Steel In H2SO4 Research Articles

The effect of alkyl chain on the corrosion inhibition of benzyldimethylammonium chloride in acidic environments

Incorporating quaternary ammonium salts (QAS) during pickling is an efficient and eco-friendly approach to mitigating metal corrosion. This study investigated the effectiveness of Benzyldimethylhexadecylammonium chloride (HDBAC) and Benzyldimethyltetradecylammonium chloride (TDBAC) in inhibiting the corrosion of Q235 steel in H2SO4, utilizing electrochemical methods, atomic force microscopy (AFM), scanning electron microscopy (SEM), and theoretical calculations. The electrochemical results demonstrated that compared with the blank impedance value of 40.68Ω cm2, HDBAC and TDBAC at 5 mM concentration showed impedance values of 997.69Ω cm2 and 676.17 Ω cm2 at 298 K, indicating that they can effectively prevent the corrosion of Q235. SEM and AFM further showed the formation of a protective barrier film by HDBAC and TDBAC on the steel surface, effectively isolating it from the corrosive medium. Theoretical calculations further elucidated the mechanism by which these inhibitors create this protective barrier. The experiment also verified the hypothesis that the length of the hydrophobic chain of surfactants affects the adsorption behavior and the inhibition efficiency. When comparing their inhibitory effects at 5 mM concentrations, HDBAC exhibited superior performance (95.92 %) against Q235 in 0.5 M H2SO4, compared to TDBAC (94.09 %). These findings provide valuable insights for developing more effective and sustainable corrosion inhibitors for industrial applications.

Anticorrosive activity of Melothria perpusilla: A renewable and sustainable inhibitor

Anticorrosive activity of Melothria perpusilla extract on mild steel in H2SO4 was examined by weight loss, potentiodynamic polarization and electrochemical impedance spectroscopy methods. The results revealed that mild steel corrosion was effectively controlled by the extract with 99.4 % efficiency at 3000mg/L concentration. The efficiency was improved with higher extract concentration but decreased as the temperature increased. The Tafel plots and its corrosion potential value (<85 mV) inferred that Melothria perpusilla acts as a mixed type inhibitor. Adsorption of phytochemicals onto the surface of mild steel is the primary factor in reducing corrosion. The increase in activation energy for adsorption from 22.73 kJ mol−1 in acid to 133.74 kJ mol−1 in extract's presence confirms the active role of phytochemicals in adsorption process. The increase in charge transfer resistance from 3.21 Ω cm2 in acid to 369.2 Ω cm2 in extract's presence, coupled with a decrease in double layer capacitance in the EIS investigation, suggests that a charge transfer mechanism is active at the mild steel-solution interface. Gas chromatography-Mass spectroscopy revealed the presence of five major phytochemicals along with other organic compounds in the extract. Fourier transform infrared and UV–visible spectroscopies indicated the active functional moieties (-COOH, –CONH2, -C-O-C-, –C=C- and long chain alkyl groups) are involved in the inhibition. Scanning electron microscopy confirmed the existence of shielding film of phytochemicals on mild steel. Density functional theory validated the inhibitory properties of the constituents. Therefore, it is concluded that Melothria perpusilla is an efficient green inhibitor in acidic condition.

Synergistic mixture of Camellia Oleifera shell extract and KI as an eco-friendly and highly efficient composite inhibitor for steel corrosion in H2SO4 media

To address the severe corrosion problems faced by steel, a natural corrosion inhibitor derived from Camellia Oleifera shell extract (COSE) was developed. The effectiveness of COSE as well as its synergistic mixture of COSE/KI in inhibiting the corrosion of steel in H2SO4 was investigated using weightlessness and electrochemical techniques. The results show that the maximum inhibition efficiency of individual COSE is 77.28 % at 20 °C, and is increased to 93.08 % for the mixture of COSE/KI. The adsorption of COSE, KI and COSE/KI on steel surface conform to Langmuir adsorption isotherm. COSE/KI has a stronger adsorption than either COSE or KI. Electrochemical analysis indicates that COSE/KI is a hybrid inhibitor primarily focusing on the cathodic inhibition. Mixing COSE with KI shows considerably larger charge transfer resistance and smaller double-layer capacitance than individual COSE and KI. Characterization tests such as metallurgical microscopy, SEM, AFM and contact angle confirm that the addition of COSE/KI could reduce the roughness of steel surface, while increase the hydrophobicity, then effectively alleviate the corrosion on the steel surface. XPS analyses demonstrated that the corrosion inhibition layer on the steel surface was induced by the adsorption of the polar groups in COSE. The components responsible for COSE’s effectiveness were thoroughly examined using FTIR and liquid chromatography-mass spectrometry (LC-MS), which identified the presence of compounds such as flavonoids and phenylpropanoids. The synergistic effect of the active ingredients (rutin, quercetin, tea saponin, tea polyphenols, et al.) with KI was also confirmed. Finally, theoretical calculations were conducted to analyze properties of rutin, quercetin and tea polyphenols on the iron layer. The results show all these molecules exhibit efficient inhibition, with quercetin showing better inhibitive ability by parallel adsorption.

UV radiation effect on the corrosion inhibition potential of Helichrysum kraussii plant extract on mild steel metal in sulphuric acid medium

The comparison of the effect of UV-radiated and non-radiated Helichrysum kraussii (H. kraussii) extracts was studied for mild steel corrosion in 1.0 M H2SO4 at 30–60 °C using Liquid chromatography-mass spectrometry (LCMS), gravimetric weight loss analysis, electrochemical analysis and Fourier Transform Infrared spectroscopy (FTIR). The LCMS confirmed the trans-to-cis shift geometrical isomerisation for H. kraussii due to UV radiation. From the gravimetric analysis data, the corrosion rate was calculated and found to be decreasing with an increase in the concentration of the inhibitor extracts, with the highest concentration at 30 °C having a corrosion rate of 3.920x10-4 and 1.700x10-4 g.cm2.h−1 for UV-radiated. Non-radiated H. kraussii extract gave the highest inhibition efficiency of 96.663 % compared to 92.503 % of the UV-radiated H. kraussii extract. The semi-circles diameter of the Nyquist plot from the electrochemical impedance spectroscopy (EIS) was found to increase with an increase in the inhibitor concentration, suggesting the increase in inhibition with an increase in the concentration of the two extracts. Functional groups such as C = C, O-H, and N-H, known to be functional groups of the most effective corrosion inhibitors, were observed for both extracts from FTIR. Based on the results obtained, it was found that the UV-radiated H. kraussii extract was more effective in inhibiting the corrosion of mild steel in sulphuric acid than the non-radiated H. kraussii extract. This suggests that UV radiation decreases the efficiency of the H. kraussii extract as a corrosion inhibitor for mild steel in H2SO4. Therefore, it is recommended that the H. kraussii extract be used only as a corrosion inhibitor for mild steel in 1.0 M H2SO4 in its original state without being exposed to UV radiation.

Testing the inhibition efficiency of the castor oil leaf as corrosion inhibitor of mild steel in H2SO4

This study focused on the testing of castor oil leaf as corrosion inhibitor of mild steel in H2SO4. It involved the examination of the dynamics of molecular forces at the inhibitor and mild steel interface. Findings of the study will promote industrial diversification of castor oil leaf. On the experiment, bio-molecular compounds of the leaf were identified by gas chromatography mass spectrophotometer. Then, gravimetric and potentiodynamic polarization techniques were employed, where the efficacy and type of the inhibitor were determined. Considering the gravimetric process, factors of inhibitor concentration (0.2 g/L - 1.0 g/L), temperature (303 K–333 K) and time (8 h–24 h) were considered, with the inhibitor efficiency as the response. The efficiency was determined and optimized using response surface methodology (RSM) and artificial neural network (ANN). On the other hand, potentiodynamic polarization process was used to identify the type of inhibitor. Adsorption quantities were ascertained through the subjection of the experimental raw data to various adsorption isotherms. The analyses showed that castor oil leaf contains methyl nicotinate and pyridine-4-carbohydrazide. The bio-molecular compounds possess heteroatoms (N, S and O), signifying strong corrosion inhibitive tendencies. High efficiency (96.25 %) was obtained, with ANN having better prediction capability than the RSM. Potentiodynamic polarization curves revealed castor oil leaf as mixed-type inhibitor. On the adsorption phenomenon, the process of the inhibition was best fitted by Frumkin isotherm, revealing physical adsorption mechanism of Gibb's free energy less than −40 kJ/mol. As a mixed-type inhibitor, castor oil leaf should be applied for mitigation of anodic and cathodic corrosion.

Comparative Studies of Corrosion Inhibition of Ethanol Extract of Nymphaeaceae and Aloe barbadenis on Mild Steel in H2SO4

Comparative Studies of Corrosion Inhibition of Ethanol Extract of Nymphaeaceae and Aloe barbadenis on Mild Steel in H2SO4

The Corrosion Behavior of Cnidoscolus aconitifolius (Chaya) Leaf Extract on Mild Steel in H2SO4 and Brine (NaCl Solution) Environments

The inhibition efficacies of extracts of Cnidoscolus aconitifolius (Chaya) leaves in the corrosion of mild steel were investigated in H2SO4, and NaCl media. Weight loss method was employed to determine corrosion rate. The ribbed mild steel rod was cut into forty (40) coupons, each measuring 16 mm (diameter) by 8 mm (length) and their initial weights taken and noted. Twenty (20) beakers containing 0.5M and 1.0M each of H2SO4 and NaCl solution separately with varying volumes of the extracts ranging from 5ml to 20ml were set up with four (4) coupons in each beaker fully immersed using nylon strings. The set up was allowed to stand for an exposure time of 672hrs with a coupon withdrawn from each beaker every 168 hours and processed using standard procedures before being reweighed using digital weighing balance. The weight difference for each coupon was obtained and used for corrosion rate calculation using the formula, CPR= K∆W/ρAt. Other corrosion parameters were also obtained using the relevant formulae: inhibition efficiency, IE%=(〖CR〗_c-〖CR〗_i)/〖CR〗_c ×100 and surface coverage, , θ=(〖CR〗_c-〖CR〗_i)/〖CR〗_c .The results obtained indicated that the normal corrosion rate profile for passivating metals was followed with the weight loss by the coupons being higher in the control media than those ones in the inhibited media. It was also observed that increase in volumes of these extracts from 5ml to 20ml decreased the corrosion rate of mild steel in the media. We found that in both media Cnidoscolus aconitifolius (Chaya) exhibited high inhibition efficiencies of 78.14% in H2SO4 and 64.15% in NaCl at extract concentration of 20 ml. Plots of the Langmuir adsorption isotherms suggest uniform surface covering of the adsorbent molecules at equilibrium state of the adsorbate–adsorbent system, with very strong adsorption forces. Based on these findings, the results suggest that Cnidoscolus aconitifolius (Chaya) leaves extract is a veritable green inhibitor for both acidic and salt media and can be a suitable alternative to the synthetic inhibitors widely used in the oil and gas industry.

Corrosion inhibition behavior and theoretical study on carbon steel in H2SO4 by Schizochytrium extract

Corrosion inhibition behavior and theoretical study on carbon steel in H2SO4 by Schizochytrium extract

Synergistic mixture of Eupatorium Adenophora Spreng stems extract/KI as an efficient inhibitor for the corrosion of steel in H2SO4

The synergistic inhibition effect of Eupatorium Adenophora Spreng stems extract (EASSE) with KI on the corrosion of cold rolled steel (CRS) in 0.50 M H2SO4 medium was examined by gravimetric and electrochemical measurements, as well as various surface characterizations. The results indicate that the maximal inhibition effectiveness of EASSE/KI reaches 93.3% and a coefficient of synergy (s) value larger than 1. Moreover, Langmuir isotherm is suitable for the adsorption of EASSE, KI and their complex on CRS surface. Individual EASSE, KI and their synergistic mixture are all mixed-type inhibitors by “geometric coverage mechanism”. Nyquist predominantly demonstrates a dispersive capacitive loop, and EASSE/KI blend synergistically decreases double layer capacitance while increases the charge transfer resistance of steel/solution interface. SEM, AFM and wettability measurements confirm that the combination of EASSE/KI synergistically suppresses the corrosion of CRS surface, and the synergistic inhibited CRS surface appears to have almost no corrosion with a greater contact angle. According to XPS, the active compounds containing polar N and O atoms in EASSE can be incorporated with KI to adsorb on CRS surface. Two kinds of flavonoids and phenylpropanoids in EASSE mainly contribute to the synergistic inhibitory effect with KI.

Corrosion inhibition of API5L X60 steel in sulfuric acid using gum arabic

The aim of this research is the evaluation of inhibitory efficiency of Gum Arabic (GA) against the corrosion of API5L X60 pipeline steel in H2SO4 (0.5M) media, using mass loss measurement and electrochemical methods. The results show that inhibition efficiency increases with inhibitor concentration to attain 83% at 4 g/L of GA. Polarization curves reveal that GA acts as a mixed-type inhibitor in sulfuric acid. The adsorption of GA on pipeline API 5L X60 steel surface obeyed the Langmuir adsorption isotherm. Gibbs free energy of adsorption indicated that the adsorption process is spontaneous and the molecules adsorbed on the metal surface by the process of physical adsorption.

Evidence of metal–organic coordination between Fe and flavonoid chrysin in a green anticorrosion film

ABSTRACT This work shows interesting results for a metal–organic complex as a green corrosion inhibitor. The study describes features of two passive films (PF) containing chrysin for mild steel in H2SO4 by means of electrochemical noise under a potentiostaic regime as a function of time. The features showed a current reduction due to the formation of a passive film with better stability and homogeneity when chrysin is absorbed at the optimal experimental potential. PF formed at 50 ppm presented a very high corrosion protection over seven hours reducing the current density seven orders of magnitude, and PF formed at 300 ppm showed two orders of magnitude decrease over 23 h. PF analysis by FT-IR spectra showed important stretch band shift vibrations in the carbonyl and hydroxyl groups as evidence of the presence of metal–organic complex. Moreover, the information provided by adsorption isotherms and quantum chemical calculations confirmed the coordinated bonds established by chemisorption process which correlates with the experimental results.

Plant extracts as corrosion inhibitors for mild steel in H2SO4 and H3PO4 media – Review II

Plant extracts as corrosion inhibitors for mild steel in H2SO4 and H3PO4 media – Review II

Naturally Occurring Exudates Gums as Ecofriendly Inhibitors for Mild Steel Corrosion in Acidic Medium

The corrosion inhibition potentials of gum exudates from Daniella oliveri (DO) and Commiphora Africana (CA) for the corrosion of mild steel in H2 SO4 have been studied using weight loss and thermometric methods at 303 and 333K. Results show that the exudates gum actually reduced the rates of corrosion of mild steel. Increase in the concentrations of the exudate’s gums increased their percentage inhibition efficiencies. Corrosion rate was found to increase with increase in temperature in the presence and absence of the gum exudates, though the corrosion rate was slower in the presence of the exudates gums. Both DO and CA exudates gums were found to obey Temkin and Langmuir adsorption models at all concentrations and temperatures studied. Physical adsorption mechanism was proposed from the adsorption parameters. Kinetic and thermodynamic parameters revealed that the adsorption process is spontaneous, exothermic and no significant difference was found between the inhibition efficiencies of DO and CA.

Corrosion Inhibition characteristics of Reinforced Steel in H2SO4 by benzoyl Thiourea

In The adsorption and corrosion inhibition performance of 3,3-diethyl(4-Chloro)benzoylthiourea, ClDEBT, at reinforced steel in H2SO4 interface was examined using gravimetric method at 303.15 K. The inhibition effectiveness of ClDEBT was improved by increasing the concentration. The adsorption data of ClDEBT on the reinforced steel surface were fitted to Langmuir, Temkin and thermodynamic–kinetic adsorption isotherms, and some thermo-dynamics functions as α, y, f, ΔGads and Kads were obtained. Activation energies of 35.69 and 55.99 kJ mol−1 for the corrosion processes of reinforced steel were observed in presence and absence of benzoylthiourea inhibitor, respectively. The adsorption of thiourea inhibitor on the surface of reinforced steel was found to be spontaneous and exothermic. Quantum parameters as the highest &amp; lowest occupied molecular orbital energy (EHOMO) &amp; (ELUMO), energy gap (ΔE), were determined and correlated to the experimental data.

Improvement of corrosion resistance of galvanization/nickel/chrome plating low carbon steels in H2SO4 under dynamic condition

In this work, the corrosion resistance of metallic coating (ISO 1416) deposited on AISI 1080 low carbon steel has been investigated under static and dynamic conditions (flow rate 30 rpm). The coated steels have been immersed into aqua solution of H2SO4 at 80 °C temperature up to 3 h where pH value 1 is maintained. The corroded surfaces are characterized by SEM, XRD, ATR, EDS and Tafel extrapolation methods. Results show that the corrosion under static condition is higher than that of dynamic condition both for coated and uncoated surfaces. The coated steels exhibit lower corrosion in comparison of uncoated steels. The low carbon steel experiences significant corrosion resistance property in combined effects of dynamic environment and coating surface. Corrosion rate is calculated by following weight loss method. The corrosion damage is remarkably high for low carbon steels. The nickel-plating steel exhibits more corrosion resistance in H2SO4 corrosive medium when comparing with chrome plating steel. On the other hand, chrome plating steel happens more corrosion resistance in comparison of galvanized steel. Besides, lower flow rate makes higher rate of corrosion and lower depth of penetration. It is expected that the outcomes of this work will contribute to the improvement of different concerned mechanical and tribological processes where the corrosion concerning issue.

Free fatty acid influenced corrosion inhibition mechanisms of some inedible plants seeds oils on low alloyed medium-carbon steel in H2SO4

PurposeThe purpose of this paper is to investigate the mechanisms of low alloyed medium-carbon steel (LAMCS) corrosion in 0.5 M H2SO4 inhibited by seeds oils of rubber (SOR), Neem (SON) and Jatropha (SOJ) containing varying degree of free fatty acid (FFA).Design/methodology/approachSpecific gravity, acid values and FFA compositions of oils were determined. Potentiodynamic polarization (PDP), electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM) and X-ray diffraction (XRD) are techniques used to investigate the corrosion inhibition mechanisms with evaluated Gibbs free energy of adsorption.FindingsCorrosion inhibition efficiencies of oils reached values >99% as obtained from PDP and EIS. Protective oxide layer was formed on LAMCS consequent on containment of carbonyl and hydroxyl groups in the FFA of SOR, SON and SOJ, respectively. The SOR and SOJ are found to be mixed inhibitors, whereas SON behaved as anodic inhibitor. Mechanism of adsorption of SOR was synergistic between physisorption and chemisorption, while SON and SOJ exhibited physisorption. SEM micrographs images showed that uninhibited sample exhibited thicker mass of corrosion products. Formation of protective oxide layer was confirmed by XRD diffractograms.Practical implicationsThis study has shown that the need for modification of vegetable seed oils containing FFA is unnecessary as the hydroxyl and carbonyl groups of the FFA contained in the respective oil were found to be the center of adsorption of the oils on the steel surface. Hence, cost and by-products associated with modification of oils used as corrosion inhibitors are eliminated.Originality/valueSOR, which has the highest percentage FFA, was found to be the most influential on the corrosion inhibition mechanism of LAMCS, specifically within 0.01–0.02 g/mL concentration. FFA contained in the respective seed oil aided formation of protective oxide layer at interface between H2SO4 and LAMCS, relative to amount composed.

Influence of wormin mebendazole on the corrosion of mild steel in 1.0M sulphuric acid

This investigation described the inhibitive influence of Mebendazole (MBZ) on mild steel corrosion in 1M sulphuric acid. Potentiodynamic polarization and scanning electron microscopy techniques were employed. Mebendazole effectively protected mild steel in H2SO4 at 298K and 333K with maximum inhibition efficiencies of 98.02% and 99.53% respectively. The adsorption of the inhibitor on the surface of mild steel followed the mixed mode physical adsorption of Langmuir adsorption model. The corrosion rate of specimens decreased from about 47.467 ​mm/yr for the blank specimen to about 1.7968 ​mm/yr for the specimen immersed in 1M sulphuric acid containing 2.5 ​g/l of MBZ at 298K. However, at 333K the corrosion rates were respectively 1455 ​mm/yr and 6.7854 ​mm/yr. Scanning electron microscopy revealed that the addition of Mebendazole to the corroding system sustained a surface morphology relatively devoid of pits on the test specimens at 5 days of immersion in 2.5 ​g/l of inhibitor in 1M sulphuric acid.

Corrosion inhibition study and statistical data of thymus mastichina and alicium verum oil on low carbon steel in dilute H2SO4 and HCl solution

Data on the corrosion inhibition of thymus mastichina and alicium verum (TA) on mild steel in H2SO4 and HCl solution was evaluated by coupon measurement and statistically through analysis of variance. The inhibition performance of TA was observed to decrease significantly with exposure time at 1% TA, beyond which the extent of decrease reduced. In HCl solution TA inhibition efficiency varied significantly with exposure time from 1%-4% TA concentration. Data showed TA effectively inhibited the mild steel after 1% concentration with optimal value of 81.24% and 5% TA concentration. TA performed poorly in HCl with optimal value of 68.33% at 5% TA concentration. Standard deviation showed variation of TA inhibition efficiency from mean inhibition value was significant at 1-5% TA concentration in HCl and at 1% TA concentration in H2SO4. 88% of TA inhibition data were above 70% inhibition with respect to exposure time and TA concentration at margin of error of +0.09% compared to 53% in HCl at margin of error of +0.1%. Analysis of variance showed TA concentration is the dominant source of variation responsible for the inhibition performance of TA with statistical relevance value of 88.83% while TA concentration and exposure time were both influential in HCl solution with values of 67.96% and 26.97%.

Corrosion behavior of CoCrNi medium-entropy alloy compared with 304 stainless steel in H2SO4 and NaOH solutions

The corrosion resistance and passive film properties of the CoCrNi medium-entropy alloy were investigated. Experimental results show that selective dissolution of elements in the CoCrNi is evident compared with the 304 SS. The passive film formed on the CoCrNi is enriched in Cr but depleted in Co and Ni, and the high content of Cr and thicker passive film are responsible for the higher anti-corrosion of the CoCrNi in H2SO4 solution; the surface is enriched in Co while depleted in Cr and Ni, and the higher dissolution rate of Cr is responsible for the lower anti-corrosion in NaOH solution.

Performance of Methyl-5-Benzoyl-2-Benzimidazole Carbamate (Mebendazole) as Corrosion Inhibitor for Mild Steel in Dilute Sulphuric Acid.

The inhibitive effect of mebendazole (MBZ) on the corrosion of low-carbon steel in H2SO4 was investigated by gravimetric and electrochemical techniques as well as examination of specimens in the scanning electron microscope with attached energy dispersive X-ray spectrometer (EDS). From gravimetric analysis, the highest inhibition efficiency of about 96.6% was obtained for 1.0 g of inhibitor in H2SO4 solution at 24 h, while with longer exposure times of between 72 to 120 h, the efficiencies averaged between 92 and 95%. Tafel extrapolations from the polarization curves showed that 1.0 g MBZ gave a maximum inhibition efficiency of approximately 99% for the investigation conducted at 30°C, whereas 1.5 g of MBZ gave a maximum inhibition efficiency of about 85% at 60°C. Inhibition efficiency increased with increasing concentrations of MBZ and decreased at elevated temperatures. The inhibitive action was attributed to physical adsorption of MBZ species on the mild steel surface which followed the Langmuir adsorption isotherm. MBZ performed as a mixed-type inhibitor on mild steel in dilute H2SO4.