Steel In HCl Medium Research Articles

Adsorption and Inhibitive Properties of Methanol Extract of Leucas aspera Leaves for the Corrosion of Mild Steel in HCl Medium

Inhibitive and adsorption properties of methanol extract of Leucas aspera leaves (MLA) on the corrosion of mild steel (MS) was studied using weight loss measurement, AC impedance spectroscopy, and potentiodynamic polarization spectroscopy, Fourier-transform infrared spectroscopy, field emission scanning electron microscope and energy-dispersive X-ray spectrometer, and GC–MS analysis. The results obtained indicated that the MLA is a good adsorption inhibitor for the corrosion of mild steel in HCl medium. The inhibition efficiency of MLA was found to increase with the increasing immersion of time and decreases with the increasing temperature. The polarization studies reveal that the extract acts as a mixed-type inhibitor. The adsorption of MLA on mild steel surface is a spontaneous and exothermic reaction and is best described by the Langmuir adsorption model. The values of activation and free energies obtained were within the range limits expected for the mechanism of physical adsorption. Examination of the FT-IR spectra of the corrosion products of mild steel and that of methanol extract of leaves of LA before and after adsorption indicates the adsorption of the inhibitor on MS surface. Field emission scanning electron microscopy confirms the adsorption of LA on the MS surface. The GC–MS analysis was used for the identification of active phytochemical compounds in MLA.

Evaluation of Ficus tikoua leaves extract as an eco-friendly corrosion inhibitor for carbon steel in HCl media

An effective and biodegradable Ficus tikoua leaves extract was studied as a corrosion inhibitor for carbon steel in hydrochloric acid. Systematic electrochemical experiments and morphological characterization were carried out to investigate the properties of the corrosion inhibitor. Meanwhile, quantum chemical calculations were performed to aid further understanding of the electrochemical mechanism. The electrochemical results reveal that the extract inhibitors act as a mixed-type with an inhibition efficiency up to 95.8% at 298 K. Moreover, this extract shows good inhibory activity at a wide range of temperatures and the corresponding results were further confirmed by morphological analysis. The chemical formulae of these major components are fully optimized in the DFT with B3LYP in the gas phase and the base set is 6-311++G (d, p).

An investigation on mitigation of corrosion of mildsteel by Origanum vulgare in acidic medium

The restraining impact of plant extract towards corrosion of mild steel has been reviewed in this paper. The purpose of the present investigation is the utilization of Origanum vulgare (oregano) extract as environment friendly corrosion inhibitor of mild steel in HCl medium. Methods include weight loss, quantum chemical calculations and SEM. The outcomes revealed that the efficiency of Origanum vulgare increased with increasing its concentration reaching maximum of 91.2% at 1000 mg/L at 30 o C. Results showed that adsorption followed Langmuir adsorption isotherm. The adsorption attributes of chosen extract were hypothetically assessed by quantum chemical and the morphology of metal was studied by using SEM analysis. KEY WORDS : Mild steel, Origanum vulgare , Corrosion inhibitor, HCl, Corrosion inhibition, Weight loss Bull. Chem. Soc. Ethiop. 2019 , 33(1), 159-168 DOI: https://dx.doi.org/10.4314/bcse.v33i1.16

Corrosion Inhibition Performance and Adsorption Mechanism of Novel Quinazoline Schiff Base on Low Alloy Steel in HCl Media

The inhibition performance of synthesized Quinazoline Schiff Bases 2-(3,3-Dimethyl-2,3-dihydro-indol-2-ylidene)-3-[(2-hydroxyphenyl) imino] propylidene (DHIP1) and 2-(3,3-Dimethyl-2,3-dihydro-indol-2-ylidene)-3-[(2-hydroxyphenly) imino] propanal (DHIP2) on low carbon steel (LAS) in 1 M HCl has been examined using weight loss, electrochemical measurements and scanning electron microscopy (SEM). The obtained experimental results indicated that both DHIP1 and DHIP2 have fairly enhanced the corrosion resistance of LAS and extremely exhibited better inhibitive efficiencies at a concentration of 5 mM. The results of potentiodynamic polarization results clarified that investigated Schiff Bases acts as mixed-type inhibitors and follow Langmuir adsorption isotherm is fitted well for adsorption. It was found that the inhibition efficiency increases with increase in inhibitor concentration as confirmed by all the measurements.

Coffee Husk as Corrosion Inhibitor for Mild Steel in HCl Media

Coffee Husk as Corrosion Inhibitor for Mild Steel in HCl Media

Electrochemical and optical studies of two synthesized cobalt complexes as anti-corrosion agent for low-carbon steel in HCl medium

Two novel synthesized Co(II) complexes, named diacetato(1-(2-methoxyphenyl)-N-(2-(phenylthio)phenyl)methanimine)cobalt(II) (CoMPM) and diacetato(2-(phenylthio)phenyl)-1-(2-(trifluoromethyl)phenyl)methanimine)cobalt(II) (CoPFM), have been investigated as an anti-corrosion agent for low-carbon steel in 1.0 M HCl solution. The protection performance of Co(II) complexes was evaluated using electrochemical and optical methods. The inhibition efficiency was investigated as a function of exposure time, inhibitor concentration, and different potentiostatic potentials. CoPFM (99.4%) was found more efficient as a corrosion inhibitor in negative potentiostatic polarization conditions than CoMPM (98.4%). However, CoMPM (99.2%) showed a better protection when it was compared to CoPFM (95.7%) at the end of 120-h immersion.

Bark resin of Schinus molle as an eco‐friendly inhibitor for API 5L X70 pipeline steel in HCl medium

The inhibition effect of bark resin of Schinus molle (BRSM) on the corrosion of API 5L X70 pipeline steel in hydrochloric acid solution has been studied for the first time by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) measurements; also, surface morphology has been analyzed by SEM‐EDX. The inhibitor (BRSM) has been characterized by Fourier transform infrared spectroscopy (FTIR). The results show that BRSM is a good inhibitor in hydrochloric acid solution. The maximum percentage inhibition efficiency is equal to 94% at 2 gL−1. The adsorption of BRSM on API 5L X70 pipeline steel surface obeys Langmuir adsorption isotherm, and involves physical adsorption. Polarization curves reveal that BRSM acts as a mixed‐type inhibitor in hydrochloride acid.

Corrosion inhibition of mild steel in HCl medium by S-benzyl-O,O'-bis(2-naphthyl)dithiophosphate with ultra-long lifespan

Herein, the target compound of S-benzyl-O,O'-bis(2-naphthyl)dithiophosphate (SBOB) as corrosion inhibitor with ultra-long lifespan was successfully synthesized and characterized by elemental analysis, single crystal X-ray diffraction and spectroscopy involving FT-IR, 1H, 13C and 31P NMR. Meanwhile, the inhibition performance and mechanism of SBOB for mild steel (MS) in HCl medium were combined to investigate by weight loss, potentiodynamic polarization, electrochemical impedance spectroscopy, scanning electron microscopy and quantum chemical calculation. The potentiodynamic polarization results indicate that SBOB is a mixed-type inhibitor. All experimental results are in good agreement and reveal that the corrosion inhibition increases with the concentration of SBOB. Weight loss results indicate that the inhibition efficiency decreases with HCl concentration and temperature increasing, but the corrosion inhibition performance of SBOB keeps almost unchanged after ultra-long storage time due to the formation of inhibitor film by the physisorption and chemisorption of SBOB on MS surface.

Theoretical and Experimental Studies About the Inhibitive Action of Ruellia tuberosa L on Mild Steel in HCl Medium

The inhibiting ability of the leaves of Ruellia tuberosa Linn (RT) extract on the corrosion of mild steel in hydrochloric acid was investigated using mass loss and electrochemical studies. The inhibition efficiency increases with increasing concentration of RT extract and decreases with increasing acid concentration and temperature. The polarization studies reveal that the extract acts as a mixed type inhibitor. Impedance results indicate adsorption of the RT extract on the mild steel surface is through charge transfer reaction. The adsorption of the inhibitor on mild steel surface is exothermic, spontaneous, and is consistent with the mechanism of physical adsorption. In addition, it has been established that the adsorption process obeyed Freundlich isotherm. The adsorption of the chemical constituents of the RT extract on mild steel surface was confirmed by Fourier transform infrared spectroscopy and field emission scanning electron microscopy. The quantum chemical calculations were made to ascertain the possible adsorption sites of the components of the extract on to the metal surface.

Excellent corrosion inhibition performance of novel quinoline derivatives on mild steel in HCl media: Experimental and computational investigations

The inhibition performance of two synthesized quinoline derivatives: 6-benzylquinoline (BQ) and 6-(quinolin-6-ylmethyl) benzene-1,2,3,4,5-pentasulfonic acid (QBPA) on mild steel in 1 M HCl has been investigated through weight loss, electrochemical measurements, scanning electron microscopy (SEM), and atomic force microscopy (AFM). All experimental results indicated that BQ and QBPA extremely enhanced the corrosion resistance of mild steel and QBPA showed a better inhibitive performance than BQ. The results of potentiodynamic polarization illustrated that BQ and QBPA performed as mixed-type inhibitors. Langmuir adsorption isotherm was well fitted for the adsorption of BQ and QBPA on mild steel surface with a competitive physisorption and chemisorption mechanism. The results of quantum chemical calculations and molecular dynamic simulations showed that benzene rings of both BQ and QBPA adsorbed on the metal surface in distinct gradient direction and quinoline ring of both BQ and QBPA adsorbed nearly parallel on the steel surface.

Improved Performance of 1-Ethyl-3-Methylimidazolium Tetrafluoroborate at Steel/HCl Interface by Iodide Ions

The corrosion and corrosion inhibition of St37 steel in 0.1 M HCl solution by 1-ethyl-3-methylimidazolium tetrafluoroborate (EMITFB) and the effect of addition of KI on the inhibitive performance of EMITFB have been examined by electrochemical [electrochemical impedance spectroscopy, potentiodynamic polarization, and dynamic electrochemical impedance spectroscopy (DEIS)] and surface examination [scanning electron microscope (SEM) and energy-dispersive X-ray spectroscopy (EDS)] techniques. Results show that EMITFB could only afford the protection of St37 steel in HCl medium on an average scale. The highest studied concentration of EMITFB (4 mM) affords optimum inhibition efficiency of 78.86% from DEIS method. Addition of iodide ions to EMITFB has beneficial effect on the inhibition efficiency; 86.10% has been achieved by addition of 1 mM KI to 4 mM EMITFB. Adsorption of EMITFB molecules onto the metal surface is via physical adsorption mechanism and follows El Awady et al. kinetic/thermodynamic adsorption isotherm model. SEM and EDS results confirm the improvement of corrosion inhibiting ability of EMITFB by iodide ions. EMITFB and EMITFB + KI behave as mixed-type corrosion inhibitor in the studied environment.

Spectral investigation of the Piperazine Dithiosemicarbazone Derivatives as inhibitor on High Carbon Steel in HCl media

Spectral investigation of the Piperazine Dithiosemicarbazone Derivatives as inhibitor on High Carbon Steel in HCl media

Electroactive Sulfonated Polysulfone Polymer as Corrosion Inhibitor for Mild Steel in Acidic Medium

The corrosion of mild steel in HCl medium containing different concentrations of sulfonated polysulfone polymer (SPS) has been evaluated by electrochemical, chemical and theoretical studies. SPS shows around 84% inhibition efficiency at 3000 ppm concentration. Inhibition efficiency increases with increase in temperature from 30 to 60 °C. The adsorption of SPS on mild steel was found to be Langmuir’s adsorption isotherm. The calculated thermodynamic functions were employed to give further insight into the mechanism of inhibition action of SPS. Quantum chemical calculations were supported the results. Dipole moment of SPS was found to be 4.6 D, ΔE (energy difference) was 5.02, and these values suggest the good interaction between inhibitor and mild steel surface. Scanning electron microscopy images confirm the adsorbed inhibitor film on the metal surface. FTIR results validate the interaction of SPS with mild steel surface.

The influence of temperature on the corrosion inhibition of API 5L X42 pipeline steel in HCl medium by gum arabic

PurposeThis paper aims to investigate the influence of temperature (25-65°C) on the adsorption and the inhibition efficiency of gum arabic (GA) for the corrosion of API 5L X42 pipeline steel in 1M HCl.Design/methodology/approachInhibition behaviour on steel in HCl has been studied in relation to the concentration of the inhibitor and the temperature using potentiodynamic polarization curves and electrochemical impedance spectroscopy. Thermodynamic parameters of adsorption were calculated from the viewpoint of adsorption theory.FindingsThe results show that at a temperature range from 25 to 65°C, GA was a good inhibitor for API 5L X42 pipeline steel, and its inhibition efficiency was significantly stable. The maximum inhibition efficiency (93 per cent) is obtained at 4 g L−1. In absence and presence of GA, there is almost no change in the corrosion mechanism regardless of the temperature. The adsorption of GA on steel surface is an exothermic process. The adsorption of GA involves physical adsorption.Practical implicationsThe use of GA as an eco-friendly corrosion inhibitor is practical for carbon steel in HCl.Originality/valueThe stability of inhibition efficiency of GA at a temperature range from 25 to 65°C could find possible applications in acid pickling, industrial acid cleaning and acid descaling.

Morpholine and piperazine based carboxamide derivatives as corrosion inhibitors of mild steel in HCl medium

Abstract N -(2-chloroethyl)morpholine-4-carboxamide (NCMC), N -(2-chloroethyl)tiomorpholine-4-carboxamide (NCTC) and N , N -bis(2-chloroethyl)piperazine-1,4-dicarboxamide (NCPD) were studied as corrosion inhibitors for mild steel using atomic absorption spectroscopy (AAS) and gravimetry and thermometry. Results obtained from the three techniques are similar and reveal that the compounds inhibit mild steel corrosion. The inhibition efficiencies increased from 35.6% to 74.9% (NCMC), 44.5% to 82.4% (NCPD) and 52.6% to 90.1% (NCTC) at 30 °C when the inhibitor concentrations increased from 10 μM to 50 μM. The maximum inhibition efficiency values (at 50 μM) decreased to 46.6%, 58.1% and 61.2% for NCMC, NCPD and NCTC respectively, when the temperature was raised to 50 °C. The decrease in inhibition efficiency with increase in temperature suggested predominant physisorption mechanism in metal/inhibitor interactions. The formation of protective films of NCMC, NCPD and NCTC molecules on mild steel surface were confirmed by FTIR and XRD. The order of inhibitive strengths of the molecules is NCTC > NCPD > NCMC. Quantum chemical calculations revealed the prospective sites through which the molecules can interact with mild steel surface and some quantum chemically derived parameters were used to corroborate experimental.

Chemical modification at the surface and corrosion inhibition response of two semicarbazones on carbon steel in HCl medium

Two similarly structured heterocyclic semicarbazones (E)-4-(5-((2-carbamoylhydrazano)methyl)furan-2-yl)benzoic acid (CPFASC) and (E)-2-((5-(4-nitrophenyl)furan-2-yl)methylene)hydrazinecarboxamide (NPFASC) were synthesized, characterized and tested for their corrosion protection capacity on carbon steel (CS) in 1 M HCl solution. Contrary to expectation the non-planar molecule NPFASC showed better inhibition efficiency on CS surface than CPFASC. At a concentration of 0.5 mM, NPFASC displayed 93.4 % while CPFASC showed 89.9 % inhibition efficiency according to impedance studies. This unusual behavior can be explained by the conversion of the nitro group present in the NPFASC molecule into amino group on approaching the metal surface in the corrosive medium. This transformation obviously changes the geometry of the molecule which is more conducive for corrosion inhibition. Analysis of the corrosion product deposited on the surface of the metal revealed the mechanism behind the inhibitive power of molecules. Adsorption studies showed that CPFASC and NPFASC follow Freundlich and El-Awady isotherms, respectively, on the carbon steel surface. Adsorption equilibrium constant and free energy of adsorption were also evaluated. The corrosion investigations were done by gravimetric, EIS and polarization studies and the surface analysis of the metal specimens was performed by SEM, AFM and IR spectral spectroscopy.

Electrochemical Corrosion of Low Carbon Steel in a Hydrochloric Acid Medium

Inhibition is one of the mechanisms used for mitigating the metallic corrosion, particularly in an acid environment. The present work aims to investigate the inhibiting effect of N-benzyl-N/-phenyl thiourea (BPTU) on the corrosion of low carbon steel in a 0.1 M hydrochloric acid (HCl) solution using a Tafel extrapolation and linear polarization techniques. The study reveals that BPTU acts as an excellent anodic inhibitor for low carbon steel in a HCl solution. The protective efficiency of the compound was found to be more than 97% even at higher temperatures. The study demonstrated that BPTU gets adsorbed on the steel surface, following Temkin’s adsorption isotherm and the inhibition is controlled by a chemisorption mechanism. The investigation shows that the results obtained from the Tafel extrapolation and linear polarization techniques for the corrosion of mild steel in HCl medium were in good agreement. The influence of temperatures and concentrations of BPTU on the corrosion of low carbon steel are also examined in the present work

Corrosion inhibition effect of novel methyl benzimidazolium ionic liquid for carbon steel in HCl medium

In the present investigation, the corrosion inhibition property of the newly synthesized3-(4-chlorobenzoylmethyl)-1-methylbenzimidazoliumbromide ([BMMB]+Br−) ionic liquid on carbon steel was investigated in 1M HCl solution using electrochemical studies. Polarization study revealed that [BMMB]+Br− is a mixed type of inhibitor. The impedance to metal dissolution was increased not only with increasing inhibitor concentration but also with temperature. The diminished current amplitude waves obtained in the electrochemical noise analysis (ENA) technique implied high noise resistances thereby indicating the formation of passive inhibitor layer. Adsorption of [BMMB]+Br− ionic liquid on carbon steel was spontaneous and followed a Langmuir adsorption isotherm. The surface examination of the coupons before and after engrossed in inhibited medium was analyzed using Attenuated total reflectance – Fourier transform infrared spectroscopy (ATR-FTIR) and scanning electrochemical microscope with energy dispersive X-ray (SEM/EDX) studies and confirmed that the surface of carbon steel was protected from corrosion by the adsorption of [BMMB]+Br− ionic liquid. Thermodynamic properties revealed that [BMMB]+Br− has both physical and chemical adsorption behavior. In addition, density functional theory (DFT) calculations were carried out to give atomic level understandings to the experimental results by deducing the electronic properties of inhibitor in proportion to inhibition efficiency in aggressive medium.

Modeling the Corrosion Inhibition of Mild Steel in HCl Medium with the Inhibitor of Pawpaw Leaves Extract

Modeling the corrosion inhibition of mild steel in HCl medium with inhibitor of pawpaw leaves extract is presented. The extract was analyzed using gas chromatography - mass spectrometry . Thermometric and gravimetric methods were employed in the corrosion inhibition study. The inhibition efficiency w as modeled and optimized using response surface methodology (RSM) . It was observed that the free energy of adsorption ( ∆ G ads ) was negative and less than the threshold value of - 40 kJ/mol . T he adsorption of the extract was spontaneous , and occurred according to the mechanism of physical adsorption . A quadratic model was generated, with optimum i nhibition efficiency of 80.29 % obtained. The extract was highly efficient in the corrosion control process . It is effective for surface treatment of mild steel in the acid medium. Therefore, i t is recommended that pawpaw leaves extract should be employed as corrosion inhibitor in oil well acidizing and surface treatment of mild steel .

Thermodynamic and Kinetic Parameters of Methanolic Extract of Leaves of Cochlospermum Tinctorium as Eco-friendly Inhibitor for Corrosion of Mild Steel in HCL Medium

Thermodynamic, kinetic and adsorptive parameters of methanolic extract of leaves of Cochlospermum tinctorium as eco-friendly inhibitor for the corrosion of mild steel in HCl medium were evaluated through the weight loss method at 303 K and 311 K. The inhibition efficiency, %IE, increased with increase in extract concentration, but found to be better at 303 K than 311 K. The decrease in %IE with increase in temperature with the average value of 81.88 kJ/mol for activation energy, E a , and the values of free energy, ÄG, for the adsorption process are all supportive of physical adsorption mechanism. The values of heat of adsorption, Q ads,, are all negative, an indication that the adsorption process was exothermal. The half-life, t 1/2 , value increased with increase in inhibitor concentration and low at high higher, implying the inhibitor performance increased with increase in the extract concentration and decreased with rise in temperature. The data best fitted the Langmuir adsorption isotherm.