Steel In Sulfuric Acid Research Articles

Inhibitory Potential of N-Methyl Formanilide on Mild Steel Corrosion in Sulfuric Acid: Quantum Chemical and Experimental Perspectives

Technological progress has led to increased use of metals and alloys such as aluminum, brass, bronze and mild steel. While mild steel is favoured for its availability, low cost and excellent mechanical properties, it is prone to corrosion. This study aims to reduce the corrosion of mild steel in sulfuric acid using N-methyl formanilide (NMF) as an inhibitor. The effectiveness of NMF was evaluated using gravimetric method (weight loss) and electrochemical impedance spectroscopy (EIS). Surface analyses were conducted using atomic force microscopy (AFM) and scanning electron microscopy (SEM). The study examined the performance of NMF at different temperatures (298 K to 338 K) and varying inhibitor concentrations. The results indicated that the percentage inhibition efficiency (%IE) of NMF increased with higher concentration but decreased with temperature. The NMF formed a protective layer on mild steel through physical adsorption, which was confirmed by El-Awady adsorption isotherm and comparing it with other adsorption models. The kinetic and thermodynamic studies were also performed, with activation energy (Ea) and adsorption free energy (ΔG°ads) being calculated. These findings were further validated using the AM1 quantum mechanical method, revealing the promising results for the investigation.

Experimental and computational analysis of poly(4-vinyl pyridine) and polyvinylpyrrolidone as effective corrosion inhibitors for low carbon steel in sulfuric acid

This study investigates the inhibitory effects of poly(4-vinyl pyridine) (P4VP) and polyvinylpyrrolidone (PVP) on the corrosion of low carbon steel (LCSt) in 1 M H2SO4. Protection efficacy (%PE) was measured using mass loss, potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS). Results showed %PE values increased with higher polymer concentration and lower temperature. At 450 mg/L, %PE reached 93.13% and 94.19% for P4VP and PVP, respectively. These polymers function as mixed inhibitors, adsorbing onto the LCSt surface per Langmuir’s model as a mode of physical adsorption. EIS indicated that higher polymer concentration increased charge transfer resistance and decreased effective double-layer capacitance. Both P4VP and PVP also reduced pitting corrosion in chloride-containing solutions. Density Functional Theory (DFT) and Time-Dependent DFT (TD-DFT) optimized the molecular structures of the inhibitors, evaluating electronic parameters such as frontier molecular orbital (FMO) energies, energy gap, softness, hardness, electron transfer fraction, dipole moment, and hyperpolarizability ( β ° ). Monte Carlo (MC) and molecular dynamics (MD) simulations provided insights into adsorption mechanisms, corroborating experimental findings and highlighting the effect of protonation. This comprehensive study enhances our understanding of the relationship between molecular structure and function in polymer inhibitors, improving their application in corrosion protection.

Corrosion mitigation potential of N-(2-(2-pentadecyl-2,5-dihydro-1H-imidazol-1-yl)ethyl)palmitamide palmitate on Q235 steel in sulfuric acid: experimental and theoretical analysis

Corrosion mitigation potential of N-(2-(2-pentadecyl-2,5-dihydro-1H-imidazol-1-yl)ethyl)palmitamide palmitate on Q235 steel in sulfuric acid: experimental and theoretical analysis

Cucumber peel extract as an eco-friendly corrosion inhibitor for low-carbon steel in sulfuric acid

Cucumber peel extract as an eco-friendly corrosion inhibitor for low-carbon steel in sulfuric acid

Electrochemical, thermodynamic and DFT studies of Fomitopsis pinicola as green corrosion inhibitor for carbon steel in sulfuric acid

In this work, the methanolic extract of Fomitopsis pinicola has been evaluated as a green corrosion inhibitor for the dissolution of 1018 carbon steel in 0.5 M sulfuric acid. For this, gravimetric tests and electrochemical methods such as potentiodynamic polarization curves, linear polarization resistance (LPR) and Electrochemical Impedance Spectroscopy (EIS) techniques were used. These tests were aided with Infrared and GC–MS analytical techniques. In addition to this, theoretical calculation with the use of the density functional theory (DFT) technique has been used to correlate the electronic extract properties and its inhibitory capacity. Weight loss results have shown an inhibitor efficiency of 85 % with the addition of 400 ppm. Thermodynamic parameters have shown that Fomitopsis pinicola extract is physically adsorbed onto the steel following a Langmuir adsorption isotherm. Potentiodynamic polarization curves showed that the extract behaves as a mixed type of corrosion inhibitor inducing the formation of a protective film onto the steel surface. In the presence of the Fomitopsis pinicola extract, a more resistive film obtained the highest polarization resistance value when 400 ppm of extract was used. In addition to this, as the concentration of the extract increased the charge transfer resistance and the double electrochemical layer capacitance decreased. GC–MS results indicated that main compounds contained in the Fomitopsis pinicola extract were Dehydrergosterol, Hydrazino-acetic acid ethyl ester, and Phthalic acid, di (2-propylpentyl) ester, whereas theoretical calculations showed that the highest EHOMO and lowest ELUMO values correspond to Dehydrergosterol and the Phthalic acid, which are the responsible for the extract inhibitory properties.

Effect of hydrocarbon chain length of alkyl trimethyl ammonium bromide on corrosion inhibition of stainless steel in sulfuric acid

Effect of hydrocarbon chain length of alkyl trimethyl ammonium bromide on corrosion inhibition of stainless steel in sulfuric acid

Okra leaves extract as green corrosion inhibitor for steel in sulfuric acid: Gravimetric, electrochemical, and surface morphological investigations

Utilizing plant extracts as an alternative source for corrosion inhibitors holds significant promise in minimizing the risk of corrosion. In this study, an okra leaf extract (OLE) was employed as a corrosion inhibitor for N80 steel in 1.0 M H2SO4. The corrosion rate was assessed concerning temperature (30, 40, 50, and 60 °C) and inhibitor concentrations (blank, 25, 50, 75, and 100 ml/l) through weight loss and electrochemical polarization techniques. The results indicated that OLE functions as a mixed-type corrosion inhibitor, with corrosion rates increasing with temperature and decreasing with inhibitor concentration. The maximum corrosion inhibition efficiency reached 96 % at 30 °C and 100 ml/l. Adsorption studies revealed that OLE physically adsorbed onto the mild steel surface, following the Langmuir adsorption isotherm. Gravimetrical and electrochemical techniques were confirmed by FTIR and UV measurements, which showed the presence of a protective layer on the metal surface. Optical microscopy, AFM, and SEM images demonstrated the formation of a protective layer on the metal surface. Thermogravimetric analysis (TGA) highlighted the thermal stability exhibited by inhibitor molecules, which showed that OLE was thermally stable up to 85 °C.

Evaluation of inhibition performance of methylimidazolium ionic liquids on surface of mild steel in sulfuric acid

In the present study, the microwave irradiation approach was used to synthesize two methylimidazolium-based ionic liquids (MImILs), specifically 1-Heptyl-3-methylimidazolium bromide [HMImBr] and 1-Benzyl-3-methylimidazolium bromide [BzMImBr]. Several spectroscopic methods have been used to characterize the produced compounds. Gravimetric and electrochemical techniques were employed to examine their ability to prevent corrosion of the mild steel in a 0.5 M sulfuric acid solution. Amongst all the evaluated ionic liquids, [BzMImBr] having an aromatic ring instead of hexyl ((–CH2)5–CH3) hydrocarbon of [HMImBr] manifests better inhibition efficiency of 95.49 % at 1000 ppm concentration. The experimental ionic liquids negatively impact both the anodic and cathodic Tafel reactions, exhibiting mixed-type inhibition properties, as demonstrated by the findings of the potentiodynamic polarization investigations. Through their adsorption employing their electron-rich centres, the examined ionic liquids create a corrosion-protective covering, and their adsorption follows the Langmuir isotherm model. Negative values of ΔGads indicate the spontaneous nature of [HMImBr] and [BzMImBr] adsorption, whereas values between −20 and −40 KJ mol−1 indicate the physio-chemisorption mode of adsorption. Energy dispersive X-ray spectroscopy (EDS), atomic force microscopy (AFM), and field emission-scanning electron microscopy (FE-SEM) techniques were used to assess and evaluate surface morphology. The DFT-based analysis indicates that aromatic rings played a significant role in the charge sharing (donation and acceptance) in [BzMImBr].

Influence of metal ions on cysteine as a corrosion inhibitor for low carbon steel in sulfuric acid: Polarization, EIS, XPS, and DFT analysis

This study examines the effectiveness of cysteine as an eco-friendly in inhibiting the corrosion of low-carbon steel in a sulfuric acid solution and the impact of adding various metal ions (Cu2+, Ni2+, and Co2+) to the media. All solutions were prepared using distilled water. The results show that 5 mM cysteine inhibits corrosion (IE = 65%), increasing to 93.5% in the presence of 4×10-5 M Cu2+ ions, but decreasing with the addition of Co2+ or Ni2+ ions. The inhibitive action of cysteine-Cu is the best one and that may be attributed to the formation of a protective coating on the metal surface, which prevents chemical reactions in an aggressive environment. Moreover, the DFT calculation found that the adsorption energy increased from −17.2 to −97.7 and −104.6 kcal/mol in the case of cysteine, Cysteine-Cu SAM, and Cysteine-Cu(II) Salt and the closest atom to the surface reduced from 2.576 to 2.128 and 2.146 Å which indicates Cysteine-Cu better adhere to the surface. SEM, XRD, and XPS were used to analyze the formation of the protective layer. This has the potential to develop new and more effective corrosion inhibitors for industrial applications.

Exploring cinnamon extract’s potential as a green corrosion inhibitor for X65 carbon steel in sulfuric acid: a comprehensive investigation

The effectiveness of cinnamon extract as an environmentally friendly corrosion inhibitor for X65 carbon steel (X65CSt) in a 1 mol/L H2SO4 solution was examined using electrochemical, chemical, and computational techniques. This inhibitor has many advantages, it is safe, environmentally friendly, harmless to human health, and economically feasible. The anticorrosion efficacy rises with rising the concentration of the cinnamon extract and reducing temperature and reaches 95.83% at 450 mg l−1 of cinnamon extract using potentiodynamic polarization. All the investigated methods confirm the anticorrosion ability of cinnamon extract as indicated by the reduced the corrosion current density values and mass loss as well as the greater charge transfer resistance. In addition, the values of the pitting potentials were also transformed in a more noble direction implying the resistance of pitting attack. The polarization technique categorized the cinnamon extract as a mixed inhibitor. The mechanism of inhibition was demonstrated in terms of adsorption of the main components of cinnamon extract onto the surface of X65CSt. of the adsorption of the main components of the cinnamon extract on the surface of the X65CSt and this adsorption is of combined type between both physical and chemical modes, as determined by the computed values of free energy of adsorption, which range between −46.96 and −37.42 kJ. mol−1. The adsorption is exposed to Langmuir isotherm. The four components of cinnamon extract were investigated through density functional theory, Monte Carlo, and Molecular dynamic simulation. The quantum parameters and the adsorption of these components on the Fe(110) reveals that cinnamaldehyde and cinnamic acid inhibitors are more effective as corrosion inhibitors.

Justicia brandegeeana as a green corrosion inhibitor for carbon steel in sulfuric acid

ABSTRACT The anti-corrosive effect of the extract in ethanol of Justicia brandegeeana (Acanthaceae) against carbon steel AISI 1020 in sulfuric acid medium 1 mol L−1 was investigated. In addition to the effect of seasonality, several techniques were used to investigate the anti-corrosive activity, such as electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PP), linear polarization resistance (LPR), and weight loss. The chelating effect was analyzed by UV-Vis spectrophotometry and the surface was analyzed by scanning electron microscopy (SEM). The results showed that the inhibition efficiency is dependent on the concentration of the extract, reaching its maximum at 1500 ppm and despite having good thermal stability (82.41% inhibition at 70°C), it decreases with increasing temperature, indicating a physisorption behavior. The extract obeyed the Langmuir isotherm and the Tafel curves characterized it as a mixed inhibitor, with a tendency to cathodic region. It also presented a 52% chelating effect against Fe+2 ions, and the SEM analysis indicated a protection with the presence of plant extract, thus minimizing surface roughness. These results indicated the J. brangeeana ethanol extract as a green anti-corrosive agent.

Study of corrosion properties of carbon steel, 304 and 316L stainless steels in sulfuric acid and their degradation products

In this study, corrosion properties of carbon steel and stainless steels, and degradation of sulfuric acid by the corrosion mechanism are presented. Carbon steel (CS), 304 stainless steel (SS304), and 316L stainless steel (SS316L) specimens were analyzed through their electrochemical response by using a potentiostat measurement. The specimens were submerged in concentrated 98 wt.% of H2SO4 acid for 0 day to 60 day. The degradation of H2SO4 was determined by its volume change, turbidity, and color due to the corrosion mechanism. Corrosion rate of CS, SS304 and SS316L specimens are 43.237 mm/year, 0.420 mm/year and 0.086 mm/year, respectively. After 60 days, the weight-loss of CS, SS304 and SS316L specimens are 48 wt%, 33 wt% and 0.1 wt%, respectively. Corrosion resistance of the materials are influenced by the passive oxide layer that forms on its surface and associated with electrochemical activity or semiconductive composition. The degradation of H2SO4 acid was observed due to the corrosion process of specimens and related to the turbidity and volume increase while the wt% concentration of H2SO4 acid decreases. In order to make material choices that enable continuous and safe operation of the process, it is important to understand the corrosion mechanism changes.

The dual nature of Cu content on the corrosion resistance of low alloy steels in sulfuric acid: A time-dependent reversal of corrosion resistance

The corrosion performance of low alloy steels with varying Cu contents (ranging from 0 to 1.2 wt%) was evaluated in a 10 wt% H2SO4 solution at room temperature. By incorporating Cu, the active dissolution of the bare steel is effectively suppressed, leading to enhance corrosion resistance as the Cu content increases. However, during immersion, the corrosion product film transitions from CuO and Cu(OH)2 dominance to Cu2O and Cu0 dominance. Simultaneously, hydrogen reduction induces cracks in the film, causing an uneven Cu distribution and gradual corrosion resistance degradation with higher Cu content and longer immersion duration.

Green corrosion and DFT studies of Ustilago maydis extract for carbon steel in sulfuric acid

A study on the use of Ustilago maydis extract as a green corrosion inhibitor for 1018 carbon steel in 0.5 m H2SO4 by using gravimetric, potentiodynamic polarization curves, linear polarization resistance and electrochemical impedance spectroscopy electrochemical techniques at 25, 40 and 60 °C. Density functional theory (DFT) calculations were performed to know the relationship between inhibitor electronic properties and inhibition efficiency. Weight loss results indicated that Ustilago maydis was a good corrosion inhibitor with an efficiency that increased with its concentration but decreased with the temperature. However, the efficiency was around 60% because it was physically adsorbed on to the steel surface according to a Langmuir type of adsorption isotherm obtaining relatively low free energy values, which lied between −14.8 and −27 kJ/mol at 25 and 60 °C respectively. Activation energy decreased in presence of Ustilago maydis making corrosion process more difficult to occur. Potentiodynamic polarization curves showed a decrease in the corrosion current density in one order of magnitude and determined this extract as a cathodic type of corrosion inhibitor affecting. There was no evidence of a passive film, whereas the corrosion mechanism was controlled by the adsorption/desorption of some intermediate species and the double electrochemical layer resistance increased with the addition of the inhibitor. Gas chromatography showed that the main compounds found in this extract included D-Mannose, β-D-Glucopyranose,4-O-β-D-galactopyranosyl, Melibiose and Arabinose, whereas quantum chemical calculations by density functional theory analysis showed that Melibiose had the highest inhibition efficiency because it had the highest EHOMO value and lowest gap energy value, ∆E.

Electrochemical study of ethanolic Lentinula Edodes extract as a “green” inhibitor for corrosion mitigation of low-carbon steel in sulfuric acid

Electrochemical study of ethanolic Lentinula Edodes extract as a “green” inhibitor for corrosion mitigation of low-carbon steel in sulfuric acid

Highly efficient green corrosion inhibitor for mild steel in sulfuric acid: Experimental and DFT approach

Chemical corrosion inhibitors are commonly used for protecting the metallic surface from corrosion. But these chemical inhibitors pollute the environment and make the residual water unfit for use. In contrast, green corrosion inhibitors (GCI) i.e., plants and their products are environment-friendly in nature and contribute towards sustainable developments. Petals of B. glabra were investigated as GCI for mild steel at different concentrations and temperatures by polarization, impedance spectroscopy, and gravimetric methods. SEM and metallurgical microscopy were used for the surface studies. Henry and Langmuir adsorption isotherms were used for adsorption studies. A computational (DFT) study was performed to augment experimental data. B. glabra shows 93.13 ± 0.02% corrosion inhibition efficiency for mild steel in 1.0 M H2SO4. The thermodynamic, kinetic, and DFT studies of the inhibitor/mild steel interface help in understanding the adsorption and corrosion mechanism. A relation between inhibition efficiency obtained from theoretical and experimental techniques was established. Waste water was analyzed for its biochemical assay after gravimetric studies, and was found within permissible limits. B. glabra extract was proved to be an effective GCI for protecting mild steel from acid corrosion and hence contribute towards sustainable developments by using natural material (plants and their products) without polluting the environment.

Experimental and theoretical investigations of three Mannich-base imidazoline quaternary ammonium salts as efficient inhibitors for Q235 steel in sulfuric acid

Three Mannich base imidazoline quaternary ammonium salt corrosion inhibitors were designed and successfully synthesized, and their inhibition properties and mechanisms for Q235 steel in H2SO4 solution were investigated by experiments and theoretical calculations. It is found that three inhibitors act as mixed inhibitors to effectively inhibit the corrosion of Q235 steel in H2SO4 solution by chemisorption, and the maximum corrosion inhibition efficiency reaches 96.9 %, 97.3 % and 98.2 %, respectively. Theoretical calculations reveal that three inhibitors exhibit multi-center adsorption features and spontaneously adsorb on the surface of Q235 steel through horizontal orientation.

Use of Cynara scolymus as Green Corrosion Inhibitor for Carbon Steel in Sulfuric Acid

Use of Cynara scolymus as Green Corrosion Inhibitor for Carbon Steel in Sulfuric Acid

Ghars date extract/iodide ions system as an eco‐friendly corrosion inhibitor for API 5L X70 steel in sulfuric acid

AbstractBackgroundGhars date fruit is very rich in polysaccharides, which qualifies it to be exploited as a green corrosion inhibitor. Ghars date is produced in large commercial quantities in Africa and Asia, which gives them the opportunity to be used as a cheap raw material for the industry of eco‐friendly inhibitors.ObjectivesThe synergy between the Ghars date extract (GDE) and iodide ions is investigated for the first time to improve the inhibition efficiency for API 5 L X70 pipeline steel in 0.5 mol L−1 sulfuric acid.MethodsThe synergistic effect of the GDE and iodide ions is studied by potentiodynamic polarization curves, electrochemical impedance spectroscopy, scanning electron microscopy and energy‐dispersive X‐ray spectroscopy.ResultsThe inhibition efficiency is 45.5% at 2 g L−1 GDE at 20°C, while it increases to 97.9% when 5 × 10−4 mol L−1 of potassium iodide is added at 25°C. The GDE/iodide ion system follows the Langmuir adsorption isotherm, involves both physical adsorption and chemical adsorption and acts as a mixed‐type inhibitor.ConclusionsIt is found that significant corrosion inhibition can be obtained in a synergistic manner between Ghars date extract and iodide ions for the API 5 L X70 pipeline steel in sulfuric acid.

Heteroatomic organic compound as a novel corrosion inhibitor for carbon steel in sulfuric acid: Detail experimental, surface, molecular docking and computational studies

The prime objective of the present research is to explore the green synthesis of nitrogen, oxygen, and sulfur-containing heteroatomic organic compound (TMP) using the ultrasound method and its application as a novel corrosion inhibitor for carbon steel in 1 M H2SO4 under hydrodynamic conditions at 1500 rpm. The performance ability of TMP rises from 42.80 % (without TMP) to 92.80 % (with TMP)/96.67 % (with TMP+KI). The TMP depicted the cathodic inhibitive nature. The charge transfer resistance (Rct) changes from 28.7 Ω cm−1 to 190.4 Ω cm−1 with the falling of double layer capacitance (Cdl) from 46 μF cm−2 to 28 μF cm−2 on the introduction of TMP supports the adsorption of TMP molecules at the active sites of the carbon steel surface. The molecular adsorption of TMP is governed by El-Awady isotherm. The results of the surface analysis support the creation of an inhibitive layer of TMP over the carbon steel surface. Density Functional Theory (DFT) and Monte Carlo simulations (MCS) calculations were further performed to justify the experimental results. Molecular docking was used to analyze the TMP and sulfate-reducing bacteria (SRB) protein interaction.