperatures (30-50 °C). Data obtained from weight loss experiments and adsorption isotherms (El-Awady, Temkin, and Freundlich) indicated that Terminalia catappa leaf extract repressed the corrosion of stainless steel in acidic media by 96.8 % at 30 °C and conforms to physisorption adsorption mechanism. Inhibition efficiency (% IE) of the extract improved with increasing extract concentration but declined with rising temperature.

Corrosion Behavior of 17-4PH Passive Stainless Steel in Acid and Alkaline Solutions

The precipitation hardening stainless steels have high corrosion resistance and excellent mechanical strength. Passivation is the formation of a protective layer on the surface of the metal, this layer significantly influences the corrosion resistance of steel. Passivated 17-4PH martensitic stainless steel is used in various applications like oil field valve parts, chemical processes, aircraft accessories, reactor components, gears, among others. In this work 17-4PH was passivated on citric acid (C6H8O7) at 15% and it was evaluated by electrochemical technique of potentiodynamic polarization (PP), it was exposed in Na2SO4 0.5M solution and adding H2SO4 in the solution to obtain different values of pH (2, 5, 8). Stainless steel 17-4PH, presented generalized corrosion, and shows passivation in a basic medium, while in acidic media it presented a tendency to passivation.

Safranin—A Potential Corrosion Inhibitor for Mild Steel in Acidic Media: A Combined Experimental and Theoretical Approach

The adsorption behavior and the inhibition performance of safranin, an azo dye, for mild steel corrosion in 0.5 M hydrochloric acid and citric acid solutions have been carried using potentiodynamic polarization and electrochemical impedance spectroscopy techniques as well quantum chemical calculations. Safranin has shown good inhibition efficiency in both acidic solutions. The impedance responses in both acids indicated that the corrosion process takes place under activation control. Langmuir and kinetic–thermodynamic adsorption isotherms were applied to clarify the mode of safranin inhibition. The obtained results revealed that the corrosion inhibition of mild steel in both acid solutions occurs through a physicochemical adsorption mechanism of safranin. The dissolution mechanism of mild steel in both acids was clarified and discussed.

Investigation of 6-[5-(4-Methoxyphenyl) furan-2-yl] Nicotinonitrile as a New Corrosion Inhibitor for Carbon Steel in Acidic Solution: Chemical, Electrochemical and Quantum Chemical Studies

Theeffect of 6-[5-(4-methoxyphenyl) furan-2-yl] nicotinonitrile (MA-1160) as a new corrosion inhibitor for carbon steel (CS) in hydrochloric acid (HCl) solution was investigated using weight loss (WL), atomic absorption spectroscopy (AAS) and electrochemical measurements. The surface morphology of CS was tested using: scanning electron microscopy, atomic force microscope, attenuated total reflection–Fourier transform infra-red and ultraviolet–visible spectroscopy methods. The adsorption of MA-1160 on CS surface obeyed the model of Langmuir isotherm. Polarization data revealed that this inhibitor behave as mixed-type inhibitor. The spectroscopic measurements revealed the formation of a protective adsorbed layer on CS surface. Quantum chemical calculations were calculated and discussed using density functional theory method. The inhibition efficiency (% €) was 84% in WL, 86.4% in AAS, 86.0% in potentiodynamic polarization and 84.8% in EIS 86% at 21 µM. Thus, all the test methods gave good agreement with each other in % €.

Fatigue Strength of Nitrided Steels in Corrosion-Active Media of the Food Enterprises

We study the effects of the modes of nitriding in glow discharge on the low- and high-cycle fatigue of structural steels in acid, alkaline, and neutral model solutions and in air.

The effect of mono ethylene glycol on the top of line corrosion rate of low carbon steel in acetic acid and elevated temperature environment

Top of line (TOL) corrosion is a common corrosion case found on pipe that flows wet gas in oil and gas industry. The present study aims to evaluate the impact of mono ethylene glycol (MEG) on the TOL corrosion rate of low carbon steel in acidic environment with increased temperature. The study was conducted at temperature 50 °C and 70 °C in a solution containing 2000 ppm of acetic acid and 50 % volume of MEG. There are four types of experimental conditions with variation in the temperature and MEG content were used. The result present that MEG effectively reduce the condensation rate and TOL corrosion rate of low carbon steel at elevated temperature environment. This revealed that increasing of TOL corrosion inhibition effect along the experimental period. Moreover, the increased level of severity was associated with increased temperature. The results concluded that this procedure resulted due to decrease in condensation rate that is likely to reduce the supply of electrolyte for the corrosion reaction.

Extratos de folhas e flores como inibidores de corrosão de origem vegetal

Extratos aquosos e etanólicos de folhas e flores de Unxia kubitzkii H. Rob foram avaliados como inibidores de corrosão de origem vegetal para o aço carbono P110 na presença de HCl 1,0 mol.L-1. As eficiências de inibição dos extratos foram calculadas a partir das taxas de corrosão, obtidas por ensaios gravimétricos com variação na concentração dos extratos. As menores taxas de corrosão foram identificadas com uso de 15% dos extratos, com os aquosos provenientes das folhas e flores apresentando valores de eficiência de, respectivamente, 91,20 e 92,55%. Na mesma concentração, o extrato etanólico das folhas proporcionou eficiência de inibição de 93,67%, enquanto o extrato das flores revelou eficiência de 72,13%. Devido aos valores de eficiências de inibição acima de 90% os extratos aquosos das folhas e flores, assim como o extrato etanólico das folhas de Unxia kubitzkii H. Rob, apresentam-se como potenciais inibidores de corrosão para o aço carbono em meio ácido.

Effect of components of solanum trilobatum-L extract as corrosion inhibitor for mild steel in acid and neutral medium

The secondary metabolites of Solanum trilobatum-L was extracted from its leaves and their components were separated by column chromatography as Fraction-A and Fraction-B. The functional groups of the extracts were identified by FT-IR spectroscopy. The inhibition efficiency of the extract and its fractions were tested for mild steel in 1 M HCl and 3% NaCl by potentiodynamic polarization and electrochemical impedance spectroscopic techniques. Plant extracts act as mixed type inhibitors in all experimental conditions, and Fraction-A has more inhibition efficiency (I.E) than crude extract and Fraction-B. The protective layer of adsorbed extract constituents were confirmed by morphological study. The surface coverage and time constant for adsorption of extract molecules were calculated using Rct and Cdl values.

Application of green products for industrially important materials protection: An amusing anticorrosive behavior of tender arecanut husk (green color) extract at metal-test solution interface

The sustainable corrosion impediment of tactic central materials such as mild steel and copper is the subject of utmost importance in contemporary civilization due to their wide spread utility in industrial sectors. This part reports the outcome of chemical (weight loss) and electrochemical measurements on the inhibition of corrosion of mild steel and copper metals in both 0.5 M HCl and 0.5 M NaOH media. Weight loss measurements divulged that, corrosion protection efficiencies were enhanced with increment in the concentration of plant extracts which indicates that dissolution process was stifled; whilst a decrease was noticed with the rise of solution temperature at habitual acid and base concentration is plausible due to thermal agitation of plant extract constituents from the metal surfaces. The maximum protection efficiency observed with immersion period of one hour at 303 K. (93.750% for copper in acid medium, 90% for copper in alkali medium, 93.478% for MS in acid medium and 91.66% for MS in alkali medium). The probable inhibitive modality mechanism of most potent green inhibitor was further corroborated by kinetic and thermodynamic models. Electrochemical studies like, Tafel plot and AC impedance studies were used for appraisingthe green inhibitor behavior. The Tafel plot studies shows that, AH extract act as mixed type corrosion inhibitor for copper in acid media, mild steel in acid and alkali media, whereas AH extract act as anodic type corrosion inhibitor for copper in alkali media. The results of chemical and electrochemical techniques proved that, tender arecanut husk (AH) extract was the most efficacious eco-friendly corrosion inhibitor for mild steel and copper metals in both HCl and NaOH media with a concentration-dependent mode. Surface depiction via scanning electron microscopy (SEM) technique surmised the dearth of corrosion products and topographic amendment of the studied metals. Therefore, technological and economic profit is envisaged from an affirmative result in this study.

Electrochemical and computational study of gum exudates from Canarium schweinfurthii as green corrosion inhibitor for mild steel in HCl solution

ABSTRACTThe inhibition efficiency of the corrosion on mild steel in acid by Canarium schweinfurthii (CS) gum as inhibitor has been studied using chemical techniques (thermometric, gasometric, spectrophotometric and weight loss) and electrochemical techniques (electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization (PDP)). Scanning Electron Spectroscopy (SEM) was used to examine the surface morphology of mild steel samples both in the presence and absence of inhibitors at optimum conditions. Results obtained indicated that CS inhibited the corrosion of mild steel in HCl. The inhibition efficiency increases with increasing the inhibitor concentration but decreases with increasing the temperature. CS behaved as mixed type inhibitor retarding both cathodic and anodic reaction with high inhibition efficiency. Gas chromatography mass spectrometer (GCMS) spectrum of CS gum showed the presence of Nonacosane; 1-piperoylp; Stearic acid, 2-(hydroxymethyl)-2-nitropropane-1,3-diol, Stigmasta-5,22-dien-3-ol, dihex-5-en-2-yl phthalate, 9-octadecenoic acid, methyl ester,, 1-penta-decarecarboxylic and Oleic acid. Inhibition action of the gum gave a strong correlation with these phytochemicals in the gum. Phenomenon of physical adsorption was proposed for the inhibition and the process followed the Langmuir adsorption isotherm with very high negative values of the free energy of adsorption (ΔGads). Both the chemical and electrochemical results are in good agreement with each other while the surface studies reveal the formation of a smooth, dense protective layer in the presence of inhibitor. Quantum chemical computations of parameters associated with the electronic structures of specific components of the gum supported their inhibiting potentials.

Two Novel Benzodiazepines as Corrosion Inhibitors for Carbon Steel in Hydrochloric Acid: Experimental and Computational Studies

Two new benzodiazepine derivatives namely, 1-ethyl-4-(2-oxopropylidene)-1,2,4,5-tetrahydro-2H-1,5-benzodiazepine-2-one (BZD-1) and 1-octyl-4-(2-oxopropylidene)-1,2,4,5-tetrahydro-2H-1,5-benzodiazepine-2-one (BZD-2) have been synthesized and used as corrosion inhibitors for carbon steel in acidic solution (1 M HCl). Corrosion inhibition evaluation was performed using weight loss, electrochemical techniques [potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS)], quantum chemical calculations, and molecular dynamic (MD) simulations. The results showed that both compounds are good corrosion inhibitors for carbon steel in 1 M HCl medium; their inhibition efficiency increased with inhibitor concentration. In addition, the results obtained from above methods reveal that BDZ-2 is an excellent inhibitor. It gives a maximum inhibition efficiency of 96.63% at 10−3 M and inhibits corrosion by adsorbing at the carbon steel surface. EIS measurements showed that the charge transfer resistance increases, whereas the double-layer capacitance decreases with the inhibitor concentration. Polarization studies showed that BDZ-1 and BDZ-2 are mixed type. The tested inhibitors have been adsorbed on the carbon steel surface according to Langmuir isotherm adsorption model. The experimental results are in reasonably close agreement with quantum chemical parameters calculated at DFT/B3LYB/3-21G and the molecular dynamic simulations results.

Dissolution Behavior of Dual Phase Steel during Pickling

Dual phase steels have been widely used in the automotive industry to produce lighter weight vehicles to meet stringent safety and fuel economy regulations. While the phenomenon of steel dissolution in acidic solution has been reported on carbon steel and stainless steel, little is known about the dissolution behavior of dual phase steel. Moreover, the resulting surface morphology after pickling could compromise the adhesion performance of Zn coating at the electrogalvanizing line (EGL). A fundamental study was undertaken to understand the dissolution behavior of dual phase steel in acid. The results show that the dissolution kinetics are strongly influenced by pickling conditions and steel microstructure. The study suggests a different dissolution mechanism for dual phase steel in hydrochloric acid (HCl) and sulfuric acid (H2SO4). Non-uniform dissolution in HCl was observed for dual phase steel in which the ferrite phase dissolved faster than the martensite phase. The preferential dissolution of the ferrite phase in dual phase steel could be attributed to the higher dissolution rate of the ferrite phase than the martensite phase due to its lower activation energy for dissolution, and the galvanic couplings formed between the ferrite phases and adjacent martensite phases.

Methanolic and Aqueous Extracts of Corn Silk as Corrosion Inhibitor for Mild Steel in Hydrochloric Acid at Different Temperatures

This research work presents a study on the methanolic and aqueous extracts of corn silk for their corrosion inhibitive effect on mild steel in 0.5M HCl media at 303K, 313K and 323K using the weight loss method. Various concentrations of Corn Silk Methanolic Extract (CSME) and Corn Silk Aqueous Extract (CSAE) (0.1w/v, 0.2w/v, 0.3w/v, 0.4w/v and 0.5w/v) were prepared from the shadow-dried corn silk. Inhibition efficiency of 95.07%, 90.91%, 83.40%; and 79.43%, 72.55%, 66.30% was obtained respectively for CSME and CSAE at 303K, 313K and 323K for the highest concentration of extracts (0.5w/v). The Inhibition efficiency increased with increase in concentration of the extracts and decreased as temperature increased. The results obtained from both extracts were compared and it showed that the methanolic extract was a better inhibitor than the aqueous extract. From this present work, both extracts was shown to be most effective at 303K than at 313K and 323K. It was observed that both extracts inhibited the corrosion of mild steel in acidic media through physical adsorption by forming a barrier on the surface of the metal. Data obtained obeyed Langmuir adsorption isotherm. The Kinetic study of the process proposed a first order reaction type. The usefulness of a waste material as corrosion inhibitor is once more reported.

Pyridazinium-based ionic liquids as novel and green corrosion inhibitors of carbon steel in acid medium: Electrochemical and molecular dynamics simulation studies

Two new pyridazinium-based ionic liquids namely 1-(6-ethoxy-6-oxohexyl)pyridazin-1-ium bromide (S1) and 1-(2-bromoacetyl) pyridazinium bromide (S2) were synthesized and their inhibitive performance towards the corrosion of mild steel in 1M hydrochloric acid was studied using electrochemical impedance spectroscopy (EIS) at various temperatures (303–333K). It was shown that the inhibition efficiency increased with the concentration of S1 and S2 and reached 84% for S1 and 82% for S2 at 10−3M (303K). Impedance measurements revealed that the charge transfer resistance (Rct) increased and the double layer capacitance (Cdl) decreased with an increase in the concentration of both the inhibitors. The thermodynamic parameters provided the evidence of the inhibitory effect. Langmuir isotherm model fitted well with the adsorption of the studied compounds. Furthermore, spontaneity of the adsorption process, evaluated from the sign of free energy (ΔGadso) values, showed an increase upon increase in temperature in the presence of inhibitors. Dynamics simulation indicated the possibility of gradual substitution of water molecules from the iron surface.