Steel In Acid Research Articles

Synthesis, electrochemical and quantum chemical studies of some prepared surfactants based on azodye and Schiff base as corrosion inhibitors for steel in acid medium

Three nonionic surfactants based on azodye and Schiff base condensed with poly ethylene glycol were prepared. Their inhibition effect towards corrosion of steel in hydrochloric acid was investigated using electrochemical frequency modulation, electrochemical impedance spectroscopy, potentiodynamic polarization, quantum chemical calculations and molecular dynamic simulation. The data revealed that the prepared surfactants had the ability to inhibit corrosion reaction with good agreement between experimental and computational results. The adsorption of surfactants on the carbon steel surface in 1M HCl was found to obey Langmuir isotherm. Polarization results showed that these inhibitors act as mixed-type inhibitors.

A comparative study of corrosion inhibition of steel and stainless steel in hydrochloric acid by N,N,N′,N′-tetramethyl-p-phenylenediamine

The corrosion of mild steel (MS) and AISI type 321 stainless steel (AISI 321) in 1 M HCl solution and the inhibitive mechanism of N,N,N′,N′-Tetramethyl-p-phenylenediamine (TMPPD) were investigated using open circuit potential measurements (OCP), potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques. Potential-time measurements showed that the addition of TMPPD to HCl solutions shifts the potential of MS and AISI 321 to more positive values. Polarization curves measurements indicated that TMPPD act as a mixed type inhibitor for the corrosion of MS and AISI 321 in HCl solutions. EIS measurements showed that the dissolution process occurs under activation control. The applied techniques explained that TMPPD is more efficient as a corrosion inhibitor for mild steel than stainless steel in acidic solutions. Theoretical fitting of different isotherms, Langmuir, Kinetic-thermodynamic, Flory–Huggins, and Temkin isotherms were tested to explain the nature of TMPPD adsorption. The associated activation parameters were also calculated and discussed.

Crystal Structure and Corrosion Inhibition Properties of Ferrocenyl- and Phenylendiamine-Iminomethylphenoxy Cobalt Complexes

The crystal structures of bis[2-(ferrocenyl-iminomethyl)phenoxy]cobalt(II) (Co II (L) 2 ) [monoclinic, a = 12.5466(3) A, b = 10.6782(3) A, c = 21.2695(6) A, α = γ = 90°, β = 92.944(2)°, V = 2845.82(13) A3, Z = 4, space group P21/c] and bis(2-[(4-dimethylamino-phenylimino)-methyl]-phenoxy) cobalt (II) (Co II (M) 2 ) [triclinic, a = 10.2916(4) A, b = 16.4867(10) A, c = 17.6782(11) A, α = 114.754(2)°, β = 96.614(4)°, γ = 97.736(4), Z = 4, space group P-1] dominated by extensive hydrogen bonding such as O–H···N, N–H···O and N–H···N interactions. In both structures the central CoII is displaying a slightly distorted tetrahedral coordination sphere involving two iminoethyl-phenoxy ligands. The inhibition efficiency of the Co complexes concerning the corrosion of mild steel in acidic solution has been investigated by electrochemical impedance spectroscopy. The crystal structures of two bis(iminomethylphenoxy) cobalt complexes containing respectively a ferrocenyl and a phenylendiamine group are described. First results on their inhibition properties concerning the corrosion of mild steel in hydrochloric acid are reported and discussed.

Inhibiting effect of Quaternary ammonium compound on the corrosion of mild steel in 1M Hydrochloric acid solution, its adsorption and kinetic characteristics

The corrosion behavior of mild steel in 1M Hydrocholoric acid containing different concentrations of1-Propanaminium N,N,N-Tripropyl Iodide(TPAI) (Quaternary ammonium compound) has been studied by, Tafel polarization and Electrochemical impedance spectroscopic(EIS) techniques at Different temperatures. The mild steel samples were also analyzed by scanning electron microscopy. Electrochemical and impedance parameters such as corrosion potential, corrosion current density, Tafel slopes, charge transfer resistance and electrical double layer were determined. The kinetic and thermodynamic parameters for mild steel corrosion and inhibitor adsorption, respectively, were determined and discussed.The results showed that% inhibition efficiency of corrosion increases with increase in concentration and increases with increase in temperature. As the inhibitor concentration increased, the charge transfer resistance increased and double layer capacitance decreased. It was found that TPAI is an excellent inhibitor for mild steel in acidic medium. Adsorption of the inhibitor molecules on the mild steel surface obeyed the Langmuir adsorption isotherm.

Anticorrosive efficacy and adsorptive study of guar gum with mild steel in acidic medium

Gums have been found to be good corrosion inhibitors due to their functional group; they form complexes with metal ions and on the metal surfaces. Most gums have -COOH functional groups, which can increase the contribution of electron or charge transfer and hence facilitate inhibition through adsorption. The corrosion and inhibition behaviors of mild steel in hydrochloric, sulphuric, and nitric acid in the presence of Cyamopsis tetragonoloba (guar gum) have been studied using the weight loss, gas chromatography mass spectrometry (GC-MS), and thermometric techniques. The temperature studies reflect that the percentage of inhibition efficiency is decreased with increase in temperature and that indicates the mechanism of physical adsorption. The calculated values of activation energy (Ea) also support the physiosorption process. The thermodynamic parameters such as heat of adsorption (Qads) and free energy of adsorption (ΔGads) suggested that the adsorption of inhibitor on the mild steel surface is exothermic and followed by spontaneous process. The formation of an adsorbed protective film of the inhibitor molecules on the mild steel surface is confirmed by scanning electron micrographs (SEM), which proves that the guar gum acts as good inhibitor at 1N acids concentration.

Capsicum extract as green corrosion extract for carbon steel in hydrochloric acid solutions

The extract of Capsicum have been evaluated as green extract for the corrosion of carbon steel in 1M HCl solution was investigated using weight loss, potentiodynamic polarization, ac electrochemical impedance spectroscopy (EIS), electrochemical frequency modulation (FEM) and energy dispersion spectroscopy (EDS) and scanning electron microscopy (SEM) methods of monitoring corrosion. The inhibitive property of the extract is attributed to the presence of Capsaicin and Ascorbic acid as major constituent in the extract. Measurements showed that this extract act as mixed-type extract. The inhibition efficiency was found to increase with extract concentration. Results obtained by various techniques are close to each other and maximum efficiency of 86 % is acknowledged at the extract concentration of 300 ppm. Langmuir isotherm model is found most suitable to explain adsorption behavior of extract for C-steel surface. Molecular adsorption of extract over C- steel surface is found responsible for corrosion inhibition of C- steel in acid.

Complexes of Imidazole with Poly(ethylene glycol) as a Corrosion Inhibitor for Carbon Steel in Sulphuric Acid

The inhibiting action of polyethylene glycol and imidazole (PEG/IMZ)) complexes prepared by a simple deprotonation procedure on carbon steel corrosion in 0.5 mol/L sulphuric acid was evaluated using the weight loss, potentiodynamic polarization, and electrochemical impedance spectroscopy techniques complemented by surface analysis using scanning electron microscopy. The inhibiting effect of the PEG/IMZ complexes on carbon steel corrosion was compared with the non-complex forms. Results obtained show that PEG/IMZ complex is a very effective corrosion inhibitor of carbon steel in the acid environment. The inhibition efficiency increased with the increase in the temperature and also with increasing percentage of imidazole in the complex. Corrosion inhibition occurs by virtue of adsorption of PEG/IMZ complexes on the steel surface which was found to follow the Temkin adsorption isotherm model. The PEG/IMZ complexes function as a mixed-type inhibitor. Results from all the methods employed are in a reasonably good agreement.

Adsorption and electrochemical studies of Pimenta dioica leaf extracts as corrosion inhibitor for mild steel in hydrochloric acid

Alcohol and water extracts of the leaves of Pimenta Dioica (PD) have been investigated as non toxic corrosion inhibitors for mild steel in acidic medium (0.5 M and 1 M HCl). Corrosion rates were evaluated at 303 K, 308 K and 313 K using electrochemical impedance spectroscopy and polarization techniques. Basic computational calculations for the component molecules and adsorption studies were also carried out for estimating the energies of frontier orbitals and the mechanism of corrosion inhibition. Electrochemical techniques reveal that PD extracts exhibit excellent inhibition efficiency and function as mixed type inhibitor at all these temperatures. Adsorption studies showed that the process follows Langmuir adsorption isotherm.

Some pyrazole derivatives as corrosion inhibitors for carbon steel in hydrochloric acid solutions

Two pyrazole derivatives, namely 2,4-diamino-5-(5-amino-3-hydroxy-1 H -pyrazole-1-carbonyl)thiophene-3-carbonitrile (I) and 1-(2,4-diamino-5-(5-amino-3-hydroxy-1 H -pyrazole-1-carbonyl)thiophen-3-yl)propan-1-one (II) were evaluated as a corrosion inhibitors for carbon steel in 1M hydrochloric acid by weight loss, potentiodynamic polarization and electrochemical impedance spectroscopy methods. Spectrophotometric and conductometric titration methods were also utilized to investigate the possibilities of chemical adsorption between the steel surface and the compounds under consideration. The results showed that the studied compounds inhibit the corrosion of steel in acidic solution at different temperatures. The adsorption followed the Langmuir isotherm. The thermodynamic and the activation parameters were also determined and discussed.

An Imidazole-Based Antifungal Drug as a Corrosion Inhibitor for Steel in Hydrochloric Acid

An imidazole-based antifungal drug, namely ketoconazole (KETO), was evaluated as a corrosion inhibitor for steel in 1 M hydrochloric acid by electrochemical impedance spectroscopy (EIS) and gravimetric method. Atomic force microscope was also utilized to investigate the corrosion inhibition properties and film formation behavior of KETO. The results showed that KETO is a good corrosion inhibitor for steel in acidic solution at different temperatures. The adsorption followed the Langmuir isotherm, and the thermodynamic parameters were also determined and discussed. Quantum chemical approach was also used to calculate some electronic properties of the molecule in order to ascertain any correlation between the inhibition effect and molecular structure of KETO.

Density functional theory studies on the corrosion inhibition of benzoin, benzil, benzoin-(4-phenylthiosemicarbazone) and benzil-(4-phenylthiosemicarbazone) of mild steel in hydrochloric acid

The density functional theory (DFT) calculations were performed on benzoin (BN), benzil (BL), benzoin-(4-phenylthiosemicarbazone) (BN4PTSC) and benzil-(4-phenylthiosemicarbazone) (BL4PTSC) used as corrosion inhibitors for mild steel in acidic medium. The quantum chemical parameters/descriptors, namely, E HOMO (highest occupied molecular orbital energy), E LUMO (lowest unoccupied molecular orbital energy), the energy difference (ΔE) between E HOMO and E LUMO, dipole moment (μD), electron affinity (A), ionization potential (I), the absolute electronegativity (χ), absolute hardness (η), softness (σ), polarizability (α), the Mulliken charges, and the fraction of electrons (ΔN) transfer from inhibitors to iron, were calculated and correlated with the experimental IE%. Condensed Fukui functions have been used to determine the sites for electrophilic and nucleophilic attacks on each of the inhibitors.

Corrosion Inhibition: Synergistic Influence of Gluconates on Mild Steel in Different Corrosive Environments. Synergetic Interactions of Corrosion Inhibition Tendency of Two Different Gluconates on Mild Steel in Different Corrosive Environments

S usceptibility of mild steel to corrosion attack has restricted its industrial appl ications , despite its numerous advantageous characteristics. Comparison of the inhibitive tendency of a mixture of zinc gluconate (ZG) and ferrous gluconate (FG) on the corrosion behavior of mild steel in acid and saline media was investigated using electr ochemical and weight loss techniques. The FG:ZG ratio was dosed from 0.5:0.5 to 2.0:2.0 g/v at an interval of 0.5:0.5. The surface morphology of the corroded mild steel samples was evaluated by high resolution scanning electron microscope equipped with ene rgy dispersive spectroscopy (HR - SEM/EDS). Experimental results indicated that the combined inhibitor significantly reduced the corrosion rates of mild steel, with the maximum inhibition efficiency (IE) of 100% and 48% at 28 o C in the presence of 1.5:1.5 g/ v concentrations in 3.5 % NaCl and 0.5 M H2SO4 solutions , respectively. The SEM micrographs of the inhibited samples show a clearly reduced surface degradation as opposed to the surface morphology without inhibitor. Potentiodynamic polarization curves stud ies showed that the combined inhibitor is a mixed type inhibitor for mild steel corrosion in 3.5 % sodium chloride and 0.5 molar sulphuric acid solutions. From the set of experimental data it was found that the combined inhibitor reduced the corrosion rate through an adsorption process and obeyed Langmuir’s adsorption isotherm in chloride medium and Freundlich adsorption isotherm in sulphuric acid medium at all concentrations and temperature studied. Good synergism exists between FG and ZG. The results obta ined from potentiodynamic polarization are consistent with the results of the weight loss method. Synergistic performance of inhibitors was perfect in saline medium. From the analysis of grey relational grade model, the significant concentration ratios wer e indentified. The results showed the influence of synergistic FG:ZG at a concentration of 1.5 g/v on the corrosion rate of mild steel. P redicted results were found to be in good agreement with experimental results .

Poly(vinyl alcohol–proline) as corrosion inhibitor for mild steel in 1M hydrochloric acid

Corrosion inhibitive behavior of newly synthesized water soluble semiconducting polymer composite poly(vinyl alcohol–proline) (PVAP) is focused in this article. The polymer was characterized by FTIR, SEM-EDX, and XRD techniques. Thermogravimetry and differential thermal analysis proved the thermal stability of PVAP. Gravimetry and electrochemical techniques were employed to study the corrosion inhibition performance of PVAP on mild steel in molar hydrochloric acid. 0.6 % (wt.) of PVAP provides a maximum inhibition efficiency of 94 % at 303 K. The role of concentration of PVAP, exposure time and solution temperature on the mild steel corrosion has been investigated. The polarization results showed that PVAP acts as mixed-type inhibitor and could serve as an effective corrosion inhibitor for mild steel in acid medium. Surface morphology of the mild steel specimen by FTIR spectroscopy proved the formation of polymer film.

Anticorrosive Activity of Kigelia pinnata Leaves Extract on Mild Steel in Acidic Media

The corrosion inhibition of mild steel in 1 M H2SO4 and 1 M HCl solution with different concentrations of Kigelia pinnata leaves extract (KPLE) was investigated using mass loss, Tafel polarization, and electrochemical impedance spectroscopy. Inhibition efficiency of KPLE is found to increase with increasing concentration but to decrease with temperature. Polarization measurements reveal that KPLE acts as a mixed type inhibitor in both acids. Impedance curves show that increasing KPLE concentration increases charge transfer resistance and decreases double layer capacitance. The adsorption of KPLE on the mild steel surface obeys the Langmuir adsorption isotherm. The experimental results reveal that KPLE inhibits the corrosion reaction in both acid environments, and inhibition efficiency follows the order H2SO4 > HCl. The kinetic and adsorption parameters for mild steel in acid in the presence and absence of KPLE were evaluated and discussed. The negative value of the standard free energy of adsorption in the presence of inhibitor suggests spontaneous adsorption of inhibitor on the mild steel surface. Protective film formation against corrosion was confirmed by ultraviolet-visible (UV-visible), X-ray diffraction, scanning electron microscopy, and Fourier transform–infrared spectroscopy techniques.

Exploration of (S)-4,5,6,7-tetrahydrobenzo[d]thiazole-2,6-diamine as feasible corrosion inhibitor for mild steel in acidic media

This study deals with the possibility of (S)-4,5,6,7-tetrahydrobenzo[d]thiazole-2,6-diamine (TDA) as a prospective corrosion inhibitor for mild steel in 1M hydrochloric acid (HCl) medium. The inhibition characteristics by means of weight loss, Tafel polarization and electrochemical impedance spectroscopic methods are reported. Results showed that the inhibition efficiencies increase with increasing concentration and while increasing temperature it shows negative effect. Associated equilibrium adsorption constant and other thermodynamic parameters suggested that TDA follows comprehensive adsorption behavior in blocking the active corrosion sites. Morphological investigation of corrosion sites was carried out by using scanning electron microscopy (SEM) and atomic force microscopy (AFM) studies, which reveal that the inhibition occurs due to the adsorption of the inhibitor molecules on the metal surface.

Enhanced corrosion resistance of mild steel in 1 M hydrochloric acid solution by alkaloids extract from Aniba rosaeodora plant: Electrochemical, phytochemical and XPS studies

The present report continues to focus on the broadening application of plant extracts for metallic corrosion control and reports on the inhibiting effect of the Aniba rosaeodora alkaloidic extract on the corrosion of C38 steel in 1M hydrochloric acid. Potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques were applied to study the metal corrosion behavior in the absence and presence of inhibitor. Studies on the phytochemical constituents were established to determine the active(s) molecule(s). XPS was also carried out to establish the mechanism of corrosion inhibition of the active molecule of C38 steel in acid solution. The inhibitor extract acted as an efficient corrosion inhibitor in 1M HCl. The experimental data obtained from EIS method show a frequency distribution and therefore a modelling element with frequency dispersion behaviour, a constant phase element (CPEα, Q) has been used. Graphical methods are illustrated by synthetic data to determine the parameter of CPE (α, Q). Polarization studies showed that the Aniba rosaeodora alkaloidic extract was a mixed-type inhibitor and its inhibition efficiency increased with the inhibitor concentration. Studies on the phytochemical constituents of the total alkaloids extract shows that it contains the anibine as the major alkaloid. The results obtained from the electrochemical study have clearly showed that the inhibition efficiency of the total extract was due to the presence of anibine. The XPS studies showed the formation of inhibitor layer containing the Aniba rosaeodora alkaloidic extract and the anibine molecules.

Semiconducting Behavior of Non-Solid Electrochemical State of Carbon Steel in Electrolyte Solution

In this paper, the semiconducting behavior of non-solid electrochemical state of carbon steel in acid, base and salt solutions was studied by utilizing potential-capacitance and Mott-Schottky analysis. It was pointed out that the capacitance variation of space charge layer of non-solid electrochemical state of carbon steel in different solution was different. The non-solid electrochemical state showed p-type semiconducting behavior in 5 sulfuric acid and 5 % sodium sulfate solution. However, it showed n-type semiconducting behavior in 5 % sodium hydroxide, suggesting that the space charge layer of non-solid electrochemical state of the carbon steel in different electrolytes might be asymmetric.

Corrosion Inhibition of Mild Steel in Acidic Medium by Jathropha Curcas Leaves Extract

Inhibition of corrosion of mild steel in sulphuric acid by acidic extract of Jatropha Curcas leaves has been studied using weight loss and thermometric measurements. It was found that the leaves extract act as a good corrosion inhibitor for mild steel in all concentrations of the extract. The inhibition action depends on the concentration of the Jatropha Curcas leaves extract in the acid solution. Results for weight loss and thermometric measurements indicate that inhibition efficiency increase with increasing inhibitor concentration. The adsorption of Jatropha curcas leaves extract on the surface of the mild steel specimens obeys Langmuir adsorption isotherm. Based on the results, Jatropha curcas leaves extract is recommended for use in industries as a replacement for toxic chemical inhibitors.

Corrosion Inhibition of Mild Steel in Acidic Medium by Jathropha Curcas Leaves Extract

Inhibition of corrosion of mild steel in sulphuric acid by acidic extract of Jatropha Curcas leaves has been studied using weight loss and thermometric measurements. It was found that the leaves extract act as a good corrosion inhibitor for mild steel in all concentrations of the extract. The inhibition action depends on the concentration of the Jatropha Curcas leaves extract in the acid solution. Results for weight loss and thermometric measurements indicate that inhibition efficiency increase with increasing inhibitor concentration. The adsorption of Jatropha curcas leaves extract on the surface of the mild steel specimens obeys Langmuir adsorption isotherm. Based on the results, Jatropha curcas leaves extract is recommended for use in industries as a replacement for toxic chemical inhibitors.

Punica granatum leave extract as green corrosion inhibitor for mild steel in Hydrochloric acid

Leave of Punica granatum extract (LPGE) as green inhibitor for the corrosion of mild steel in 1M HCl solution was studied using weight-loss and potentiodynamic polarization measurements. The results obtained revealed that LPGE has fairly good inhibiting properties for mild steel corrosion in 1M HCl solution, with efficiency of around 94 % at a concentration of 1 g/l. The inhibition was of a mixed anodic–cathodic nature. The film which is formed over the metal surface was analysed by FT-IR spectroscopy. Further examination using X-ray diffraction confirms the role of LPGE as an effective corrosion inhibitor for mild steel in acid media.