scholarly journals ELECTROCHEMICAL BEHAVIOR OF MILD STEEL IN HCL 1M MEDIUM WITH THE PRESENCE OF ROSE MYRTLE LEAVES EXTRACTION

2018 ◽  
Vol 56 (3B) ◽  
pp. 63
Author(s):  
Quan Vo An ◽  
Tuan Anh Nguyen ◽  
Ha Tran Thi ◽  
Que Le Xuan

As the growing interest on green corrosion inhibitors, plant extracts have gradually showed the potential in replacing the traditional hazardous chemicals due to the eco-friendly and economy characteristics. Previous study reported that rose myrtle leaf-extract (Rhodomyrtus tomentosa, Myrtaceae) was as an efficient corrosion inhibitor for rust removal process of mild steel in H2SO4 acid medium. This study presents the corrosion inhibition assessments of rose myrtle leaf-extract on mild steel surface in HCl 1M solution. The potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) methods have been used to study the corrosion behaviors of mild steel. The corrosion rate, corrosion current and corrosion potential results indicate that only small amount of the leaf-extract (2% vol.) was required for high inhibition efficiency (Hin=83.9%). By affecting on both anodic and cathodic branches of the Tafel plot, the corrosion inhibition mechanism is proposed by an adsorption forming different barriers on the steel surface.Green inhibitor, Rhodomyrtus tomentosa, steel corrosion, EIS

2019 ◽  
Vol 233 (11) ◽  
pp. 1553-1569 ◽  
Author(s):  
Rola N. Tabesh ◽  
Ashraf Moustafa Abdel-Gaber ◽  
Hassan H. Hammud ◽  
Rami Al-Oweini

Abstract The ligands 1,10-phenanthroline, (P) and para-aminobenzoate, (B); as well as their corresponding MnPB complex [bis-(dimanganese di-μ-paraaminobenzoate dichloro diphenanthroline)] have been investigated as inhibitors of mild steel corrosion in H2SO4 (0.5 M) solutions via potentiodynamic and electrochemical impedance spectroscopy techniques. Stability of the prepared complex was examined by UV-visible spectroscopy. The corrosion inhibition, thermodynamics, and adsorptive properties obtained have shown that MnPB complex has remarkable effects in the acidic solutions. Theoretical fitting of different adsorption isotherms such as Langmuir, Flory–Huggins, and the kinetic-thermodynamic models were tested and the thermodynamic activation parameters were calculated. The data revealed that the corrosion inhibition mechanism of mild steel in acidic solutions by the MnPB complex goes via physicochemical adsorption.


2018 ◽  
Vol 55 (5B) ◽  
pp. 103
Author(s):  
Bui Thi Thanh Huyen

This paper deals with the effect of anion groups (SO42- and Cl-) on inhibition behaviours of Vietnam orange peel essential oil (OPE) for corrosion process of mild steel in acidic media. The electrochemical techniques (potentiodynamic, electrochemical impedance spectroscopy (EIS)), weight loss and scanning electron microscopy (SEM) analyses are used in this study. The results show that anion groups do not affect the inhibition mechanism of OPE. The OPE ­behaves as mixed inhibitor for mild steel corrosion in both 1N HCl and H2SO4 acid. The inhibition efficiency of OPE in 1N HCl is greater than that in 1N H2SO4 which implies that the adsorption of the inhibitor is influenced by the nature of anions in acidic solutions. Moreover, the OPE inhibits both general and pitting corrosion for mild steel in the acidic media. 


Author(s):  
Moussa Ouakki ◽  
Mouhsine Galai ◽  
Mohammed Cherkaoui ◽  
Mohamed Ebn Touhami ◽  
E. H. Rifi ◽  
...  

The corrosion inhibition of mild steel in hydrochloric, sulfuric, and phosphoric acids solutions containing a mineral compound-based phosphate (apatite) was evaluated by potentiodynamic polarization and electrochemical impedance spectroscopy. Potentio-dynamic polarization measurements reveal that the inhibition efficiency increased with the concentration of the apatite, which appears to be a cathodic type inhibitor in the three mediums. Electrochemical impedance spectroscopy confirms this result; indeed, the transfer resistance increases with apatite concentration. The authors note that the double layer capacitance decreases simultaneously suggesting the formation of an adsorbed layer on the mild steel surface. The inhibition mechanism has been elucidated by a thermodynamic study, which showed that the film was formed by physi-sorption. The adsorption model obeys to the Langmuir adsorption isotherm. The parameters of activation energy were evaluated and discussed.


2019 ◽  
Vol 233 (12) ◽  
pp. 1713-1739
Author(s):  
Emad E. El-Katori ◽  
A.S. Fouda ◽  
Rahma R. Mohamed

AbstractHerein, the corrosion inhibition performance of mild steel (MS) in an acidic environment (1.0 M HCl) by the valerian extract has been studied via weight loss method (WL), potentiodynamic polarization (PP), electrochemical impedance spectroscopy (EIS) and electrochemical frequency modulation (EFM) techniques. The results illustrated that the inhibition efficiency, raised by the rise of the extract concentrations. The inhibitory mechanism depended on the creation of a stable plant extract-complex on the mild steel surface. Polarization studies confirmed that the extract behaved as a mixed type inhibitor. The corrosion inhibition was supposed to exist via adsorption of the main components of the valerian extract. Attenuated total reflection-infrared spectroscopy (ATR-IR), scanning electron microscopy (SEM) and atomic force microscopy (AFM) were applied to investigate the change in the surface morphology and confirmed the corrosion inhibition mechanism. The complete study confirmed that the efficiency of the valerian extract as a safe, eco-friendly and exchange corrosion inhibition for mild steel in an acidic environment.


2019 ◽  
Vol 66 (5) ◽  
pp. 583-594
Author(s):  
Esma Sezer ◽  
İpek Öztürk

Purpose Tannic acid (TA) is one of the green corrosion inhibitors for mild steel; its anti-corrosive performance in alkaline water on mild steel when it is used together with polyaspartic acid (PASA) still has not been investigated. The purpose of this study is to develop an effective, biodegradable and environment-friendly novel corrosion inhibitor based on TA and PASA as an alternative to the conventional inorganic inhibitors for mild steel in decarbonised water, which is common in cooling systems. Design/methodology/approach Corrosion inhibition mechanism is investigated by electrochemical techniques such as polarisation measurements and electrochemical impedance spectroscopy, and results were evaluated to determine the optimum inhibitor concentration for industrial applications. Additionally, practice-like conditions are carried out in pilot plant studies to simulate the conditions in cooling systems. Thus, the efficiencies of the inhibitors are evaluated through both weight loss and linear polarisation resistance measurements. Moreover, the corrosion product is characterised by scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX) and Fourier-transform infrared spectroscopy (FTIR) analysis. Findings TA shows high inhibition efficiency especially towards pitting corrosion for mild steel in decarbonised water. PASA addition in the cooling systems improves the inhibition efficiency of TA, and at lower concentrations of TA + PASA, it is possible to obtained better inhibition efficiency than TA alone at higher inhibitor amounts, which is essential in economic and environmental aspect. Originality/value A blended inhibitor program including TA and PASA with suggested concentrations in this work can be used as an environmental friendly treatment concept for the mild steel corrosion inhibition at cooling systems.


Chemistry ◽  
2020 ◽  
Vol 2 (4) ◽  
pp. 900-917
Author(s):  
George M. Tsoeunyane ◽  
Elizabeth M. Makhatha

The synthesis and corrosion inhibition performance of poly(butylene-succinate)-L-proline (PBSLP) prepared by solution polymerization are reported. PBSLP was characterized by FTIR, XRD, and SEM/energy dispersive X-ray (EDX). PBSLP was used to protect mild steel in 1 M hydrochloric acid. An SEM and an atomic force microscope (AFM) were used to characterize the surface morphology of the mild steel coupons. Potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) were used to characterize the inhibition mechanism of PBSLP, and the inhibitor was a mixed-type corrosion inhibitor with a maximum corrosion inhibition efficiency of 93.0%. Adsorption studies revealed the adsorption of PBSLP to be a monolayer process and therefore, obeyed the Langmuir isotherm model.


Author(s):  
Prakash Katuwal ◽  
Ramesh Regmi ◽  
Susan Joshi ◽  
Jagadeesh Bhattarai

Effects of Nepal origin plant species of Vitex negundo, Catharanthus roseu, Aegle marmelos and Elaeocarpus ganitrus extracts on mild steel corrosion were explored in bioethanol (E100) and its blend (E15) in airtight condition at 25±2 °C using static immersion, inhibition efficiency and mechanism tests which were complemented with adsorption isotherms and potentiodynamic polarization studies. Corrosion resistance of the mild steel was increased with increasing 500-2000 ppm concentrations of each plant extract in E100 and E15 biofuels. Additions of V. negundo and C. roseus extract separately in both the biofuels seems to be more effective inhibition actions to prevent the mild steel corrosion than A. marmelos or E. ganitrus addition so as the corrosion rates of the mild steel in E100 and E15 are successfully lowered even than in commercial gasoline (E0). The results obtained from the corrosion rate revealed the order of the corrosion inhibition efficiency (IE) as V. negundo > C. roseus > A. marmelos > E. ganitrus. The maximum IE (IEmax) in V. negundo and C. roseus leaves was showed about 89-86% and 71-75%, respectively, at 2000 ppm concentration, in spite of the other two more plants leaf extract also used as the corrosion inhibitors for the mild steel in both E100 and E15 biofuels. The IE increased on increasing inhibitor concentration following the Langmuir and Temkin adsorption isotherms but decreased with immersion time which suggested that the corrosion inhibition mechanism is of physical type of adsorption of the leaves constituents on the mild steel surface. A. marmelos extract acted as an anodic type of inhibitor in E100 and E15, while E. ganitrus acted as mixed


2017 ◽  
Vol 35 (2) ◽  
pp. 95-110 ◽  
Author(s):  
Rajeev Kumar ◽  
Savita Chahal ◽  
Shefali Dahiya ◽  
Naveen Dahiya ◽  
Sumit Kumar ◽  
...  

Abstract3-Formyl chromone (3FC) derivatives, viz. 5-methoxy-3FC (5-Me-3FC), 6-hydroxy-3FC (6-OH-3FC), and 7-hydroxy-3FC (7-OH-3FC), were studied for the inhibition of mild steel corrosion in 1 m H2SO4 at different temperatures and concentrations. The inhibition was studied using mass loss method, polarization technique, electrochemical impedance spectroscopy (EIS), scanning electron microscopy, and quantum chemical calculations. The results from mass loss, potentiodynamic polarization, and EIS showed that inhibition efficiency (IE) increased with gradual increments in concentration of 3FC derivatives. The polarization study revealed that these compounds act as mixed-type inhibitors and Langmuir adsorption isotherm is fitted well for adsorption behavior. The order of IE provided by all the three compounds is 7-OH-3FC≈6-OH-3FC>5-Me-3FC and lies in the range of 85%–95%. A proposed inhibition mechanism has been further described, including the support from all the experimental and theoretical techniques.


Author(s):  
Hamze Foratirad ◽  
Majid Golabadi ◽  
Masoud Asgari ◽  
Mohammad Ghasem Gholami ◽  
Meysam Karimi

Abstract In this study, the synergistic effects of 2-mercaptobenzotiazole molecules and zinc nitrate on the corrosion behavior of carbon steel were investigated using electrochemical techniques in 3.5% NaCl solution. The experimental results revealed that combination of 2-mercaptobenzoimidazole (MBT) and zinc nitrate with ratio of 100 ppm : 100 ppm, resulted in the least corrosion current (1.03 lA cm-2) and the highest corrosion inhibition efficiency. Polarization results showed that the inhibition mechanism of inhibitor was mixed-type (anodic and cathodic mechanism) corrosion inhibition which was predominantly influenced by a reduction in dissolution rate of the substrate (decrease in anodic current density). Electrochemical impedance spectroscopy analysis yielded more accurate results about the formation mechanism and stability of the inhibitor film over prolonged time. The precipitation of chelate from inhibitor molecules and zinc cations on steel surface was found to be the main mechanism for increasing the corrosion resistance of steel substrate.


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