Correlation between Electrical Properties of the Passive Film on Carbon Steel and Inhibition Efficiency by Phosphate and Nitrite Ions

2017 ◽  
Vol 80 (10) ◽  
pp. 621-633
Author(s):  
Maria Alejandra Frontini ◽  
Marcela Vázquez ◽  
María Beatriz Valcarce
Molecules ◽  
2021 ◽  
Vol 26 (12) ◽  
pp. 3535
Author(s):  
Naba Jasim Mohammed ◽  
Norinsan Kamil Othman ◽  
Mohamad Fariz Mohamad Taib ◽  
Mohd Hazrie Samat ◽  
Solhan Yahya

Extracts from plant materials have great potential as alternatives to inorganic corrosion inhibitors, which typically have harmful consequences. Experimental and theoretical methodologies studied the effectiveness of agricultural waste, namely, date palm seed extract as a green anti-corrosive agent in 0.5 M hydrochloric acid. Experimental results showed that immersion time and temperature are closely related to the effectivity of date palm seed as a corrosion inhibitor. The inhibition efficiency reduced from 95% to 91% at 1400 ppm when the immersion time was increased from 72 h to 168 h. The experimental results also indicated that the inhibition efficiency decreased as the temperature increased. The presence of a protective layer of organic matter was corroborated by scanning electron microscopy. The adsorption studies indicated that date palm seed obeyed Langmuir adsorption isotherm on the carbon steel surface, and Gibbs free energy values were in the range of −33.45 to −38.41 kJ·mol−1. These results suggested that the date palm seed molecules interacted with the carbon steel surface through mixture adsorption. Theoretical calculations using density functional theory showed that the capability to donate and accept electrons between the alloy surface and the date palm seed inhibitor molecules is critical for adsorption effectiveness. The HOMO and LUMO result indicated that the carboxyl (COOH) group and C=C bond were the most active sites for the electron donation-acceptance type of interaction and most auxiliary to the adsorption process over the Fe surface.


2011 ◽  
Vol 301-303 ◽  
pp. 109-115
Author(s):  
Lin Lin Liu ◽  
Yuan Li ◽  
Bao Wei Hao ◽  
Shi Zhao Wang

Little attention has been paid to the nano-TiO2as corrosion inhibitor before. In this paper, Myristic acid-modified nano-TiO2(MA-TiO2) were synthesized by Myristic acid and tetrabutyl titanate via the sol-gel method, and it was characterized by IR and TEM. MA-TiO2was dispersed in oil, and used as a corrosion inhibitor. From the Tafel plots and EIS spectra, we can know that the values of the current densities decreased by the addition of MA-TiO2. Because of the MA-TiO2formed a deposition layer in the surface of 45#carbon steel panels, the current density of the the base oil with MA-TiO2is much smaller than the base oil. The inhibition efficiency was over 90% with added 5 wt % TiO2.


2019 ◽  
Vol 66 (1) ◽  
pp. 121-126 ◽  
Author(s):  
Walid Belmaghraoui ◽  
Aimad Mazkour ◽  
Hicham Harhar ◽  
Mourad Harir ◽  
Souad El Hajjaji

Purpose This study aims to investigate the corrosion inhibition effect of extracted oil from Ziziphus lotus fruit on corrosion of C38 carbon steel in 5.5 M H3PO4 solution using potentiodynamic polarization and impedance techniques. Design/methodology/approach Oil composition was determined using gas chromatography, and the results showed that oleic and palmitic acids present approximately 84.0 per cent of its total chemical content. Electrochemical impedance spectroscopy (EIS) data were analyzed by adapting it to a well-developed electric circuit model. The inhibition efficiency of Z. lotus oil was calculated and compared using Tafel polarization and EIS. Findings Accordingly, the oil extract was found to act as an anodic type inhibitor. Furthermore, inhibition efficiency of Z. lotus oil extract increase with oil concentrations and achieve approximately 70.5 per cent at 3 g/L solution of Z. lotus oil. Originality/value The results obtained from different tested methods were in line, and the oil was able to reduce significantly the kinetics of the corrosion process of C38 carbon steel.


2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
K. S. Shaju ◽  
K. Joby Thomas ◽  
Vinod P. Raphael ◽  
Aby Paul

The corrosion inhibition efficiency of a potential polynuclear Schiff base, (s)-2-(anthracene-9 (10H)-ylidene amino)-5-guanidinopentanoic acid (A9Y5GPA), on carbon steel (CS) in 1 M hydrochloric acid solution has been investigated using weight loss measurements, electrochemical impedance spectroscopy (EIS), and potentiodynamic polarization studies. The corrosion inhibition efficiencies of parent amine [(s)-2-amino-5-guanidinopentanoic acid] and parent ketone (anthracene-9 (10H)-one) on carbon steel in 1.0 M hydrochloric acid solution have also been investigated using weight loss studies. The electrochemical and weight loss data established that the inhibition efficiency on CS increases with the increase in the concentration of inhibitor, A9Y5GPA. The adsorption of A9Y5GPA obeys the Langmuir adsorption isotherm. Thermodynamic parameters (Kads, ΔGads0) were calculated using the adsorption isotherm. Activation parameters of the corrosion process (Ea, ΔH* and ΔS*) were also calculated from the corrosion rates obtained from temperature studies. Tafel plot analysis revealed that A9Y5GPA acts as a mixed-type inhibitor. A probable inhibition mechanism was also proposed. Surface morphology of the carbon steel specimens in the presence and absence of the inhibitor was evaluated by SEM analysis.


Author(s):  
Truong Thao

Abstract: Corrosion inhibition of mild carbon steel, CT3,  in 1.0 M HCl solution by iodide  (with different concentrations, from 0.1g/l to 5.0g/l), mix of caffeine and iodide was investigated by electrochemical methods and micro surface observations (SEM). Experiment result showed that: (1) as the concentration of iodide increases, the inhibition efficiency increases;  Iodide acts as a mix – type inhibitor but inhibits anodic reaction is predominant. (2) Mix of 1.0 g/l iodide ang caffeine acts as a typical mix – type inhibitor. the current densities of both of anodic and cathode are decline when concentration of caffeine is 1.0 g/l or more. Inhibition efficiency max is approximately 96% at concentration of 5.0 g/l caffeine, the inhibition efficiency maintained relatively stable within 5 days.  


2018 ◽  
Vol 6 (11) ◽  
pp. 153-162
Author(s):  
Rajesh V. ◽  
E. U. B. Reddi ◽  
T. Byragi Reddy ◽  
Ch. Durga Prasad ◽  
B. Prasanna Kumar

The present study was initiated with an objective of investigating a plant extract as an effective corrosion inhibitor useful for protection of carbon steel in aqueous environment containing chloride ions. For this purpose, the leaf extract of the plant ‘Aerva lanata’ belonging to Amaranthaceae family of genus Aerva was chosen. The required optimum concentration of the extract for an effective inhibition was found to be 5 %, resulting in the inhibition efficiency of 95 % against corrosion of carbon steel in 200 ppm of NaCl solution. The extract introduced as a corrosion inhibitor was found to be effective in the pH range from 4.0 to 9.0. The extract could retain its inhibition efficiency for about an immersion period of 60 days and also up to a temperature of 333 K. The 5 % extract was found to control corrosion of carbon steel in highly aggressive medium containing 300 ppm of NaCl also. In order to maintain the protective nature, the required concentration of the extract was 2 %. From these studies, it was inferred that the Aerva lanata leaf extract exhibits good inhibitive properties for carbon steel in aqueous environment in wide ranges of pH, temperature and aggressiveness of medium.


MRS Advances ◽  
2017 ◽  
Vol 2 (62) ◽  
pp. 3909-3915
Author(s):  
Héctor M. Barbosa Cásarez ◽  
Araceli Espinoza Vázquez ◽  
Francisco J. Rodríguez-Gomez

AbstractPhenylcoumarin glucoside (4-PC) is a compound extracted from the plant Hintona latiflora and was studied as inhibitor for AISI 1018 steel corrosion in 3% NaCl solution using potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques, which may find application as eco-friendly corrosion inhibitors. The 4-PC provides inhibitor properties that protect AISI 1018 low carbon steel against corrosion at low concentrations (5 ppm) obtained by EIS. Polarization studies showed that the inhibitor was of mixed type. The inhibition efficiency by the two electrochemical techniques shows similar results. The inhibitor adsorption was demonstrated to be a combined process (physisorption and chemisorption) according to the Langmuir isotherm.


2014 ◽  
Vol 61 (5) ◽  
pp. 300-306 ◽  
Author(s):  
B.P. Markhali ◽  
R. Naderi ◽  
M. Sayebani ◽  
M. Mahdavian

Purpose – The purpose of this paper is investigate the inhibition efficiency of three similar bi-cyclic organic compounds, namely, benzimidazole (BI), benzotriazole (BTAH) and benzothiazole (BTH) on carbon steel in 1 M hydrochloric acid (HCl) solution. Organic inhibitors are widely used to protect metals in acidic media. Among abundant suggestions for acid corrosion inhibitors, azole compounds have gained attention. Design/methodology/approach – The inhibition efficiency of the three organic compounds was investigated using potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). Findings – Superiorities of BTH and BTAH corrosion inhibitors were shown by EIS data and polarization curves. Moreover, the results revealed that BTAH and BTH can function as effective mixed-type adsorptive inhibitors, whereas no inhibition behavior was observed for BI. Both BTAH and BTH obeyed Longmuir adsorption isotherm. The results obtained from this isotherm showed that both inhibitors adsorbed on the specimen surface physically and chemically. The difference in inhibition efficiencies of BTAH, BTH and BI was related to the presence of nitrogen and sulfur hetero atoms on their molecular structures. Originality/value – This study evaluated inhibition efficiency of BI, BTAH and BTH using electrochemical methods. In addition, the study attempted to find inhibition mechanism of the inhibitors and to find modes of adsorption of the inhibitors, correlating effects of heteroatoms and inhibition efficiency.


2016 ◽  
Vol 1133 ◽  
pp. 366-370 ◽  
Author(s):  
Izni Mariah Ibrahim ◽  
Junaidah Jai ◽  
Md Amin Hashim

The effect of hydrazine, N2H4 in the presence of fatty amide as corrosion inhibitor on corrosion of carbon steel in 3.5 wt% NaCl solution was studied by linear polarization resistance method (LPRM) at room temperature and static condition. The specimens’ surface analysis was done using atomic force microscope (AFM). The inhibition efficiency improved to more than 80% when 500, 100 and 2000 ppm of hydrazine were added to the inhibited solution containing 20 ppm fatty amide. The results obtained show that the inhibition effect is increased with increase of hydrazine concentration in inhibited solution. It indicates that hydrazine retards the reduction of oxygen in the corrosion process by reacting with dissolved oxygen in the solution and thus, further it reduces the corrosion rate of carbon steel.


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