Mild Steel In Acidic Solution Research Articles

Uvaria chamea root as green corrosion inhibitor for mild steel in acidic solution

The corrosion inhibition of mild steel is the subject of tremendous technological importance due to the increased industrial applications of these materials. This study reports the corrosion inhibition of mild steel in acidic solution of 0.5 M HCl using root extract of Uvaria chamea by way of gravimetric measurements. It was shown that the presence of U. chamea root extract inhibited the corrosion of mild steel in the test solution and the inhibition efficiency depended on the concentration of the plant extract as well as on the time of exposure of the mild steel samples in HCl solutions containing the extract. The experimental data complied to the Langmuir and Temkin adsorption isotherms. From the results obtained authenticates that the root extracts of U. chameafavours both cathodic and anodic inhibitor. The adsorption mechanism is both chemisorptions and physisorption. Key words: Corrosion inhibition, mild steel, adsorption mechanism, Uvaria chamea, Langmuir and Temkin isotherms.

Differences in the corrosion inhibition of water extracts ofCassia fistulaL. pods ando-phenanthroline on steel in acidic solutions in the presence and absence of chloride ions

AbstractThe corrosion inhibition of water extract of Cassia fistula L. pods and o-phenanthroline on mild steel in acid solution in the absence and presence of 0.1 M NaCl have been investigated using weight loss measurements in addition to the potentiodynamic polarization technique. FTIR and GC-mass were used to identify the chemical composition of C. fistula L. pods. The inhibition efficiencies of C. fistula L. pods were 95.19% in 2 M H2SO4 and 86.13% in 0.5 M nitric acid solutions in the presence of chloride ions, while o-phenanthroline recorded 86.09 and 72.76% for the above acid solutions, respectively. All the ΔGads were negative which indicates spontaneous adsorption on the steel surface. Consequently the relationship between log (c/) and log c indicates that the adsorption of inhibitor onto steel surface follows the Langmuir adsorption isotherm.

Surface morphological and impedance spectroscopic studies on the interaction of polyethylene glycol (PEG) and polyvinyl pyrrolidone (PVP) with mild steel in acid solutions

The inhibition of mild steel corrosion in aerated acid mixture of 0.5 N H2SO4 and 0.5 N HCl solution was investigated using potentiodynamic polarization studies, linear polarization studies, electrochemical impedance spectroscopy, adsorption, and surface morphological studies. The effect of inhibitor concentration on corrosion rate, degree of surface coverage, adsorption kinetics, and surface morphology is investigated. The inhibition efficiency increased markedly with increase in additive concentration. The presence of PEG and PVP decreases the double-layer capacitance and increases the charge-transfer resistance. The inhibitor molecules first adsorb on the metal surface following a Langmuir adsorption isotherm. Both PEG and PVP offer good inhibition properties for mild steel and act as mixed-type inhibitors. Surface analysis by scanning electron microscopy (SEM) and atomic force microscopy (AFM) shows that PVP offers better protection than PEG.

Electrochemical investigation of Substituted Pyranopyrazoles Adsorption on Mild Steel in Acid Solution

Four substituted pyranopyrazole derivatives (PPZs) were synthesized and their effects on the electrochemical behavior of mild steel in 1 M HCl were investigated using gravimetric measurements, Tafel extrapolation method, linear polarization resistance (LPR), and electrochemical impedance spectroscopy (EIS). Tafel polarization measurements revealed that these compounds effectively suppressed both the anodic and cathodic processes of mild steel corrosion in acid solution and acted as mixed-type inhibitors. Scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) examinations of electrode surface confirmed the existence of adherent layer of inhibitor on electrode surface. The UV–visible absorption spectrum of inhibitor solution containing mild steel indicated the formation of Fe–PPZ complex. Quantum chemical calculations have been used to evaluate the structural, electronic, and reactivity parameters of the selected pyranopyrazole derivatives in relation to their inhibition action.

A comprehensive study on crude methanolic extract of Artemisia pallens (Asteraceae) and its active component as effective corrosion inhibitors of mild steel in acid solution

Corrosion inhibition effects of crude methanolic extract of Artemisia pallens on mild steel in 1moll−1 HCl were studied by weight loss and electrochemical technique. Arbutin, an active principle from A. pallens and the crude methanolic extract exhibited inhibition efficiency of 93% and 98% in 400mgl−1 concentration at 30°C respectively. The results indicated that arbutin in acidic medium acted as good anti-corrosive agent synergistically with its hydrolyzed products hydroquinone and d-glucose. Adsorption of both the inhibitors on mild steel surface conformed to the Langmuir isotherm with standard adsorption free energy of −33.07kJmol−1 for arbutin.

A study of differential polarization curves and thermodynamic properties for mild steel in acidic solution with nitrophenyltriazole derivative

The nitrophenyltriazole derivative, namely 2-[1,2,4]-triazole-methyl-4-acetyl-5-nitrophenyl-[1,3,4]-oxadiazole (TMANO) was synthesized and its inhibiting action on the corrosion of mild steel in 0.5M H2SO4 solution was investigated by weight loss test, electrochemical impedance spectroscopy (EIS), potentiodynamic polarization and scanning electron microscopy (SEM). The selective desorption of TMANO from mild steel surface was also studied by the differential polarization curves. Both thermodynamic and kinetic parameters were calculated and discussed. The results showed that the adsorption of TMANO on steel surface obeys the Langmuir adsorption isotherm. The calculated values of ΔHads0 and ΔSads0 indicated that the adsorption process of TMANO on steel surface was exothermic and accompanied by a decrease in entropy.

Novel and Effective Pyridyl Substituted 1, 2, 4-Triazole as Corrosion Inhibitor for Mild Steel in Acid Solution

Novel and Effective Pyridyl Substituted 1, 2, 4-Triazole as Corrosion Inhibitor for Mild Steel in Acid Solution

Adsorption and Inhibitory Mechanism of 1H-1,2,4-Triazol-l-yl-methyl-2-(4-chlorophenoxy) Acetate on Corrosion of Mild Steel in Acidic Solution

The triazole-acetate derivative TMCA was synthesized and its inhibiting action on the corrosion of mild steel in sulphuric acid was investigated by means of weight loss, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), and scanning electronic microscope (SEM). The potentiodynamic polarization measurements show that the TMCA acts essentially as a mixed-type inhibitor, and EIS confirmed that changes in the impedance parameters were due to surface adsorption. The inhibition efficiencies (IE%) obtained from weight loss measurement and electrochemical tests were in good agreement. Substitutional inhibition mechanism of mild steel was established according to the fitted results at different temperatures. The number of water molecules (X) replaced by a molecule of organic adsorbate was determined from the different substitutional adsorption isotherms applied to the data obtained from weight loss experiments.

Corrosion Inhibition of 45# Mild Steel in Acidic Solution by Some Norfloxacin

The corrosion inhibition of 45# mild steel in 3%HCL solution by norfloxacin has been studied by weight loss measurement, Tafel polarization, electrochemical impedance spectroscopy (EIS) and quantum chemical study. The inhibitor of norfloxacin shows 93.2% inhibition efficiency at optimum concentration 400mg/L. The polarization studies suggest that norfloxacin is the mixed-type inhibitor for 45# carbon steel in 3%HCL. Electrochemical impedance spectroscopy techniques are also used to investigate the mechanism of corrosion inhibition. What is more, the adsorption model obeys Langmuir adsorption isotherm at 298K. And the calculated quantum chemical also suggests that norfloxacin have excellent inhibition properties.

Effects of Nanoclay and Polyurethanes on Inhibition of Mild Steel Corrosion

Sulfonated polyurethanes (SPU) were used as corrosion inhibitor for mild steel in acidic solution. The sulfonation of the > N-H groups of the urethane linkages was confirmed from Nuclear Magnetic Resonance (NMR) and Fourier Transform Infra Red (FTIR) spectroscopic techniques. The inhibition efficiency of sulfonated polyurethanes, prepared from two different routes, was investigated using different techniques. The effects of microstructure of polyurethane (PU), degree of sulfonation, time of immersion and temperature on the inhibition of corrosion were discussed. The disc-like nanoparticles, so-called nanoclay, either suspended or chemically attached to SPU chains (nanocomposites) dramatically enhanced the inhibition efficiency for mild steel in acidic medium. All the inhibitors retard the corrosion rate by getting themselves adsorbed on the corroding surface by following the Langmuir adsorption isotherm. The surface analysis of inhibited and uninhibited samples was performed using Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM). Among the various inhibitors used, the nanocomposite of polyurethane was the most effective. Molecular modeling helped in determining the extent of packing of the SPU chains leading to better inhibition efficiency.

Corrosion Inhibition of Mild Steel in Acid Solution by 3,4,5-Trimethoxyphenyl-2-imidazolines

A heterocyclic imidazoline, 3,4,5-trimethoxyphenyl-2-imidazolines (TMP2I) was tested for its corrosion inhibition in 0.5 M H2SO4and 1 M HCl using weight loss, Tafel polarisation and electrochemical impedance techniques. The results show that the inhibition efficiency increases with the increase in concentration of TMP2I and the higher efficiency of about 98% is obtained in both the acid media at 20 ppm. The adsorption of TMP2I obeys Langmuir adsorption isotherm and occurs spontaneously. Cathodic and anodic polarization curves of mild steel in the presence of different concentrations of TMP2I at 300C reveal that it is a mixed type of inhibitor. Electrochemical impedance studies reveal that the system follows mixed mode of inhibition. The surface morphology of the mild steel specimens was evaluated using SEM images

The corrosion inhibition and adsorption behavior of Uncaria gambir extract on mild steel in 1 M HCl

The inhibitive effect of the ethyl acetate extract of Uncaria gambir on the corrosion of mild steel in 1 M HCl solution has been investigated by weight loss measurement as well as potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques. The presence of this catechin-containing extract reduces remarkably the corrosion rate of mild steel in acidic solution. The effect of temperature on the corrosion behavior of mild steel was studied in the range of 303–333 K. The results from this corrosion test clearly reveal that the extract behaves as a mixed type corrosion inhibitor with the highest inhibition at 1000 ppm. Surface analyses via scanning electron microscope (SEM) shows a significant improvement on the surface morphology of the mild steel plate. Linearity of Langmuir isotherm adsorptions indicated the monolayer formation of inhibitor on mild steel surface.

Experimental and quantum chemical characterization of the adsorption of some Schiff base compounds of phthaloyl thiocarbohydrazide on the mild steel in acid solutions

Three derivatives of 2-[2-(hydrazinecarbonothioyl)hydrazinecarbonyl]benzoic acid (IL 1) have been evaluated as new corrosion inhibitors for the corrosion of mild steel in 1 M HCl solutions using weight loss, polarization and electrochemical impedance spectroscopy (EIS) techniques. The adsorption of these compounds has been tested thermodynamically which was found to be of neither a typical physisorption nor a typical chemisorption mode. The thermodynamic functions (such as E a, Δ H° ads, Δ S° ads and Δ G° ads) of dissolution and adsorption processes have been evaluated. The polarization measurements indicated that the inhibitors are of mixed type. The adsorption of the compounds was found to obey Langmuir's adsorption isotherm. In addition, quantum chemical calculations have been made to correlate inhibition efficiencies determined experimentally.

Corrosion Inhibition Property of Some 1, 3, 4- Thiadiazolines on Mild Steel in Acidic Medium

The present work deals with the corrosion behavior of mild steel in acidic medium. The inhibitive effect of substituted 1, 3, 4-Thiadiazol-2-amines on the corrosion of mild steel in 1 M H2SO4has been studied by weight loss and electrochemical methods. The electrochemical parameters for mild steel in acidic solution with and without inhibitor were calculated. The effect of temperature on the corrosion rate, activation energy and free energy of adsorption were also calculated. The synergistic effect has been studied by weight loss and electrochemical methods. The electrochemical parameters for mild steel in acidic solution were also calculated.

Role of polyethylene glycol tert-octylphenyl ether on corrosion behaviour of mild steel in acidic solution

In recent years, polymeric surfactants have been investigated as efficient corrosion inhibitors for iron in acidic media. In this study, the inhibition performance of polyethylene glycol tert-octylphenyl ether (Triton X-114) for the corrosion of iron in 1M HCl solution has been evaluated. Potentiodynamic polarisation, electrochemical impedance spectroscopy, linear polarisation resistance techniques and long term experiments were used to achieve electrochemical studies. The effect of polyethylene glycol tert-octylphenyl ether on cathodic hydrogen evolution reaction was also investigated. The inhibition efficiency has increased with increasing inhibitor concentration. The standard free energy of adsorption (ΔG°ads) was calculated. The inhibitor adsorbed on the iron surface was found to be in a good agreement with the Langmuir adsorption isotherm. Polyethylene glycol tert-octylphenyl ether has improved the passivation characteristics of mild steel and inhibited the corrosion effectively in short time tests. The corrosion behaviour of mild steel was also supported by micrographing of the iron surfaces in 1M HCl solution with or without inhibitor.

Corrosion inhibition of mild steel in acidic solution by some oxo-triazole derivatives

The oxo-triazole derivative (DTP) was synthesized and its inhibiting action on the corrosion of mild steel in sulphuric acid was investigated by means of weight loss, potentiodynamic polarization, EIS and SEM. The results revealed that DTP was an excellent inhibitor and the inhibition efficiencies obtained from weight loss experiment and electrochemical experiment were in good agreement. Potentiodynamic polarization studies clearly revealed that DTP acted essentially as the mixed-type inhibitor. Thermodynamic and kinetic parameters were obtained from weight loss of the different experimental temperatures, which suggested that at different temperatures (298–333 K) the adsorption of DTP on metal surface obeyed Langmuir adsorption isotherm model.

Systematic corrosion investigation of various Cu–Sn alloys electrodeposited on mild steel in acidic solution: Dependence of alloy composition

Copper–tin alloy films were galvanostatically electrodeposited on the mild steel (MS) by combining the different amount of Cu and Sn electrolytes at a constant temperature (55 °C) and pH (3.5). Alloy films were characterized by using the energy dispersive X-ray analysis (EDX), scanning electron microscopy (SEM), X-ray diffraction (XRD) and micrographing techniques. Corrosion behaviours were evaluated with electrochemical impedance spectrometry (EIS) and electrochemical polarization measurements. Time gradient of electrolysis process was adjusted to obtain same thickness of investigated alloys on MS. The systematic corrosion investigation of various Cu x –Sn 100− x ( x = 0–100) alloy depositions on MS substrate were carried out in 0.1 M sulphuric acid medium. Results indicate that the corrosion resistance of the alloy coatings depended on the alloy composition, and the corrosion resistance increased at Cu–Sn alloy deposits in proportion to Sn ratio.

Green Approach to Corrosion Inhibition by Black Pepper Extract in Hydrochloric Acid Solution

In the present work the corrosion inhibition of mild steel in hydrochloric solution by Black pepper extract (Piper nigrum fem. Piperaceae) was studied. The techniques employed for study were mass loss measurements, poten- tiodynamic polarisation, linear polarization resistance and electrochemical impedance spectroscopy (EIS). The results ob- tained revealed that Black pepper extract was a good corrosion inhibitor for mild steel in hydrochloric acid medium and maximum inhibition efficiency (98%) was found at 120 ppm at 35 oC. Potentiodynamic polarization curves showed that black pepper extract is a mixed-type inhibitor. EIS showed that the charge transfer controls the corrosion process in inhib- ited solutions. Adsorption of the inhibitor on the mild steel surface followed Langmuir adsorption isotherm. The value of the free energy of adsorption, � Gads, indicated that the adsorption of inhibitor molecules was typical of chemisorption. The results obtained show that the Black pepper extract which mainly contains alkaloid 'Piperine' could serve as an excel- lent green inhibitor for corrosion of mild steel in acid solutions.

Inhibitive effect of Prosopis cineraria on mild steel in acidic media

The alcoholic extracts of stem bark, leaves and fruit from the Prosopis cineraria are tested for their effectiveness to combat corrosion of mild steel in hydrochloric acid, sulphuric acid and in acid mixture (hydrochloric acid z sulphuric acid) by the mass loss method. It was found that the presence of the extracts reduces the corrosion rate of mild steel in acidic solution. The inhibition efficiency increases as the extract concentration is increased. The fruit extract of Prosopis cineraria shows a maximum corrosion inhibition efficiency in the acid mixture solution compared to leaves and stem bark extracts. The Prosopis extract provides a good protection to mild steel against corrosion.

Investigation on inhibition behavior of S-triazole–triazole derivatives in acidic solution

Four main methods, such as weight loss test, EIS, adsorption isotherm and quantum chemical calculation were employed to study the inhibition efficiency and mechanism of three derivatives on mild steel in acid solution, whose inhibition efficiency were proved to follow the order of DMTT > NMTT > PMTT. The adsorption model of DMTT was established at different temperature according to the fitted results. The quantum chemical results indicated that the adsorption sites of the derivatives were strongly centralized on benzene ring, triazole ring, etc. QSAR was set up to explain the relationship of molecular structure and the inhibition effect of the derivatives.