Inhibition of Aluminium Corrosion in Hydrochloric Acid Using Nizoral and the Effect of Iodide Ion Addition

Directory of Open Access Journals (Sweden)

I. B. Obot

2010-01-01

Full Text Available The effect of nizoral (NZR on the corrosion inhibition of aluminium alloy AA 1060 in 2 M HCl solution was investigated using the mylius thermometric technique. Results of the study revealed that nizoral acts as corrosion inhibitor for aluminium in the acidic medium. In general, at constant acid concentration, the inhibition efficiency increases with increase in the inhibitor concentration. The addition of KI to the inhibitor enhanced the inhibition efficiency to a considerable extent. The adsorption of nizoral onto the aluminium surface was found to obey the Fruendlich adsorption isotherm. The value of the free energy for the adsorption process shows that the process is spontaneous.

Corrosion Inhibition of Mild Steel in Hydrochloric Acid by Sodium Lauryl Sulfate (SLS)

OpenAIRE

Atul Kumar

2008-01-01

Effect of Sodium Lauryl Sulfate (SLS), a surfactant on corrosion of mild steel in 1 M hydrochloric acid was studied using three techniques namely: weight loss, electrochemical polarization and metallurgical research microscopy. Results obtained reveal that SLS is good inhibitor and shows very good corrosion inhibition efficiency (IE). The IE was found to vary with concentration of inhibitor and temperature. The electrochemical polarization result revealed that SLS is anodic in nature.

Synthesis and corrosion inhibition application of NATN on mild steel surface in acidic media complemented with DFT studies

Science.gov (United States)

Al-Baghdadi, Shaimaa B.; Hashim, Fanar G.; Salam, Ahmed Q.; Abed, Talib K.; Gaaz, Tayser Sumer; Al-Amiery, Ahmed A.; Kadhum, Abdul Amir H.; Reda, Khalid S.; Ahmed, Wahab K.

2018-03-01

The corrosion inhibition effectiveness of thiosemicarbazide compound, namely 3-nitro-5-(2-amino-1,3,4-thiadiazolyl)nitrobenzene (NATN), on mild steel in 1 M hydrochloric acid media has been investigated by weight loss technique. The results exhibit that the corrosion ratio of mild steel was reduced regarding to adding NATN. The corrosion inhibition rate for the NATN was 92.3% at the highest investigated NATN concentration. From the weight loss results it could be concluded that NATN with sulfur, nitrogen and oxygen atoms has clarified best corrosion inhibition achievement comparing to 3,5-dinitrobenzoic acid. Regarding to theoretical studies, DFT was employee to figured geometrical structure and electronic characteristics on NATN. The investigation have been extensive to the HOMO and LUMO analysis to evaluate the energy gap, Ionization potential, Electron Affinity, Global Hardness, Chemical Potential, Electrophilicity, Electronegativity and Polarizability.

Adsorption and inhibitive properties of Tryptophan on low alloy steel corrosion in acidic media

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Hesham T.M. Abdel-Fatah

2017-02-01

Corrosion inhibition was studied using electrochemical methods (electrochemical impedance spectroscopy; EIS and the new technique electrochemical frequency modulation; EFM and weight loss measurements. The influence of inhibitor concentration, solution temperature, and immersion time on the corrosion resistance of low alloy steel (LAS has been investigated. Trp proved to be a very good inhibitor for low alloy steel acid corrosion. EFM measurements showed that Trp is a mixed type inhibitor. Trp behaved better in 0.6 M HCl than in 0.6 M HSO3NH2. Moreover, it was found that the inhibition efficiency increased with increasing inhibitor concentration, while a decrease was detected with the rise of temperature and immersion time. The associated activation energy (Ea has been determined. The values of Ea indicate that the type of adsorption of Trp on the steel surface in both acids belongs to physical adsorption. The adsorption process was tested using Temkin adsorption isotherm.

Corrosion Inhibition of Mild Steel in Hydrochloric Acid by Sodium Lauryl Sulfate (SLS

Directory of Open Access Journals (Sweden)

Atul Kumar

2008-01-01

Full Text Available Effect of Sodium Lauryl Sulfate (SLS, a surfactant on corrosion of mild steel in 1 M hydrochloric acid was studied using three techniques namely: weight loss, electrochemical polarization and metallurgical research microscopy. Results obtained reveal that SLS is good inhibitor and shows very good corrosion inhibition efficiency (IE. The IE was found to vary with concentration of inhibitor and temperature. The electrochemical polarization result revealed that SLS is anodic in nature.

Experimental and quantum chemical studies on corrosion inhibition ...

Indian Academy of Sciences (India)

Abstract. The corrosion inhibition effect of fluconazole (FLU) was investigated on steel in 1 M hydrochloric acid solution. Weight loss measurements and atomic force microscope analysis were utilized to investigate the corrosion inhibition properties and film formation behaviour of FLU. Quantum chemical approach was also ...

Experimental and quantum chemical studies on corrosion inhibition

Indian Academy of Sciences (India)

The corrosion inhibition effect of fluconazole (FLU) was investigated on steel in 1 M hydrochloric acid solution. Weight loss measurements and atomic force microscope analysis were utilized to investigate the corrosion inhibition properties and film formation behaviour of FLU. Quantum chemical approach was also used to ...

Effect of Adenine Concentration on the Corrosion Inhibition of Aisi ...

African Journals Online (AJOL)

This gave a surface coverage of 0.8956 and corrosion penetration rate of 0.022132mm/yr. Hence, the best adenine concentration for the corrosion inhibition of alloys 304L in 1.0M sulphuric acid solution to obtain optimum inhibition efficiency is 0.011M. Keywords: Corrosion, AISI 304L Steel, Inhibition efficiency, Degree of ...

Study of Temperature Effect on the Corrosion Inhibition of C38 Carbon Steel Using Amino-tris(Methylenephosphonic Acid in Hydrochloric Acid Solution

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Najoua Labjar

2011-01-01

Full Text Available Tafel polarization method was used to assess the corrosion inhibitive and adsorption behaviours of amino-tris(methylenephosphonic acid (ATMP for C38 carbon steel in 1 M HCl solution in the temperature range from 30 to 60∘C. It was shown that the corrosion inhibition efficiency was found to increase with increase in ATMP concentration but decreased with temperature, which is suggestive of physical adsorption mechanism. The adsorption of the ATMP onto the C38 steel surface was found to follow Langmuir adsorption isotherm model. The corrosion inhibition mechanism was further corroborated by the values of kinetic and thermodynamic parameters obtained from the experimental data.

Organic compounds as corrosion inhibitors for mild steel in acidic media: correlation between inhibition efficiency and chemical structure

Energy Technology Data Exchange (ETDEWEB)

Elias, Elizandra C.S.; Chrisman, Erika C.A.N. [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil). Escola de Quimica

2009-12-19

The use of inhibitors for mild steels corrosion control which are in contact with aggressive environment is an accepted practice in acid treatment of oil-wells. Organic compounds have been studied to evaluate their corrosion inhibition potential. Film-forming corrosion inhibitors, commonly used to protect oil-field equipment, can be absorbed on the steel surface to give structurally ordered layers. Therefore, the electrons should act as an important role for this adsorption. Studies reveal that organic compounds show significant inhibition efficiency. For this purpose, their molecules should contain N, O and S heteroatoms in various functional groups, long hydrocarbon linear or branched radical and anion and cation active components. However, most of these compounds are not only expensive but also toxic to living beings. According to the 'Green Chemistry' rules, corrosion inhibitors based on organic compounds should be cheap, with low toxicity and have high inhibition efficiency. In this study, the effects of some organic compounds with different groups such as amide, ether, phenyldiamine, anime and aminophenol on the corrosion behavior of mild steel in acidic media have been investigated. The experimental data were obtained by gravimetric measurements. The results show that these compounds reveal a promising corrosion inhibition where phenyldiamine is the most efficient. The effect of molecular structure on the corrosion inhibition efficiency was investigated by semi-empirical quantum chemical calculations. The electronic properties such as highest occupied molecular orbital (HOMO), lowest unoccupied molecular orbital (LUMO) energy levels, and LUMO-HOMO energy gap orbital density were calculated. The relations between the inhibition efficiency and some quantum parameters are discussed and correlations are proposed. The highest values for the HOMO densities were found in the vicinity nitrogen atom, indicating that it is the most probable adsorption center

Inhibition treatment of the corrosion of lead artefacts in atmospheric conditions and by acetic acid vapour: use of sodium decanoate

International Nuclear Information System (INIS)

Rocca, E.; Rapin, C.; Mirambet, F.

2004-01-01

The efficiency of linear sodium decanoate, CH 3 (CH 2 ) 8 COONa (noted NaC 10 ), as corrosion inhibitor of lead was determined by electrochemical techniques in two corrosive mediums: ASTM D1384 standard water and acetic acid-enriched solutions. Best results were obtained with 0.05 mol l -1 of NaC 10 solution. In these conditions, the inhibition efficiency can be estimated of 99.9%. The corrosion inhibition effect was confirmed by cyclic atmospheric tests in a climatic chamber in two different conditions: water saturated vapour, and acid acetic enriched vapour simulating the atmosphere in the wooden displays in museums. Surface analyses by SEM and X-ray diffraction indicate that the metal protection is due to the formation of a protective layer mainly composed of lead decanoate Pb(C 10 ) 2 (metallic soap). This inhibition treatment was applied on objects of metallic cultural heritage: gallo-roman sarcophagus in lead. Electrochemical methods confirm the efficiency of treatment on archaeological materials. In conclusion, this inhibitor treatment seems to be very promising against the atmospheric corrosion and the corrosion by organic acid vapour in museums

Inhibition of aluminum corrosion using Opuntia extract

International Nuclear Information System (INIS)

El-Etre, A.Y.

2003-01-01

The inhibitive action of the mucilage extracted from the modified stems of prickly pears, toward acid corrosion of aluminum, is tested using weight loss, thermometry, hydrogen evolution and polarization techniques. It was found that the extract acts as a good corrosion inhibitor for aluminum corrosion in 2.0 M HCl solution. The inhibition action of the extract was discussed in view of Langmuir adsorption isotherm. It was found that the adsorption of the extract on aluminum surface is a spontaneous process. The inhibition efficiency (IE) increases as the extract concentration is increased. The effect of temperature on the IE was studied. It was found that the presence of extract increases the activation energy of the corrosion reaction. Moreover, the thermodynamic parameters of the adsorption process were calculated. It was found also that the Opuntia extract provides a good protection to aluminum against pitting corrosion in chloride ion containing solutions

Kinetics of Corrosion Inhibition of Aluminum in Acidic Media by Water-Soluble Natural Polymeric Pectates as Anionic Polyelectrolyte Inhibitors.

Science.gov (United States)

Hassan, Refat M; Zaafarany, Ishaq A

2013-06-17

Corrosion inhibition of aluminum (Al) in hydrochloric acid by anionic polyeletrolyte pectates (PEC) as a water-soluble natural polymer polysaccharide has been studied using both gasometric and weight loss techniques. The results drawn from these two techniques are comparable and exhibit negligible differences. The inhibition efficiency was found to increase with increasing inhibitor concentration and decrease with increasing temperature. The inhibition action of PEC on Al metal surface was found to obey the Freundlich isotherm. Factors such as the concentration and geometrical structure of the inhibitor, concentration of the corrosive medium, and temperature affecting the corrosion rates were examined. The kinetic parameters were evaluated and a suitable corrosion mechanism consistent with the kinetic results is discussed in the paper.

Kinetics of Corrosion Inhibition of Aluminum in Acidic Media by Water-Soluble Natural Polymeric Pectates as Anionic Polyelectrolyte Inhibitors

Directory of Open Access Journals (Sweden)

Refat M. Hassan

2013-06-01

Full Text Available Corrosion inhibition of aluminum (Al in hydrochloric acid by anionic polyeletrolyte pectates (PEC as a water-soluble natural polymer polysaccharide has been studied using both gasometric and weight loss techniques. The results drawn from these two techniques are comparable and exhibit negligible differences. The inhibition efficiency was found to increase with increasing inhibitor concentration and decrease with increasing temperature. The inhibition action of PEC on Al metal surface was found to obey the Freundlich isotherm. Factors such as the concentration and geometrical structure of the inhibitor, concentration of the corrosive medium, and temperature affecting the corrosion rates were examined. The kinetic parameters were evaluated and a suitable corrosion mechanism consistent with the kinetic results is discussed in the paper.

Synergistic inhibition between o-phenanthroline and chloride ion for steel corrosion in sulphuric acid

International Nuclear Information System (INIS)

Li Xueming; Tang Libin; Li Lin; Mu Guannan; Liu Guangheng

2006-01-01

The corrosion inhibition of cold rolled steel in 0.5 M sulphuric acid in the presence of o-phenanthroline and sodium chloride (NaCl) has been investigated by using weight loss and electrochemical techniques. The experimental data suggest that the inhibition efficiency increases with increasing NaCl concentration in the presence of 0.0002 M o-phenanthroline, but decreases with increasing temperature. A synergistic effect is observed when o-phenanthroline and chloride ions are used together to prevent cold rolled steel corrosion in 0.5 M sulphuric acid. The polarization curves showed that the complex of o-phenanthroline and NaCl acts as a mixed type inhibitor. The experimental results suggested that the presence of chloride ions in the solution stabilized the adsorption of o-phenanthroline molecules on the metal surface and improved the inhibition efficiency of o-phenanthroline. The adsorption of the complex accords with the Langmuir adsorption isotherm. Some thermodynamic parameters such as adsorption heat, adsorption entropy and adsorption free energy have been calculated by employing thermodynamic equations. Kinetic parameters such as apparent activation energy and pre-exponential factor have been calculated and discussed

Corrosion inhibition of mild steel in 1 M HCl solution by henna extract: A comparative study of the inhibition by henna and its constituents (Lawsone, Gallic acid, {alpha}-D-Glucose and Tannic acid)

Energy Technology Data Exchange (ETDEWEB)

Ostovari, A. [Technical Inspection Engineering Department, Petroleum University of Technology, Abadan (Iran, Islamic Republic of)], E-mail: A.Ostovari@gmail.com; Hoseinieh, S.M.; Peikari, M. [Technical Inspection Engineering Department, Petroleum University of Technology, Abadan (Iran, Islamic Republic of); Shadizadeh, S.R. [Petroleum Engineering Department, Petroleum University of Technology, Abadan (Iran, Islamic Republic of); Hashemi, S.J. [Technical Inspection Engineering Department, Petroleum University of Technology, Abadan (Iran, Islamic Republic of)

2009-09-15

The inhibitive action of henna extract (Lawsonia inermis) and its main constituents (lawsone, gallic acid, {alpha}-D-Glucose and tannic acid) on corrosion of mild steel in 1 M HCl solution was investigated through electrochemical techniques and surface analysis (SEM/EDS). Polarization measurements indicate that all the examined compounds act as a mixed inhibitor and inhibition efficiency increases with inhibitor concentration. Maximum inhibition efficiency (92.06%) is obtained at 1.2 g/l henna extract. Inhibition efficiency increases in the order: lawsone > henna extract > gallic acid > {alpha}-D-Glucose > tannic acid. Also, inhibition mechanism and thermodynamic parameters are discussed.

Corrosion inhibition of mild steel in 1 M HCl solution by henna extract: A comparative study of the inhibition by henna and its constituents (Lawsone, Gallic acid, α-D-Glucose and Tannic acid)

International Nuclear Information System (INIS)

Ostovari, A.; Hoseinieh, S.M.; Peikari, M.; Shadizadeh, S.R.; Hashemi, S.J.

2009-01-01

The inhibitive action of henna extract (Lawsonia inermis) and its main constituents (lawsone, gallic acid, α-D-Glucose and tannic acid) on corrosion of mild steel in 1 M HCl solution was investigated through electrochemical techniques and surface analysis (SEM/EDS). Polarization measurements indicate that all the examined compounds act as a mixed inhibitor and inhibition efficiency increases with inhibitor concentration. Maximum inhibition efficiency (92.06%) is obtained at 1.2 g/l henna extract. Inhibition efficiency increases in the order: lawsone > henna extract > gallic acid > α-D-Glucose > tannic acid. Also, inhibition mechanism and thermodynamic parameters are discussed.

Corrosion Inhibition and Adsorption Behavior of Clove Oil on Iron in Acidic Medium

Directory of Open Access Journals (Sweden)

Archana Saxena

2012-01-01

Full Text Available Corrosion behavior of iron in hydrochloric acid solution was studied using weight loss as well Scanning electron microscopy study without and with clove oil. The percentage inhibition efficiency increases with increasing clove oil concentration. All the data revel that the oil acts as an excellent inhibitor for the corrosion of iron in HCl solution. Thermodynamic, kinetic parameters and equilibrium constant for adsorption process were calculated from the experimental data. The adsorption of clove oil on experimental metals was found to follow the Langmuir adsorption isotherm at all the concentration studies. Scanning electron microscope (SEM, investigations also indicate that clove oil greatly lowers the dissolution currents.

Electrochemical study of corrosion inhibition of stainless steel in phosphoric medium

Energy Technology Data Exchange (ETDEWEB)

Hnini, K.; Chtaini, A. [Laboratoire d' Electrochimie et de Bio Corrosion, Faculte des Sciences et Techniques, Beni-Mellal (Morocco); Khouili, M.; Elbouadili, A. [Laboratoire de Chimie Organique et Analytique, Faculte des Sciences et Techniques, Beni-Mellal (Morocco)

2004-07-01

The corrosion of metals represents a terrible waste of both natural resources and money, the failure of some stainless steel resulting from pitting corrosion is some times considered a technological problem, consequently, much effort has been expended in attempting to understand and overcome the corrosion therefore, many stainless steel/ environment combinations have been studied. The use of heterocyclic compounds as inhibitors is one of the most practical methods for protection against corrosion in acidic media. In continuation of our work on development of macrocyclic compounds as corrosion inhibitors we report in our study the corrosion inhibiting behaviour of organic compound Methoxy-2-Allyl-4 Phenol (MAP) containing coordinating and conjugation groups, at three forms (natural, polymerized and chemically treated) on the corrosion of stainless steel in phosphoric acid. This study focused on the comparison for corrosion inhibition proprieties of these different applications using potentiodynamic polarization, electrochemical impedance spectroscopy and SEM. The specimen was evaluated to determine change in his corrosion potential and resistance polarization; These MAP products have exhibited corrosion inhibition by maintaining a high resistance polarization (low corrosion rate) in each application. These results reveal that this compound is efficient inhibitor in all forms; the most inhibition efficiency is obtained with polymerized form. To further evaluate the test data, the steel surfaces were analyzed using scanning electron microscopy, SEM observations of surface treated concrete confirmed presence of inhibitor on the steel surfaces. (authors)

Surface coverage and corrosion inhibition effect of Rosmarinus officinalis and zinc oxide on the electrochemical performance of low carbon steel in dilute acid solutions

Directory of Open Access Journals (Sweden)

Roland Tolulope Loto

2018-03-01

Full Text Available Electrochemical analysis of the corrosion inhibition and surface protection properties of the combined admixture of Rosmarinus officinalis and zinc oxide on low carbon steel in 1 M HCl and H2SO4 solution was studied by potentiodynamic polarization, open circuit potential measurement, optical microscopy and ATR-FTIR spectroscopy. Results obtained confirmed the compound to be more effective in HCl solution, with optimal inhibition efficiencies of 93.26% in HCl and 87.7% in H2SO4 acid solutions with mixed type inhibition behavior in both acids. The compound shifts the corrosion potential values of the steel cathodically in HCl and anodically in H2SO4 signifying specific corrosion inhibition behavior without applied potential. Identified functional groups of alcohols, phenols, 1°, 2° amines, amides, carbonyls (general, esters, saturated aliphatic, carboxylic acids, ethers, aliphatic amines, alkenes, aromatics, alkyl halides and alkynes within the compound completely adsorbed onto the steel forming a protective covering. Thermodynamic calculations showed physisorption molecular interaction with the steel’s surface according to Langmuir and Frumkin adsorption isotherms. Optical microscopy images of the inhibited and uninhibited steels contrast each other with steel specimens from HCl solution showing a better morphology. Keywords: Corrosion, Inhibitor, Adsorption, Steel, Acid

Nontoxic corrosion inhibitors for N80 steel in hydrochloric acid

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M. Yadav

2016-11-01

Full Text Available The purpose of this paper is to evaluate the protective ability of 1-(2-aminoethyl-2-oleylimidazoline (AEOI and 1-(2-oleylamidoethyl-2-oleylimidazoline (OAEOI as corrosion inhibitors for N80 steel in 15% hydrochloric acid, which may find application as eco-friendly corrosion inhibitors in acidizing processes in petroleum industry. Different concentrations of synthesized inhibitors AEOI and OAEOI were added to the test solution (15% HCl and the corrosion inhibition of N80 steel in hydrochloric acid medium containing inhibitors was tested by weight loss, potentiodynamic polarization and AC impedance measurements. Influence of temperature (298–323 K on the inhibition behavior was studied. Surface studies were performed by using FTIR spectra and SEM. Both the inhibitors, AEOI and OAEOI at 150 ppm concentration show maximum efficiency 90.26% and 96.23%, respectively at 298 K in 15% HCl solution. Both the inhibitors act as mixed corrosion inhibitors. The adsorption of the corrosion inhibitors at the surface of N80 steel is the root cause of corrosion inhibition.

Evaluation of the inhibitive effect of some plant extracts on the acid corrosion of mild steel

International Nuclear Information System (INIS)

Oguzie, Emeka E.

2008-01-01

Corrosion inhibition of mild steel in 2 M HCl and 1 M H 2 SO 4 by extracts of selected plants was investigated using a gasometric technique at temperatures of 30 and 60 deg. C. The studied plants materials include leaf extracts Occimum viridis (OV), Telferia occidentalis (TO), Azadirachta indica (AI) and Hibiscus sabdariffa (HS) as well as extracts from the seeds of Garcinia kola (GK). The results indicate that all the extracts inhibited the corrosion process in both acid media by virtue of adsorption and inhibition efficiency improved with concentration. Synergistic effects increased the inhibition efficiency in the presence of halide additives. Inhibition mechanisms were deduced from the temperature dependence of the inhibition efficiency as well as from assessment of kinetic and activation parameters that govern the processes. Comparative analysis of the inhibitor adsorption behaviour in 2 M HCl and 1 M H 2 SO 4 as well as the effects of temperature and halide additives suggest that both protonated and molecular species could be responsible for the inhibiting action of the extracts

Evaluation of the inhibitive effect of some plant extracts on the acid corrosion of mild steel

Energy Technology Data Exchange (ETDEWEB)

Oguzie, Emeka E. [Electrochemistry and Materials Science Research Laboratory, Department of Chemistry, Federal University of Technology, PMB 1526, Owerri (Nigeria)], E-mail: oguziemeka@yahoo.com

2008-11-15

Corrosion inhibition of mild steel in 2 M HCl and 1 M H{sub 2}SO{sub 4} by extracts of selected plants was investigated using a gasometric technique at temperatures of 30 and 60 deg. C. The studied plants materials include leaf extracts Occimum viridis (OV), Telferia occidentalis (TO), Azadirachta indica (AI) and Hibiscus sabdariffa (HS) as well as extracts from the seeds of Garcinia kola (GK). The results indicate that all the extracts inhibited the corrosion process in both acid media by virtue of adsorption and inhibition efficiency improved with concentration. Synergistic effects increased the inhibition efficiency in the presence of halide additives. Inhibition mechanisms were deduced from the temperature dependence of the inhibition efficiency as well as from assessment of kinetic and activation parameters that govern the processes. Comparative analysis of the inhibitor adsorption behaviour in 2 M HCl and 1 M H{sub 2}SO{sub 4} as well as the effects of temperature and halide additives suggest that both protonated and molecular species could be responsible for the inhibiting action of the extracts.

Kinetics of corrosion inhibition of aluminum in acidic media by water-soluble natural polymeric chondroitin-4-sulfate as anionic polyelectrolyte inhibitor.

Science.gov (United States)

Hassan, Refat M; Ibrahim, Samia M; Takagi, Hideo D; Sayed, Suzan A

2018-07-15

Corrosion inhibition of aluminum (Al) in hydrochloric acid by anionic polyelectrolyte chondroitin-4-sulfate (CS) polysaccharide has been studied using both gasometrical and weight-loss techniques. The results drawn from these two techniques are comparable and exhibit negligible differences. The inhibition efficiency was found to increase with increasing the inhibitor concentration and decreased with increasing temperature. The inhibition action of CS on Al metal surface was found to obey both of Langmuir and Freundlich isotherms. The factors affecting the corrosion rates such as the concentration and geometrical structure of the inhibitor, concentration of the corrosive medium, and the temperature were examined. The kinetic parameters were evaluated and a suitable corrosion mechanism consistent with the results obtained is discussed. Copyright © 2018. Published by Elsevier Ltd.

Corrosion behavior of corrosion resistant alloys in stimulation acids

Energy Technology Data Exchange (ETDEWEB)

Cheldi, Tiziana [ENI E and P Division, 20097 San Donato Milanese Milano (Italy); Piccolo, Eugenio Lo; Scoppio, Lucrezia [Centro Sviluppo Materiali, via Castel Romano 100, 00128 Rome (Italy)

2004-07-01

In the oil and gas industry, selection of CRAs for downhole tubulars is generally based on resistance to corrosive species in the production environment containing CO{sub 2}, H{sub 2}S, chloride and in some case elemental sulphur. However, there are non-production environments to which these materials must also be resistant for either short term or prolonged duration; these environments include stimulation acids, brine and completion fluids. This paper reports the main results of a laboratory study performed to evaluate the corrosion and stress corrosion behaviour to the acidizing treatments of the most used CRAs for production tubing and casing. Laboratory tests were performed to simulate both 'active' and 'spent' acids operative phases, selecting various environmental conditions. The selected steel pipes were a low alloyed steel, martensitic, super-martensitic, duplex 22 Cr, superduplex 25 Cr and super-austenitic stainless steels (25 Cr 35 Ni). Results obtained in the 'active' acid environments over the temperature range of 100-140 deg. C, showed that the blend acids with HCl at high concentration and HCl + HF represented too much severe conditions, where preventing high general corrosion and heavy localised corrosion by inhibition package becomes very difficult, especially for duplex steel pipe, where, in some case, the specimens were completely dissolved into the solution. On the contrary, all steels pipes were successfully protected by inhibitor when organic acid solution (HCOOH + CH{sub 3}COOH) were used. Furthermore, different effectiveness on corrosion protection was showed by the tested inhibitors packages: e.g. in the 90% HCl at 12% + 10 CH{sub 3}COOH acid blend. In 'spent' acid environments, all steel pipes showed to be less susceptible to the localised and general corrosion attack. Moreover, no Sulphide Stress Corrosion Cracking (SSC) was observed. Only one super-austenitic stainless steel U-bend specimen showed

Synergistic Effect on Corrosion Inhibition Efficiency of Ginger Affinale Extract in Controlling Corrosion of Mild Steel in Acid Medium

International Nuclear Information System (INIS)

Subramanian, Ananth Kumar; Arumugam, Sankar; Mallaiya, Kumaravel; Subramaniam, Rameshkumar

2013-01-01

The corrosion inhibition nature of Ginger affinale extract for the corrosion of mild steel in 0.5N H 2 SO 4 was investigated using weight loss, electrochemical impedance and potentiodynamic polarization methods. The results revealed that Ginger affinale extract acts as a good corrosion inhibitor in 0.5N H 2 SO 4 medium. The inhibition efficiency increased with an increase in inhibitor concentration. The inhibition could be attributed to the adsorption of the inhibitor on the steel surface

Synergistic Effect on Corrosion Inhibition Efficiency of Ginger Affinale Extract in Controlling Corrosion of Mild Steel in Acid Medium

Energy Technology Data Exchange (ETDEWEB)

Subramanian, Ananth Kumar; Arumugam, Sankar [Kandaswami Kandar' s College, Namakkal (India); Mallaiya, Kumaravel; Subramaniam, Rameshkumar [PSG College of Technology Peelamedu, Coimbatore (India)

2013-12-15

The corrosion inhibition nature of Ginger affinale extract for the corrosion of mild steel in 0.5N H{sub 2}SO{sub 4} was investigated using weight loss, electrochemical impedance and potentiodynamic polarization methods. The results revealed that Ginger affinale extract acts as a good corrosion inhibitor in 0.5N H{sub 2}SO{sub 4} medium. The inhibition efficiency increased with an increase in inhibitor concentration. The inhibition could be attributed to the adsorption of the inhibitor on the steel surface.

Corrosion Inhibition of Carbon Steel in HCl Solution by Some Plant Extracts

Directory of Open Access Journals (Sweden)

Ambrish Singh

2012-01-01

Full Text Available The strict environmental legislations and increasing ecological awareness among scientists have led to the development of “green” alternatives to mitigate corrosion. In the present work, literature on green corrosion inhibitors has been reviewed, and the salient features of our work on green corrosion inhibitors have been highlighted. Among the studied leaves, extract Andrographis paniculata showed better inhibition performance (98% than the other leaves extract. Strychnos nuxvomica showed better inhibition (98% than the other seed extracts. Moringa oleifera is reflected as a good corrosion inhibitor of mild steel in 1 M HCl with 98% inhibition efficiency among the studied fruits extract. Bacopa monnieri showed its maximum inhibition performance to be 95% at 600 ppm among the investigated stem extracts. All the reported plant extracts were found to inhibit the corrosion of mild steel in acid media.

Corrosion inhibition of carbon steel in acidic medium by orange peel extract and its main antioxidant compounds

International Nuclear Information System (INIS)

M’hiri, Nouha; Veys-Renaux, Delphine; Rocca, Emmanuel; Ioannou, Irina; Boudhrioua, Nourhéne Mihoubi; Ghoul, Mohamed

2016-01-01

Highlights: • Catechol and derived functions are responsible for flavonoids antioxidant activity. • Antioxidant activity of adsorbed molecules explains cathodic inhibition. • Orange peel extract inhibition is enhanced by the precipitation of a covering film. - Abstract: Chemical compounds of orange peel extracts were identified and their antioxidant activities were determined. The inhibiting effect on acidic steel corrosion brought by the extract and selected antioxidant compounds (neohesperidin, naringin, ascorbic acid) was evaluated separately by electrochemical methods. Whatever the extract concentration, a significant inhibition is observed, whereas selected antioxidant compounds show only a slight effect. Both electrochemical impedance spectroscopy results and scanning electron microscopy observations after immersion reveal that the inhibiting efficiency of orange peel extract is not only due to the antioxidant activity of its compounds but also to the precipitation of a surface film.

Corrosion of alloy C-22 in organic acid solutions

International Nuclear Information System (INIS)

Carranza, Ricardo M.; Rodriguez, Martin A.; Giordano, Celia M.

2007-01-01

Electrochemical studies such as cyclic potentiodynamic polarization (CPP) and electrochemical impedance spectroscopy (EIS) were performed to determine the corrosion behavior of Alloy 22 (N06022) in 1M NaCl solutions at various pH values from acidic to neutral at 90 C degrees. All the tested material was wrought Mill Annealed (MA). Tests were also performed in NaCl solutions containing weak organic acids such as oxalic, acetic, citric and picric acids. Results show that the corrosion rate of Alloy 22 was significantly higher in solutions containing oxalic acid than in solutions of pure NaCl at the same pH. Citric and Picric acids showed a slightly higher corrosion rate, and Acetic acid maintained the corrosion rate of pure chloride solutions at the same pH. Organic acids revealed to be weak inhibitors for crevice corrosion. Higher concentration ratios, compared to nitrate ions, were needed to completely inhibit crevice corrosion in chloride solutions. Results are discussed considering acid dissociation constants, buffer capacity and complex formation constants of the different weak acids. (author) [es

Corrosion inhibition properties of pyrazolylindolenine compounds on copper surface in acidic media

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Ebadi Mehdi

2012-12-01

Full Text Available Abstract Background The corrosion inhibition performance of pyrazolylindolenine compounds, namely 4-(3,3-dimethyl-3H-indol-2-yl-pyrazole-1-carbothioamide (InPzTAm, 4-(3,3-dimethyl-3H-indol-2-yl-1H-pyrazole-1-carbothiohydrazide (InPzTH and 3,3-dimethyl-2-(1-phenyl-1H-pyrazol-4-yl-3H-indole (InPzPh, on copper in 1M HCl solution is investigated by electrochemical impedance spectroscopy (EIS, open circuit potential (OCP and linear scan voltammetry (LSV techniques. Results The results show that the corrosion rate of copper is diminished by the compounds with the inhibition strength in the order of: InPzTAm> InPzTH > InPzPh. The corrosion inhibition efficiencies for the three inhibitors are 94.0, 91.4 and 79.3, for InPzTAm, InPzTH and InPzPh respectively with the same inhibitor concentration (2 mM. Conclusion From the EIS, OCP and LSV results it was concluded that pyrazolylindolenine compounds with S-atom (with an amine group have illustrated better corrosion inhibition performance compared to hydrazine and phenyl group.

Surface coverage and corrosion inhibition effect of Rosmarinus officinalis and zinc oxide on the electrochemical performance of low carbon steel in dilute acid solutions

Science.gov (United States)

Loto, Roland Tolulope

2018-03-01

Electrochemical analysis of the corrosion inhibition and surface protection properties of the combined admixture of Rosmarinus officinalis and zinc oxide on low carbon steel in 1 M HCl and H2SO4 solution was studied by potentiodynamic polarization, open circuit potential measurement, optical microscopy and ATR-FTIR spectroscopy. Results obtained confirmed the compound to be more effective in HCl solution, with optimal inhibition efficiencies of 93.26% in HCl and 87.7% in H2SO4 acid solutions with mixed type inhibition behavior in both acids. The compound shifts the corrosion potential values of the steel cathodically in HCl and anodically in H2SO4 signifying specific corrosion inhibition behavior without applied potential. Identified functional groups of alcohols, phenols, 1°, 2° amines, amides, carbonyls (general), esters, saturated aliphatic, carboxylic acids, ethers, aliphatic amines, alkenes, aromatics, alkyl halides and alkynes within the compound completely adsorbed onto the steel forming a protective covering. Thermodynamic calculations showed physisorption molecular interaction with the steel's surface according to Langmuir and Frumkin adsorption isotherms. Optical microscopy images of the inhibited and uninhibited steels contrast each other with steel specimens from HCl solution showing a better morphology.

Influence of poly(aminoquinone) on corrosion inhibition of iron in acid media

Science.gov (United States)

Jeyaprabha, C.; Sathiyanarayanan, S.; Phani, K. L. N.; Venkatachari, G.

2005-11-01

The inhibitor performance of chemically synthesized water soluble poly(aminoquinone) (PAQ) on iron corrosion in 0.5 M sulphuric acid was studied in relation to inhibitor concentration using potentiodynamic polarization and electrochemical impedance spectroscopy measurements. On comparing the inhibition performance of PAQ with that of the monomer o-phenylenediamine (OPD), the OPD gave an efficiency of 80% for 1000 ppm while it was 90% for 100 ppm of PAQ. PAQ was found to be a mixed inhibitor. Besides, PAQ was able to improve the passivation tendency of iron in 0.5 M H 2SO 4 markedly.

Green approach to corrosion inhibition of mild steel in two acidic solutions by the extract of Punica granatum peel and main constituents

Energy Technology Data Exchange (ETDEWEB)

Behpour, M., E-mail: m.behpour@kashanu.ac.ir [Department of Analytical Chemistry, Faculty of Chemistry, University of Kashan, Kashan, I.R. 87317-51167 (Iran, Islamic Republic of); Ghoreishi, S.M.; Khayatkashani, M. [Department of Analytical Chemistry, Faculty of Chemistry, University of Kashan, Kashan, I.R. 87317-51167 (Iran, Islamic Republic of); Soltani, N. [Department of Chemistry, Payame Noor University (PNU), 19395-4697 Tehran (Iran, Islamic Republic of)

2012-01-05

Graphical abstract: Ellagic acid (EA) and tannic acid (TA) were studied as corrosion inhibitors. The electron density HOMO and LUMO of EA and TA were used to explain difference in behavior of them. Highlights: Black-Right-Pointing-Pointer The extract of Punica granatum (PG) and their main constituent (ellagic acid (EA)) are found to be good inhibitors for the corrosion of mild steel in 1 M H{sub 2}SO{sub 4} and 2 M HCl. Black-Right-Pointing-Pointer The electrochemical inhibitive mechanism is explained by potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS) results. Black-Right-Pointing-Pointer The adsorption of ALLOX on mild steel surface was found to accord with the Temkin adsorption isotherm. Black-Right-Pointing-Pointer The effect of temperature on the corrosion behavior of mild steel in 2 M HCl and 1 M H{sub 2}SO{sub 4} without and with the PG extract was studied. - Abstract: The effect of the extract of Punica granatum (PG) and their main constituents involve ellagic acid (EA) and tannic acid (TA), as mild steel corrosion inhibitor in 2 M HCl and 1 M H{sub 2}SO{sub 4} solutions was investigated by weight loss measurements. The results obtained from the weight loss measurements show that the inhibition efficiency of TA even in high concentration is very low. Thus, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) investigations were used for different concentrations of PG and EA and best concentration of TA. Potentiodynamic polarization curves indicated that PG and EA behave as mixed-type inhibitors. EIS measurements show an increase of the transfer resistance with increasing inhibitor concentration. The temperature effect on the corrosion behavior of steel without and with the PG extract was studied. The inhibition action of the extract was discussed in view of Langmuir adsorption isotherm.

Green approach to corrosion inhibition of mild steel in two acidic solutions by the extract of Punica granatum peel and main constituents

International Nuclear Information System (INIS)

Behpour, M.; Ghoreishi, S.M.; Khayatkashani, M.; Soltani, N.

2012-01-01

Graphical abstract: Ellagic acid (EA) and tannic acid (TA) were studied as corrosion inhibitors. The electron density HOMO and LUMO of EA and TA were used to explain difference in behavior of them. Highlights: ► The extract of Punica granatum (PG) and their main constituent (ellagic acid (EA)) are found to be good inhibitors for the corrosion of mild steel in 1 M H 2 SO 4 and 2 M HCl. ► The electrochemical inhibitive mechanism is explained by potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS) results. ► The adsorption of ALLOX on mild steel surface was found to accord with the Temkin adsorption isotherm. ► The effect of temperature on the corrosion behavior of mild steel in 2 M HCl and 1 M H 2 SO 4 without and with the PG extract was studied. - Abstract: The effect of the extract of Punica granatum (PG) and their main constituents involve ellagic acid (EA) and tannic acid (TA), as mild steel corrosion inhibitor in 2 M HCl and 1 M H 2 SO 4 solutions was investigated by weight loss measurements. The results obtained from the weight loss measurements show that the inhibition efficiency of TA even in high concentration is very low. Thus, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) investigations were used for different concentrations of PG and EA and best concentration of TA. Potentiodynamic polarization curves indicated that PG and EA behave as mixed-type inhibitors. EIS measurements show an increase of the transfer resistance with increasing inhibitor concentration. The temperature effect on the corrosion behavior of steel without and with the PG extract was studied. The inhibition action of the extract was discussed in view of Langmuir adsorption isotherm.

Electrodeposited Organic Layers Formed from Aryl Diazonium Salts for Inhibition of Copper Corrosion

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Ana Chira

2017-02-01

Full Text Available Copper substrates deposed on a gold screen-printed electrode were covered with different aryl diazonium salts by electrodeposition at 0.25 mA for 30 or 300 s. Seven compounds were investigated: 4-aminophenylacetic acid, 4-aminophenethyl alcohol, 4-fluoroaniline, 4-(heptadecafluorooctylaniline, 4-aminoantipyrine, 4-(4-aminophenylbutyric acid and 3,4,5-trimethoxyaniline. Quantitative monitoring of the electrodeposition process was carried out by electrogravimetry using quartz crystal microbalance (QCM. The electrodeposited mass varies between 26 ng/cm2 for 4-fluoroaniline formed during 30 s to 442 ng/cm2 for 4-phenylbutyric acid formed during 300 s. The corrosion inhibition properties of aryl-modified layers have been studied in buffer citrate with pH = 3 or 3.5% NaCl solutions using electrochemical noise (ECN and Tafel potentiodynamic polarization measurements. A corrosion inhibiting efficiency up to 90% was found. The highest corrosion inhibition was obtained for 4-(4-aminophenylbutyric acid and the lowest for 4-fluoroaniline. A relation between the inhibition efficiency and the chemical nature of the substituents in the protective layer was found.

Electrodeposited Organic Layers Formed from Aryl Diazonium Salts for Inhibition of Copper Corrosion.

Science.gov (United States)

Chira, Ana; Bucur, Bogdan; Radu, Gabriel-Lucian

2017-02-28

Copper substrates deposed on a gold screen-printed electrode were covered with different aryl diazonium salts by electrodeposition at 0.25 mA for 30 or 300 s. Seven compounds were investigated: 4-aminophenylacetic acid, 4-aminophenethyl alcohol, 4-fluoroaniline, 4-(heptadecafluorooctyl)aniline, 4-aminoantipyrine, 4-(4-aminophenyl)butyric acid and 3,4,5-trimethoxyaniline. Quantitative monitoring of the electrodeposition process was carried out by electrogravimetry using quartz crystal microbalance (QCM). The electrodeposited mass varies between 26 ng/cm² for 4-fluoroaniline formed during 30 s to 442 ng/cm² for 4-phenylbutyric acid formed during 300 s. The corrosion inhibition properties of aryl-modified layers have been studied in buffer citrate with pH = 3 or 3.5% NaCl solutions using electrochemical noise (ECN) and Tafel potentiodynamic polarization measurements. A corrosion inhibiting efficiency up to 90% was found. The highest corrosion inhibition was obtained for 4-(4-aminophenyl)butyric acid and the lowest for 4-fluoroaniline. A relation between the inhibition efficiency and the chemical nature of the substituents in the protective layer was found.

Studies on the Inhibition of Mild Steel Corrosion by Rauvolfia serpentina in Acid Media

Science.gov (United States)

Bothi Raja, P.; Sethuraman, M. G.

2010-07-01

Alkaloid extract of Rauvolfia serpentina was tested as corrosion inhibitor for mild steel in 1 M HCl and H2SO4 using weight loss method at three different temperatures, viz., 303, 313, and 323 K, potentiodynamic polarization, electrochemical impedance spectroscopy and scanning electron microscope (SEM) studies. It is evident from the results of this study that R. serpentina effectively inhibits the corrosion in both the acids through adsorption process following Tempkin adsorption isotherm. The protection efficiency increased with increase in inhibitor concentration and temperature. Free energy of adsorption calculated from the temperature studies also revealed the chemisorption. The mixed mode of action exhibited by the inhibitor was confirmed by the polarization studies while SEM analysis substantiated the formation of protective layer over the mild steel surface.

A study of the inhibition of iron corrosion in HCl solutions by some amino acids

International Nuclear Information System (INIS)

Amin, Mohammed A.; Khaled, K.F.; Mohsen, Q.; Arida, H.A.

2010-01-01

The performance of three selected amino acids, namely alanine (Ala), cysteine (Cys) and S-methyl cysteine (S-MCys) as safe corrosion inhibitors for iron in aerated stagnant 1.0 M HCl solutions was evaluated by Tafel polarization and impedance measurements. Results indicate that Ala acts mainly as a cathodic inhibitor, while Cys and S-MCys function as mixed-type inhibitors. Cys, which contains a mercapto group in its molecular structure, was the most effective among the inhibitors tested, while Ala was less effective than S-MCys. The low inhibition efficiency recorded for S-MCys compared with that of Cys was attributed to steric effects caused by the substituent methyl on the mercapto group. Electrochemical frequency modulation (EFM) technique and inductively coupled plasma atomic emission spectrometry (ICP-AES), were also applied to make accurate determination of corrosion rates. Validation of the Tafel extrapolation method for measuring corrosion rates was tested. Rates of corrosion rates (in μm y -1 ) obtained from Tafel extrapolation method are in good agreement with those measured using EFM and ICP methods. Some theoretical studies, including molecular dynamics (MD) and density functional theory (DFT), were also employed to establish the correlation between the structure (molecular and electronic) of the three tested inhibitors and the inhibition efficiency. Adsorption via hydrogen bonding was discussed here based on some theoretical studies. Experimental and theoretical results were in good agreement.

Corrosion Inhibition of Aluminium by Treculia Africana Leaves Extract in Acid Medium

OpenAIRE

Ejikeme, P.M.; Umana, S.G.; Onukwuli, O.D.

2012-01-01

The inhibitive effect of Treculia Africana leaves extract (TALE) in the corrosion of aluminium in HCl solution was studied using weight loss and thermometric methods at 30-60 °C. The results showed that TALE acted as a corrosion inhibitor of aluminium in HCl. Inhibition efficiency increased with increase in TALE concentration, but decreased with increase in temperature. TALE interaction with the metal surface was found to obey Freundlich and El-Awady adsorption isotherms. The obtained heats o...

Modelling and Optimization of Corrosion Inhibition of Mild Steel in Phosphoric Acid by Red Pomegranate Peels Aqueous Extract

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Khalid Hamid Rashid

2011-11-01

Full Text Available Taguchi experimental design (TED is applied to find the optimum effectiveness of aqueous Red Pomegranate Peel (RPP extract as a green inhibitor for the corrosion of mild steel in 2M H3PO4 solution. The Taguchi methodology has been used to study the effects of changing, temperature, RPP concentration and contact period, at three levels. Weight-loss measurements were designed by construction a L9 orthogonal arrangement of experiments. Results of the efficiencies of inhibition were embraced for the signal to noise proportion & investigation of variance (ANOVA. The results were further processed with a MINITAB-17 software package to find the optimal conditions for inhibitor usage. Second order polynomial model was used for experimental data fitting. Optimum conditions for achieving the maximum corrosion inhibition efficiency are obtained from optimizing the above model and are found as follow: 39.66 °C temperature of acidic media, 38.29 ml/L inhibitor concentration and 2.95 h contact period. Results demonstrated that rate of corrosion was increased with temperature increasing & decreasing inhibitor concentration. It was concluded that the Taguchi design was adequately useful in the optimization of operating parameters and that RPP sufficiently inhibited the corrosion of steel at the range of variables studied.

Inhibition of the corrosion of steel in hydrochloric acid solution by some organic molecules containing the methylthiophenyl moiety

International Nuclear Information System (INIS)

Nataraja, S.E.; Venkatesha, T.V.; Manjunatha, K.; Poojary, Boja; Pavithra, M.K.; Tandon, H.C.

2011-01-01

Highlights: → Acid corrosion inhibition. → Work in small concentration. → Effective at higher temperature. → Effect of different functional groups, cyclisation and aromaticity. - Abstract: The corrosion inhibition effect of 2-[4-(methylthio) phenyl] acetohydrazide (HYD), 2-{[4-(methylthio) phenyl] acetyl} hydrazinecarbothioamide (TAD) and 5-[4-(methylthio) benzyl]-4H-1,2,4-triazole-3-thiol (TRD) on steel in 1.0 M HCl was investigated by mass loss and electrochemical methods. The effect of concentration, temperature and immersion time was studied. The results indicated that the compounds are efficient, mixed type and pursue Flory-Huggins adsorption isotherm. The inhibition efficiency at lower concentration of inhibitor decreased with temperature while at higher concentration, it is retained and the calculated free energy attributes this to comprehensive adsorption. The efficiency stands in the order TRD > TAD > HYD and is confirmed by the Quantum studies.

The Inhibition of Aluminum Corrosion in Sulfuric Acid by Poly(1-vinyl-3-alkyl-imidazolium Hexafluorophosphate).

Science.gov (United States)

Arellanes-Lozada, Paulina; Olivares-Xometl, Octavio; Guzmán-Lucero, Diego; Likhanova, Natalya V; Domínguez-Aguilar, Marco A; Lijanova, Irina V; Arce-Estrada, Elsa

2014-08-07

Compounds of poly(ionic liquid)s (PILs), derived from imidazole with different alkylic chain lengths located in the third position of the imidazolium ring (poly(1-vinyl-3-dodecyl-imidazolium) (PImC 12 ), poly(1-vinyl-3-octylimidazolium) (PImC₈) and poly(1-vinyl-3-butylimidazolium) (PImC₄) hexafluorophosphate) were synthesized. These compounds were tested as corrosion inhibitors on aluminum alloy AA6061 in diluted sulfuric acid (0.1-1 M H₂SO₄) by weight loss tests, polarization resistance measurements and inductively coupled plasma optical emission spectroscopy. Langmuir's isotherms suggested film formation on bare alloy while standard free energy indicated inhibition by a physisorption process. However, compound efficiencies as inhibitors ranked low (PImC 12 > PImC₈ > PImC₄) to reach 61% for PImC 12 in highly diluted acidic solution. Apparently, the high mobility of sulfates favored their adsorption in comparison to PILs. The surface film displayed general corrosion, and pitting occurred as a consequence of PILs' partial inhibition along with a continuous dissolution of defective patchy film on formation. A slight improvement in efficiency was displayed by compounds having high molecular weight and a long alkyl chain, as a consequence of steric hindrance and PIL interactions.

Ginger extract as green corrosion inhibitor of mild steel in hydrochloric acid solution

Science.gov (United States)

Fidrusli, A.; Suryanto; Mahmood, M.

2018-01-01

Ginger extract as corrosion inhibitor from natural resources was studied to prevent corrosion of mild steel in acid media. Ginger rhizome was extracted to produce green corrosion inhibitor (G-1) while ginger powder bought at supermarket was also extract to form green corrosion inhibitor (G-2). Effectiveness of inhibitor in preventing corrosion process of mild steel was studied in 1.0 M of hydrochloric acid. The experiment of weight loss method and polarization technique were conducted to measure corrosion rate and inhibition efficiency of mild steel in solution containing 1.0 M of hydrochloric acid with various concentration of inhibitor at room temperature. The results showed that, the rate of corrosion dropped from 8.09 mmpy in solution containing no inhibitor to 0.72 mmpy in solution containing 150g/l inhibitor while inhibition efficiency up to 91% was obtained. The polarization curve in polarization experiments shows that the inhibition efficiency is 86% with high concentration of inhibitor. The adsorption of ginger extract on the surface of mild steel was observed by using optical microscope and the characterization analysis was done by using pH measurement method. When high concentration of green inhibitor in the acid solution is used, the pH at the surface of steel is increasing.

Inhibitive Effect of Butyltin Trichloride on Dissolution and Localized Corrosion of Aluminium in Sodium Hydroxide and Hydrochloric Acid

OpenAIRE

Mourad, M.Y.; Ibrahim, E.H.; Seliman, S.A.

1990-01-01

The dissolution of aluminium in sodium hydroxide and hydrochloric acid in the presence of butyltin trichloride as corrosion inhibitor has been studied by hydrogen evolution and thermometric methods. Experimental findings indicate that the inhibition effect of butyltin trichloride takes place through an adsorption mechanism following the Frumkin's isotherm. Butyltin trichloride acts as a weakly adsorbed inhibitor in NaOH and as a strongly adsorbed inhibitor in hydrochloric acid medium. Wile...

Application of electrochemical frequency modulation for monitoring corrosion and corrosion inhibition of iron by some indole derivatives in molar hydrochloric acid

International Nuclear Information System (INIS)

Khaled, K.F.

2008-01-01

The corrosion inhibition effect of four indole derivatives, namely indole (IND), benzotriazole (BTA), benzothiazole (BSA) and benzoimidazole (BIA), have been used as possible corrosion inhibitors for pure iron in 1 M HCl. In this study, electrochemical frequency modulation, EFM was used as an effective method for corrosion rate determination in corrosion inhibition studies. By using EFM measurements, corrosion current density was determined without prior knowledge of Tafel slopes. Corrosion rates obtained using EFM, were compared to that obtained from other chemical and electrochemical techniques. The results obtained from EFM, EIS, Tafel and weight loss measurements were in good agreement. Tafel polarization measurements show that indole derivatives are cathodic-type inhibitors. Molecular simulation studies were applied to optimize the adsorption structures of indole derivatives. The inhibitor/iron/solvent interfaces were simulated and the adsorption energies of these inhibitors were calculated. Quantum chemical calculations have been performed and several quantum chemical indices were calculated and correlated with the corresponding inhibition efficiencies

Inhibition of Mild Steel Corrosion in Hydrochloric Acid Solution by New Coumarin

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Abdul Amir H. Kadhum

2014-06-01

Full Text Available A new coumarin derivative, N,N′-((2E,2′E-2,2′-(1,4-phenylenebis (methanylylidenebis(hydrazinecarbonothioylbis(2-oxo-2H-chromene-3-carboxamide PMBH, was synthesized and its chemical structure was elucidated and confirmed using spectroscopic techniques (Infrared spectroscopy IR, Proton nuclear  magnetic resonance, 1H-NMR and carbon-13 nuclear magnetic resonance 13C-NMR. The corrosion inhibition effect of PMBH on mild steel in 1.0 M HCl was investigated using corrosion potential (ECORR, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS, and electrochemical frequency modulation (EFM measurements. The obtained results indicated that PMBH has promising inhibitive effects on the corrosion of mild steel in 1.0 M HCl across all of the conditions examined. Scanning electron microscopy (SEM was used to investigate the morphology of the mild steel before and after immersion in 1.0 M HCl solution containing 0.5 mM of PMBH. Surface analysis revealed improvement of corrosion resistance in presence of PMBH.

Inhibition of Mild Steel Corrosion in Hydrochloric Acid Solution by New Coumarin

Science.gov (United States)

Kadhum, Abdul Amir H.; Mohamad, Abu Bakar; Hammed, Leiqaa A.; Al-Amiery, Ahmed A.; San, Ng Hooi; Musa, Ahmed Y.

2014-01-01

A new coumarin derivative, N,N′-((2E,2′E)-2,2′-(1,4-phenylenebis(methanylylidene))bis(hydrazinecarbonothioyl))bis(2-oxo-2H-chromene-3-carboxamide) PMBH, was synthesized and its chemical structure was elucidated and confirmed using spectroscopic techniques (Infrared spectroscopy IR, Proton nuclear magnetic resonance, 1H-NMR and carbon-13 nuclear magnetic resonance 13C-NMR). The corrosion inhibition effect of PMBH on mild steel in 1.0 M HCl was investigated using corrosion potential (ECORR), potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), and electrochemical frequency modulation (EFM) measurements. The obtained results indicated that PMBH has promising inhibitive effects on the corrosion of mild steel in 1.0 M HCl across all of the conditions examined. Scanning electron microscopy (SEM) was used to investigate the morphology of the mild steel before and after immersion in 1.0 M HCl solution containing 0.5 mM of PMBH. Surface analysis revealed improvement of corrosion resistance in presence of PMBH. PMID:28788680

Nontoxic corrosion inhibitors for N80 steel in hydrochloric acid

OpenAIRE

M. Yadav; Debasis Behera; Usha Sharma

2016-01-01

The purpose of this paper is to evaluate the protective ability of 1-(2-aminoethyl)-2-oleylimidazoline (AEOI) and 1-(2-oleylamidoethyl)-2-oleylimidazoline (OAEOI) as corrosion inhibitors for N80 steel in 15% hydrochloric acid, which may find application as eco-friendly corrosion inhibitors in acidizing processes in petroleum industry. Different concentrations of synthesized inhibitors AEOI and OAEOI were added to the test solution (15% HCl) and the corrosion inhibition of N80 steel in hydroch...

CORROSION INHIBITION OF ALUMINUM ALLOY 3SR IN HCl BY POLYVINYLPYRROLIDONE AND POLYACRYLAMIDE: EFFECT OF MOLECULAR STRUCTURE ON INHIBITION EFFICIENCY

OpenAIRE

S. A. UMOREN

2009-01-01

The inhibitive performance of two water soluble polymers–polyacrylamide (PA) and polyvinylpyrrolidone (PVP) on the corrosion behavior of aluminum alloy 3SR in HCl solution was investigated using weight loss, hydrogen evolution, and thermometric methods at 30–60°C. Results obtained indicate that both polymers inhibited acid-induced corrosion of aluminum at the temperatures studied. PVP was found to be a better corrosion inhibitor than PA. All measurements from the three techniques show that in...

Polyaspartic acid as a green corrosion inhibitor for carbon steel

Energy Technology Data Exchange (ETDEWEB)

Cui, R. [Department of Chemistry, Hebei Normal University, Shijiazhuang 050016 (China); Department of Chemistry and Materials Engineering, Changshu Institute of Technology, Changshu 215500 (China); Gu, N.; Li, C. [Department of Chemistry, Hebei Normal University, Shijiazhuang 050016 (China)

2011-04-15

The inhibitor effect of the environmentally friendly corrosion inhibitor polyaspartic acid (PASP) on the corrosion of carbon steel in 0.5 M H{sub 2}SO{sub 4} was investigated by weight loss, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), and scanning electron microscopy (SEM). Polarization curve results clearly reveal the fact that PASP is a good anode-type inhibitor. EIS results confirm its corrosion inhibition ability. The inhibition efficiency increases with increasing PASP concentration, and the maximum inhibition efficiency was 80.33% at 10 C. SEM reveals that a protective film forms on the surface of the inhibited sample. The adsorption of this inhibitor is found to follow the Freundlich adsorption isotherm. A mechanism is proposed to explain the inhibitory action of the corrosion inhibitor. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Polyaspartic acid as a corrosion inhibitor for WE43 magnesium alloy

OpenAIRE

Lihui Yang; Yantao Li; Bei Qian; Baorong Hou

2015-01-01

The inhibition behavior of polyaspartic acid (PASP) as an environment-friendly corrosion inhibitor for WE43 magnesium alloy was investigated in 3.5 wt.% NaCl solution by means for EIS measurement, potentiodynamic polarization curve, and scanning electron microscopy. The results show that PASP can inhibit the corrosion of WE43 magnesium alloy. The maximum inhibition efficiency is achieved when PASP concentration is 400 ppm in this study.

Electrochemical evaluation of inhibition efficiency of ciprofloxacin on the corrosion of copper in acid media

Energy Technology Data Exchange (ETDEWEB)

Thanapackiam, P. [Department of Chemistry, Coimbatore Institute of Technology, Coimbatore, Tamilnadu, 641 014 (India); Rameshkumar, Subramaniam [Department of Chemistry, Sri Vasavi College, Erode, Tamilnadu, 638 316 (India); Subramanian, S.S. [Department of Chemistry, PSG College of Technology, Coimbatore, Tamilnadu, 641 004 (India); Mallaiya, Kumaravel, E-mail: mkvteam.research@gmail.com [Department of Chemistry, PSG College of Technology, Coimbatore, Tamilnadu, 641 004 (India)

2016-05-01

The inhibition efficiency of ciprofloxacin on the corrosion of copper was studied in 1.0MHNO{sub 3} and 0.5MH{sub 2}SO{sub 4} solutions by electrochemical impedance spectroscopy and potentiodynamic polarization techniques. The corrosion inhibition action of ciprofloxacin was observed to be of mixed type in both the acid media, but with more of a cathodic nature. The experimental data were found to fit well with the Langmuir adsorption isotherm. The thermodynamic parameters such as adsorption equilibrium constant(K{sub ads}), free energy of adsorption(ΔG{sub ads}), activation energy(E{sub a}) and potential of zero charge(PZC) showed that the adsorption of ciprofloxacin onto copper surface involves both physisorption and chemisorption. - Highlights: • The inhibitor efficiency increases with increase in ciprofloxacin concentration. • Polarization measurements show that ciprofloxacin acts as a mixed type inhibitor. • The adsorption of the inhibitor on copper surface follows Langmuir adsorption isotherm. • The negative values of ΔG{sub ads} indicates that the adsorption is spontaneous and exothermic.

Effect of Benzamide on the Corrosion Inhibition of Mild Steel in ...

African Journals Online (AJOL)

NICOLAAS

2SO4 was studied at .... The structure and chemistry of benzamide is expected to give .... corrosion inhibition of mild steel in the sulphuric acid strength ... tion and formation of a compact barrier film on the metal elec- .... metal–acid interface.

The Inhibition of Aluminum Corrosion in Sulfuric Acid by Poly(1-vinyl-3-alkyl-imidazolium Hexafluorophosphate

Directory of Open Access Journals (Sweden)

Paulina Arellanes-Lozada

2014-08-01

Full Text Available Compounds of poly(ionic liquids (PILs, derived from imidazole with different alkylic chain lengths located in the third position of the imidazolium ring (poly(1-vinyl-3-dodecyl-imidazolium (PImC12, poly(1-vinyl-3-octylimidazolium (PImC8 and poly(1-vinyl-3-butylimidazolium (PImC4 hexafluorophosphate were synthesized. These compounds were tested as corrosion inhibitors on aluminum alloy AA6061 in diluted sulfuric acid (0.1–1 M H2SO4 by weight loss tests, polarization resistance measurements and inductively coupled plasma optical emission spectroscopy. Langmuir’s isotherms suggested film formation on bare alloy while standard free energy indicated inhibition by a physisorption process. However, compound efficiencies as inhibitors ranked low (PImC12 > PImC8 > PImC4 to reach 61% for PImC12 in highly diluted acidic solution. Apparently, the high mobility of sulfates favored their adsorption in comparison to PILs. The surface film displayed general corrosion, and pitting occurred as a consequence of PILs’ partial inhibition along with a continuous dissolution of defective patchy film on formation. A slight improvement in efficiency was displayed by compounds having high molecular weight and a long alkyl chain, as a consequence of steric hindrance and PIL interactions.

Polyaspartic acid as a corrosion inhibitor for WE43 magnesium alloy

Directory of Open Access Journals (Sweden)

Lihui Yang

2015-03-01

Full Text Available The inhibition behavior of polyaspartic acid (PASP as an environment-friendly corrosion inhibitor for WE43 magnesium alloy was investigated in 3.5 wt.% NaCl solution by means for EIS measurement, potentiodynamic polarization curve, and scanning electron microscopy. The results show that PASP can inhibit the corrosion of WE43 magnesium alloy. The maximum inhibition efficiency is achieved when PASP concentration is 400 ppm in this study.

Intramolecular synergistic effect of glutamic acid, cysteine and glycine against copper corrosion in hydrochloric acid solution

International Nuclear Information System (INIS)

Zhang Daquan; Xie Bin; Gao Lixin; Cai Qirui; Joo, Hyung Goun; Lee, Kang Yong

2011-01-01

The corrosion protection of copper by glutamic acid, cysteine, glycine and their derivative (glutathione) in 0.5 M hydrochloric acid solution has been studied by the electrochemical impedance spectroscopy and cyclic voltammetry. The inhibition efficiency of the organic inhibitors on copper corrosion increases in the order: glutathione > cysteine > cysteine + glutamic acid + glycine > glutamic acid > glycine. Maximum inhibition efficiency for cysteine reaches about 92.9% at 15 mM concentration level. The glutathione can give 96.4% inhibition efficiency at a concentration of 10 mM. The molecular structure parameters were obtained by PM3 (Parametric Method 3) semi-empirical calculation. The intramolecular synergistic effect of glutamic acid, cysteine and glycine moieties in glutathione is attributed to the lower energy of the lowest unoccupied molecular orbital (E LUMO ) level and to the excess hetero-atom adsorption centers and the bigger coverage on the copper surface.

Effect of Rice Straw Extract and Alkali Lignin on the Corrosion Inhibition of Carbon Steel

International Nuclear Information System (INIS)

Rabiahtul Zulkafli; Norinsan Kamil Othman; Irman Abdul Rahman; Azman Jalar

2014-01-01

A paddy residue based corrosion inhibitor was prepared by treating finely powdered rice straw with aqueous ethanol under acid catalyst (0.01 M H 2 SO 4 ). Commercial alkali lignin was obtained from Sigma-Aldrich. Prior to the corrosion test, the extraction yield and alkali lignin was characterized via FTIR to determine the functional group. The effect of paddy residue extract and commercial alkali lignin on the corrosion inhibition of carbon steel in 1 M HCl was investigated through the weight loss method, potentiodynamic polarization technique and scanning electron microscopy (SEM). The corrosion inhibition efficiency of the extract and alkali lignin at different immersion times (3 h, 24 h and 42 h) was evaluated. The results show that the paddy waste extract exhibited lesser weight loss of carbon steel in the acidic medium in comparison to the commercial alkali lignin, suggesting that the paddy residue extract is more effective than the commercial alkali lignin in terms of its corrosion inhibition properties. The results obtained proves that the extract from paddy residue could serve as an effective inhibitor for carbon steel in acidic mediums. (author)

Plastics for corrosion inhibition

CERN Document Server

Goldade, Victor A; Makarevich, Anna V; Kestelman, Vladimir N

2005-01-01

The development of polymer composites containing inhibitors of metal corrosion is an important endeavour in modern materials science and technology. Corrosion inhibitors can be located in a polymer matrix in the solid, liquid or gaseous phase. This book details the thermodynamic principles for selecting these components, their compatibility and their effectiveness. The various mechanisms of metal protection – barrier, inhibiting and electromechanical – are considered, as are the conflicting requirements placed on the structure of the combined material. Two main classes of inhibited materials (structural and films/coatings) are described in detail. Examples are given of structural plastics used in friction units subjected to mechano-chemical wear and of polymer films/coatings for protecting metal objects against corrosion.

Thermometric Study of Inhibition of Aluminium Corrosion in Hydrochloric Acid Solution

OpenAIRE

Al Gaber, A.S. [امينة سلطان الجابر; Seliman, S. A.; Mourad, M.

1997-01-01

The use of 6- amino - 4- (4-phenyl)-l,4- dihydro -3- methylpyrano [2,3- c] pyrazole -5- carbonitrile and some related compounds as corrosion inhibitors for aluminium in 2 M HCl solution was studied by the thermometric method. The results indicate that the additives reduce the corrosion rate via weak adsorption through the cationic oxygen of the pyran ring. They act as mixed inhibitors and their adsorption was found to obey Frumkin's isotherm. The inhibition efficiency of the additives is rela...

Inhibition Effects of a Synthesized Novel 4-Aminoantipyrine Derivative on the Corrosion of Mild Steel in Hydrochloric Acid Solution together with Quantum Chemical Studies

Directory of Open Access Journals (Sweden)

Abu Bakar Mohamad

2013-06-01

Full Text Available 1,5-Dimethyl-4-((2-methylbenzylideneamino-2-phenyl-1H-pyrazol-3(2H-one (DMPO was synthesized to be evaluated as a corrosion inhibitor. The corrosion inhibitory effects of DMPO on mild steel in 1.0 M HCl were investigated using electrochemical impedance spectroscopy (EIS, potentiodynamic polarization, open circuit potential (OCP and electrochemical frequency modulation (EFM. The results showed that DMPO inhibited mild steel corrosion in acid solution and indicated that the inhibition efficiency increased with increasing inhibitor concentration. Changes in the impedance parameters suggested an adsorption of DMPO onto the mild steel surface, leading to the formation of protective films. The novel synthesized corrosion inhibitor was characterized using UV-Vis, FT-IR and NMR spectral analyses. Electronic properties such as highest occupied molecular orbital energy, lowest unoccupied molecular orbital energy (EHOMO and ELUMO, respectively and dipole moment (μ were calculated and discussed. The results showed that the corrosion inhibition efficiency increased with an increase in the EHOMO values but with a decrease in the ELUMO value.

Inhibition Effects of a Synthesized Novel 4-Aminoantipyrine Derivative on the Corrosion of Mild Steel in Hydrochloric Acid Solution together with Quantum Chemical Studies

Science.gov (United States)

Junaedi, Sutiana; Al-Amiery, Ahmed A.; Kadihum, Abdulhadi; Kadhum, Abdul Amir H.; Mohamad, Abu Bakar

2013-01-01

1,5-Dimethyl-4-((2-methylbenzylidene)amino)-2-phenyl-1H-pyrazol-3(2H)-one (DMPO) was synthesized to be evaluated as a corrosion inhibitor. The corrosion inhibitory effects of DMPO on mild steel in 1.0 M HCl were investigated using electrochemical impedance spectroscopy (EIS), potentiodynamic polarization, open circuit potential (OCP) and electrochemical frequency modulation (EFM). The results showed that DMPO inhibited mild steel corrosion in acid solution and indicated that the inhibition efficiency increased with increasing inhibitor concentration. Changes in the impedance parameters suggested an adsorption of DMPO onto the mild steel surface, leading to the formation of protective films. The novel synthesized corrosion inhibitor was characterized using UV-Vis, FT-IR and NMR spectral analyses. Electronic properties such as highest occupied molecular orbital energy, lowest unoccupied molecular orbital energy (EHOMO and ELUMO, respectively) and dipole moment (μ) were calculated and discussed. The results showed that the corrosion inhibition efficiency increased with an increase in the EHOMO values but with a decrease in the ELUMO value. PMID:23736696

Corrosion inhibition behavior of Ketosulfone for Zinc in acidic medium

African Journals Online (AJOL)

The corrosion inhibition behavior of Ketosulfone for zinc is investigated by polarization and AC-impedance techniques at 303-333K. The Tafel plots indicates that the Ketosulfone is a mixed type inhibitor. The interaction between metal and inhibitor is explained by Langmuir adsorption isotherm. DG0ads andDH0ads value ...

Furfuryl alcohol as corrosion inhibitor for N80 steel in hydrochloric acid

International Nuclear Information System (INIS)

Vishwanatham, S.; Haldar, N.

2008-01-01

The ability of furfuryl alcohol (FA) as corrosion inhibitor in controlling corrosion of N80 steel in 15% hydrochloric acid has been investigated. It is found that the percentage inhibition of FA increases almost linearly with its concentration (in the range 10 mM-80 mM) and attains about 91% at 80 mM. FA shows significant inhibition at higher temperatures also (∼82% at 60 deg. C;∼74% at 110 deg. C with 80 mM concentration). FA undergoes acid catalyzed polymerization under the experimental conditions to give polyfurfuryl alcohols (PFA) as evidenced by FTIR and NMR spectral data. Thermodynamic parameters for the corrosion of steel in presence and absence of the inhibitor have been calculated. The inhibitive action may be attributed to adsorption of inhibitor molecules on the active sites of the metal surface following Temkin adsorption isotherm. Potentiodynamic polarization curves indicate that FA acts as mixed type inhibitor. A plausible mechanism for the mode of inhibition has been proposed

Inhibition of mild steel corrosion in acidic medium using synthetic and naturally occurring polymers and synergistic halide additives

Energy Technology Data Exchange (ETDEWEB)

Umoren, S.A. [Department of Chemistry, Faculty of Science, University of Uyo, P.M.B 1017 Uyo (Nigeria)], E-mail: saviourumoren@yahoo.com; Ogbobe, O.; Igwe, I.O. [Department of Polymer and Textile Engineering, School of Engineering and Engineering Technology, Federal University of Technology, P.M.B. 1526 Owerri (Nigeria); Ebenso, E.E. [Department of Chemistry and Chemical Technology, National University of Lesotho, P. O. Roma180, Lesotho (South Africa)

2008-07-15

The corrosion inhibition of mild steel in H{sub 2}SO{sub 4} in the presence of gum arabic (GA) (naturally occurring polymer) and polyethylene glycol (PEG) (synthetic polymer) was studied using weight loss, hydrogen evolution and thermometric methods at 30-60 deg. C. PEG was found to be a better inhibitor for mild steel corrosion in acidic medium than GA. The effect of addition of halides (KCl, KBr and KI) was also studied. Results obtained showed that inhibition efficiency (I%) increased with increase in GA and PEG concentration, addition of halides and with increase in temperature. Increase in inhibition efficiency (I%) and degree of surface coverage ({theta}) was found to follow the trend Cl{sup -} < Br{sup -} < I{sup -} which indicates that the radii and electronegativity of the halide ions play a significant role in the adsorption process. GA and PEG alone and in combination with halides were found to obey Temkin adsorption isotherm. Phenomenon of chemical adsorption is proposed from the trend of inhibition efficiency with temperature and values {delta}G{sub ads}{sup 0} obtained. The synergism parameter, S{sub I} evaluated is found to be greater than unity indicating that the enhanced inhibition efficiency caused by the addition of halides is only due to synergism.

Inhibiting effects of some oxadiazole derivatives on the corrosion of mild steel in perchloric acid solution

International Nuclear Information System (INIS)

Lebrini, Mounim; Bentiss, Fouad; Vezin, Herve; Lagrenee, Michel

2005-01-01

The efficiency of 3,5-bis(n-pyridyl)-1,3,4-oxadiazole (n-POX, n = 1, 2, 3), as corrosion inhibitors for mild steel in 1 M perchloric acid (HClO 4 ) have been determined by weight loss measurements and electrochemical studies. The results show that these inhibitors revealed a good corrosion inhibition even at very low concentrations. Comparison of results among those obtained by the studied oxadiazoles shows that 3-POX was the best inhibitor. Polarisation curves indicate that n-pyridyl substituted-1,3,4-oxadiazoles are mixed type inhibitors in 1 M HClO 4 . The adsorption of these inhibitors follows a Langmuir isotherm model. The electronic properties of n-POX, obtained using the AM1 semi-empirical quantum chemical approach, were correlated with their experimental efficiencies using the linear resistance model (LR)

Quantum chemical studies on the corrosion inhibition of some sulphonamides on mild steel in acidic medium

International Nuclear Information System (INIS)

Arslan, Taner; Kandemirli, Fatma; Ebenso, Eno E.; Love, Ian; Alemu, Hailemichael

2009-01-01

Quantum chemical calculations using the density functional theory (DFT) and some semi-empirical methods were performed on four sulphonamides (sulfaguanidine, sulfamethazine, sulfamethoxazole and sulfadiazine) used as corrosion inhibitors for mild steel in acidic medium to determine the relationship between molecular structure and their inhibition efficiencies. The results of the quantum chemical calculations and experimental %IE were subjected to correlation analysis and indicate that their inhibition effect are closely related to E HOMO , E LUMO , hardness, polarizability, dipole moment and charges. The %IE increased with increase in the E HOMO and decrease in E HOMO - E LUMO . The negative sign of the E HOMO values and other kinetic and thermodynamic parameters indicates that the data obtained support physical adsorption mechanism

Graphene: corrosion-inhibiting coating.

Science.gov (United States)

Prasai, Dhiraj; Tuberquia, Juan Carlos; Harl, Robert R; Jennings, G Kane; Rogers, Bridget R; Bolotin, Kirill I

2012-02-28

We report the use of atomically thin layers of graphene as a protective coating that inhibits corrosion of underlying metals. Here, we employ electrochemical methods to study the corrosion inhibition of copper and nickel by either growing graphene on these metals, or by mechanically transferring multilayer graphene onto them. Cyclic voltammetry measurements reveal that the graphene coating effectively suppresses metal oxidation and oxygen reduction. Electrochemical impedance spectroscopy measurements suggest that while graphene itself is not damaged, the metal under it is corroded at cracks in the graphene film. Finally, we use Tafel analysis to quantify the corrosion rates of samples with and without graphene coatings. These results indicate that copper films coated with graphene grown via chemical vapor deposition are corroded 7 times slower in an aerated Na(2)SO(4) solution as compared to the corrosion rate of bare copper. Tafel analysis reveals that nickel with a multilayer graphene film grown on it corrodes 20 times slower while nickel surfaces coated with four layers of mechanically transferred graphene corrode 4 times slower than bare nickel. These findings establish graphene as the thinnest known corrosion-protecting coating.

Corrosion behavior of niobium coated 304 stainless steel in acid solution

Energy Technology Data Exchange (ETDEWEB)

Pan, T.J., E-mail: tjpan@cczu.edu.cn [School of Material Science and Engineering, Jiangsu Collaborative Innovation Center for Photovolatic Science and Engineering, Changzhou University, Changzhou 213164 (China); Jiangsu Key Laboratory of Material Surface Technology, Changzhou 213164 (China); Chen, Y.; Zhang, B. [School of Material Science and Engineering, Jiangsu Collaborative Innovation Center for Photovolatic Science and Engineering, Changzhou University, Changzhou 213164 (China); Hu, J. [School of Material Science and Engineering, Jiangsu Collaborative Innovation Center for Photovolatic Science and Engineering, Changzhou University, Changzhou 213164 (China); Jiangsu Key Laboratory of Material Surface Technology, Changzhou 213164 (China); Li, C. [Light Industry College of Liaoning University, Shenyang 110036 (China)

2016-04-30

Highlights: • The Nb coating produced by HEMAA offers good protection for 304SS in acid solution. • The coating increases corrosion potential and induces decrease of corrosion rate. • The protection of coating is ascribed to the stability of Nb in acid solution. - Abstract: The niobium coating is fabricated on the surface of AISI Type 304 stainless steel (304SS) by using a high energy micro arc alloying technique in order to improvecorrosion resistance of the steel against acidic environments. The electrochemical corrosion resistance of the niobium coating in 0.7 M sulfuric acid solutions is evaluated by electrochemical impedance spectroscopy, potentiodynamic polarization and the open circuit potential versus time. Electrochemical measurements indicate that the niobium coating increases the free corrosion potential of the substrate by 110 mV and a reduction in the corrosion rate by two orders of magnitude compared to the substrate alone. The niobium coating maintains large impedance and effectively offers good protection for the substrate during the long-term exposure tests, which is mainly ascribed to the niobium coating acting inhibiting permeation of corrosive species. Finally, the corresponding electrochemical impedance models are proposed to elucidate the corrosion resistance behavior of the niobium coating in acid solutions.

Corrosion behavior of niobium coated 304 stainless steel in acid solution

International Nuclear Information System (INIS)

Pan, T.J.; Chen, Y.; Zhang, B.; Hu, J.; Li, C.

2016-01-01

Highlights: • The Nb coating produced by HEMAA offers good protection for 304SS in acid solution. • The coating increases corrosion potential and induces decrease of corrosion rate. • The protection of coating is ascribed to the stability of Nb in acid solution. - Abstract: The niobium coating is fabricated on the surface of AISI Type 304 stainless steel (304SS) by using a high energy micro arc alloying technique in order to improvecorrosion resistance of the steel against acidic environments. The electrochemical corrosion resistance of the niobium coating in 0.7 M sulfuric acid solutions is evaluated by electrochemical impedance spectroscopy, potentiodynamic polarization and the open circuit potential versus time. Electrochemical measurements indicate that the niobium coating increases the free corrosion potential of the substrate by 110 mV and a reduction in the corrosion rate by two orders of magnitude compared to the substrate alone. The niobium coating maintains large impedance and effectively offers good protection for the substrate during the long-term exposure tests, which is mainly ascribed to the niobium coating acting inhibiting permeation of corrosive species. Finally, the corresponding electrochemical impedance models are proposed to elucidate the corrosion resistance behavior of the niobium coating in acid solutions.

Corrosion inhibition of magnesium heated in wet air, by surface fluoridation; Inhibition de la corrosion du magnesium chauffe dans l'air humide, par fluoruration superficielle

Energy Technology Data Exchange (ETDEWEB)

Caillat, R; Darras, R; Leclercq, D [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

1960-07-01

The maximum temperature (350 deg. C) of magnesium corrosion resistance in wet air may be raised to 490-500 deg. C by the formation of a superficial fluoride film. This can be obtained by two different ways: either by addition of hydrofluoric acid to the corroding medium in a very small proportion such as 0,003 mg/litre; at atmospheric pressure, or by dipping the magnesium in a dilute aqueous solution of nitric and hydrofluoric acids at room temperature before exposing it to the corroding atmosphere. In both cases the corrosion inhibition is effective over a very long time, even several thousand hours. (author) [French] La temperature limite (350 deg. C) de resistance du magnesium a la corrosion par l'air humide, peut etre elevee jusque 490-500 deg. C par la formation d'une couche fluoruree superficielle. Deux procedes permettent d'obtenir ce resultat: l'atmosphere corrodante peut etre additionnee d'acide fluorhydrique a une concentration aussi faible que 0,003 mg/litre, a la pression atmospherique, ou bien le magnesium peut etre traite a froid, avant exposition a la corrosion, dans une solution aqueuse diluee d'acides nitrique et fluorhydrique. Dans les deux cas, la protection est assuree, meme pour de tres longues durees d'exposition: plusieurs milliers d'heures. (auteur)

Inhibition effect of phosphorus-based chemicals on corrosion of carbon steel in secondary-treated municipal wastewater.

Science.gov (United States)

Shen, Zhanhui; Ren, Hongqiang; Xu, Ke; Geng, Jinju; Ding, Lili

2013-01-01

Secondary-treated municipal wastewater (MWW) could supply a viable alternative water resource for cooling water systems. Inorganic salts in the concentrated cooling water pose a great challenge to corrosion control chemicals. In this study, the inhibition effect of 1-hydroxy ethylidene-1,1-diphosphonic acid (HEDP), trimethylene phosphonic acid (ATMP) and 2-phosphonobutane-1,2,4-tricarboxylic acid (PBTCA) on corrosion of carbon steel in secondary-treated MWW was investigated by the means of potentiodynamic polarization and electrochemical impedance spectroscopy. The inhibition effect increased with increasing concentration of inhibitors. The corrosion rates of carbon steel were 1.5, 0.8, 0.2 and 0.5 mm a(-1) for blank, HEDP, ATMP and PBTCA samples at 50 mg L(-1), respectively. The phosphorus-based chemicals could adsorb onto the surface of the carbon steel electrode, form a coat of protective film and then protect the carbon steel from corrosion in the test solution.

Corrosion inhibition by lithium zinc phosphate pigment

International Nuclear Information System (INIS)

Alibakhshi, E.; Ghasemi, E.; Mahdavian, M.

2013-01-01

Highlights: •Synthesis of lithium zinc phosphate (LZP) by chemical co-precipitation method. •Corrosion inhibition activity of pigments compare with zinc phosphate (ZP). •LZP showed superior corrosion inhibition effect in EIS measurements. •Evaluation of adhesion strength and dispersion stability. -- Abstract: Lithium zinc phosphate (LZP) has been synthesized through a co-precipitation process and characterized by XRD and IR spectroscopy. The inhibitive performances of this pigment for corrosion of mild steel have been discussed in comparison with the zinc phosphate (ZP) in the pigment extract solution by means of EIS and in the epoxy coating by means of salt spray. The EIS and salt spray results revealed the superior corrosion inhibitive effect of LZP compared to ZP. Moreover, adhesion strength and dispersion stability of the pigmented epoxy coating showed the advantage of LZP compared to ZP

Cefuroxime axetil: A commercially available drug as corrosion inhibitor for aluminum in hydrochloric acid solution

OpenAIRE

Ameh, Paul O.; Sani, Umar M.

2016-01-01

Cefuroxime axetil (CA) a prodrug was tested as corrosion inhibitor for aluminum in hydrochloric acid solution using thermometric, gasometric weight loss and scanning electron microscope (SEM) techniques. Results obtained showed that this compound has a good inhibiting properties for aluminum corrosion in acidic medium, with inhibition efficiencies values reaching 89.87 % at 0.5 g / L . It was also found out that the results from weight loss method are highly consistent with those obtained by ...

Corrosion Inhibition and Adsorption Characteristics of Tarivid on Mild Steel in H2SO4

Directory of Open Access Journals (Sweden)

N. O. Eddy

2010-01-01

Full Text Available The corrosion inhibition and adsorption characteristics of (+/--9-fluoro-2,3-dihydro-3-methyl-10-(4-methyl-1-piperazinyl-7-oxo-7H-pyrido[1,2,3-de]-1,4-benzoxazine-6-carboxylic acid (Tarivid on the corrosion of mild steel has been studied using thermometric and gasometric methods. The study reveals that tarivid inhibits the corrosion of mild steel in H2SO4. The values of inhibition efficiency of tarivid were found to increase as its concentration increased but decreased with increase in temperature. Activation energies of the inhibited corrosion of mild steel ranged from 39.05 to 50.61 kJ/mol. Values of enthalpy change and free energy of adsorption were negative which indicated exothermic and spontaneous adsorption process. Physical adsorption mechanism is proposed from the obtained kinetic and thermodynamic parameters. Langmuir adsorption isotherm model is obeyed from the fit of the experimental data.

CORROSION INHIBITIVE PROPERTIES OF EXTRACT OF JATROPHA CURCAS LEAVES ON MILD STEEL IN HYDROCHLORIC ACID ENVIRONMENT

Directory of Open Access Journals (Sweden)

J. Odusote

2016-09-01

Full Text Available Jatropha curcas leaves extract was tested as a green corrosion inhibitor for mild steel in aqueous hydrochloric acid solution using gravimetric and thermometric techniques. The results reveal that the inhibition efficiency vary with concentration of the leaf extract and the time of immersion. Maximum inhibition efficiency was found to be 95.92% in 2M HCl with 0.5 g/l concentration of the extract in gravimetric method, while 87.04% was obtained in thermometric method. The inhibiting effect was attributed to the presence of alkaloids, flavonoids, saponins, tannins and phenol in the extract. The adsorption processes of the Jatropha curcas leaves extract onto the mild steel is consistent with the assumptions of Langmuir isotherm model and also found to be spontaneous. From the results, a physical adsorption mechanism is proposed for the adsorption of Jatropha curcas leaves extract onto mild steel surface.

Nicotinic acid as a nontoxic corrosion inhibitor for hot dipped Zn and Zn-Al alloy coatings on steels in diluted hydrochloric acid

Energy Technology Data Exchange (ETDEWEB)

Ju Hong [Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071 (China); Graduate School, Chinese Academy of Sciences, Beijing 100039 (China); Li Yan [Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071 (China)], E-mail: yanlee@ms.qdio.ac.cn

2007-11-15

The inhibition effect of nicotinic acid for corrosion of hot dipped Zn and Zn-Al alloy coatings in diluted hydrochloric acid was investigated using quantum chemistry analysis, weight loss test, electrochemical measurement, and scanning electronic microscope (SEM) analysis. Quantum chemistry calculation results showed that nicotinic acid possessed planar structure with a number of active centers, and the populations of the Mulliken charge, the highest occupied molecular orbital (HOMO), and the lowest unoccupied molecular orbital (LUMO) were found mainly focused around oxygen and nitrogen atoms, and the cyclic of the benzene as well. The results of weight loss test and electrochemical measurement indicated that inhibition efficiency (IE%) increased with inhibitor concentration, and the highest inhibition efficiency was up to 96.7%. The corrosion inhibition of these coatings was discussed in terms of blocking the electrode reaction by adsorption of the molecules at the active centers on the electrode surface. It was found that the adsorption of nicotinic acid on coating surface followed Langmuir adsorption isotherm with single molecular layer, and nicotinic acid adsorbed on the coating surface probably by chemisorption. Nicotinic acid, therefore, can act as a good nontoxic corrosion inhibitor for hot dipped Zn and Zn-Al alloy coatings in diluted hydrochloric acid solution.

Corrosion inhibition of magnesium heated in wet air, by surface fluoridation

International Nuclear Information System (INIS)

Caillat, R.; Darras, R.; Leclercq, D.

1960-01-01

The maximum temperature (350 deg. C) of magnesium corrosion resistance in wet air may be raised to 490-500 deg. C by the formation of a superficial fluoride film. This can be obtained by two different ways: either by addition of hydrofluoric acid to the corroding medium in a very small proportion such as 0,003 mg/litre; at atmospheric pressure, or by dipping the magnesium in a dilute aqueous solution of nitric and hydrofluoric acids at room temperature before exposing it to the corroding atmosphere. In both cases the corrosion inhibition is effective over a very long time, even several thousand hours. (author) [fr

Protection of copper surface with phytic acid against corrosion in chloride solution.

Science.gov (United States)

Peca, Dunja; Pihlar, Boris; Ingrid, Milošev

2014-01-01

Phytic acid (inositol hexaphosphate) was tested as a corrosion inhibitor for copper in 3% sodium chloride. Phytic acid is a natural compound derived from plants, it is not toxic and can be considered as a green inhibitor. Electrochemical methods of linear polarization and potentiodynamic polarization were used to study the electrochemical behaviour and evaluate the inhibition effectiveness. To obtain the optimal corrosion protection the following experimental conditions were investigated: effect of surface pre-treatment (abrasion and three procedures of surface roughening), pre-formation of the layer of phytic acid, time of immersion and concentration of phytic acid. To evaluate the surface pre-treatment procedures the surface roughness and contact angle were measured. Optimal conditions for formation of phytic layer were selected resulting in the inhibition effectiveness of nearly 80%. Morphology and composition of the layer were further studied by scanning electron microscopy, energy dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy. The layer of phytic acid with thickness in the nanometer range homogeneously covers the copper surface. The obtained results show that this natural compound can be used as a mildly effective corrosion inhibitor for copper in chloride solution.

Inhibition of Mild Steel Corrosion in Sulfuric Acid Solution by New Schiff Base

Directory of Open Access Journals (Sweden)

Ahmed A. Al-Amiery

2014-01-01

Full Text Available The efficiency of Schiff base derived from 4-aminoantipyrine, namely 2-(1,5-dimethyl-4-(2-methylbenzylideneamino-2-phenyl-1H-pyrazol-3(2H-ylidene hydrazinecarbothioamide as a corrosion inhibitor on mild steel in 1.0 M H2SO4 was investigated using electrochemical impedance spectroscopy (EIS, potentiodynamic polarization (PD and electrochemical frequently modulation (EFM in addition to the adsorption isotherm, corrosion kinetic parameters and scanning electron microscopy (SEM. The results showed that this inhibitor behaved as a good corrosion inhibitor, even at low concentration, with a mean efficiency of 93% and, also, a reduction of the inhibition efficiency as the solution temperature increases. A polarization technique and EIS were tested for different concentrations and different temperatures to reveal that this compound is adsorbed on the mild steel, therefore blocking the active sites, and the adsorption follows the Langmuir adsorption isotherm model. The excellent inhibition effectiveness of 2-(1,5-dimethyl-4-(2-methylbenzylideneamino-2-phenyl-1H-pyrazol-3(2H-ylidenehydrazinecarbothioamide was also verified by scanning electron microscope (SEM.

Inhibition of Mild Steel Corrosion in Sulfuric Acid Solution by New Schiff Base

Science.gov (United States)

Al-Amiery, Ahmed A.; Kadhum, Abdul Amir H.; Kadihum, Abdulhadi; Mohamad, Abu Bakar; How, Chong K.; Junaedi, Sutiana

2014-01-01

The efficiency of Schiff base derived from 4-aminoantipyrine, namely 2-(1,5-dimethyl-4-(2-methylbenzylidene)amino)-2-phenyl-1H-pyrazol-3(2H)-ylidene) hydrazinecarbothioamide as a corrosion inhibitor on mild steel in 1.0 M H2SO4 was investigated using electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PD) and electrochemical frequently modulation (EFM) in addition to the adsorption isotherm, corrosion kinetic parameters and scanning electron microscopy (SEM). The results showed that this inhibitor behaved as a good corrosion inhibitor, even at low concentration, with a mean efficiency of 93% and, also, a reduction of the inhibition efficiency as the solution temperature increases. A polarization technique and EIS were tested for different concentrations and different temperatures to reveal that this compound is adsorbed on the mild steel, therefore blocking the active sites, and the adsorption follows the Langmuir adsorption isotherm model. The excellent inhibition effectiveness of 2-(1,5-dimethyl-4-(2-methylbenzylidene)amino)-2-phenyl-1H-pyrazol-3(2H)-ylidene)hydrazinecarbothioamide was also verified by scanning electron microscope (SEM). PMID:28788488

Correlating electronic structure with corrosion inhibition potentiality of some bis-benzimidazole derivatives for mild steel in hydrochloric acid: Combined experimental and theoretical studies

International Nuclear Information System (INIS)

Dutta, Alokdut; Saha, Sourav Kr.; Banerjee, Priyabrata; Sukul, Dipankar

2015-01-01

Highlights: • Bis-benzimidazole derivatives as good corrosion inhibitors for mild steel in acid. • Simultaneous both way electron-transfer is expected to occur during adsorption. • Role of molecular conformation on inhibition efficiency is demonstrated. • Good correlation between inhibition efficiency and molecular parameters established. • MD simulation results support experimental observations. - Abstract: Four different bis-benzimidazole (BBI) derivatives, tested as potential corrosion inhibitors for mild steel in 1 M HCl, have revealed good inhibition efficiency for long period of exposure. Inhibitors impart high resistance towards charge transfer across metal–electrolyte interface and behave broadly as mixed type. DFT calculations are used to correlate inhibition potentiality with intrinsic molecular parameters. From the optimized geometry of BBI derivatives, electron distribution in HOMO and LUMO and Fukui indices of each atom, possible modes of interaction of BBI derivatives with mild steel surface have been predicted. Energy corresponding to inhibitor-metal surface interaction is evaluated following molecular dynamics simulation

Corrosion inhibition of magnesium heated in wet air, by surface fluoridation; Inhibition de la corrosion du magnesium chauffe dans l'air humide, par fluoruration superficielle

Energy Technology Data Exchange (ETDEWEB)

Caillat, R.; Darras, R.; Leclercq, D. [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

1960-07-01

The maximum temperature (350 deg. C) of magnesium corrosion resistance in wet air may be raised to 490-500 deg. C by the formation of a superficial fluoride film. This can be obtained by two different ways: either by addition of hydrofluoric acid to the corroding medium in a very small proportion such as 0,003 mg/litre; at atmospheric pressure, or by dipping the magnesium in a dilute aqueous solution of nitric and hydrofluoric acids at room temperature before exposing it to the corroding atmosphere. In both cases the corrosion inhibition is effective over a very long time, even several thousand hours. (author) [French] La temperature limite (350 deg. C) de resistance du magnesium a la corrosion par l'air humide, peut etre elevee jusque 490-500 deg. C par la formation d'une couche fluoruree superficielle. Deux procedes permettent d'obtenir ce resultat: l'atmosphere corrodante peut etre additionnee d'acide fluorhydrique a une concentration aussi faible que 0,003 mg/litre, a la pression atmospherique, ou bien le magnesium peut etre traite a froid, avant exposition a la corrosion, dans une solution aqueuse diluee d'acides nitrique et fluorhydrique. Dans les deux cas, la protection est assuree, meme pour de tres longues durees d'exposition: plusieurs milliers d'heures. (auteur)

Inhibition of the Cu65/Zn35 brass corrosion by natural extract of Camellia sinensis

International Nuclear Information System (INIS)

Ramde, Tambi; Rossi, Stefano; Zanella, Caterina

2014-01-01

In this work, the corrosion inhibition of brass was studied using natural plant extract, Camellia sinensis, in 0.1 M Na2SO4 solutions with pH 7 and pH 4. Electrochemical techniques (potentiodynamic polarization, electrochemical impedance spectroscopy) and scanning electron microscopy (SEM) were applied to study the brass corrosion behavior in presence and absence of the extract. The results indicated that the extract is a very effective corrosion inhibitor for brass corrosion process in both the acidic and neutral media by virtue of adsorption. The inhibition effect increases by time as demonstrated by the EIS monitoring for 120 h. In the blank solution the corrosion process leads to the formation of a dark oxide patina at pH 7 and induces localized corrosion morphology at pH 4. The extract presence can avoid both the dark patina and the pits formation.

Inhibition of the Cu65/Zn35 brass corrosion by natural extract of Camellia sinensis

Energy Technology Data Exchange (ETDEWEB)

Ramde, Tambi, E-mail: t_ramde@univ-ouaga.bf [Equipe Chimie Physique et Electrochimie, Laboratoire de Chimie Moléculaire et des Matériaux, Université de Ouagadougou, 03 BP 7021 Ouagadougou 03 (Burkina Faso); Department of Industrial Engineering, University of Trento, via Sommarive 9, 38123 Trento (Italy); Rossi, Stefano; Zanella, Caterina [Department of Industrial Engineering, University of Trento, via Sommarive 9, 38123 Trento (Italy)

2014-07-01

In this work, the corrosion inhibition of brass was studied using natural plant extract, Camellia sinensis, in 0.1 M Na2SO4 solutions with pH 7 and pH 4. Electrochemical techniques (potentiodynamic polarization, electrochemical impedance spectroscopy) and scanning electron microscopy (SEM) were applied to study the brass corrosion behavior in presence and absence of the extract. The results indicated that the extract is a very effective corrosion inhibitor for brass corrosion process in both the acidic and neutral media by virtue of adsorption. The inhibition effect increases by time as demonstrated by the EIS monitoring for 120 h. In the blank solution the corrosion process leads to the formation of a dark oxide patina at pH 7 and induces localized corrosion morphology at pH 4. The extract presence can avoid both the dark patina and the pits formation.

Corrosion Inhibition of Aluminium by Capparis deciduas in Acidic Media

OpenAIRE

P. Arora; S. Kumar; M. K. Sharma; S. P. Mathur

2007-01-01

The inhibition efficiency of ethanolic extract of different parts of Capparis deciduas (Ker) in acidic medium has been evaluated by mass loss and thermometric methods. Values of inhibition efficiency obtained from the two methods are in good agreement and are dependent upon the concentration of inhibitor and acid.

Antibacterial drugs as corrosion inhibitors for bronze surfaces in acidic solutions

Energy Technology Data Exchange (ETDEWEB)

Rotaru, Ileana [Department of Chemical Engineering, “Babes-Bolyai” University, 11 Arany-Janos St., 400028 Cluj-Napoca (Romania); Varvara, Simona, E-mail: svarvara@uab.ro [Department of Exact Sciences and Engineering, “1 Decembrie 1918” University, 11-13 Nicolae Iorga St., 510009 Alba Iulia (Romania); Gaina, Luiza [Department of Chemical Engineering, “Babes-Bolyai” University, 11 Arany-Janos St., 400028 Cluj-Napoca (Romania); Muresan, Liana Maria, E-mail: limur@chem.ubbcluj.ro [Department of Chemical Engineering, “Babes-Bolyai” University, 11 Arany-Janos St., 400028 Cluj-Napoca (Romania)

2014-12-01

Graphical abstract: - Highlights: • All four investigated antibacterial drugs act as corrosion inhibitors for bronze surface. • In the presence of antibiotics, a 3RC electric circuit simulates the corrosion system. • The electrochemical results indicate as best inhibitors Doxy, followed by Strepto. • HOMO–LUMO energy gap increases in the order: Doxy > Strepto > Cipro > Amoxi. • The thin protective film on bronze is reinforced by the presence of the antibiotics. - Abstract: The present study is aiming to investigate the effect of four antibiotics (amoxicillin, ciprofloxacin, doxycycline and streptomycin,) belonging to different classes of antibacterial drugs on bronze corrosion in a solution simulating an acid rain (pH 4). Due to their ability to form protective films on the metal surface, the tested antibiotics act as corrosion inhibitors for bronze. The antibiotics were tested at various concentrations in order to determine the optimal concentration range for the best corrosion inhibiting effect. In evaluating the inhibition efficiency, polarization curves, electrochemical impedance spectroscopy, SEM and XPS measurements were used. Moreover, a correlation between the inhibition efficiency of some antibacterial drugs and certain molecular parameters was determined by quantum chemical computations. Parameters like energies E{sub HOMO} and E{sub LUMO} and HOMO–LUMO energy gap were used for correlation with the corrosion data.

Antibacterial drugs as corrosion inhibitors for bronze surfaces in acidic solutions

International Nuclear Information System (INIS)

Rotaru, Ileana; Varvara, Simona; Gaina, Luiza; Muresan, Liana Maria

2014-01-01

Graphical abstract: - Highlights: • All four investigated antibacterial drugs act as corrosion inhibitors for bronze surface. • In the presence of antibiotics, a 3RC electric circuit simulates the corrosion system. • The electrochemical results indicate as best inhibitors Doxy, followed by Strepto. • HOMO–LUMO energy gap increases in the order: Doxy > Strepto > Cipro > Amoxi. • The thin protective film on bronze is reinforced by the presence of the antibiotics. - Abstract: The present study is aiming to investigate the effect of four antibiotics (amoxicillin, ciprofloxacin, doxycycline and streptomycin,) belonging to different classes of antibacterial drugs on bronze corrosion in a solution simulating an acid rain (pH 4). Due to their ability to form protective films on the metal surface, the tested antibiotics act as corrosion inhibitors for bronze. The antibiotics were tested at various concentrations in order to determine the optimal concentration range for the best corrosion inhibiting effect. In evaluating the inhibition efficiency, polarization curves, electrochemical impedance spectroscopy, SEM and XPS measurements were used. Moreover, a correlation between the inhibition efficiency of some antibacterial drugs and certain molecular parameters was determined by quantum chemical computations. Parameters like energies E HOMO and E LUMO and HOMO–LUMO energy gap were used for correlation with the corrosion data

Corrosion Inhibition of Aluminium by Capparis deciduas in Acidic Media

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P. Arora

2007-01-01

Full Text Available The inhibition efficiency of ethanolic extract of different parts of Capparis deciduas (Ker in acidic medium has been evaluated by mass loss and thermometric methods. Values of inhibition efficiency obtained from the two methods are in good agreement and are dependent upon the concentration of inhibitor and acid.

Inhibition of the corrosion of mild steel in hydrochloric acid by isatin and isatin glycine

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B.I. Ita

2006-12-01

Full Text Available The inhibition of corrosion of mild steel in hydrochloric acid by isatin glycine (ING and isatin (IN at 30-60 oC and concentrations of 0.0001 M to 0.0005 M was studied via weight loss method. At the highest inhibitor concentration studied ING exhibited inhibition efficiency of 87% while IN exhibited 84% at 60 oC. A chemical adsorption mechanism was proposed on the basis of the temperature effect and obtained average activation energy values of 143.9 kJ/mol for ING and 118.5 kJ/mol for IN. The two inhibitors were confirmed to obey the Langmuir adsorption isotherm equation at the concentrations studied. Also a first-order type of mechanism was proposed from the kinetic treatment of the result. The difference in the inhibitory properties of the inhibitors was explained in terms of the difference in their molecular structures and solubility rather than difference in molecular weights alone.

Effect of Tryptophan on the corrosion behavior of low alloy steel in sulfamic acid

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Hesham T.M. Abdel-Fatah

2016-11-01

Full Text Available Sulfamic acid is widely used in various industrial acid cleaning applications. In the present work, the inhibition effect of Tryptophan (Tryp on the corrosion of low alloy steel in sulfamic acid solutions at four different temperatures was studied. The investigations involved electrochemical methods (electrochemical impedance spectroscopy; EIS and the new technique electrochemical frequency modulation; EFM as well as gravimetric measurements. The inhibition efficiency and the apparent activation energy have been calculated in the presence and in the absence of Tryp. It is most probable that the inhibition property of Tryp was due to the electrostatic adsorption of the protonated form of Tryp on the steel surface. Adsorption of the inhibitor molecule, onto the steel surface followed the Temkin adsorption isotherm. The thermodynamic parameters of adsorption were determined and discussed. All of the obtained data from the three techniques were in close agreement, which confirmed that EFM technique can be used efficiently for monitoring the corrosion inhibition under the studied conditions.

Synergy effect of naphthenic acid corrosion and sulfur corrosion in crude oil distillation unit

Energy Technology Data Exchange (ETDEWEB)

Huang, B.S., E-mail: yinwenfeng2010@163.com [College of Materials Science and Engineering, Southwest Petroleum University, Sichuan, Chengdu, 610500 (China); Yin, W.F. [College of Mechatronic Engineering, Southwest Petroleum University, Sichuan, Chengdu, 610500 (China); Sang, D.H. [Sheng Li Construction Group International Engineering Department, Shandong, Dongying, 257000 (China); Jiang, Z.Y. [College of Materials Science and Engineering, Southwest Petroleum University, Sichuan, Chengdu, 610500 (China)

2012-10-15

Highlights: Black-Right-Pointing-Pointer The corrosion of a carbon-manganese steel and a stainless steel in sulfur and/or naphthenic acid media was investigated. Black-Right-Pointing-Pointer The corrosion rate of the carbon-manganese steel increased with the increase of the acid value and sulfur content. Black-Right-Pointing-Pointer The critical values of the concentration of sulfur and acid for corrosion rate of the stainless steel were ascertained respectively. Black-Right-Pointing-Pointer The stainless steel is superior to the carbon-manganese steel in corrosion resistance because of the presence of stable Cr{sub 5}S{sub 8} phases. - Abstract: The synergy effect of naphthenic acid corrosion and sulfur corrosion at high temperature in crude oil distillation unit was studied using Q235 carbon-manganese steel and 316 stainless steel. The corrosion of Q235 and 316 in corrosion media containing sulfur and/or naphthenic acid at 280 Degree-Sign C was investigated by weight loss, scanning electron microscope (SEM), EDS and X-ray diffractometer (XRD) analysis. The results showed that in corrosion media containing only sulfur, the corrosion rate of Q235 and 316 first increased and then decreased with the increase of sulfur content. In corrosion media containing naphthenic acid and sulfur, with the variations of acid value or sulfur content, the synergy effect of naphthenic acid corrosion and sulfur corrosion has a great influence on the corrosion rate of Q235 and 316. It was indicated that the sulfur accelerated naphthenic acid corrosion below a certain sulfur content but prevented naphthenic acid corrosion above that. The corrosion products on two steels after exposure to corrosion media were investigated. The stable Cr{sub 5}S{sub 8} phases detected in the corrosion products film of 316 were considered as the reason why 316 has greater corrosion resistance to that of Q235.

Synergy effect of naphthenic acid corrosion and sulfur corrosion in crude oil distillation unit

Science.gov (United States)

Huang, B. S.; Yin, W. F.; Sang, D. H.; Jiang, Z. Y.

2012-10-01

The synergy effect of naphthenic acid corrosion and sulfur corrosion at high temperature in crude oil distillation unit was studied using Q235 carbon-manganese steel and 316 stainless steel. The corrosion of Q235 and 316 in corrosion media containing sulfur and/or naphthenic acid at 280 °C was investigated by weight loss, scanning electron microscope (SEM), EDS and X-ray diffractometer (XRD) analysis. The results showed that in corrosion media containing only sulfur, the corrosion rate of Q235 and 316 first increased and then decreased with the increase of sulfur content. In corrosion media containing naphthenic acid and sulfur, with the variations of acid value or sulfur content, the synergy effect of naphthenic acid corrosion and sulfur corrosion has a great influence on the corrosion rate of Q235 and 316. It was indicated that the sulfur accelerated naphthenic acid corrosion below a certain sulfur content but prevented naphthenic acid corrosion above that. The corrosion products on two steels after exposure to corrosion media were investigated. The stable Cr5S8 phases detected in the corrosion products film of 316 were considered as the reason why 316 has greater corrosion resistance to that of Q235.

Gallic acid as a corrosion inhibitor of carbon steel in chemical decontamination formulation

International Nuclear Information System (INIS)

Keny, S.J.; Kumbhar, A.G.; Thinaharan, C.; Venkateswaran, G.

2008-01-01

Gallic acid (GA) was found to provide corrosion inhibition to carbon steel (CS) at 4.25 mM concentration. Inherent stability to radiation degradation as compared to other reductant and coupled with its anionic nature with respect to removal using ion exchange column makes it suitable for using as both reductant as well as corrosion inhibitor in dilute decontamination formulations operating in the regenerative mode. A formulation containing CA (1.4 mM), EDTA/NTA (1.4 mM), AA (1.0-2.0 mM) and GA (4.25 mM) was found to be more efficient in dissolving hematite and providing 31% corrosion inhibition (passivation) to the CS

Corrosion inhibition of Eleusine aegyptiaca and Croton rottleri leaf extracts on cast iron surface in 1 M HCl medium

International Nuclear Information System (INIS)

Rajeswari, Velayutham; Kesavan, Devarayan; Gopiraman, Mayakrishnan; Viswanathamurthi, Periasamy; Poonkuzhali, Kaliyaperumal; Palvannan, Thayumanavan

2014-01-01

Graphical abstract: - Highlights: • Eleusine aegyptiaca and Croton rottleri are commonly available, less-toxic and eco-friendly inhibitors for cast iron corrosion. • The active constituents present in extracts adsorbed on the iron surface to inhibit the acidic corrosion. • The higher values of E a and ΔH * point out the higher inhibition efficiency noticed for the inhibitors. • Weight loss methods at various temperature and spectral data provides evidence for adsorption mechanism of inhibitors. - Abstract: The adsorption and corrosion inhibition activities of Eleusine aegyptiaca (E. aegyptiaca) and Croton rottleri (C. rottleri) leaf extracts on cast iron corrosion in 1 M hydrochloric acid solution were studied first time by weight loss and electrochemical techniques viz., Tafel polarization and electrochemical impedance spectroscopy. The results obtained from the weight loss and electrochemical methods showed that the inhibition efficiency increased with inhibitor concentrations. It was found that the extracts acted as mixed-type inhibitors. The addition of halide additives (KCl, KBr, and KI) on the inhibition efficiency has also been investigated. The adsorption of the inhibitors on cast iron surface both in the presence and absence of halides follows the Langmuir adsorption isotherm model. The inhibiting nature of the inhibitors was supported by FT-IR, UV–vis, Wide-angle X-ray diffraction and SEM methods

Anionic Surfactant as a Corrosion Inhibitor for Synthesized Ferrous Alloy in Acidic Solution

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Farida Kellou-Kerkouche

2013-01-01

Full Text Available The effect of temperature on the corrosion behaviour of a synthesized iron-based alloy in 1 N sulphuric acid solution has been examined by means of three electrochemical techniques. Thereafter, we studied the influence of an anionic surfactant (sodium dodecyl benzene sulfonate at various concentrations on the electrochemical behaviour of the ferrous alloy. The obtained results show that the temperature increase reduced the performance of the used alloy, in the acidic environment. Otherwise, the surfactant inhibits the alloy dissolution in the sulphuric acid, through its adsorption on the metal surface without modifying the mechanism of corrosion process. We also noticed that the highest inhibition effect is obtained at a concentration above its critical micelle concentration (CMC. Langmuir adsorption isotherm fits well with the experimental data.

Study on Corrosion of Materials by Fluoric Acid and Silicofluoric Acid

International Nuclear Information System (INIS)

Park, Kun You; Kwon, Yeong Soo; Kuk, Myung Ho; Kim, Myun Sup

1986-01-01

The corrosion properties of 304 Stainless steel, Cupro-nickel, NiCrMo alloy in hydrofluoric acid and silicofluoric acid has been studied. The corrosion resistance of NiCrMo alloy and Cupro-nickel in hydrofluoric acid or mixed acid of hydrofluoric and sulfuric acid is excellent. Because of lower corrosion resistance of 304 Stainless steel, it would not be used for these corrosion resistant materials. The corrosion activation energy of 304 Stainless steel, Cupro-nickel and NiCrMo alloy in 40% HF solution are 42.7, 58.9 and 89.7 kJ/mol, respectively. By these values, it is assumed that the corrosion rate determining step is the chemical reaction on surface of metals. In the plastics, Teflon and polychloro tetrafluoroethylene are most excellent for corrosion resistance in hydrofluoric acid

Initiation and inhibition of pitting corrosion on reinforcing steel under natural corrosion conditions

Energy Technology Data Exchange (ETDEWEB)

Abd El Wanees, S., E-mail: s_wanees@yahoo.com [Chemistry Department, Faculty of Science, University of Tabuk, Tabuk (Saudi Arabia); Chemistry Department, Faculty of Science, Zagazig University, Zagazig 44519 (Egypt); Bahgat Radwan, A. [Center for Advanced Materials, Qatar University, Doha 2713 (Qatar); Alsharif, M.A. [Chemistry Department, Faculty of Science, University of Tabuk, Tabuk (Saudi Arabia); Abd El Haleem, S.M. [Chemistry Department, Faculty of Science, Zagazig University, Zagazig 44519 (Egypt)

2017-04-01

Initiation and inhibition of pitting corrosion on reinforcing steel in saturated, naturally aerated Ca(OH){sub 2} solutions, under natural corrosion conditions, are followed through measurements of corrosion current, electrochemical impedance spectroscopy and SEM investigation. Induction period for pit initiation and limiting corrosion current for pit propagation are found to depend on aggressive salt anion and cation-types, as well as, concentration. Ammonium chlorides and sulfates are more corrosive than the corresponding sodium salts. Benzotriazole and two of its derivatives are found to be good inhibitors for pitting corrosion of reinforcing steel. Adsorption of these compounds follows a Langmuir adsorption isotherm. The thermodynamic functions ΔE{sup ∗}, ΔH{sup ∗} and ΔS{sup ∗} for pitting corrosion processes in the absence and presence of inhibitor are calculated and discussed. - Highlights: • Cl{sup −} and SO{sub 4} {sup 2-} induce pitting corrosion on passive reinforcing steel. • Initiation and propagation of pitting depend on cation and anion types. • Inhibition is based on adsorption according to Langmuir isotherm.

Corrosion Inhibition of High Speed Steel by Biopolymer HPMC Derivatives

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Shih-Chen Shi

2016-07-01

Full Text Available The corrosion inhibition characteristics of the derivatives of biopolymer hydroxypropyl methylcellulose (HPMC, hydroxypropyl methylcellulose phthalate (HPMCP, and hydroxypropyl methylcellulose acetate succinate (HPMCAS film are investigated. Based on electrochemical impedance spectroscopic measurements and potentiodynamic polarization, the corrosion inhibition performance of high speed steel coated with HPMC derivatives is evaluated. The Nyquist plot and Tafel polarization demonstrate promising anti-corrosion performance of HPMC and HPMCP. With increasing film thickness, both materials reveal improvement in corrosion inhibition. Moreover, because of a hydrophobic surface and lower moisture content, HPMCP shows better anti-corrosion performance than HPMCAS. The study is of certain importance for designing green corrosion inhibitors of high speed steel surfaces by the use of biopolymer derivatives.

Study of a Triazole Derivative as Corrosion Inhibitor for Mild Steel in Phosphoric Acid Solution

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Lin Wang

2012-01-01

Full Text Available The corrosion inhibition by a triazole derivative (PAMT on mild steel in phosphoric acid (H3PO4 solution has been investigated by weight loss and polarization methods. The experimental results reveal that the compound has a significant inhibiting effect on the corrosion of steel in H3PO4 solution. It also shows good corrosion inhibition at higher concentration of H3PO4. Potentiodynamic polarization studies have shown that the compound acts as a mixed-type inhibitor retarding the anodic and cathodic corrosion reactions with predominant effect on the cathodic reaction. The values of inhibition efficiency obtained from weight loss and polarization measurements are in good agreement. The adsorption of this compound is found to obey the Langmuir adsorption isotherm. Some kinetic and thermodynamic parameters such as apparent activation energy, frequency factor, and adsorption free energy have been calculated and discussed.

Corrosion Inhibition of Cold-rolled Low Carbon Steel with Pulse Fiber Laser Ablation in Water

Science.gov (United States)

Chan, Sze Ney; Wong, Wai Yin; Walvekar, Rashmi; Kadhum, Abdul Amir H.; Khalid, Mohammad; Lim, Kean Long

2018-04-01

This study aims at the use of a fiber laser for modifying the surface properties of cold-rolled low carbon steel via a pulse laser ablation technique in water. The effect on the corrosion behavior of the fiber laser-treated metal surface was investigated in NaCl and HCl environments. Electrochemical tests showed significant improvement in the corrosion resistance of the laser-treated sample in NaCl, with an increase in open-circuit potential (OCP) from - 0.65 to - 0.60 V and an inhibition efficiency of 89.22% as obtained from the impedance study. Such improvement was less significant in an acidic environment. Lower corrosion rates of 20.9 mpy and 5.819 × 103 mpy were obtained for the laser-treated samples in neutral and acidic electrolytes, respectively, than the corrosion rates obtained for the as-received samples (33.2 mpy and 11.98 × 103 mpy). Morphological analysis indicated a passive film built by spherical grains of regular size on the metal surface after laser treatment. The corrosion inhibition effects in NaCl were evident by the nonexistence of the common corrosion products of lepidocrocite and crystalline structures that were seen on as-received samples; only polyhedral crystals with micrograins grown on them were seen covering the laser-treated surface. Therefore, the laser treatment using a fiber laser source improved the corrosion resistance of cold-rolled low carbon steel.

EIS study on corrosion and scale processes and their inhibition in cooling system media

International Nuclear Information System (INIS)

Marin-Cruz, J.; Cabrera-Sierra, R.; Pech-Canul, M.A.; Gonzalez, I.

2006-01-01

A study of the carbon steel/cooling water interface was carried out using electrochemical impedance spectroscopy (EIS). EIS spectra reveal that a layer of corrosion and scale products forms naturally and evolves with the immersion time modifying the carbon steel/cooling water interface and giving rise to corrosion and scale processes. In addition, the nature of the layer formed on the metal was found to depend on the inhibitor used. It was established that the corrosion inhibitor (hydroxyphosphonoacetic acid (HPA)) chelates with Ca(II) ion generating a layer with resistive properties that provides good protection against corrosion. In contrast, the scale inhibitor (1-hydroxy-ethane-1,1-diphosphonic acid (HEDP)) is incorporated into the calcium carbonate crystals at the surface, modifying the structure and diminishing scale formation in the surface; this additive additionally inhibited corrosion. These observations were supported by scanning electronic microscopy (SEM) and corroborate previous studies performed by other techniques on HPA and HEDP. Finally, a synergistic effect was observed between these inhibitors that provides good protection to steel against corrosion and scaling in cooling media

EIS study on corrosion and scale processes and their inhibition in cooling system media

Energy Technology Data Exchange (ETDEWEB)

Marin-Cruz, J. [Universidad Autonoma Metropolitana, Departamento de Quimica, Apdo. Postal 55-534, 09340 Mexico, DF (Mexico) and Instituto Mexicano del Petroleo, Coordinacion de Ingenieria Molecular, Competencia de Quimica Aplicada, Eje Central Lazaro Cardenas No. 152, CP 07730, DF (Mexico)]. E-mail: jmarin@imp.mx; Cabrera-Sierra, R. [Universidad Autonoma Metropolitana, Departamento de Quimica, Apdo. Postal 55-534, 09340 Mexico, DF (Mexico); Escuela Superior de Ingenieria Quimica e Industrias Extractivas (ESIQIE-IPN), Departamento de Metalurgia, UPALM Zacatenco AP 75-874, CP 07338, DF (Mexico); Pech-Canul, M.A. [Departamento de Fisica Aplicada, Centro de Investigacion y de Estudios, Avanzados del IPN, AP 73 Cordemex, CP 97310, Merida, Yucatan (Mexico); Gonzalez, I. [Universidad Autonoma Metropolitana, Departamento de Quimica, Apdo. Postal 55-534, 09340 Mexico, DF (Mexico)]. E-mail: igm@xanum.uam.mx

2006-01-20

A study of the carbon steel/cooling water interface was carried out using electrochemical impedance spectroscopy (EIS). EIS spectra reveal that a layer of corrosion and scale products forms naturally and evolves with the immersion time modifying the carbon steel/cooling water interface and giving rise to corrosion and scale processes. In addition, the nature of the layer formed on the metal was found to depend on the inhibitor used. It was established that the corrosion inhibitor (hydroxyphosphonoacetic acid (HPA)) chelates with Ca(II) ion generating a layer with resistive properties that provides good protection against corrosion. In contrast, the scale inhibitor (1-hydroxy-ethane-1,1-diphosphonic acid (HEDP)) is incorporated into the calcium carbonate crystals at the surface, modifying the structure and diminishing scale formation in the surface; this additive additionally inhibited corrosion. These observations were supported by scanning electronic microscopy (SEM) and corroborate previous studies performed by other techniques on HPA and HEDP. Finally, a synergistic effect was observed between these inhibitors that provides good protection to steel against corrosion and scaling in cooling media.

Corrosion inhibition of mild steel in acidic media using newly synthesized heterocyclic organic molecules: Correlation between inhibition efficiency and chemical structure

Energy Technology Data Exchange (ETDEWEB)

Ouici, H. B., E-mail: ouici.houari@yahoo.fr; Guendouzi, A., E-mail: guendouzzi@yahoo.fr [Departement of Chimistry, Faculty of Sciences, University of Saïda (Algeria); Benali, O. [Department of Biology, Faculty of Science, University of Saida (Algeria)

2015-03-30

The corrosion inhibition of mild steel in 5% HCl solutions by some new synthesized organic compounds namely 3-(2-methoxyphenyl) 5-mercapto-1. 2. 4-triazole (2-MMT), 3-(3-methoxyphenyl) 5-mercapto-1. 2. 4-triazole (3-MMT) and 3-(2-hydroxyphenyl) 5-mercapto-1. 2. 4-triazole (2-HMT) was investigated using weight loss and potentiostatic polarization techniques. These measurements reveal that the inhibition efficiency obtained by these compounds increased by increasing their concentration. The inhibition efficiency follows the order 2-MMT >3-MMT >2-HMT. Polarization studies show that these compounds are of the mixed type but dominantly act as a cathodic inhibitors for mild steel in 5% HCl solutions. These inhibitors function through adsorption following Langmuir isotherm. Activation energy and Gibbs free energy for adsorption of inhibitors are calculated. Molecular modeling has been conducted to correlate the corrosion inhibition properties with the calculated quantum chemical parameters.

Corrosion Inhibition by Sodium Gluconate-Zn2+-DTPMP System

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P. Manjula

2009-01-01

Full Text Available The inhibition efficiency of a phosphonic acid, Diethylene Triamine Pentamethylene Phosphonic acid (DTPMP in controlling corrosion of carbon steel immersed in an aqueous solution containing 60 ppm of Cl- has been evaluated by weight loss method in the absence and presence of Zn2+. The formulation consisting of DTPMP and Zn2+ has excellent inhibition efficiency (IE. A synergistic effect is noticed between Zn2+ and DTPMP. Addition of sodium gluconate (SG enhances the IE of Zn2+ and DTPMP system. The DTPMP-Zn2+-SG system function as a mixed inhibitor as revealed by polarization study. AC impedance spectrum, optical and atomic force micrographs reveal the formation of a protective film on the metal surface. FTIR spectra reveal that the protective film consists of Fe2+-DTPMP complex, Fe2+-SG complex and Zn(OH2.

Novel cationic surfactants from fatty acids and their corrosion inhibition efficiency for carbon steel pipelines in 1 M HCl

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A.M. Al-Sabagh

2011-06-01

Full Text Available Four fatty acids were used as a source of alkyl halides. Untraditionally tertiary amines were prepared by ethoxylation of aromatic and aliphatic fatty amines. These alkyl halide and tertiary amines were used to prepare 20 cationic quaternary ammonium surfactants (QASS. Their chemical structures were characterized and they tested as corrosion inhibitors for carbon steel in 1 M HCl solution. The corrosion inhibition efficiency was measured using, weight loss and potentiodynamic polarization methods. The inhibition efficiencies obtained from the two employed methods are nearly closed. From the obtained data it was found that, the inhibition efficiency increases with increasing the inhibitor concentration until the optimum one. Also, it was found that the inhibition efficiency of QASs which based on ethoxylated aromatic tertiary amine is greater than the obtained efficiencies by the QASs which based on ethoxylated aliphatic tertiary amines. The QASs based on alkyl halide C16 exhibited the maximum inhibition efficiency 98.8%. Adsorption of the inhibitors on the carbon steel surface was found to obey Langmuir’s adsorption isotherm. The quantum chemical calculations were done for some selected quaternary ammonium compounds based on their chemical structures QL1,4,5–QP3,4,5. The following quantum chemical indices such as the bond length, bond angle, charge density distribution, highest occupied molecular orbital (HOMO, lowest unoccupied molecular orbital (LUMO, energy gap ΔE = HOMO − LUMO, and dipole moment (u were considered. The relation between these parameters and the inhibition efficiencies was explained on the light of the chemical structure of the used inhibitors.

Acid corrosion inhibitor

Energy Technology Data Exchange (ETDEWEB)

Chen, N G

1964-04-28

An acid corrosion inhibitor is prepared by a 2-stage vacuum evaporation of effluents obtained from the ammonia columns of the coking oven plant. The effluent, leaving a scrubber in which the phenols are removed at a temperature of 98$C, passes through a quartz filter and flows into a heated chamber in which it is used for preheating a solution circulating through a vacuum unit, maintaining the temperature of the solution at 55$ to 60$C. The effluent enters a large tank in which it is boiled at 55$ to 60$C under 635 to 640 mm Hg pressure. Double evaporation of this solution yields a very effective acid corrosion inhibitor. Its corrosion-preventing effect is 97.9% compared with 90.1% for thiourea and 88.5% for urotropin under identical conditions.

Corrosion inhibitors for aluminium in hydrochloric acid. Vanilline on aluminium 2S, 57S and 65S

Energy Technology Data Exchange (ETDEWEB)

Desai, M.N.

1972-12-01

So far, the only aldehyde reported in literature for the inhibition of the corrosion of aluminum in hydrochloric acid, is furfuraldehyde. This study reports vanilline as a corrosion inhibitor for aluminum alloys 2S, 57S, and 65S. These specifications for the alloys are listed. The influence of inhibitor concentration and time on inhibitor efficiency is given in tabular data and illustrated graphically. The corrosion of aluminum alloys 2S, 57S, and 65S increases with time and hydrochloric acid concentration. Polarization measurements indicate that the corrosion of aluminum alloys in hydrochloric acid is cathodically controlled. The behavior of vanilline as a corrosion inhibitor is very interesting. In 2.0N solution of hydrochloric acid, vanilline affords nearly complete protection (97 to 99%) to all the 3 aluminum alloys investigated up to 60 min. However, in 1.0N solutions of hydrochloric acid, the corrosion of aluminum 2S is severely accelerated by vanilline.

The Inhibitive Action Of Sodium Soya Sulphonate Towards The Corrosion Of Aluminium In Hydrochloric Acid

OpenAIRE

Mourad, M. Y.; Mead, A. I.; Seliman, S. A.

1993-01-01

The dissolution of aluminium in 2M hydrochloric acid in the presence of sodium soya sulphonate (SSS) as corrosion inhibitor has been studied using hydrogen evolution and thermometric methods. The two methods gave consistent results. The results obtained indicate that the inhibitive effect of the sulphonated mixture relates to chemisorption mechanism on the metal surface via the n electrons in the double bonds. تمت دراسة ذوبان الألمونيوم في محلول 2 مولارى من حمض الهيدروكلوريك في وجود سلفونا...

Study of Plant Cordia Dichotoma as Green Corrosion Inhibitor for Mild Steel in Different Acid Media

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R. Khandelwal

2011-01-01

Full Text Available The corrosion inhibition of mild steel using extracts of Cordia dichotoma in different acid media was investigated by mass loss and thermometric methods. The experiments were carried out at 299±0.2 K in presence of different concentrations of dry fruit, leaves and stem extracts of Cordia dichotoma. The results reveal that the alcoholic extracts of Cordia dichotoma is a better corrosion inhibitor than that of toxic chemicals. The fruit extract is more potent than leaves and stem extracts to inhibit the corrosion rate. The study seeks to investigate the possibility of using extracts of Cordia dichotoma as a green corrosion inhibitor for mild steel.

Sucrose fatty esters from underutilized seed oil of Terminalia catappa as potential steel corrosion inhibitor in acidic medium

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Adewale Adewuyi

2016-12-01

Full Text Available Corrosion of metals is a common problem which requires definite attention. In response to this, the oil was extracted from the seed of Terminalia catappa and used to synthesize sucrose fatty esters via simple reaction mechanism which was considered eco-friendly and sustainable. The corrosion inhibition capacity of sucrose fatty esters for mild steel in 1 M HCl was studied using the weight loss method. It was shown that sucrose fatty ester inhibited corrosion process of mild steel and obeyed Langmuir isotherm. Corrosion rate and inhibition efficiency of sucrose fatty esters were found to reduce with increase of immersion time. The study presented sucrose fatty ester as a promising inhibitor of mild steel corrosion in acidic medium.

Development of a functionalized coating for inhibition of marine corrosion and biofouling

Science.gov (United States)

Gittens, Jeanette Elizabeth

The financial loss incurred by corrosion of metals in the marine environment has led to a need to develop effective, economic and environmentally friendly methods of protection. Traditional methods of counteracting the development of surface biofilms and biofouling within aqueous environments have involved implementing chemical biocides, often with a deleterious effect on non-target organisms. Sol gel coating technology offers a convenient route for immobilizing functional additives, such as inhibitors or, in the case of this study, biologically active microorganisms. Paenibacillus polymyxa biofilms inhibit the corrosion of metal substrates and this strain has the advantage of forming endospores can withstand the solvent and acid concentrations required in sol-gel formulation. Encapsulation of viable P. polymyxa endospores within the sol-gel matrix allowed germination on exposure to nutrients, when germinating endospores and vegetative cells were seen after fluorescence microscopy to be distributed throughout the coating. Laboratory electrochemical impedance tests were used to characterize the corrosion behaviour of the endospore-containing (biotic) sol-gel coating in comparison to an abiotic (no endospores) sol-gel only coating and one containing non-viable (killed) endospores. The technology enabled manipulation of the sol-gel formulation and the method of application to produce biotic sol-gel with enhanced corrosion inhibition properties on aluminium alloy. Field trials in a marine environment confirmed the corrosion protecting properties of the biotic coating and that the biotic coatings inhibited macroscopic biofouling for at least 29 weeks relative to the controls without encapsulated live endospores. Production of polymyxin by the encapsulated bacteria, which was proposed as a mechanism by which they inhibit MIC, was less than 1 mug per ml and below the threshold of detection by liquid chromatography mass spectrometry and antimicrobial bioassay. Microcosm

Effect of Organic Acid Additions on the General and Localized Corrosion Susceptibility of Alloy 22 in Chloride Solutions

Energy Technology Data Exchange (ETDEWEB)

Carranza, R M; Giordano, C M; Rodr?guez, M A; Ilevbare, G O; Rebak, R B

2007-08-28

Electrochemical studies such as cyclic potentiodynamic polarization (CPP) and electrochemical impedance spectroscopy (EIS) were performed to determine the corrosion behavior of Alloy 22 (N06022) in 1M NaCl solutions at various pH values from acidic to neutral at 90 C. All the tested material was wrought Mill Annealed (MA). Tests were also performed in NaCl solutions containing weak organic acids such as oxalic, acetic, citric and picric. Results show that the corrosion rate of Alloy 22 was significantly higher in solutions containing oxalic acid than in solutions of pure NaCl at the same pH. Citric and picric acids showed a slightly higher corrosion rate, and acetic acid maintained the corrosion rate of pure chloride solutions at the same pH. Organic acids revealed to be weak inhibitors for crevice corrosion. Higher concentration ratios, compared to nitrate ions, were needed to completely inhibit crevice corrosion in chloride solutions. Results are discussed considering acid dissociation constants, buffer capacity and complex formation constants of the different weak acids.

Corrosion Inhibition of Q235A Steel in Acid Medium Using Isatin Derivatives: A Qsar Study

International Nuclear Information System (INIS)

Abdo M Al-Fakih; Madzlan Aziz; Abdo M Al-Fakih; Abdallah, H.H.; Hasmerya Maarof; Rosmahaida Jamaludin; Bishir Usman

2016-01-01

Quantitative Structure-Activity Relationship (QSAR) study was performed on 10 isatin derivatives which were reportedly used as corrosion inhibitors. Dragon software was used to calculate the molecular descriptors. Partial least square (PLS) method was used to run the regression analysis between the descriptors and the corrosion inhibition efficiencies (IE) of the inhibitors. A predictive QSAR model was developed with a correlation coefficient (r 2 cal ) of 0.9676. The model validity was assessed through internal and external validation. The results show that cross-validation regression coefficient (r 2 cv ) and prediction regression coefficient (r 2 pred ) are 0.8163 and 0.9189, respectively. The model was used to predict the IE for ten isatin derivatives. The results confirm a good stability and predictive ability of the model. Dragon-based descriptors provide a very good description of the corrosion inhibition properties of the inhibitors. The results of the QSAR study were found to be consistent with the experimental data. (author)

Evaluation of Corrosion Inhibition of Mild Steel in 1 M Hydrochloric Acid Solution by Mollugo cerviana

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P. Arockiasamy

2014-01-01

Full Text Available The inhibiting effect of methanolic extract of Mollugo cerviana plant on the corrosion of mild steel in 1 M HCl solution has been investigated by different techniques like potentiodynamic polarization, electrochemical impedance spectroscopy, and weight loss methods for five different concentrations of plant extract ranging from 25 to 1000 mg/L. The results indicated that the corrosion inhibition efficiency increased on increasing plant extract concentration till 500 mg/L and decreased on further increasing concentration. The extract was a mixed type inhibitor with the optimum inhibition concentration of 500 mg/L in potentiodynamic polarization. The adsorption of the plant extract on the mild steel surface was found to obey Langmuir adsorption isotherm. Surface analysis was also carried out to find out the surface morphology of the mild steel in the presence and in the absence of the inhibitor to find out its efficiency. The obtained results showed that the Mollugo cerviana extract acts as a good inhibitor for the corrosion of mild steel in 1 M HCl solution.

Corrosion Inhibition of AISI/SAE Steel in a Marine Environment

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Fatai Olufemi ARAMIDE

2009-12-01

Full Text Available Effect of Sodium nitrite as a corrosion inhibitor of mild steel in sea water wasinvestigated, using the conventional weight loss method. Differentpercentages of sodium nitrite were used from 0% to 10% in sea water.Samples of mild steel were exposed to these corrosive media and the weightloss was calculated at intervals of 120 hours, 168 hours, 208 hours, 256 hours,304 hours and 352 hours. It was observed that corrosion rate increases withtime of exposure to the corrosive medium (inhibited or non-inhibited and thatsodium nitrite can be used to retards the corrosion rate of mild steel if theappropriate concentration is used in sea water. It was concluded that theoptimum percentage of sodium nitrate in sea water that gives the optimumcorrosion inhibition of mild steel is 4%.

Corrosion inhibition efficiency of linear alkyl benzene derivatives for carbon steel pipelines in 1M HCl

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A.M. Al-Sabagh

2011-06-01

Full Text Available Linear alkyl benzene sulfonic acid (L and three of its ester derivatives (L1, L2, L3 were prepared, followed by quaternization of these esters (L1Q, L2Q, L3Q. The corrosion inhibition effect on carbon steel in 1 M HCl was studied using weight loss and potentiodynamic polarization measurements. The adsorption of the inhibitors on carbon steel surface obeyed the Langmuir’s adsorption isotherm. The associated activation energy of corrosion and other thermodynamic parameters such as enthalpy (ΔH∗, entropy (ΔS∗ of activation, adsorption–desorption equilibrium constant (Kads, standard free energy of adsorption (ΔGoads, heat (ΔHoads, and entropy of adsorption (ΔSoads were calculated to elaborate the corrosion inhibition mechanism.

Corrosion resistance of zirconium in nitric acid

International Nuclear Information System (INIS)

Kajimura, H.; Morikawa, H.; Nagano, H.

1987-01-01

Slow strain rate tests are effected on zirconium in boiling nitric acid to study the influence of nitric acid concentration, of oxidizing ions (Cr and Ce) and of electric potential. Corrosion resistance is excellent and stress corrosion cracking occurs only for severe conditions: 350 mV over electric potential for corrosion with nitric acid concentration of 40 % [fr

Research on corrosion mechanism of suspension insulator steel foot of direct current system and measures for corrosion inhibition

Science.gov (United States)

Chen, He; Yang, Yueguang; Su, Guolei; Wang, Xiaoqing; Zhang, Hourong; Sun, Xiaoyu; Fan, Youping

2017-09-01

There are increasingly serious electrocorrosion phenomena on insulator hardware caused by direct current transmission due to the wide-range popularization of extra high voltage direct current transmission engineering in our country. Steel foot corrosion is the main corrosion for insulators on positive polarity side of transmission lines. On one hand, the corrosion leads to the tapering off of steel foot diameter, having a direct influence on mechanical property of insulators; on the other hand, in condition of corrosion on steel foot wrapped in porcelain ware, the volume of the corrosion product is at least 50% more than that of the original steel foot, leading to bursting of porcelain ware, threatening safe operation of transmission lines. Therefore, it is necessary to conduct research on the phenomenon and propose feasible measures for corrosion inhibition. Starting with the corrosion mechanism, this article proposes two measures for corrosion inhibition, and verifies the inhibition effect in laboratory conditions, providing reference for application in engineering.

Adsorption properties and inhibition of mild steel corrosion in sulphuric acid solution by ketoconazole: Experimental and theoretical investigation

Energy Technology Data Exchange (ETDEWEB)

Obot, I.B. [Department of Chemistry, Faculty of Science, University of Uyo, P.M.B. 1017, Uyo, Akwa Ibom State (Nigeria)], E-mail: proffoime@yahoo.com; Obi-Egbedi, N.O. [Department of Chemistry, University of Ibadan, Ibadan (Nigeria)

2010-01-15

Ketoconazole (KCZ) has been evaluated as a corrosion inhibitor for mild steel in aerated 0.1 M H{sub 2}SO{sub 4} by gravimetric method. The effect of KCZ on the corrosion rate was determined at various temperatures and concentrations. The inhibition efficiency increases with increase in inhibitor concentration but decrease with rise in temperature. Adsorption followed the Langmuir isotherm with negative values of {delta}G{sub ads}{sup 0}, suggesting a stable and a spontaneous inhibition process. Quantum chemical approach was further used to calculate some electronic properties of the molecule in order to ascertain any correlation between the inhibitive effect and molecular structure of ketoconazole.

On the relationship between corrosion inhibiting effect and molecular structure of 2,5-bis(n-pyridyl)-1,3,4-thiadiazole derivatives in acidic media: Ac impedance and DFT studies

Energy Technology Data Exchange (ETDEWEB)

Bentiss, F., E-mail: fbentiss@enscl.f [Laboratoire de Chimie de Coordination et d' Analytique (LCCA), Faculte des Sciences, Universite Chouaib Doukkali, B.P. 20, M-24000 El Jadida (Morocco); Mernari, B. [Laboratoire de Chimie de Coordination et d' Analytique (LCCA), Faculte des Sciences, Universite Chouaib Doukkali, B.P. 20, M-24000 El Jadida (Morocco); Traisnel, M. [Unite Materiaux et Transformations (UMET), Ingenierie des Systemes Polymeres, CNRS UMR 8207, ENSCL, B.P. 90108, F-59652 Villeneuve d' Ascq Cedex (France); Vezin, H. [Laboratoire de Spectrochimie Infrarouge et Raman (LASIR), UMR-CNRS 8516, Universite des Sciences et Technologies de Lille, Batiment C5, F-59655 Villeneuve d' Ascq Cedex (France); Lagrenee, M., E-mail: michel.lagrenee@ensc-lille.f [Unite de Catalyse et de Chimie du Solide (UCCS), UMR-CNRS 8181, ENSCL, B.P. 90108, F-59652 Villeneuve d' Ascq Cedex (France)

2011-01-15

Research highlights: {yields}2,5-Bis(n-pyridyl)-1,3,4-thiadiazoles (n-PTH) act as good inhibitors for the mild steel in acidic media. {yields}The inhibiting protection depends on the position of the nitrogen on the pyridinium substituent according to order 3-PTH > 2-PTH > 4-PTH. {yields}The adsorption of n-PTH is found to follow the Langmuir's adsorption isotherm. {yields}Data obtained from quantum chemical calculations using DFT method were correlated to the experimentally obtained inhibition efficiencies. - Abstract: The inhibition properties of 2,5-bis(n-pyridyl)-1,3,4-thiadiazoles (n-PTH) on corrosion of mild steel in different acidic media (1 M HCl, 0.5 M H{sub 2}SO{sub 4} and 1 M HClO{sub 4}) were analyzed by electrochemical impedance spectroscopy (EIS). The n-PTH derivatives exhibit good inhibition properties in different acidic solutions and the calculated values of {Delta}G{sub ads}{sup 0} revealed that the adsorption mechanism of n-PTH on steel surface is mainly due to chemisorption. While in 1 M HClO{sub 4}, both 2-PTH and 4-PTH isomers stimulate the corrosion process especially at low concentrations. Quantum chemical calculations using the density functional theory (DFT) were performed on n-PTH derivatives to determine the relationship between molecular structure and their inhibition efficiencies. The results of the quantum chemical calculations and experimental inhibition efficiency were subjected to correlation analysis and indicate that the inhibition effects of n-PTH may be explained in terms of electronic properties.

Baphia nitida Leaves Extract as a Green Corrosion Inhibitor for the Corrosion of Mild Steel in Acidic Media

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V. O. Njoku

2014-01-01

Full Text Available The inhibiting effect of Baphia nitida (BN leaves extract on the corrosion of mild steel in 1 M H2SO4 and 2 M HCl was studied at different temperatures using gasometric and weight loss techniques. The results showed that the leaves extract is a good inhibitor for mild steel corrosion in both acid media and better performances were obtained in 2 M HCl solutions. Inhibition efficiency was found to increase with increasing inhibitor concentration and decreasing temperature. The addition of halides to the extract enhanced the inhibition efficiency due to synergistic effect which improved adsorption of cationic species present in the extract and was in the order KCl < KBr < KI suggesting possible role of radii of the halide ions. Thermodynamic parameters determined showed that the adsorption of BN on the metal surface is an exothermic and spontaneous process and that the adsorption was via a physisorption mechanism.

Boric Acid Corrosion of Concrete Rebar

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Yang L.

2013-07-01

Full Text Available Borated water leakage through spent fuel pools (SFPs at pressurized water reactors is a concern because it could cause corrosion of reinforcement steel in the concrete structure and compromise the integrity of the structure. Because corrosion rate of carbon steel in concrete in the presence of boric acid is lacking in published literature and available data are equivocal on the effect of boric acid on rebar corrosion, corrosion rate measurements were conducted in this study using several test methods. Rebar corrosion rates were measured in (i borated water flowing in a simulated concrete crack, (ii borated water flowing over a concrete surface, (iii borated water that has reacted with concrete, and (iv 2,400 ppm boric acid solutions with pH adjusted to a range of 6.0 to 7.7. The corrosion rates were measured using coupled multielectrode array sensor (CMAS and linear polarization resistance (LPR probes, both made using carbon steel. The results indicate that rebar corrosion rates are low (~1 μm/yr or lesswhen the solution pH is ~7.1 or higher. Below pH ~7.1, the corrosion rate increases with decreasing pH and can reach ~100 μm/yr in solutions with pH less than ~6.7. The threshold pH for carbon steel corrosion in borated solution is between 6.8 and 7.3.

Enhanced corrosion resistance of stainless steel type 316 in sulphuric acid solution using eco-friendly waste product

Science.gov (United States)

Sanni, O.; Popoola, A. P. I.; Fayomi, O. S. I.

2018-06-01

Literature has shown that different organic compounds are effective corrosion inhibitors for metal in acidic environments. Such compounds usually contain oxygen, nitrogen or sulphur and function through adsorption on the metal surface, thereby creating a barrier for corrosion attack. Unfortunately, these organic compounds are toxic, scarce and expensive. Therefore, plants, natural product and natural oils have been posed as cheap, environmentally acceptable, abundant, readily available and effective molecules having low environmental impact. The corrosion resistance of austenitic stainless steel Type 316 in the presence of eco-friendly waste product was studied using weight loss and potentiodynamic polarization techniques in 0.5 M H2SO4. The corrosion rate and corrosion potential of the steel was significantly altered by the studied inhibitor. Results show that increase in concentration of the inhibitor hinders the formation of the passive film. Experimental observation shows that its pitting potential depends on the concentration of the inhibitor in the acid solution due to adsorption of anions at the metal film interface. The presence of egg shell powder had a strong influence on the corrosion resistance of stainless steel Type 316 with highest inhibition efficiency of 94.74% from weight loss analysis, this is as a result of electrochemical action and inhibition of the steel by the ionized molecules of the inhibiting compound which influenced the mechanism of the redox reactions responsible for corrosion and surface deterioration. Inhibitor adsorption fits the Langmuir isotherm model. The two methods employed for the corrosion assessment were in good agreement.

Synthesis and characterization of an effective organic/inorganic hybrid green corrosion inhibitive complex based on zinc acetate/Urtica Dioica

International Nuclear Information System (INIS)

Salehi, E.; Naderi, Reza; Ramezanzadeh, B.

2017-01-01

Highlights: • An organic/inorganic hybrid green corrosion inhibitive pigment was synthesized and characterized. • Chemical structure and morphology of the hybrid complex were characterized. • Zinc acetate/Urtica Dioica showed effective inhibition action in saline solution on carbon steel. • The synergistic effect between Zn 2+ cations and inhibitive compounds existed in U.D resulted in protective film deposition on the steel surface. - Abstract: This study aims at synthesis and characterization of an effective corrosion inhibitive complex based on zinc acetate/Urtica Dioica (ZnA-U.D) for corrosion protection of mild steel in chloride solution. The chemical structure and morphology of the complex were characterized by Fourier transform infrared spectroscopy (FT-IR), UV–vis, thermal gravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). The corrosion protection performance of the mild steel samples dipped in 3.5 wt.% NaCl solutions with and without ZnA-U.D extract was investigated by visual observations, open circuit potential (OCP) measurements, electrochemical impedance spectroscopy (EIS) and polarization test. Results revealed that the ZnA successfully chelated with organic inhibitive compounds (i.e Quercetin, Quinic acid, Caffeic acid, Hystamine and Serotonin) present in the U.D extract. The electrochemical measurements revealed the effective inhibition action of ZnA-U.D complex in the sodium chloride solution on the mild steel. The synergistic effect between Zn 2+ and organic compounds present in the U.D extract resulted in protective film deposition on the steel surface, which was proved by SEM and XPS analyses.

Synthesis and characterization of an effective organic/inorganic hybrid green corrosion inhibitive complex based on zinc acetate/Urtica Dioica

Energy Technology Data Exchange (ETDEWEB)

Salehi, E.; Naderi, Reza [School of Metallurgy and Materials Engineering, College of Engineering, University of Tehran, P.O. Box 11155-4563, Tehran (Iran, Islamic Republic of); Ramezanzadeh, B., E-mail: ramezanzadeh@aut.ac.ir [Department of Surface Coatings and Corrosion, Institute for Color Science and Technology (ICST), PO 16765-654, Tehran (Iran, Islamic Republic of)

2017-02-28

Highlights: • An organic/inorganic hybrid green corrosion inhibitive pigment was synthesized and characterized. • Chemical structure and morphology of the hybrid complex were characterized. • Zinc acetate/Urtica Dioica showed effective inhibition action in saline solution on carbon steel. • The synergistic effect between Zn{sup 2+} cations and inhibitive compounds existed in U.D resulted in protective film deposition on the steel surface. - Abstract: This study aims at synthesis and characterization of an effective corrosion inhibitive complex based on zinc acetate/Urtica Dioica (ZnA-U.D) for corrosion protection of mild steel in chloride solution. The chemical structure and morphology of the complex were characterized by Fourier transform infrared spectroscopy (FT-IR), UV–vis, thermal gravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). The corrosion protection performance of the mild steel samples dipped in 3.5 wt.% NaCl solutions with and without ZnA-U.D extract was investigated by visual observations, open circuit potential (OCP) measurements, electrochemical impedance spectroscopy (EIS) and polarization test. Results revealed that the ZnA successfully chelated with organic inhibitive compounds (i.e Quercetin, Quinic acid, Caffeic acid, Hystamine and Serotonin) present in the U.D extract. The electrochemical measurements revealed the effective inhibition action of ZnA-U.D complex in the sodium chloride solution on the mild steel. The synergistic effect between Zn{sup 2+} and organic compounds present in the U.D extract resulted in protective film deposition on the steel surface, which was proved by SEM and XPS analyses.

Corrosion inhibition of austenitic stainless steel by clay in polluted phosphoric acid with presence of SiC abrasif

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Skal S.

2018-01-01

Full Text Available Stainless steels have many properties mechanical and chemical resistances resulting from the formation of the protective layer (passive film on their surface which prevents the metal to react with corrosive environments such as, phosphoric acid. This acid contains various impurities, including agressive agents and solid particles of gypsum, increase the risk of corrosion damage depending on the type of stainless steel used. In addition, it has been show that abrasion-corrosion causes an acceleration electrochemical process leading to a decrease in the resistance of materials. This work is to find a solution through an ecological inhibitor. That why we have been studied the effect of crude clay on corrosion behavior of Alloy 31 in polluted phosphoric acid with abrasive by electrochemical impedance spectroscopy (EIS . The clay was characterized by X-ray fluorescence spectroscopy (FX, X-ray diffraction (DRX and infrared spectroscopy (IR. EIS exhibited that resistance of Alloy 31 increased with increase the concentration of inhibitor.

In hydrofluoric acid corrosion-resistant materials

International Nuclear Information System (INIS)

Hauffe, K.

1985-01-01

Copper, red brass (Cu-15 Zn), special treated carbon steel and chromium-nickel-molybdenum steel represent materials of high resistivity against concentrated hydrofluoric acid ( 2 O 3 ) are employed for windows in the presence of hydrogen fluoride and/or hydrofluoric acid because of their superior optical properties and their excellent corrosion resistance. Polyethylen, polypropylene and polyvinyl chloride (PVC) belong to the cheapest corrosion resistant material for container and for coatings in the presence of hydrofluoric acid. Special polyester resins reinforced by glass or graphite fibers have been successfully employed as material for production units with hydrofluoric acid containing liquids up to 330 K. By carbon reinforced epoxy resin represents a corrosion resistant coating. Because of their excellent friction and corrosion resistance against concentrated hot hydrofluoric acid and HNO 3 -HF-solutions, PTFE and polyvinylidene fluoride are used as material for valves and axles in such environment. The expensive alloys, as for instance hastelloy and monel, are substituted more and more by fiber-reinfored polyolefins, PVC and fluorine containing polymers. (orig.) [de

The synergistic inhibitive effect and some quantum chemical parameters of 2,3-diaminonaphthalene and iodide ions on the hydrochloric acid corrosion of aluminium

International Nuclear Information System (INIS)

Obot, I.B.; Obi-Egbedi, N.O.; Umoren, S.A.

2009-01-01

The effect of iodide ions on the inhibitive performance of 2,3-diaminonaphthalene (2,3-DAN) in 1 M HCl for aluminium corrosion has been studied using hydrogen evolution (gasometry) measurements at 30 and 40 deg. C. Results obtained showed that the presence of 2,3-DAN molecules in the corrosive medium (1 M HCl solution) inhibits the corrosion process of aluminium and as the concentration of 2,3-DAN increases the inhibition efficiency also increased at the studied temperatures. A synergistic effect was observed between KI and 2,3-DAN. The experimental results suggest that the presence of iodide ions in the solutions stabilized the adsorption of 2,3-DAN molecules on the metal surfaces and, therefore improve the inhibition efficiency of 2,3-DAN. Phenomenon of physical adsorption is proposed for the inhibition and the process followed the Freundlich adsorption isotherm. The activation energy (E a ), heat of adsorption (Q ads ) and free energy of adsorption for the corrosion process (ΔG ads ) have been evaluated at the different temperatures and the values support the results obtained. Some quantum chemical parameters and the Mulliken charge densities for 2,3-diaminonaphthalene were calculated by the AM1 Semi-empirical method to provide further insight into the mechanism of inhibition of the corrosion process

Study on the Synthesis and Corrosion Inhibition Performance of Mannich-Modified Imidazoline

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Xiangjun Kong

2016-07-01

Full Text Available A novel Mannich-modified imidazoline (MMI as cationic emulsifier was synthesised for corrosion harm reduction, through three steps — acylation, cyclization, and Mannich reaction. The surface activity was characterized by determination of surface tensions and critical micelle concentration (CMC. The corrosion inhibition performance of five types of steels in the simulated corrosion solution in the presence of the MMI was investigated by static weight loss tests. The results showed that the MMI had good surface activities, with CMC of 19.8 μg g−1 and surface tension of 36.4 mN m−1. The corrosion test results indicated that the corrosion rates of different materials were decreased significantly, and degrees of corrosion inhibition were always higher than 80.0 %. The main inhibition mechanism was most likely due to the adsorption of the corrosion inhibitor on the steel surface, leading to the prevention of corrosion medium from the metal surface.

Effect of boric acid on intergranular corrosion in tube support plate crevices

International Nuclear Information System (INIS)

Brunet, J.P.; Campan, J.L.

1993-10-01

Intergranular attack on steam generator tubing is one important phenomenon involved in availability of Pressurized Water Reactors. Boric acid appears to be a possible candidate for inhibiting the corrosion process. The program performed in Cadarache was supposed to give statistical informations on the boric acid effect. It was based on a large number of samples initially attacked during a program performed by BABCOCK ampersand WILCOX. These samples were sleeved onto Alloy 690 tubes, in order to prevent premature cracking. Unfortunately it was not possible to find chemical conditions able to produce significant additional corrosion; we postulated mainly due to a drastic reduction of the thermal flux resulting from the increase of the tube wall thickness under the tube support plates (TSP). The tests demonstrate that such sleeve could be a possible remedy of the corrosion when introduced under the TSP. The tests show indications of a possible beneficial effect of the boric acid, a large variability of the heats sensitivity to the IGA and a predominant effect of Na 2 CO 3 on IGA production

Effect of Schiff's Bases as Corrosion Inhibitors on Mild Steel in Sulphuric Acid

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R. K. Upadhyay

2007-01-01

Full Text Available Mass loss and thermometric methods have been used to study the corrosion inhibitory effect of synthesised Schiff's bases viz. N-(furfurilidine – 4- methoxy aniline (SB1, N-(furfurilidine – 4- methylaniline (SB2, N-(salicylidine – 4- methoxy aniline (SB3, N-(cinnamalidine – 4 –methoxy aniline (SB4 and N-(cinnamalidine - 2-methylaniline (SB5 on mild steel in sulphuric acid solutions. Results show that both methods have good agreement with each other and inhibition efficiency depends upon the concentration of inhibitor as well as that of acid. Maximum inhibition efficiency is shown at highest concentration of Schiff's bases at the highest strength of acid.

Inhibition of mild steel corrosion using Jatropha Curcas leaf extract

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OLORUNFEMI MICHAEL AJAYI

2014-05-01

Full Text Available Jatropha Curcas leaf was investigated as a green inhibitor on the degradation of mild steel in 4 M HCl and 4 M H2SO4 aqueous solutions using gasometric technique. Mild steel coupons of dimension 2 × 1.5 cm were immersed in test solutions of uninhibited acid and also those with extract concentrations of 4 ml, 6 ml, 8 ml and 10 ml at 30 oC, for up to 30 minutes. The results showed that as the concentration of the extract increases, there was reduction in the corrosion rate. As the extract concentration increased from 4 ml to 10 ml at 30 minutes exposure, the volume of hydrogen gas evolved decreased from 19.1 cm3 to 11.2 cm3 in H2SO4 medium, while it reduced to 5 cm3 from 9 cm3 in HCl medium. Also, the metal surface-phytoconstituent interaction mechanism showed that 6 minutes is the best exposure time for the adsorption of the extract in both acidic media. The Jatropha Curcas leaf extract was adsorbed on the mild steel surface to inhibit corrosion, while the experimental data obtained at 30 minutes exposure in both acidic media were well fitted with the Langmuir adsorption isotherm. Hence, Jatropha Curcas leaf extract is a good and safe inhibitor in both acidic solutions.

Axenic aerobic biofilms inhibit corrosion of copper and aluminum.

Science.gov (United States)

Jayaraman, A; Ornek, D; Duarte, D A; Lee, C C; Mansfeld, F B; Wood, T K

1999-11-01

The corrosion behavior of unalloyed copper and aluminum alloy 2024 in modified Baar's medium has been studied with continuous reactors using electrochemical impedance spectroscopy. An axenic aerobic biofilm of either Pseudomonas fragi K or Bacillus brevis 18 was able to lessen corrosion as evidenced by a consistent 20-fold increase in the low-frequency impedance value of copper as well as by a consistent four- to seven-fold increase in the polarization resistance of aluminum 2024 after six days exposure compared to sterile controls. This is the first report of axenic aerobic biofilms inhibiting generalized corrosion of copper and aluminum. Addition of the representative sulfate-reducing bacterium (SRB) Desulfovibrio vulgaris (to simulate consortia corrosion behavior) to either the P. fragi K or B. brevis 18 protective biofilm on copper increased the corrosion to that of the sterile control unless antibiotic (ampicillin) was added to inhibit the growth of SRB in the biofilm.

Interaction of Benzimidazoles and Benzotriazole: Its Corrosion Protection Properties on Mild Steel in Hydrochloric Acid

Science.gov (United States)

Ramya, K.; Mohan, Revathi; Joseph, Abraham

2014-11-01

Synergistic hydrogen-bonded interaction of alkyl benzimidazoles and 1,2,3-benzotrizole and its corrosion protection properties on mild steel in hydrochloric acid at different temperatures have been studied using polarization, EIS, adsorption, surface studies, and computational methods. The extent of synergistic interaction increases with temperature. Quantum chemical approach is used to calculate some electronic properties of the molecules and to ascertain the synergistic interaction, inhibitive effect, and molecular structures. The corrosion inhibition efficiencies and the global chemical reactivity relate to some parameters, such as total energy, E HOMO, E LUMO, and gap energy (Δ E). 1,2,3-Benzotrizole interacts with benzimidazoles derivatives up to a bond length of approximately 1.99 Å. This interaction represents the formation of a hydrogen bond between the 1,2,3-benzotrizole and benzimidazoles. This synergistic interaction of 1,2,3-benzotrizole and benzimidazole derivatives offers extended inhibition efficiency toward mild steel in hydrochloric acid.

Effect of 4-(N,N-diethylamino)benzaldehyde thiosemicarbazone on the corrosion of aged 18 Ni 250 grade maraging steel in phosphoric acid solution

International Nuclear Information System (INIS)

Poornima, T.; Nayak, Jagannath; Nityananda Shetty, A.

2011-01-01

Highlights: → DEABT as corrosion inhibitor for maraging steel in phosphoric acid. → Inhibition efficiency increases with increase in inhibitor concentration. → Inhibition efficiency decreases with increase in temperature. → Adsorption obeys Langmuir adsorption isotherm. - Abstract: 4-(N,N-diethylamino)benzaldehyde thiosemicarbazone (DEABT) was studied for its corrosion inhibition property on the corrosion of aged 18 Ni 250 grade maraging steel in 0.67 M phosphoric acid at 30-50 deg. C by potentiodynamic polarization, EIS and weight loss techniques. Inhibition efficiency of DEABT was found to increase with the increase in DEABT concentration and decrease with the increase in temperature. The activation energy E a and other thermodynamic parameters (ΔG ads 0 , ΔH ads 0 , ΔS ads 0 ) have been evaluated and discussed. The adsorption of DEABT on aged maraging steel surface obeys the Langmuir adsorption isotherm model and the inhibitor showed mixed type inhibition behavior.

Synthesis and characterization of an effective organic/inorganic hybrid green corrosion inhibitive complex based on zinc acetate/Urtica Dioica

Science.gov (United States)

Salehi, E.; Naderi, Reza; Ramezanzadeh, B.

2017-02-01

This study aims at synthesis and characterization of an effective corrosion inhibitive complex based on zinc acetate/Urtica Dioica (ZnA-U.D) for corrosion protection of mild steel in chloride solution. The chemical structure and morphology of the complex were characterized by Fourier transform infrared spectroscopy (FT-IR), UV-vis, thermal gravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). The corrosion protection performance of the mild steel samples dipped in 3.5 wt.% NaCl solutions with and without ZnA-U.D extract was investigated by visual observations, open circuit potential (OCP) measurements, electrochemical impedance spectroscopy (EIS) and polarization test. Results revealed that the ZnA successfully chelated with organic inhibitive compounds (i.e Quercetin, Quinic acid, Caffeic acid, Hystamine and Serotonin) present in the U.D extract. The electrochemical measurements revealed the effective inhibition action of ZnA-U.D complex in the sodium chloride solution on the mild steel. The synergistic effect between Zn2+ and organic compounds present in the U.D extract resulted in protective film deposition on the steel surface, which was proved by SEM and XPS analyses.

Electrochemical studies of novel corrosion inhibitor for mild steel in 1 M hydrochloric acid

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Ahmed A. Al-Amiery

2018-06-01

Full Text Available The electrochemical performance of a novel organic corrosion inhibitor 6-(4-hydroxyphenyl-3-mercapto-7,8-dihydro-[1,2,4]triazolo[4,3-b][1,2,4,5]tetrazine [HT3], for mild steel in 1 M hydrochloric acid is evaluated by potentiodynamic curves. The experimental results show that the investigated inhibitor [HT3], which can effectively retard the corrosion process that occurs to mild steel with a hydrochloric acid solution by providing a protective coating for the mild steel that, can be weakened by increasing the temperature. Furthermore, the inhibition efficiency of [HT3] increased with increasing the concentrations of the inhibitors and decreased with increasing temperature. Keywords: Corrosion, Inhibitor, Mild steel, Potentiodynamic polarization, HT3, NMR, FT-IR

Mangrove tannins and their flavanoid monomers as alternative steel corrosion inhibitors in acidic medium

Energy Technology Data Exchange (ETDEWEB)

Rahim, Afidah A. [School of Chemical Sciences, University Sains Malaysia, 11800 Penang (Malaysia)]. E-mail: afidah@usm.my; Rocca, E. [Laboratoire de Chimie du Solide Mineral, Universite Henri Poincare, Nancy I BP 239, 54506 Vandoeuvre Les Nancy (France); Steinmetz, J. [Laboratoire de Chimie du Solide Mineral, Universite Henri Poincare, Nancy I BP 239, 54506 Vandoeuvre Les Nancy (France); Kassim, M.J. [School of Chemical Sciences, University Sains Malaysia, 11800 Penang (Malaysia); Adnan, R. [School of Chemical Sciences, University Sains Malaysia, 11800 Penang (Malaysia); Sani Ibrahim, M. [School of Chemical Sciences, University Sains Malaysia, 11800 Penang (Malaysia)

2007-02-15

The inhibitive behaviour on steel of flavanoid monomers that constitute mangrove tannins namely catechin, epicatechin, epigallocatechin and epicatechingallate was investigated in an aerated HCl solution via electrochemical methods. The monomers were found to be mainly cathodic inhibitors and the inhibition efficiency was dependent on concentration. To explain the adsorptive behaviour of the molecules on the steel surface, a semiempirical approach involving quantum chemical calculations using HyperChem 6.0 was undertaken. The HOMO electronic density of the molecule was used to explain the inhibiting mechanism. The most probable adsorption centers were found in the vicinity of the phenolic groups. In a second part, the use of mangrove tannin, extracted from the mangrove barks as steel corrosion inhibitors in acidic media was investigated and its inhibitive efficiency was compared with that of commercial mimosa, quebracho and chestnut tannins. The inhibitive performance of mangrove tannins was comparable to the other tannins investigated, indicating their potential in corrosion protection.

Mangrove tannins and their flavanoid monomers as alternative steel corrosion inhibitors in acidic medium

International Nuclear Information System (INIS)

Rahim, Afidah A.; Rocca, E.; Steinmetz, J.; Kassim, M.J.; Adnan, R.; Sani Ibrahim, M.

2007-01-01

The inhibitive behaviour on steel of flavanoid monomers that constitute mangrove tannins namely catechin, epicatechin, epigallocatechin and epicatechingallate was investigated in an aerated HCl solution via electrochemical methods. The monomers were found to be mainly cathodic inhibitors and the inhibition efficiency was dependent on concentration. To explain the adsorptive behaviour of the molecules on the steel surface, a semiempirical approach involving quantum chemical calculations using HyperChem 6.0 was undertaken. The HOMO electronic density of the molecule was used to explain the inhibiting mechanism. The most probable adsorption centers were found in the vicinity of the phenolic groups. In a second part, the use of mangrove tannin, extracted from the mangrove barks as steel corrosion inhibitors in acidic media was investigated and its inhibitive efficiency was compared with that of commercial mimosa, quebracho and chestnut tannins. The inhibitive performance of mangrove tannins was comparable to the other tannins investigated, indicating their potential in corrosion protection

Thermodynamic studies on corrosion inhibition of aqueous solutions of amino/carboxylic acids toward copper by EMF measurement

International Nuclear Information System (INIS)

Spah, Manjula; Spah, Dal Chand; Deshwal, Balraj; Lee, Seungmoon; Chae, Yoon-Keun; Park, Jin Won

2009-01-01

Electromotive force (E) measurements were made on an electrochemical cell [Cu x Hg|CuCl 2 (m) in a solvent S|AgCl-Ag] (where S is a dilute aqueous solution (0.01 m) of amino acid (glycine, alanine, methionine and glutamic acid) or aliphatic carboxylic acid (formic acid, acetic acid, n-butyric acid and glutaric acid)) at 30 deg. C. These measured E values were used to compute the dissociation constants (K 1 and K 2 ) and the degree of dissociation (α 1 and α 2 ) by iterative procedures. The standard cell potential (E o ) and the mean activity coefficient (γ ± ) of CuCl 2 were also determined. The E o data were next used to evaluate the Gibbs energy of transfer (ΔG tr 0 ) of CuCl 2 from water to dilute aqueous solutions of the amino/carboxylic acids. The negative ΔG tr 0 values suggested that these acids act as potential corrosion inhibitors. The magnitudes of ΔG tr 0 values show that the amino acids act as better corrosion inhibitors towards copper than the aliphatic carboxylic acids.

Adsorption and Corrosion Inhibition Studies of Some Selected Dyes as Corrosion Inhibitors for Mild Steel in Acidic Medium: Gravimetric, Electrochemical, Quantum Chemical Studies and Synergistic Effect with Iodide Ions

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Thabo Peme

2015-09-01

Full Text Available The corrosion inhibition properties of some organic dyes, namely Sunset Yellow (SS, Amaranth (AM, Allura Red (AR, Tartrazine (TZ and Fast Green (FG, for mild steel corrosion in 0.5 M HCl solution, were investigated using gravimetric, potentiodynamic polarization techniques and quantum chemical calculations. The results showed that the studied dyes are good corrosion inhibitors with enhanced inhibition efficiencies. The inhibition efficiency of all the studied dyes increases with increase in concentration, and decreases with increase in temperature. The results showed that the inhibition efficiency of the dyes increases in the presence of KI due to synergistic interactions of the dye molecules with iodide (I− ions. Potentiodynamic polarization results revealed that the studied dyes are mixed-type inhibitors both in the absence and presence of KI. The adsorption of the studied dyes on mild steel surface, with and without KI, obeys the Langmuir adsorption isotherm and involves physical adsorption mechanism. Quantum chemical calculations revealed that the most likely sites in the dye molecules for interactions with mild steel are the S, O, and N heteroatoms.

Adsorption and Corrosion Inhibition Studies of Some Selected Dyes as Corrosion Inhibitors for Mild Steel in Acidic Medium: Gravimetric, Electrochemical, Quantum Chemical Studies and Synergistic Effect with Iodide Ions.

Science.gov (United States)

Peme, Thabo; Olasunkanmi, Lukman O; Bahadur, Indra; Adekunle, Abolanle S; Kabanda, Mwadham M; Ebenso, Eno E

2015-09-02

The corrosion inhibition properties of some organic dyes, namely Sunset Yellow (SS), Amaranth (AM), Allura Red (AR), Tartrazine (TZ) and Fast Green (FG), for mild steel corrosion in 0.5 M HCl solution, were investigated using gravimetric, potentiodynamic polarization techniques and quantum chemical calculations. The results showed that the studied dyes are good corrosion inhibitors with enhanced inhibition efficiencies. The inhibition efficiency of all the studied dyes increases with increase in concentration, and decreases with increase in temperature. The results showed that the inhibition efficiency of the dyes increases in the presence of KI due to synergistic interactions of the dye molecules with iodide (I(-)) ions. Potentiodynamic polarization results revealed that the studied dyes are mixed-type inhibitors both in the absence and presence of KI. The adsorption of the studied dyes on mild steel surface, with and without KI, obeys the Langmuir adsorption isotherm and involves physical adsorption mechanism. Quantum chemical calculations revealed that the most likely sites in the dye molecules for interactions with mild steel are the S, O, and N heteroatoms.

Corrosion polarization behaviour and inhibition of S40977 stainless steel in benzosulfonazole/3 M H2SO4 solution

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Roland Tolulope Loto

2017-12-01

Full Text Available Benzosulfonazole was evaluated for its corrosion inhibition effect on S40977 stainless steel in 3 M H2SO4 solution through potentiodynamic polarization, open circuit potential measurement, optical microscopy and IR spectroscopy. Results obtained showed the effective performance of the compound with values of 77.33%–88.32% inhibition efficiency, at 0.25%–1.25% inhibitor concentration from electrochemical analysis. Corrosion potential value decreased from −0.359 V to −0.306 V upon addition of the compound at 0.25% concentration, which decreased progressively to −0.278 at 1.25% concentration. Identified functional groups of alcohols, phenols, amines, amides, carboxylic acids, aliphatic amines, esters and ethers within the compound completely adsorbed onto the steel from analysis of the adsorption spectra while others decreased in intensity due to partial adsorption. Thermodynamic calculations showed the cationic adsorption to be through chemisorption mechanism according to Langmuir, Freundlich and Temkin adsorption isotherms. Micro-analytical images showed a severely corroded morphology with corrosion pits in the absence of benzosulfonazole which contrast the images obtained with the inhibitor addition. The compound was determined to be mixed type inhibition. Keywords: Corrosion, Inhibitor, Benzosulfonazole, Sulphuric acid

Synergistic Effect of L-Methionine and KI on Copper Corrosion Inhibition in HNO3 (1M

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Amel SEDIK

2014-05-01

Full Text Available L-Methionine (L-Met efficiency as a non-toxic corrosion inhibitor for copper in 1M HNO3 has been studied by using electrochemical impedance spectroscopy (EIS and potentiodynamic polarization. Copper corrosion rate significant decrease was observed in the presence of L-Met at 10-4M. The Obtained Results from potentiodynamic polarization and impedance measurements are in good agreement. L-Methionine adsorption on copper surface follows Langmuir isotherm. L-Met free energy adsorption on copper (-30 KJ mol-1 reveals an inhibition strong physical adsorption on copper surface. In order to evaluate the L-Met effect, L-Met and iodide ion’synergistic effect was used to prevent copper corrosion in nitric acid. It was found that inhibitor efficiency (IE reached 98.27 % in 1M solution containing 10-4M L-Met and 10- 3 M KI. The synergistic effect was attributed to iodide ions adsorption on copper surface, which facilitated the L-Met adsorption and an inhibitive film formation.

Propolis as a green corrosion inhibitor for bronze in weakly acidic solution

Science.gov (United States)

Varvara, Simona; Bostan, Roxana; Bobis, Otilia; Găină, Luiza; Popa, Florin; Mena, Vicente; Souto, Ricardo M.

2017-12-01

In the present work, the inhibitive action of natural propolis on bronze corrosion in a weakly acidic solution containing Na2SO4 and NaHCO3 at pH 5 was evaluated using multiscale electrochemical techniques, namely potentiodynamic polarization, electrochemical impedance spectroscopy and scanning vibrating electrode technique measurements. The major constituents of propolis were identified by HPLC. Surface characterization was performed by SEM-EDX and AFM analysis. Experiments were performed as a function of the propolis concentration and immersion time in the corrosive electrolyte. The obtained results showed that propolis presents good anticorrosive properties on bronze, acting as a mixed-type inhibitor, but its protective effectiveness is time-dependent. The highest inhibiting efficiency of 98.9% was obtained in the presence of 100 ppm propolis, after about 12 h of exposure to inhibitor-containing electrolyte through the stabilization of Cu2O on the bronze surface. The inhibitive properties of propolis on bronze corrosion are likely due to the adsorption of its main constituents (flavonoids and phenolic compounds), through the oxygen atoms in their functional groups and aromatic rings, which have been evidenced by FT-IR spectra. The adsorption of propolis on bronze was found to follow Langmuir adsorption isotherm.

Inhibition of Bio corrosion of steel coupon by sulphate reducing ...

African Journals Online (AJOL)

ADOWIE PERE

Inhibition of Bio corrosion of steel coupon by sulphate reducing bacteria and Iron oxidizing bacteria using .... Ethanol for 24 h. The extract was ... with distilled water to get a zero reading from the meter before .... Ethanol extract of musa species peels as a green corrosion ... Eco friendly extract of banana peel as corrosion ...

Corrosion and inhibition of stainless steel pitting corrosion in alkaline medium and the effect of Cl- and Br- anions

International Nuclear Information System (INIS)

Refaey, S.A.M.; Taha, F.; El-Malak, A.M. Abd

2005-01-01

The effect of carbonate anion on the pitting corrosion and inhibition behavior of stainless steel samples (304L SS and 316L SS) has been studied using potentiodynamic and scanning electron microscope (SEM) techniques. The effect of concentration of CO 3 2- ions, pH, potential scanning rate and the composition of stainless steel are discussed. Additions of Cl - and Br - ions into the carbonate solution increase the anodic dissolution of stainless steel and decrease its pitting corrosion resistance. The effect of CO 3 2- anion on the inhibition of chloride and bromide pitting corrosion of the two stainless steel types has been studied also. Pitting corrosion decrease with the increasing of sodium carbonate concentration, i.e. increases the resistance of stainless steels towards the chloride and bromide pitting corrosion. This inhibition effect argued to formation of [Fe,Cr]CO 3 film caused by preferential adsorption of the CO 3 2- ion, leading to instantaneous repair of weak sites for pit nucleation

Gossipium hirsutum L. extract as green corrosion inhibitor for ...

African Journals Online (AJOL)

Inhibitive effect of Gossipium hirsutum L. leaves extract on the acid corrosion of aluminum in 1 M HCl solution was studied by weight loss technique. The extract at optimum concentration inhibited the corrosion of aluminum, with about 92% inhibition efficiency and the inhibition efficiency increased with increasing ...

Inhibition study of additives towards the corrosion of ferrous metal in palm biodiesel

International Nuclear Information System (INIS)

Fazal, M.A.; Sazzad, B.S.; Haseeb, A.S.M.A.; Masjuki, H.H.

2016-01-01

Highlights: • TBA doped biodiesel exhibits fairly good corrosion inhibition efficiency. • TBA forms nitrogen-containing layer on metal surface and protects the corrosion. • Materials exposed to TBA doped biodiesel show less surface roughness. - Abstract: Some efforts have already been given by other researchers to characterize the corrosion behavior of different metals in biodiesel. However, there is very limited information on its remedial measure. Therefore, this study investigates the effects of tert-butylamine (TBA), benzotriazole (BTA), butylate-dhydroxytoluene (BHT), and pyrogallol (PY) on the corrosion of cast iron (CI) and low carbon steel (LCS) through an immersion test in palm biodiesel (B100) at 300 K. Result shows that TBA-doped biodiesel exhibits fairly good corrosion-inhibiting properties for materials exposed to B100. Inhibition efficiency of TBA is found to be 86.54% and 86.71% for CI and LCS, respectively which is far better than other tested additives in this study. The high inhibition efficiency could be attributed to the dominant physical adsorption of N-containing compound which creates a protective layer over the metal surface and prevents corrosion.

Some aromatic hydrazone derivatives as inhibitors for the corrosion of C-steel in phosphoric acid solution.

Science.gov (United States)

Fouda, Abd El-Aziz S; Al-Sarawy, Ahmed A; Radwan, Mohamed S

2006-01-01

The effect of furfural benzoylhydrazone and its derivatives (I-VII) as corrosion inhibitors for C-steel in 1M phosphoric acid solution has been studied by weight-loss and galvanostatic polarization techniques. A significant decrease in the corrosion rate of C-steel was observed in the presence of the investigated inhibitors. This study revealed that, the inhibition efficiency increases with increasing the inhibitor concentration, and the addition of iodide ions enhances it to a considerable extent. The effect of temperature on the inhibition efficiency of these compounds was studied using weight-loss method. Activation energy (E(a)*) and other thermodynamic parameters for the corrosion process were calculated and discussed. The galvanostatic polarization data indicated that, the inhibitors were of mixed-type, but the cathode is more polarized than the anode. The adsorption of these compounds on C-steel surface has been found to obey Frumkin's adsorption isotherm. The mechanism of inhibition was discussed in the light of the chemical structure of the undertaken inhibitors.

Corrosion inhibitors

International Nuclear Information System (INIS)

El Ashry, El Sayed H.; El Nemr, Ahmed; Esawy, Sami A.; Ragab, Safaa

2006-01-01

The corrosion inhibition efficiencies of some triazole, oxadiazole and thiadiazole derivatives for steel in presence of acidic medium have been studied by using AM1, PM3, MINDO/3 and MNDO semi-empirical SCF molecular orbital methods. Geometric structures, total negative charge on the molecule (TNC), highest occupied molecular energy level (E HOMO ), lowest unoccupied molecular energy level (E LUMO ), core-core repulsion (CCR), dipole moment (μ) and linear solvation energy terms, molecular volume (V i ) and dipolar-polarization (π *), were correlated to corrosion inhibition efficiency. Four equations were proposed to calculate corrosion inhibition efficiency. The agreement with the experimental data was found to be satisfactory; the standard deviations between the calculated and experimental results ranged between ±0.03 and ±4.18. The inhibition efficiency was closely related to orbital energies (E HOMO and E LUMO ) and μ. The correlation between quantum parameters and experimental inhibition efficiency has been validated by single point calculations for the semi-empirical AM1 structures using B3LYP/6-31G** as a higher level of theory. The proposed equations were applied to predict the corrosion inhibition efficiency of some related structures to select molecules of possible activity from a presumable library of compounds

Synthesis and Application of Phenyl Nitrone Derivatives as Acidic and Microbial Corrosion Inhibitors

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Shijun Chen

2015-01-01

Full Text Available Nitrone has drawn great attention due to its wide applications as a 1,3-dipole in heterocyclic compounds synthesis and the bioactivities. With the special structure, nitrone can also be used as ligand in inorganic chemistry. Based on the current research, the nitrones are anticipated to be effective inhibitors against acidic and microbial corrosion. The aim of this work is to investigate the inhibitory action of nitrones. In this work, a series of phenyl nitrone derivatives (PN was synthesized and used as acidic and microbial corrosion inhibitors. The results indicate that several compounds show moderate to high inhibition efficiency (IE in 3% HCl. Accompanied with HMTA or BOZ, the IEs greatly increase, and the highest efficiency of 98.5% was obtained by using PN4 + BOZ. Investigation of the antibacterial activity against oilfield microorganism shows that the nitrone derivatives can inhibit SRB, IB, and TGB with moderate to high efficiency under 1,000 mg/L, which makes them potential to be used as bifunctional oilfield chemicals.

Corrosion Chemistry in Inhibited HDA.

Science.gov (United States)

1980-11-30

which are likely to resemble authentic Modified HDA corrosion products, and reactions of a range of metal fluorides with difluorphosphoric acid have i...Introduction 10 (b) Solutions of HF in nitric acid and in HDA 10 (c) Solutions of PF5 in HDA 10 (d) Solutions of HPO 2 F2 in HDA 15 (e) Solutions of...of metals with HPO F in HDA 2 2 solution. 166 Iron. 166 Nickel. 166 (c) Reactions of metal fluorides with difluorophosphoric acid . 169 B-FeF 3.3H 2 0

Corrosion inhibition performance of imidazolium ionic liquids and their influence on surface ferrous carbonate layer formation

Science.gov (United States)

Yang, Dongrui

Corrosion inhibitors as effective anti-corrosion applications were widely studied and drawn much attention in both academe and industrial area. In this work, a systematic work, including inhibitors selection, anti-corrosion property and characterization, influence on scale formation, testing system design and so on, were reported. The corrosion inhibition performance of four imidazolium ionic liquids in carbon dioxide saturated NaCl solution was investigated by using electrochemical and surface analysis technologies. The four compounds are 1-ethyl-3-methylimidazolium chloride (a), 1-butyl-3-methylimidazolium chloride (b), 1-hexyl-3-methylimidazolium chloride (c), 1-decyl-3-methylimidazolium chloride (d). Under the testing conditions, compound d showed the highest inhibition efficiency and selected as the main object of further study. As a selected representative formula, 1-decyl-3-methylimidazolium chloride was studied in detail about its corrosion inhibition performance on mild steel in carbon dioxide saturated NaCl brine at pH 3.8 and 6.8. Electrochemical and surface analysis techniques were used to characterize the specimen corrosion process during the immersion in the blank and inhibiting solutions. The precorrosion of specimen surface showed significant and different influences on the anti-corrosion property of DMICL at pH 3.8 and 6.8. The corrosion inhibition efficiency (IE) was calculated based on parameters obtained from electrochemical techniques; the achieved IE was higher than 98% at the 25th hour for the steel with a well-polished surface at pH 3.8. The fitting parameters obtained from electrochemical data helped to account for the interfacial changes. As proved in previous research, 1-decyl-3-methylimidazolium chloride could be used as good corrosion inhibitors under certain conditions. However, under other conditions, such chemicals, as well as other species in oil transporting system, could be a factor influencing the evolution of protective surface

Corrosion inhibition of iota-carrageenan natural polymer on aluminum in presence of zwitterion mediator in HCl media

International Nuclear Information System (INIS)

Fares, Mohammad M.; Maayta, A.K.; Al-Mustafa, Jamil A.

2012-01-01

Highlights: ► Inhibition of Al by ι-carrageenan in the presence of zwitterion mediator was investigated. ► Considerable improvement in inhibition efficiency observed in the presence of zwitterion mediator. ► Coherent physical adsorption layer was evidenced by kinetic and thermodynamic parameters. ► Small but consistent fractured island layers observed after acid exposure as revealed by SEM images. - Abstract: ι-Carrageenan a natural polymer has been used as corrosion inhibitor of aluminum in presence of pefloxacin mesylate, acting as zwitterionic mediator, in acidic medium. Considerable improvement in inhibition efficiency occurred in the presence of the mediator. Activation energy of corrosion and other thermodynamic parameters such as standard free energy, standard enthalpy, and standard entropy of the adsorption process revealed better and well-ordered physical adsorption layers in presence of pefloxacin. Adsorption isotherms in absence or presence of pefloxacin mediator appropriately fit in the Langmuir isotherms. The scanning electron microscope (SEM) images demonstrated smooth, glossy, and relatively coherent adsorption layers of the inhibitor on the metal surface in aqueous solution. After the exposure to 2.0 M HCl for 2 h, a smaller but consistent regular shaped fractured layer is obtained.

Xanthium strumarium leaves extracts as a friendly corrosion inhibitor of low carbon steel in hydrochloric acid: Kinetics and mathematical studies

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Anees A. Khadom

2018-06-01

Full Text Available Corrosion inhibition of low carbon steel in 1 M HCl was investigated in absence and presence of Xanthium strumarium leaves (XSL extracts as a friendly corrosion inhibitor. The effect of temperature and inhibitor concentration was studied using weight loss method. The result obtained shown that Xanthium strumarium leaves extracts act as an inhibitor for low carbon steel in HCl and reduces the corrosion rate. The inhibition efficiency was found to increases with increase in inhibitor concentration and temperature. Higher inhibition efficiency was 94.82% at higher level of inhibitor concentration and temperature. The adsorption of Xanthium strumarium leaves extracts was found to obey Langmuir adsorption isotherm model. The values of the free energy of adsorption was more than −20 kJ/mol, which is indicative of mixed mode of physical and chemical adsorption. Keywords: Corrosion, Green inhibitor, Natural extracts, Low carbon steel, Acid, Adsorption

Inhibition of corrosion of carbon steel by heptane sulphonic acid – Zn2+ system

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C. MARY ANBARAS

2012-03-01

Full Text Available Corrosion inhibition of carbon steel in dam water by sodium heptane sulphonate (SHS and zinc ion system was investigated using weight loss and potentiodynamic polarization methods. Results of weight loss method indicated that inhibition efficiency (IE increased as the inhibitor concentration increased. A synergistic effect existed between SHS and Zn2+. The influence of sodium potassium tartrate (SPT on the IE of the SHS-Zn2+ system was evaluated. As the immersion period increased, the IE decreased. Polarization study revealed that SHS-Zn2+ system functioned as a cathodic inhibitor. AC impedance spectra revealed that a protective film was formed on the metal surface. The nature of the metal surface was analyzed by FTIR spectra, SEM and AFM analyses.

Corrosion Inhibition in the Secondary Cooling System of ETRR-2, Egypt

International Nuclear Information System (INIS)

Aly, A.H.; Gad, M.M.A.; Abdel-Karim, R.; Abdel-Salam, O.F.

2003-01-01

The second Egyptian research reactor (ETRR-2) is a light water type of 22 MW thermal power. Proper cooling water treatment is necessary to set the water chemical characteristics within a specified window to avoid or minimize corrosion problems, scale formation, fouling, and microbiological contamination. Selection of a proper and economic corrosion inhibitor is of great importance. This selection depends, among other factors, on the availability as well as cost. The corrosion behaviour of water of ETRR-2 site and its inhibition by different inhibitors was studied in a special test rig designed for this purpose. Sodium salts of polyphosphate, phosphate, molybdate, and tungstate were used to treat and qualify the cooling water. Results showed that the corrosion resistance of the test material depends on both type and concentration of the applied inhibitor. Using 30-ppm tungstate, molybdate, and phosphate (as anodic inhibitors) reduced the corrosion rate, and inhibitor efficiencies of about 97% 86%, and 68% were achieved respectively. Accordingly, sodium tungstate could be ranked as the best anodic inhibitor used followed by molybdate. Sodium phosphate could be ranked as the least efficient one. Adding the same concentration of sodium polyphosphate (as a cathodic inhibitor) yields almost the same inhibition efficiency as tungstate type. However, at higher concentration(40 ppm), an inhibition efficiency of 100% was obtained, Which corresponds to almost zero-corrosion rate

Corrosion inhibition of aluminum with a series of aniline monomeric surfactants and their analog polymers in 0.5 M HCl solution

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M.M. El-Deeb

2015-07-01

Full Text Available The inhibition effect of 3-(12-sodiumsulfonate dodecyloxy aniline monomeric surfactant (MC12 and its analog polymer Poly 3-(dodecyloxy sulfonic acid aniline (PC12 on the corrosion of aluminum in 0.5 M HCl solution was investigated using weight loss and potentiodynamic polarization techniques. The presence of these two compounds in 0.5 M HCl inhibits the corrosion of aluminum without modifying the mechanism of corrosion process. It was found that these inhibitors act as mixed-type inhibitors with anodic predominance as well as the inhibition efficiency increases with increasing inhibitor concentration, but decreases with raising temperature. Langmuir and Frumkin adsorption isotherms fit well with the experimental data. Thermodynamic functions for both dissolution and adsorption processes were determined. The obtained results from weight loss and potentiodynamic polarization techniques are in good agreement with contact angle measurements.

Study on Corrosion Inhibition Efficiency of Stem Alkaloid Extract of Different Varieties of Holy Basil on Aluminium in HCl Solution

Energy Technology Data Exchange (ETDEWEB)

Kumpawat, Nutan; Chaturvedi, Alok; Upadhyay, R. K. [Synthetic and Surface Science Laboratory, Ajmer (India)

2012-08-15

Corrosion inhibition efficiencies of holy basil on Al in HCl solution were studied by weight loss and thermometric methods in presence and in absence of stem extract of three different varieties of holy basil viz. ocimum basilicum (E{sub B}), ocimum canum (E{sub C}) and ocimum sanctum (E{sub S}). Inhibition efficiency increases with the increasing concentration of stem extract and decreases with increases in acid strength. Results show that all varieties under study are good corrosion inhibitors, among which, E{sub B} is most effective. Maximum inhibition efficiency was found 97.09% in 0.5N HCl solution with 0.6% stem extract. The Langmuir adsorption isotherm indicates that surface coverage also increases with increasing in the concentration of extract of stem in HCl solution.

Study on Corrosion Inhibition Efficiency of Stem Alkaloid Extract of Different Varieties of Holy Basil on Aluminium in HCl Solution

International Nuclear Information System (INIS)

Kumpawat, Nutan; Chaturvedi, Alok; Upadhyay, R. K.

2012-01-01

Corrosion inhibition efficiencies of holy basil on Al in HCl solution were studied by weight loss and thermometric methods in presence and in absence of stem extract of three different varieties of holy basil viz. ocimum basilicum (E B ), ocimum canum (E C ) and ocimum sanctum (E S ). Inhibition efficiency increases with the increasing concentration of stem extract and decreases with increases in acid strength. Results show that all varieties under study are good corrosion inhibitors, among which, E B is most effective. Maximum inhibition efficiency was found 97.09% in 0.5N HCl solution with 0.6% stem extract. The Langmuir adsorption isotherm indicates that surface coverage also increases with increasing in the concentration of extract of stem in HCl solution

Boric acid corrosion of low alloy steel

Energy Technology Data Exchange (ETDEWEB)

Jones, R.; White, G.; Collin, J.; Marks, C. [Dominion Engineering, Inc., Reston, Virginia (United States); Reid, R.; Crooker, P. [Electric Power Research Inst., Palo Alto, California (United States)

2010-07-01

In the last decade, the industry has been aware of a potential loss of coolant accident (LOCA) per the following scenario: primary water stress corrosion cracking (PWSCC) of a primary system component or weld leads to a coolant leak, the coolant corrodes a low alloy steel structural component (e.g., the reactor vessel (RV) or the reactor vessel head (RVH)), and corrosion degrades the pressure boundary leading to a loss of coolant accident. The industry has taken several steps to address this concern, including replacement of the most susceptible components (RVH replacement), enhanced inspection (both NDE of components and visual inspections for boric acid deposits), and safety analyses to determine appropriate inspection intervals. Although these measures are generally thought to have adequately addressed this issue, there have been some uncertainties in the safety analyses which the industry has sought to address in order to quantify the extent of conservatism in the safety analyses. Specifically, there has been some uncertainty regarding the rate of boric acid corrosion under various conditions which might arise due to a PWSCC leak and the extent to which boric acid deposits are retained near the leak under various geometries. This paper reviews the results of the Electric Power Research Institute (EPRI) Materials Reliability Program (MRP) boric acid corrosion (BAC) test programs conducted over the last 8 years, focusing on the most recent results of full-scale mockup testing of CRDM nozzle and bottom mounted nozzle (BMN) configurations. The main purpose of this presentation is to provide an overview of the latest understanding of the risk of boric acid corrosion as it is informed by the results of the testing conducted over the last eight years. The rate of boric acid corrosion has been found to be a function of many factors, including initial chemistry, the extent of concentration due to boiling, the temperature at which concentration takes place, the velocity

A New Green Ionic Liquid-Based Corrosion Inhibitor for Steel in Acidic Environments

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Ayman M. Atta

2015-06-01

Full Text Available This work examines the use of new hydrophobic ionic liquid derivatives, namely octadecylammonium tosylate (ODA-TS and oleylammonium tosylate (OA-TS for corrosion protection of steel in 1 M hydrochloric acid solution. Their chemical structures were determined from NMR analyses. The surface activity characteristics of the prepared ODA-TS and OA-TS were evaluated from conductance, surface tension and contact angle measurements. The data indicate the presence of a double bond in the chemical structure of OA-TS modified its surface activity parameters. Potentiodynamic polarization, electrochemical impedance spectroscopy (EIS measurements, scanning electron microscope (SEM, Energy dispersive X-rays (EDX analysis and contact angle measurements were utilized to investigate the corrosion protection performance of ODA-TS and OA-TS on steel in acidic solution. The OA-TS and ODA-TS compounds showed good protection performance in acidic chloride solution due to formation of an inhibitive film on the steel surface.

Electrochemical measurements for the corrosion inhibition of mild steel in 1 M hydrochloric acid by using an aromatic hydrazide derivative

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P. Preethi Kumari

2017-07-01

Full Text Available The influence of an aromatic hydrazide derivative, 2-(3,4,5-trimethoxybenzylidene hydrazinecarbothioamide (TMBHC as corrosion inhibitor on mild steel in 1 M hydrochloric acid was studied by Tafel polarization and electrochemical impedance spectroscopy (EIS technique. The results showed that the inhibition efficiency (% IE of TMBHC increased with increasing inhibitor concentrations and also with increase in temperatures. TMBHC acted as a mixed type of inhibitor and its adsorption on mild steel surface was found to follow Langmuir’s adsorption isotherm. The evaluation of thermodynamic and activation parameters indicated that the adsorption of TMBHC takes place through chemisorption. The formation of protective film was further confirmed by scanning electron microscopy (SEM.

A comparative study of the corrosion inhibition of mild steel in sulphuric acid by 4,4-dimethyloxazolidine-2-thione

International Nuclear Information System (INIS)

Musa, Ahmed Y.; Kadhum, Abdul Amir H.; Mohamad, Abu Bakar; Daud, Abdul Razak; Takriff, Mohd Sobri; Kamarudin, Siti Kartom

2009-01-01

The corrosion protection of mild steel in a 2.5 M H 2 SO 4 solution by 4,4-dimethyloxazolidine-2-thione (DMT) was studied at different temperatures by measuring changes in open circuit potential (OCP), potentiodynamic polarisation and electrochemical impedance spectroscopy (EIS). Corrosion current densities calculated from EIS data were comparable to those obtained from polarisation measurements. Results showed that DMT inhibited mild steel corrosion in a 2.5 M H 2 SO 4 solution and indicated that the inhibition efficiencies increased with the concentration of inhibitor, but decreased proportionally with temperature. Polarisation curves showed that DMT is a mixed-type inhibitor. Changes in impedance parameters suggested the adsorption of DMT on the mild steel surface, leading to the formation of protective films. The DMT adsorption on the mild steel surface followed the Langmuir adsorption isotherm. The kinetic and thermodynamic parameters for dissolution and adsorption were investigated. Comprehensive adsorption (physisorption and chemisorption) of the inhibitor molecules on the mild steel surface was suggested based on the thermodynamic adsorption parameters.

Inhibition Effect of Deanol on Mild Steel Corrosion in Dilute ...

African Journals Online (AJOL)

NICOLAAS

2014-06-23

Jun 23, 2014 ... The influence of deanol on the corrosion behaviour of mild steel in dilute sulphuric acid with sodium ... the formation of a complex precipitate of protective film, which ... silicon carbide abrasive papers of 80, 120, 220, 800 and 1000 grit ...... ions in sulphuric acid on the corrosion behaviour of stainless steel,.

Synergistic Effect of Azadirachta Indica Extract and Iodide Ions on the Corrosion Inhibition of Aluminium in Acid Media

Energy Technology Data Exchange (ETDEWEB)

Arab, S. T.; Al- Turkustani, A. M.; Al- Dhahiri, R. H. [King Abd El- Aziz University, Jeddah (Saudi Arabia)

2008-06-15

The synergistic action caused by iodide ions on the corrosion inhibition of aluminium (Al) in 0.5 M HCl in the presence of Azadirachta Indica (AZI) plant extract has been investigated using potintiodynamic polarization and impedance techniques. It is found that AZI extract inhibits the corrosion of aluminium in 0.5 M HCl. The inhibition efficiency increases with the increase in AZI extract concentration, until 24% v/v of AZI extract, then Inh.% is decreased with father increase in AZI extract concentration. The adsorption of this extract in the studied concentration is found to obey Frewendlish adsorption isotherm. The addition of iodide ions enhances the inhibition efficiency to a considerable extent. The increase in Inh.% values in presence of fixed concentration of iodide ions indicates that AZI extract forms an insoluble complex at lower AZI extract concentrations by undergoing a joint adsorption. But at higher concentrations of AZI extract, competitive adsorption is found between iodide ions and the formed complex leading to less Inh.%. The Inh.% decreased in presence of iodide ions with AZI extract than in presence of AZI extract alone at all studied iodide concentrations. The synergism parameter S {sub θ} is defined and calculated from surface coverage values. This parameter in the case of AZI extract is found to be more than unity, indicating that the enhanced inhibition efficiency caused by the addition of iodide ions.

The corrosion protection of several aluminum alloys by chromic acid and sulfuric acid anodizing

Science.gov (United States)

Danford, M. D.

1994-01-01

The corrosion protection afforded 7075-T6, 7075-T3, 6061-T6, and 2024-T3 aluminum alloys by chromic acid and sulfuric acid anodizing was examined using electrochemical techniques. From these studies, it is concluded that sulfuric acid anodizing provides superior corrosion protection compared to chromic acid anodizing.

Bacillus sp. Acting as Dual Role for Corrosion Induction and Corrosion Inhibition with Carbon Steel (CS

Directory of Open Access Journals (Sweden)

Santosh K. Karn

2017-10-01

Full Text Available Present work investigated the role of five different bacteria species as a corrosion inducer as well as corrosion inhibitor with carbon steel (CS. We observed the ability of different bacteria species on the metal surface attachment, biofilm formation, and determined Peroxidase, Catalase enzyme activity in the detached biofilm from the CS surface. We found that each strain has diverse conduct for surface attachment like DS1 3.3, DS2 2.5, DS3 4.3, DS4 4.0, and DS5 4.71 log cfu/cm2 and for biofilm 8.3 log cfu/cm2. The enzyme Peroxidase, Catalase was found in huge concentration inside the biofilm Peroxidase was maximum for DS4 36.0 U/ml and least for DS3 19.54 U/ml. Whereas, Catalase was highest for DS4, DS5 70.14 U/ml and least 57.2 U/ml for DS2. Scanning electron microscopy (SEM was conducted to examine the biofilm and electrochemical impedance spectroscopy (EIS were utilized to observe corrosion in the presence of bacteria. The electrochemical results confirmed that DS1, DS3, DS4, and DS5 strains have statistically significant MIC-factors (Microbially Influenced Corrosion of 5.46, 8.51, 2.36, and 1.04, while DS2 protective effect factor of 0.89. Weight reduction results with carbon steel likewise supports that corrosion was initiated by DS1 and DS3, while DS2 and DS5 have no any impact though with DS4 we watched less weight reduction however assumed no role in the corrosion. We established the relation of Peroxidase enzyme activity of the isolates. DS1, DS3 and having Peroxidase in the range 22.18, 19.54 U/ml which induce the corrosion whereas DS2 and DS5 having 28.57 and 27.0 U/ml has no any effect and DS4 36 U/ml has inhibitory effect, increasing concentration inhibiting the corrosion. For Catalase DS1, DS3 have 67.28, 61.57 U/ml which induce corrosion while DS2 and DS5 57.71 and 59.14 U/ml also has no effect whereas DS4 70.14 U/ml can inhibit corrosion. Results clearly express that in a specific range both enzymes can induce the corrosion

Electrochemical investigation of the properties of Co doped ZnO nanoparticle as a corrosion inhibitive pigment for modifying corrosion resistance of the epoxy coating

International Nuclear Information System (INIS)

Rostami, M.; Rasouli, S.; Ramezanzadeh, B.; Askari, A.

2014-01-01

Highlights: • Corrosion inhibitive pigment based on ZnOCo was synthesized through combustion method. • Doping ZnO nanoparticle with Co enhanced its inhibition properties considerably. • ZnOCo nanoparticle could enhance corrosion protective performance of epoxy coating. • Co doped ZnO nanoparticles behaved as efficient barrier and inhibitive pigment. - Abstract: Co doped ZnO nanoparticles were synthesized by combustion method. Then, the epoxy nanocomposites were prepared using various amounts of nanoparticles. Salt spray and electrochemical impedance spectroscopy (EIS) were used in order to investigate the corrosion inhibition effects of nanoparticles on the steel substrate. The morphology and composition of the films precipitated on the steel surface were investigated by scanning electron microscope (SEM) and energy dispersive spectroscopy. Results revealed that the corrosion inhibition properties of ZnO nanoparticle were significantly enhanced after doping with Co. Moreover, Co doped ZnO nanoparticles enhanced the corrosion resistance of the epoxy coating effectively

Study of Plant Cordia Dichotoma as Green Corrosion Inhibitor for Mild Steel in Different Acid Media

OpenAIRE

R. Khandelwal; S. K. Arora; S. P. Mathur

2011-01-01

The corrosion inhibition of mild steel using extracts of Cordia dichotoma in different acid media was investigated by mass loss and thermometric methods. The experiments were carried out at 299±0.2 K in presence of different concentrations of dry fruit, leaves and stem extracts of Cordia dichotoma. The results reveal that the alcoholic extracts of Cordia dichotoma is a better corrosion inhibitor than that of toxic chemicals. The fruit extract is more potent than leaves and stem extracts to in...

Inhibition of mild steel corrosion in acid solution by Pheniramine drug: Experimental and theoretical study

International Nuclear Information System (INIS)

Ahamad, Ishtiaque; Prasad, Rajendra; Quraishi, M.A.

2010-01-01

Inhibition of mild steel corrosion in 1 M HCl solution by Pheniramine drug was studied using weight loss, electrochemical impedance spectroscopy, linear polarization resistance, and potentiodynamic polarization measurements. The values of activation energy (E a ) and different thermodynamic parameters such as adsorption equilibrium constant (K ads ), free energy of adsorption (ΔG ads o ), adsorption enthalpy (ΔH ads o ) and adsorption entropy (ΔS ads o ) were calculated and discussed. The adsorption process of studied drug on mild steel surface obeys the Langmuir adsorption isotherm. Potentiodynamic polarization measurements showed that Pheniramine is mixed-type inhibitor. Further, theoretical calculations were carried out and relations between computed parameters and experimental inhibition efficiency were discussed.

Investigation on synergism of composite additives for zinc corrosion inhibition in alkaline solution

Energy Technology Data Exchange (ETDEWEB)

Zhou Hebing [School of Materials Science and Engineering, South China University of Technology, Guangzhou 510641 (China); Key Laboratory of Electrochemical Technology on Energy Storage and Power Generation of Guangdong Higher Education Institutes, South China Normal University, Guangzhou 510006 (China); Engineering Research Center of Materials and Technology for Electrochemical Energy Storage (Ministry of Education), South China Normal University, Guangzhou 510006 (China); Huang Qiming; Liang Man; Lv Dongsheng; Xu Mengqing; Li Hong [Key Laboratory of Electrochemical Technology on Energy Storage and Power Generation of Guangdong Higher Education Institutes, South China Normal University, Guangzhou 510006 (China); Engineering Research Center of Materials and Technology for Electrochemical Energy Storage (Ministry of Education), South China Normal University, Guangzhou 510006 (China); Li Weishan, E-mail: liwsh@scnu.edu.cn [School of Materials Science and Engineering, South China University of Technology, Guangzhou 510641 (China); Key Laboratory of Electrochemical Technology on Energy Storage and Power Generation of Guangdong Higher Education Institutes, South China Normal University, Guangzhou 510006 (China); Engineering Research Center of Materials and Technology for Electrochemical Energy Storage (Ministry of Education), South China Normal University, Guangzhou 510006 (China)

2011-07-15

Highlights: {yields} An kind of environmentally benign organic composite additives is used firstly. {yields} The corrosion of zinc is inhibited used the organic compound as additive. {yields} The rate performance of the battery used the organic compound as additive is improved. {yields} The synergism of composite additives for zinc corrosion inhibition is investigated. - Abstract: The synergism of imidazole (IMZ) and poly(ethylene glycol) 600 (PEG) for zinc corrosion inhibition in 3 mol L{sup -1} KOH solution was investigated using a combination of electrochemical and gravimetric methods, and the surface morphology of the zinc was observed by scanning electron microscopy. It is found that there is a synergistic effect between IMZ and PEG for the zinc corrosion inhibition. The difference in molecular structure, ring for IMZ and chain for PEG, and in binding atoms with zinc, nitrogen in IMZ and oxygen in PEG, contributes to this synergistic effect. IMZ inhibits zinc corrosion by mainly depressing the anodic reaction, whereas PEG by depressing the cathodic reaction. The storage performance of the zinc-manganese dioxide batteries using IMZ and/or PEG as inhibitors was determined by discharge test, with a comparison of the battery using mercury as the inhibitor. The battery containing 0.05% IMZ + 0.05% PEG exhibits better performance than the mercury-containing battery, especially when discharged at high rate.

Synthesis and characterization of a novel organic corrosion inhibitor for mild steel in 1 M hydrochloric acid

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Mohammed H. Othman Ahmed

2018-03-01

Full Text Available The synthesis and characterization of a novel organic corrosion inhibitor (4-(3-mercapto-5,6,7,8-tetrahydro-[1,2,4]triazolo[4,3-b][1,2,4,5]tetrazin-6-ylphenol, for mild steel in 1 M hydrochloric acid (HCl has been successfully reported for the first time. The inhibitor evaluated as corrosion inhibitor for mild steel in 1 M of Hydrochloric acid solution using electrochemical impedance spectroscopy (EIS, and electrochemical frequency modulation (EFM measurement techniques. Changes in the impedance parameters suggested an adsorption of the inhibitor onto the mild steel surface, leading to the formation of protective films. The results show that the inhibition efficiencies increased with increasing the concentrations of the inhibitors and decreased with increasing temperature. The maximum inhibition efficiency up to 67% at the maximum concentration 0.5 mM. This shows that those inhibitors are effective in helping to reduce and slowing down the corrosion process that occurs to mild steel with a hydrochloric acid solution by providing an organic inhibitor for the mild steel that can be weakened by increasing the temperature. The adsorption process of the synthesized organic inhibitor depends on its electronic characteristics in addition to steric effects and the nature of metal surface, temperature degree and the varying degrees of surface-site activity. The synthesized inhibitor molecules were absorbed by metal surface and follow Langmuir isotherms. Keywords: Corrosion, Inhibitor, Mild steel, EIS spectroscopy

Polarized Neutron Reflectometry of Nickel Corrosion Inhibitors.

Science.gov (United States)

Wood, Mary H; Welbourn, Rebecca J L; Zarbakhsh, Ali; Gutfreund, Philipp; Clarke, Stuart M

2015-06-30

Polarized neutron reflectometry has been used to investigate the detailed adsorption behavior and corrosion inhibition mechanism of two surfactants on a nickel surface under acidic conditions. Both the corrosion of the nickel surface and the structure of the adsorbed surfactant layer could be monitored in situ by the use of different solvent contrasts. Layer thicknesses and roughnesses were evaluated over a range of pH values, showing distinctly the superior corrosion inhibition of one negatively charged surfactant (sodium dodecyl sulfate) compared to a positively charged example (dodecyl trimethylammonium bromide) due to its stronger binding interaction with the surface. It was found that adequate corrosion inhibition occurs at significantly less than full surface coverage.

The Inhibition Effect of Potassium Iodide on the Corrosion of Pure Iron in Sulphuric Acid

Directory of Open Access Journals (Sweden)

Tarik Attar

2014-01-01

Full Text Available The use of inorganic inhibitors as an alternative to organic compounds is based on the possibility of degradation of organic compounds with time and temperature. The inhibition effect of potassium iodide on the corrosion of pure iron in 0.5 M H2SO4 has been studied by weight loss. It has been observed from the results that the inhibition efficiency (IE% of KI increases from 82.17% to 97.51% with the increase in inhibitor concentration from 1·10−4 to 2·10−3 M. The apparent activation energy (Ea and the equilibrium constant of adsorption (Kads were calculated. The adsorption of the inhibitor on the pure iron surface is in agreement with Langmuir adsorption isotherm.

Inhibition of mild steel corrosion in acid solution by Pheniramine drug: Experimental and theoretical study

Energy Technology Data Exchange (ETDEWEB)

Ahamad, Ishtiaque [Department of Applied Chemistry, Institute of Technology, Banaras Hindu University, Varanasi 221 005 (India); Prasad, Rajendra [Department of Chemistry, SGB Amravati University, Amravati 444 602 (India); Quraishi, M.A., E-mail: maquraishi@rediffmail.co [Department of Applied Chemistry, Institute of Technology, Banaras Hindu University, Varanasi 221 005 (India)

2010-09-15

Inhibition of mild steel corrosion in 1 M HCl solution by Pheniramine drug was studied using weight loss, electrochemical impedance spectroscopy, linear polarization resistance, and potentiodynamic polarization measurements. The values of activation energy (E{sub a}) and different thermodynamic parameters such as adsorption equilibrium constant (K{sub ads}), free energy of adsorption ({Delta}G{sub ads}{sup o}), adsorption enthalpy ({Delta}H{sub ads}{sup o}) and adsorption entropy ({Delta}S{sub ads}{sup o}) were calculated and discussed. The adsorption process of studied drug on mild steel surface obeys the Langmuir adsorption isotherm. Potentiodynamic polarization measurements showed that Pheniramine is mixed-type inhibitor. Further, theoretical calculations were carried out and relations between computed parameters and experimental inhibition efficiency were discussed.

Synthesis and characterization of a novel organic corrosion inhibitor for mild steel in 1 M hydrochloric acid

Science.gov (United States)

Ahmed, Mohammed H. Othman; Al-Amiery, Ahmed A.; Al-Majedy, Yasmin K.; Kadhum, Abdul Amir H.; Mohamad, Abu Bakar; Gaaz, Tayser Sumer

2018-03-01

The synthesis and characterization of a novel organic corrosion inhibitor (4-(3-mercapto-5,6,7,8-tetrahydro-[1,2,4]triazolo[4,3-b][1,2,4,5]tetrazin-6-yl)phenol), for mild steel in 1 M hydrochloric acid (HCl) has been successfully reported for the first time. The inhibitor evaluated as corrosion inhibitor for mild steel in 1 M of Hydrochloric acid solution using electrochemical impedance spectroscopy (EIS), and electrochemical frequency modulation (EFM) measurement techniques. Changes in the impedance parameters suggested an adsorption of the inhibitor onto the mild steel surface, leading to the formation of protective films. The results show that the inhibition efficiencies increased with increasing the concentrations of the inhibitors and decreased with increasing temperature. The maximum inhibition efficiency up to 67% at the maximum concentration 0.5 mM. This shows that those inhibitors are effective in helping to reduce and slowing down the corrosion process that occurs to mild steel with a hydrochloric acid solution by providing an organic inhibitor for the mild steel that can be weakened by increasing the temperature. The adsorption process of the synthesized organic inhibitor depends on its electronic characteristics in addition to steric effects and the nature of metal surface, temperature degree and the varying degrees of surface-site activity. The synthesized inhibitor molecules were absorbed by metal surface and follow Langmuir isotherms.

CHROMATE INHIBITION OF THE LOCALIZED CORROSION OF ALUMINUM: MEASUREMENTS OF ELECTROCHEMICAL TRANSIENTS

International Nuclear Information System (INIS)

SASAKI, K.; ISAACS, H.S.

2001-01-01

We investigated the inhibition by chromate ions of the localized corrosion of aluminum by electrochemical transient measurements. In agreement with other work, the measurements demonstrated that chromate is a cathodic inhibitor for aluminum in open circuit. The reduction of hexavalent chromium to trivalent chromium is assumed to take place on catalyzed sites of the surface. The resulting products inhibit oxygen reduction reactions at these sites, thereby retarding pitting corrosion

Comparison Of Metal Corrosion Inhibition By Gravimetric And Linear Polarization Resistance Methods

OpenAIRE

Banerji, Shankha

1992-01-01

Studies were conducted to evaluate the effectiveness of various dosages of the selected silicate and phosphate compounds applied for corrosion inhibition of cast iron, copper, lead, and galvanized steel specimens. The compounds selected for study were zinc polyphosphate (Calgon C-39), zinc orthophosphate (Virchem V-931), sodium metasilicate and glassy silicate. The effectiveness of these compounds for corrosion inhibition were studied under differing water quality conditions using gravimetric...

Corrosion inhibition of mild steel by Capsicum annuum fruit paste

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Chandan M. Reddy

2016-09-01

Full Text Available The anti-corrosive property of Capsicum annuum fruit paste (CFP on mild steel was investigated. Weight loss and SEM analysis showed that the aqueous and ethanolic solutions of CFP exhibits excellent corrosion inhibition in 2 M HCl. Contact angle, surface atomic composition and FTIR studies verified the presence of an organic film on the mild steel surface. The FTIR spectra also indicated the formation of active compound-Fe complex. CFP thus shows potential as an inexpensive environment friendly corrosion inhibitor for mild steel.

Improving the Corrosion Inhibitive Strength of Sodium Sulphite in Hydrogen Cyanide Solution Using Sodium Benzoate

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Muhammed Olawale Hakeem AMUDA

2008-12-01

Full Text Available The improvement in the inhibitive strength of sodium sulphite on corrosion of mild steel in hydrogen cyanide by adding sodium benzoate in regulated volume was investigated using the fundamental weight loss measurement.500 ppm concentration inhibitive mixtures of sodium benzoate and sodium sulphite in three different volume ratios (5/15, 10/10, 15/5 were formulated and studied for corrosion rate in 200ml hydrogen cyanide fluid. Result obtained indicates that the corrosion rate of mild steel in hydrogen cyanide in the presence of sodium benzoate/sodium sulphite inhibitive mixtures range 0.322mmpy to 1.1269mmpy across the three volumetric ratios considered. The 15ml5ml sodium benzoatesodium sulphite mixture had the best average corrosion rate of 0.5123mmpy.The corrosion rate followed reducing pattern after the first 200 hours of immersion. The average corrosion rate in the sodium benzoate / sodium sulphite mixture is less than the rate in sodium sulphite and the mixture is only effective after long time exposure.It is concluded that adding sodium benzoate to sodium sulphite in the volumetric ratio 155ml improves the inhibitive strength of sodium sulphite on the corrosion of mild steel in hydrogen cyanide environment.

Effect of acidity upon attrition-corrosion of human dental enamel.

Science.gov (United States)

Wu, Yun-Qi; Arsecularatne, Joseph A; Hoffman, Mark

2015-04-01

Attrition-corrosion is a synthesized human enamel wear process combined mechanical effects (attrition) with corrosion. With the rising consumption of acidic food and beverages, attrition-corrosion is becoming increasingly common. Yet, research is limited and the underlying mechanism remains unclear. In this study, in vitro wear loss of human enamel was investigated and the attrition-corrosion process and wear mechanism were elucidated by the analysis of the wear scar and its subsurface using focused ion beam (FIB) sectioning and scanning electron microscopy (SEM). Human enamel flat-surface samples were prepared with enamel cusps as the wear antagonists. Reciprocating wear testing was undertaken under load of 5N at the speed of 66 cycle/min for 2250 cycles with lubricants including citric acid (at pH 3.2 and 5.5), acetic acid (at pH 3.2 and 5.5) and distilled water. All lubricants were used at 37°C. Similar human enamel flat-surface samples were also exposed to the same solutions as a control group. The substance loss of enamel during wear can be linked to the corrosion potential of a lubricant used. Using a lubricant with very low corrosion potential (such as distilled water), the wear mechanism was dominated by delamination with high wear loss. Conversely, the wear mechanism changed to shaving of the softened layer with less material loss in an environment with medium corrosion potential such as citric acid at pH 3.2 and 5.5 and acetic acid at pH 5.5. However, a highly corrosive environment (e.g., acetic acid at pH 3.2) caused the greatest loss of substance during wear. Copyright © 2015 Elsevier Ltd. All rights reserved.

Corrosion of cupronickel alloy in permanganate under acidic condition

International Nuclear Information System (INIS)

Subramanian, Veena; Chandramohan, P.; Srinivasan, M.P.; Velmurugan, S.; Narasimhan, S.V.

2007-01-01

Cupronickel alloys are used as heat exchanger tube materials in nuclear power plant auxiliary coolant systems. In this work, the corrosion behaviour of cupronickel (70:30) alloy in permanganic acid medium was studied. Corrosion rate was found to follow logarithmic kinetics. Cyclic polarization studies showed that cupronickel did not undergo pitting in permanganic acid medium but uniform corrosion was observed. Presence of 0.43 mol/m 3 chromate in 2.5 mol/m 3 permanganic acid was found to decrease the corrosion rate of cupronickel by 50%. EIS and XPS studies revealed that the film formed on cupronickel was protective in nature and contained oxides of copper, nickel and manganese (mainly MnOOH). The composition of the film on cupronickel that had undergone chromate treatment also showed similar film except that it contained some chromium (III)

Experimental and Theoretical Studies on Corrosion Inhibition of Niobium and Tantalum Surfaces by Carboxylated Graphene Oxide

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Valbonë Mehmeti

2018-05-01

Full Text Available The corrosion of two different metals, niobium and tantalum, in aqueous sulfuric acid solution has been studied in the presence and absence of carboxylated graphene oxide. Potentiodynamic measurements indicate that this nanomaterial inhibits corrosion due to its adsorption on the metal surfaces. The adsorbed layer of carboxylated graphene hinders two electrochemical reactions: the oxidation of the metal and the transport of metal ions from the metal to the solution but also hydrogen evolution reaction by acting as a protective barrier. The adsorption behavior at the molecular level of the carboxylated graphene oxide with respect to Nb, NbO, Ta, and TaO (111 surfaces is also investigated using Molecular Dynamic and Monte Carlo calculations.

Benzaldehyde, 2-hydroxybenzoyl hydrazone derivatives as inhibitors of the corrosion of aluminium in hydrochloric acid.

Science.gov (United States)

Fouda, A S; Gouda, M M; El-Rahman, S I

2000-05-01

The effect of benzaldehyde, 2-hydroxybenzoyl hydrazone derivatives on the corrosion of aluminium in hydrochloric acid has been investigated using thermometric and polarization techniques. The inhibitive efficiency ranking of these compounds from both techniques was found to be: 2>3>1>4. The inhibitors acted as mixed-type inhibitors but the cathode is more polarized. The relative inhibitive efficiency of these compounds has been explained on the basis of structure of the inhibitors and their mode of interaction at the surface. Results show that these additives are adsorbed on an aluminium surface according to the Langmuir isotherm. Polarization measurements indicated that the rate of corrosion of aluminium rapidly increases with temperature over the range 30-55 degrees C both in the absence and in the presence of inhibitors. Some thermodynamic data of the adsorption process are calculated and discussed.

Mechanism of magnetite formation in high temperature corrosion by model naphthenic acids

International Nuclear Information System (INIS)

Jin, Peng; Robbins, Winston; Bota, Gheorghe

2016-01-01

Highlights: • Magnetite scales were found in naphthenic acid (NAP) corrosion. • Magnetite scales were formed due to thermal decomposition of iron naphthenates. • Formation and protectiveness of magnetite scales depended on structure of NAP. • Carboxylic acids confirm corrosion observations for commercial NAP. - Abstract: Naphthenic acid (NAP) corrosion is a major concern for refineries. The complexity of NAP in crude oil and the sulfidation process hinder a fundamental knowledge of their corrosive behavior. Studies with model acids were performed to explore the corrosion mechanism and magnetite scales were found on carbon steel. Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), and X-ray diffraction methods detected differences in the quantity and quality of magnetite formed by model acids. These scales exhibited different resistance to higher severity NAP corrosion in a flow through apparatus. Magnetite is proposed to be formed by thermal decomposition of iron naphthenates.

Some observations on phosphate based corrosion inhibitors in preventing carbon steel corrosion

International Nuclear Information System (INIS)

Anupkumar, B.; Satpathy, K.K.

2000-01-01

Among the various types of phosphonic acid based inhibitors assayed, namely HEDP, ATMP and a commercial corrosion inhibitor (code named Betz), it was found that Betz has the maximum amount of organic phosphate followed by HEDP and ATMP. The corrosion rate studies show that Betz gives the highest inhibition efficiency followed by HEDP and ATMP. This shows that organic phosphate plays a significant role in corrosion protection. However, it was observed that due to synergestic effect, HEDP in the presence of Zn 2+ gave a better corrosion protection than Betz. The results are discussed in the light of available literature. (author)

Mechanism of Corrosion by Naphthenic Acids and Organosulfur Compounds at High Temperatures

Science.gov (United States)

Jin, Peng

Due to the law of supply and demand, the last decade has witnessed a skyrocketing in the price of light sweet crude oil. Therefore, refineries are increasingly interested in "opportunity crudes", characterized by their discounted price and relative ease of procurement. However, the attractive economics of opportunity crudes come with the disadvantage of high acid/organosulfur compound content, which could lead to corrosion and even failure of facilities in refineries. However, it is generally accepted that organosulfur compounds may form protective iron sulfide layers on the metal surface and decrease the corrosion rate. Therefore, it is necessary to investigate the corrosive property of crudes at high temperatures, the mechanism of corrosion by acids (naphthenic acids) in the presence of organosulfur compounds, and methods to mitigate its corrosive effect. In 2004, an industrial project was initiated at the Institute for Corrosion and Multiphase Technology to investigate the corrosion by naphthenic acids and organosulfur compounds. In this project, for each experiment there were two experimentation phases: pretreatment and challenge. In the first pretreatment phase, a stirred autoclave was filled with a real crude oil fraction or model oil of different acidity and organosulfur compound concentration. Then, the stirred autoclave was heated to high temperatures to examine the corrosivity of the oil to different materials (specimens made from CS and 5% Cr containing steel were used). During the pretreatment, corrosion product layers were formed on the metal surface. In the second challenge phase, the steel specimens pretreated in the first phase were inserted into a rotating cylinder autoclave, called High Velocity Rig (HVR). The HVR was fed with a high-temperature oil solution of naphthenic acids to attack the iron sulfide layers. Based on the difference of specimen weight loss between the two steps, the net corrosion rate could be calculated and the protectiveness

Corrosion and hydrogen absorption of commercially pure zirconium in acid fluoride solutions

International Nuclear Information System (INIS)

Yokoyama, Ken’ichi; Yamada, Daisuke; Sakai, Jun’ichi

2013-01-01

Highlights: •Zirconium corrodes and absorbs hydrogen in acid fluoride solutions. •Hydrogen thermal desorption is observed at 300–700 °C. •The resistance to hydrogen absorption of zirconium is higher than that of titanium. -- Abstract: The corrosion and hydrogen absorption of commercially pure zirconium have been investigated in acidulated phosphate fluoride (APF) solutions. Upon immersion in 2.0% APF solution of pH 5.0 at 25 °C, a granular corrosion product (Na 3 ZrF 7 ) deposits over the entire side surface of the specimen, thereby inhibiting further corrosion. In 0.2% APF solution, marked corrosion is observed from the early stage of immersion; no deposition of the corrosion product is observed by scanning electron microscopy. A substantial amount of hydrogen absorption is confirmed in both APF solutions by hydrogen thermal desorption analysis. The amount of absorbed hydrogen of the specimen immersed in the 2.0% APF solution is smaller than that in the 0.2% APF solution in the early stage of immersion. The hydrogen absorption behavior is not always consistent with the corrosion behavior. Hydrogen thermal desorption occurs in the temperature range of 300–700 °C for the specimen without the corrosion product. Under the same immersion conditions, the amount of absorbed hydrogen in commercially pure zirconium is smaller than that in commercially pure titanium as reported previously. The present results suggest that commercially pure zirconium, compared with commercially pure titanium, is highly resistant to hydrogen absorption, although corrosion occurs in fluoride solutions

General corrosion of metallic materials in boric acid environments

International Nuclear Information System (INIS)

Gras, J.M.

1994-05-01

Certain low-alloy steel components in PWR primary circuit were corroded by leaking water containing boric acid. A number of studies have been performed by manufacturers in the USA and by EDF in France to determine the rate of general corrosion for low-alloy steels in media containing varying concentrations of boric acid. The first part of this paper summarizes the studies performed and indicates how far work has advanced to date in establishing the resistance of stainless steels to general corrosion in concentrated boric acid solutions. The second part of the paper discusses the mechanism of corrosion and proposes a model. Carbon steels and low-alloy steels - carbon steels and low-alloy steels in deaerated diluted boric acid solutions (pH > 4) corrode very slowly ( -1 . (author). 31 refs., 12 figs., 13 tabs

Laser Surface Alloying of Aluminum for Improving Acid Corrosion Resistance

Science.gov (United States)

Jiru, Woldetinsay Gutu; Sankar, Mamilla Ravi; Dixit, Uday Shanker

2018-04-01

In the present study, laser surface alloying of aluminum with magnesium, manganese, titanium and zinc, respectively, was carried out to improve acid corrosion resistance. Laser surface alloying was conducted using 1600 and 1800 W power source using CO2 laser. Acid corrosion resistance was tested by dipping the samples in a solution of 2.5% H2SO4 for 200 h. The weight loss due to acid corrosion was reduced by 55% for AlTi, 41% for AlMg alloy, 36% for AlZn and 22% for AlMn alloy. Laser surface alloyed samples offered greater corrosion resistance than the aluminum substrate. It was observed that localized pitting corrosion was the major factor to damage the surface when exposed for a long time. The hardness after laser surface alloying was increased by a factor of 8.7, 3.4, 2.7 and 2 by alloying with Mn, Mg, Ti and Zn, respectively. After corrosion test, hardness was reduced by 51% for AlTi sample, 40% for AlMg sample, 41.4% for AlMn sample and 33% for AlZn sample.

Evaluation of corrosion products formed by sulfidation as inhibitors of the naphthenic corrosion of AISI-316 steel

Science.gov (United States)

Sanabria-Cala, J. A.; Montañez, N. D.; Laverde Cataño, D.; Y Peña Ballesteros, D.; Mejía, C. A.

2017-12-01

Naphthenic acids present in oil from most regions worldwide currently stand as the main responsible for the naphthenic corrosion problems, affecting the oil-refining industry. The phenomenon of sulfidation, accompanying corrosion processes brought about by naphthenic acids in high-temperature refining plant applications, takes place when the combination of sulfidic acid (H2S) with Fe forms layers of iron sulphide (FeS) on the material surface, layers with the potential to protect the material from attack by other corrosive species like naphthenic acids. This work assessed corrosion products formed by sulfidation as inhibitors of naphthenic corrosion rate in AISI-316 steel exposed to processing conditions of simulated crude oil in a dynamic autoclave. Calculation of the sulfidation and naphthenic corrosion rates were determined by gravimetry. The surfaces of the AISI-316 gravimetric coupons exposed to acid systems; were characterized morphologically by X-Ray Diffraction (XRD) and X-ray Fluorescence by Energy Dispersive Spectroscopy (EDS) combined with Scanning Electron Microscopy (SEM). One of the results obtained was the determination of an inhibiting effect of corrosion products at 250 and 300°C, where lower corrosion rate levels were detected. For the temperature of 350°C, naphthenic corrosion rates increased due to deposition of naphthenic acids on the areas where corrosion products formed by sulfidation have lower homogeneity and stability on the surface, thus accelerating the destruction of AISI-316 steel. The above provides an initial contribution to oil industry in search of new alternatives to corrosion control by the attack of naphthenic acids, from the formation of FeS layers on exposed materials in the processing of heavy crude oils with high sulphur content.

Two pyrazine derivatives as inhibitors of the cold rolled steel corrosion in hydrochloric acid solution

Energy Technology Data Exchange (ETDEWEB)

Deng Shuduan, E-mail: dengshuduan@163.co [Faculty of Wood Science and Decoration Technology, Southwest Forestry University, Kunming 650224 (China); Li Xianghong; Fu Hui [Department of Fundamental Courses, Southwest Forestry University, Kunming 650224 (China)

2011-02-15

Research highlights: Two pyrazine derivatives of 2-aminopyrazine (AP) and 2-amino-5-bromopyrazine (ABP) are good inhibitors for the corrosion of steel in 1.0 M HCl solution. The inhibition efficiency follows the order: ABP > AP. The substitution Br of ABP is the additional centre of adsorption and increases the electron density of pyrazine ring, which can facilitate its adsorption on the metal surface. For either ABP or AP, the adsorption obeys Langmuir adsorption isotherm. Both ABP and AP act as mixed-type inhibitors. - Abstract: The inhibition effect of two pyrazine derivatives of 2-aminopyrazine (AP) and 2-amino-5-bromopyrazine (ABP) on the corrosion of cold rolled steel (CRS) in 1.0 M hydrochloric acid (HCl) was studied by weight loss, potentiodynamic polarization curves, and electrochemical impedance spectroscopy (EIS) methods. The results show that both AP and ABP are good inhibitors, and inhibition efficiency follows the order: ABP > AP. The adsorption of each inhibitor on CRS surface obeys Langmuir adsorption isotherm. Potentiodynamic polarization curves show that two pyrazine derivatives act as mixed-type inhibitors. EIS spectra exhibit one capacitive loop and confirm the inhibitive ability.

Two pyrazine derivatives as inhibitors of the cold rolled steel corrosion in hydrochloric acid solution

International Nuclear Information System (INIS)

Deng Shuduan; Li Xianghong; Fu Hui

2011-01-01

Research highlights: → Two pyrazine derivatives of 2-aminopyrazine (AP) and 2-amino-5-bromopyrazine (ABP) are good inhibitors for the corrosion of steel in 1.0 M HCl solution. → The inhibition efficiency follows the order: ABP > AP. The substitution Br of ABP is the additional centre of adsorption and increases the electron density of pyrazine ring, which can facilitate its adsorption on the metal surface. → For either ABP or AP, the adsorption obeys Langmuir adsorption isotherm. → Both ABP and AP act as mixed-type inhibitors. - Abstract: The inhibition effect of two pyrazine derivatives of 2-aminopyrazine (AP) and 2-amino-5-bromopyrazine (ABP) on the corrosion of cold rolled steel (CRS) in 1.0 M hydrochloric acid (HCl) was studied by weight loss, potentiodynamic polarization curves, and electrochemical impedance spectroscopy (EIS) methods. The results show that both AP and ABP are good inhibitors, and inhibition efficiency follows the order: ABP > AP. The adsorption of each inhibitor on CRS surface obeys Langmuir adsorption isotherm. Potentiodynamic polarization curves show that two pyrazine derivatives act as mixed-type inhibitors. EIS spectra exhibit one capacitive loop and confirm the inhibitive ability.

Synergistic effect of halide ions on the corrosion inhibition of aluminium in H2SO4 using 2-acetylphenothiazine

International Nuclear Information System (INIS)

Ebenso, E.E.

2003-01-01

The corrosion inhibition of aluminium in H 2 SO 4 in the presence of 2-acetylphenothiazine (2APTZ) at temperature range of 30-60 deg. C was studied using the weight loss and thermometric techniques. The effect of addition of halides (KCl, KBr, KI) is also reported. The inhibition efficiency (I, %) increased with increase in concentration of 2APTZ. The addition of the halides increased the inhibition efficiency to a considerable extent. The temperature increased the corrosion rate and inhibition efficiency in the range 30-60 deg. C in the absence and presence of the inhibitor and halides. Phenomenon of chemical adsorption is proposed. Flory-Huggins adsorption isotherm equation was obeyed at all the concentrations studied. The decrease in inhibition efficiency (and surface coverage values) was found to be in the order I - >Br - >Cl - which clearly indicates that the radii and the electronegativity of halides play a significant role in the adsorption process. All the data acquired reveal that 2APTZ acts as an inhibitor in the acid environment from the two techniques used. The synergistic effect of 2APTZ and halide ions is discussed

Inhibition of Corrosion of Carbon Steel in 3.5% NaCl Solution by Myrmecodia Pendans Extract

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Atria Pradityana

2016-01-01

Full Text Available Inhibitor is a substance that is added to the corrosive media to inhibit corrosion rate. Organic inhibitors are preferred to inorganic ones since they are environmentally friendly. One of the organic compounds which is rarely reported as a corrosion inhibitor is Myrmecodia Pendans. The organic compounds can be adsorbed on the metal surface and block the active surface to reduce the rate of corrosion. In this study, the used pipe was carbon steel API 5L Grade B with 3.5% NaCl solution as the corrosion medium. The objective of this research was to analyze the inhibition mechanism Myrmecodia Pendans towards carbon steel in a corrosion medium. Concentration variations of extract Myrmecodia Pendans were 0–500 ppm. Fourier Transform Infrared (FTIR was used for chemical characterization of Myrmecodia Pendans. Polarization and Electrochemical Impedance Spectroscopy (EIS were used to measure the corrosion rate and behaviour. From the electrochemical measurements, it was found that the addition of 400 mg/L inhibitor gave the highest inhibition efficiency. Myrmecodia Pendans acted as a corrosion inhibitor by forming a thin layer on the metal surface.

Improving the Corrosion Inhibitive Strength of Sodium Sulphite in Hydrogen Cyanide Solution Using Sodium Benzoate

OpenAIRE

Muhammed Olawale Hakeem AMUDA; Olusegun Olusoji SOREMEKUN; Olakunle Wasiu SUBAIR; Atinuke OLADOYE

2008-01-01

The improvement in the inhibitive strength of sodium sulphite on corrosion of mild steel in hydrogen cyanide by adding sodium benzoate in regulated volume was investigated using the fundamental weight loss measurement.500 ppm concentration inhibitive mixtures of sodium benzoate and sodium sulphite in three different volume ratios (5/15, 10/10, 15/5) were formulated and studied for corrosion rate in 200ml hydrogen cyanide fluid. Result obtained indicates that the corrosion rate of mild steel i...

Adsorption properties and inhibition of mild steel corrosion in hydrochloric solution by some newly synthesized diamine derivatives: Experimental and theoretical investigations

Energy Technology Data Exchange (ETDEWEB)

Herrag, L.; Hammouti, B.; Elkadiri, S.; Aouniti, A. [Laboratoire de Chimie Appliquee et Environnement, LCAE-URAC18, Faculte des Sciences, Universite Mohammed Premier, B.P. 717, M-6000 Oujda (Morocco); Jama, C. [Unite Materiaux et Transformations (UMET), Ingenierie des Systemes Polymeres, CNRS UMR 8207, ENSCL, B.P. 90108, F-59652 Villeneuve d' Ascq Cedex (France); Vezin, H. [Laboratoire de Spectrochimie Infrarouge et Raman (LASIR), UMR-CNRS 8516, Universite des Sciences et Technologies de Lille, Batiment C5, F-59655 Villeneuve d' Ascq Cedex (France); Bentiss, F., E-mail: fbentiss@enscl.f [Laboratoire de Chimie de Coordination et d' Analytique (LCCA), Faculte des Sciences, Universite Chouaib Doukkali, B.P. 20, M-24000 El Jadida (Morocco)

2010-09-15

New diamine derivatives, namely 2-[{l_brace}2-[bis-(2-hydroxyethyl)amino]ethyl{r_brace}(2-hydroxyethyl)amino]ethanol (DAME) and 2-[{l_brace}2-[bis-(2-hydroxyethyl)amino]ethyl{r_brace}(2-hydroxyethyl)amino]propanol (DAMP) were synthesised and their inhibitive action against the corrosion of mild steel in 1 M HCl solution were investigated at 308 K. The detailed study of DAME is given using gravimetric measurements and polarization curves method. Results show that DAME is a good inhibitor and inhibition efficiency reaches 91.7% at 10{sup -3} M. Tafel polarization study revealed that DAME acts as a mixed-type inhibitor. The inhibitor adsorption process in mild steel/DAME/hydrochloric acid system was studied at different temperatures (308-353 K) by means of weight loss measurements. The adsorption of DAME on steel surface obeyed Langmuir's adsorption isotherm. The kinetic and thermodynamic parameters for mild steel corrosion and inhibitor adsorption, respectively, were determined and discussed. The comparative study of inhibitive performance of the two diamine derivatives revealed that DAME is more effective than DAMP. Quantitative Structure-Activity Relationship (QSAR) approach has been conducted in attempt to correlate the corrosion inhibition properties of these diamine derivatives with their calculated quantum chemical parameters.

Theoretical studies of three triazole derivatives as corrosion inhibitors for mild steel in acidic medium

International Nuclear Information System (INIS)

Guo, Lei; Zhu, Shanhong; Zhang, Shengtao; He, Qiao; Li, Weihua

2014-01-01

Highlights: • Three triazole derivatives as corrosion inhibitors were theoretically investigated. • Quantum chemical calculations and Monte Carlo simulations were performed. • Quantitative structure activity relationship (QSAR) approach has been used. • Theoretical conclusions are validated by the consistency with experimental findings. - Abstract: Corrosion inhibitive performance of 4-chloro-acetophenone-O-1′-(1′.3′.4′-triazolyl)-metheneoxime (CATM), 4-fluoro-acetophenone-O-1′-(1′.3′.4′-triazolyl)-metheneoxime (FATM), and 3,4-dichloro-acetophenone-O-1′-(1′.3′.4′-triazolyl)-metheneoxime (DATM) during the acidic corrosion of mild steel surface was investigated using density functional theory (DFT). Quantum chemical parameters such as the highest occupied molecular orbital energy (E HOMO ), the lowest unoccupied molecular orbital energy (E LUMO ), energy gap (ΔE), Mulliken charges, hardness (ξ), dipole moment (μ), and the fraction of electrons transferred (ΔN), were calculated. Quantitative structure activity relationship (QSAR) approach has been used, and a composite index of above-mentioned descriptors was performed to characterize the inhibition performance of the studied molecules. Furthermore, Monte Carlo simulation studies were applied to search for the best configurational space of iron/triazole derivative system

Corrosion inhibition and adsorption characteristics of camel foot ...

African Journals Online (AJOL)

Inhibitive performance of Camel foot (Piliostigma thonningii) leave extract was investigated on corrosion of mild steel in 1.5M hydrochloric at different temperature (25oC to 60oC) using weight loss and hydrogen evolution measurement. Phytochemical screening was carried out on the extract and characterized with Gas ...

Corrosion behaviour of Nd-Fe-B magnets containing Co and Cr

International Nuclear Information System (INIS)

Pawlowska, G.; Bala, H.; Szymura, S.

1993-01-01

The effect of partial substitution of iron by Co and Cr on corrosion behaviour of Nd 16 Fe 76 B 8 permanent magnets has been investigated. Small additions of Cr (1 to 4%at) are enough to ensure maximal corrosion inhibition. Greater amount of Cr into Nd-Fe-B alloy (>8%at), against expectations, practically do not affect the corrosion behaviour and additionally, considerably worsen its magnetic properties. Corrosion tests have shown a distinct effect of cobalt addition on the inhibition of both acid corrosion and the abnormal dissolution process of the Nd-Fe-Co-B magnets. Cobalt additions inhibit the atmosphere corrosion of Nd-Fe-B permanent magnets, especially a salt-spray environment. (author). 6 refs, 4 figs, 1 tab

Corrosion resistance of aluminum-magnesium alloys in glacial acetic acid

International Nuclear Information System (INIS)

Zaitseva, L.V.; Romaniv, V.I.

1984-01-01

Vessels for the storage and conveyance of glacial acetic acid are produced from ADO and AD1 aluminum, which are distinguished by corrosion resistance, weldability and workability in the hot and cold conditions but have low tensile strength. Aluminum-magnesium alloys are stronger materials close in corrosion resistance to technical purity aluminum. An investigation was made of the basic alloying components on the corrosion resistance of these alloys in glacial acetic acid. Both the base metal and the weld joints were tested. With an increase in temperature the corrosion rate of all of the tested materials increases by tens of times. The metals with higher magnesium content show more pitting damage. The relationship of the corrosion resistance of the alloys to magnesium content is confirmed by the similar intensity of failure of the joint metal of all of the investigated alloys and by electrochemical investigations. The data shows that AMg3 alloy is close to technically pure ADO aluminum. However, the susceptibility of even this material to local corrosion eliminates the possibility of the use of aluminum-magnesium alloys as reliable constructional materials in glacial acetic acid

Anti-corrosion and Anti-bacteria Property of Modified Pomegranate Peel Extract

Science.gov (United States)

Gu, Xue-Fan; Chang, Xiao-Feng; Cheng, Chao; Zhang, Li; Zhang, Yong-Ming; Zhang, Jie; Chen, Gang

2018-03-01

Using weight loss method, the pomegranate peel extract (PPE), that is a green corrosion inhibitors, have been studied in the corrosion inhibition of Q235A steel in 1M hydrochloric acid solution at 30°C, 45°C, 60°C, respectively. The inhibition rate of extract varies with the extraction concentration in the range of 10 ∼ 1000mg / L, up to 92.7%. Extract inhibits corrosion through adsorption mechanisms. Besides polyphenols hydroxyl and ether groups can slow down corrosion by capturing H+. Polyphenols can remove the dissolved O2, and curb oxygen reducing corrosion. PPE is antifungal active against TGB and FB, but not so active against SRB.

Corrosion of graphite composites in phosphoric acid fuel cells

Science.gov (United States)

Christner, L. G.; Dhar, H. P.; Farooque, M.; Kush, A. K.

1986-01-01

Polymers, polymer-graphite composites and different carbon materials are being considered for many of the fuel cell stack components. Exposure to concentrated phosphoric acid in the fuel cell environment and to high anodic potential results in corrosion. Relative corrosion rates of these materials, failure modes, plausible mechanisms of corrosion and methods for improvement of these materials are investigated.

Dissolution properties of cerium dibutylphosphate corrosion inhibitors

NARCIS (Netherlands)

Soestbergen, van M.; Erich, S.J.F.; Huinink, H.P.; Adan, O.C.G.

2013-01-01

The corrosion inhibitor cerium dibutylphosphate, Ce(dbp)3, prevents corrosion by cerium and dbp deposition at the alkaline cathode and acidic anode respectively. The pH dependent Ce(dbp)3 solubility seems to play an essential role in the inhibition degree. We found that Ce(dbp)3 scarcely dissolves

Corrosion Inhibition of Mild Steel in Seawater using Jatropha Stem

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Olawale Olamide

2016-10-01

Full Text Available The present work investigate the inhibition of Jatropha Stem Extract (JSE in sea water using mild steel coupons of dimension 5 × 5 × 0.5 cm. The cupons were immersed in test solutions of sea water and varied concentrations of extracts of 0.1g/l to 0.9g/l was used. The functional groups of the compounds was analyzed using an FTIR. The results showed that as the concentration of the extract increases, there was a reduction in the corrosion rates. Furthermore, as the extract concentrations increased from 0.1g/l to 0.4g/l at 48hrs exposure time, the weight loss decreased by 14.3% in the medium. However, the Jatropha Stem Extract was absorbed on the substrate surface to inhibit corrosion, the morphology of phases formed from the scanning Electron Microscopy examination confirmed this trend. Hence, JSE is a good and safe inhibitor in sea water solution. The FT-IR results also indicates the presence of active corrosion inhibitor present in the Jatropha Stem.

Electrochemical analysis of the corrosion inhibition effect of trypsin complex on the pitting corrosion of 420 martensitic stainless steel in 2M H2SO4 solution.

Science.gov (United States)

Loto, Roland Tolulope

2018-01-01

Inhibition effect of trypsin complex (TC) on the pitting corrosion of martensitic stainless steel (type 420) in 1M H2SO4 solution was studied with potentiodynamic polarization, open circuit potential measurement and optical microscopy. TC reduced the corrosion rate of the steel with maximum inhibition efficiency of 80.75%. Corrosion potential shifted anodically due to the electrochemical action of TC. The pitting potential increased from 1.088VAg/AgCl (3M) at 0% TC to 1.365VAg/AgCl(3M) at 4% TC. TC shifts the open circuit corrosion potential from -0.270s at 0% TC concentration to -0.255V at 5% TC. The compound completely adsorbed onto the steel according to Langmuir, Frumkin and Temkin isotherms. ATF-FTIR spectroscopy confirmed the inhibition mode to be through surface coverage. Thermodynamic calculations showed physisorption molecular interaction. Corrosion pits are present on the uninhibited 420 morphology in comparison to TC inhibited surface which slightly deteriorated.

Solid Obtained by Electrocoagulation of Vinasse, new Inhibitor for Acid Corrosion of Brass

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Elaine Ojeda-Armaignac

2016-07-01

Full Text Available This work is part of research related to obtaining a corrosion inhibitor from vinasse, whose basic advantages is the possibility of using an industrial waste from distilleries ethyl alcohol as raw material in the production of a solid corrosion inhibitor of national production by electrocoagulation, which implies import substitution and cost reductions. The inhibitory action of the solids obtained by electrocoagulation of vinasse was investigated by potentiodynamic polarization techniques and electrochemical impedance spectroscopy. It was found that the efficiencies of inhibition against the brass into the electrolyte solution were very good, behaving as an efficient inhibitor in acid medium. Inhibition efficiency increases with increasing concentration. The maximum inhibition efficiency was of 93,43 % for the concentration of 2 mg / L of vinasse. Thermodynamic parameters were obtained at the study temperature. It was found that the adsorption of inhibitor molecules on the surface of brass obey the Langmuir isotherm, and the values of adsorción free energy of - 23.06 kJ mol-1 show the spontaneity of adsorption and indicate that the inhibitor is strongly adsorbed on the surface of brass, study of potentiodynamic polarization curves confirmed that it is a mixed type inhibitor, with an anode predominance and there is a predominant mechanism of physical adsorption combined with a chemisorption.

Corrosion of stainless steels and nickel-base alloys in solutions of nitric acid and hydrofluoric acid

International Nuclear Information System (INIS)

Horn, E.M.; Renner, M.

1992-01-01

Reactions involving nitric acid may always result in the contamination of this acid with fluorides. In highly concentrted nitric acid, the presence of small amounts of HF will substantially reduce the corrosion of metallic materials. Mixtures consisting of hydrofluoric acid and hypo-azeotropic nitric acid on the other hand will strongly attack: the metal loss will markedly increase with increasing HNO 3 and HF concentrations as well as with rising temperatures. The investigation covered 12 stainless steel grades and nickel-base alloys. With constant HNO 3 content, corrosion rates will rise linearly when increasing the HF concentration. With constant HF concentration (0,25 M), corrosion rates will increase rapidly with increasing nitric acid concentration (from 0.3 M to 14.8 M). This can best be described by superimposing a linear function and a hyperbolic function that is reflecting the change in the HNO 3 content. Alloys containing as much chromium as possible (up to 46 wt.%) will exhibit the best corrosion resistance. Alloy NiCr30FeMo (Hastelloy alloy G-30) proved to be well suitable in this investigation. (orig.) [de

Controlled Release from Core-Shell Nanoporous Silica Particles for Corrosion Inhibition of Aluminum Alloys

Directory of Open Access Journals (Sweden)

Xingmao Jiang

2011-01-01

Full Text Available Cerium (Ce corrosion inhibitors were encapsulated into hexagonally ordered nanoporous silica particles via single-step aerosol-assisted self-assembly. The core/shell structured particles are effective for corrosion inhibition of aluminum alloy AA2024-T3. Numerical simulation proved that the core-shell nanostructure delays the release process. The effective diffusion coefficient elucidated from release data for monodisperse particles in water was 1.0×10−14 m2s for Ce3+ compared to 2.5×10−13 m2s for NaCl. The pore size, pore surface chemistry, and the inhibitor solubility are crucial factors for the application. Microporous hydrophobic particles encapsulating a less soluble corrosion inhibitor are desirable for long-term corrosion inhibition.

Corrosion inhibition of 7000 series aluminium alloys with cerium diphenyl phosphate

Energy Technology Data Exchange (ETDEWEB)

Hill, Julie-Anne [Department of Materials Engineering and Australian Centre of Excellence for Electromaterials Science, Wellington Rd, Monash University, Clayton, Victoria (Australia); Markley, Tracey [Department of Materials Engineering and Australian Centre of Excellence for Electromaterials Science, Wellington Rd, Monash University, Clayton, Victoria (Australia); CSIRO, Division of Materials Science and Technology, Clayton, Victoria (Australia); Forsyth, Maria, E-mail: maria.forsyth@deakin.edu.au [Department of Materials Engineering and Australian Centre of Excellence for Electromaterials Science, Wellington Rd, Monash University, Clayton, Victoria (Australia); Howlett, Patrick C. [Department of Materials Engineering and Australian Centre of Excellence for Electromaterials Science, Wellington Rd, Monash University, Clayton, Victoria (Australia); Hinton, Bruce R.W. [Department of Materials Engineering and Australian Centre of Excellence for Electromaterials Science, Wellington Rd, Monash University, Clayton, Victoria (Australia); Defence Science and Technology Organisation, Melbourne, Victoria (Australia)

2011-02-03

Graphical abstract: Scanning electron micrographs of microtomed surface shows pristine surface free of corrosion related 'mud cracking' inset for an inhibited AA7050 specimen when only 150 ppm Ce(dpp)3 is present in 0.1 M NaCl solution. Display Omitted Research highlights: > The thin film of hydrolysis products of Ce(dpp)3 and aluminium oxide is proposed to cause the inhibition. > The film consists of discrete Ce rich particles and a thin film over the matrix of Ce, P and Al oxides. > Discrete deposition of Ce is specifically influenced by Cu rich intermetallics. - Abstract: Cerium diphenyl phosphate (Ce(dpp){sub 3}) has previously been shown to be a strong corrosion inhibitor for aluminium-copper magnesium alloy AA2024-T3 and AA7075 in chloride solutions. Surface characterisation including SEM and ToF-SIMS coupled with electrochemical impedance spectroscopy (EIS) measurements are used to propose a mechanism of corrosion inhibition which appears to involve the formation of a complex oxide film of aluminium and cerium also incorporating the organophosphate component. The formation of a thin complex film consisting of hydrolysis products of the Ce(dpp){sub 3} compound and aluminium oxide is proposed to lead to the observed inhibition. SEM analysis shows that some intermetallics favour the creation of thicker deposits predominantly containing cerium oxide compounds.

Synthesis of Dipeptide Benzoylalanylglycine Methyl Ester and Corrosion Inhibitor Evaluation by Tafel Equation

International Nuclear Information System (INIS)

Abdurrahman, J.; Wahyuningrum, D.; Achmad, S.; Bundjali, B.

2011-01-01

Corrosion is one of the major problems in petroleum mining and processing industry. The pipelines used to transport crude oil from reservoir to the processing installation were made from carbon steel that is susceptible towards corrosion. One of the best methods to prevent corrosion that occurred at the inner parts of carbon steel pipelines is to use organic corrosion inhibitor. One of the potent organic corrosion inhibitors is amino acids derivatives. In this study, dipeptide compound namely benzoylalanylglycine methyl ester and benzoylalanylglycine have been synthesized. The structure elucidation of the products was performed by IR, MS and NMR spectroscopy. The determination of corrosion inhibition activity utilized the Tafel method. The corrosion inhibition efficiency of glycine methyl ester, benzoyl alanine, dipeptide benzoylalanylglycine methyl ester and dipeptide benzoylalanylglycine were 63.34 %, 35.86 %, 68.40 % and 27.72 %, respectively. These results showed that the formation of dipeptide benzoylalanylglycine methyl ester, derived from carboxylic protected glycine and amine protected alanine, increased the corrosion inhibition activity due to the loss of acidity center in the structure of glycine and L-alanine that would induce the corrosive environment towards carbon steel. (author)

The use of water-soluble hydrazones as inhibitors for the corrosion of C-steel in acidic medium

Energy Technology Data Exchange (ETDEWEB)

Moussa, M.N.H.; El-Far, A.A. [Department of Chemistry, Faculty of Science, Mansoura University, ET-35516 Mansoura (Egypt); El-Shafei, A.A. [Department of Chemistry, Faculty of Science, Mansoura University, ET-35516 Mansoura (Egypt)], E-mail: ashafei@mans.edu.eg

2007-09-15

Inhibition efficiency of some water-soluble hydrazones for C-steel corrosion in hydrochloric acid has been tested by weight loss, polarisation measurements and open circuit technique. The inhibition effect was attributed to the adsorption of the additives on the C-steel surface as supported by adsorption measurements at Pt electrode using cyclic voltammetry. Electrochemical measurements indicated that all the additives behave as cathodic-type inhibitors. The data obtained fit well to both the Temkin adsorption isotherm and the kinetic-thermodynamic model. The inhibition behaviour and its order were explained with the help of the proposed skeletal representation.

The use of water-soluble hydrazones as inhibitors for the corrosion of C-steel in acidic medium

International Nuclear Information System (INIS)

Moussa, M.N.H.; El-Far, A.A.; El-Shafei, A.A.

2007-01-01

Inhibition efficiency of some water-soluble hydrazones for C-steel corrosion in hydrochloric acid has been tested by weight loss, polarisation measurements and open circuit technique. The inhibition effect was attributed to the adsorption of the additives on the C-steel surface as supported by adsorption measurements at Pt electrode using cyclic voltammetry. Electrochemical measurements indicated that all the additives behave as cathodic-type inhibitors. The data obtained fit well to both the Temkin adsorption isotherm and the kinetic-thermodynamic model. The inhibition behaviour and its order were explained with the help of the proposed skeletal representation

The water soluble composite poly(vinylpyrrolidone–methylaniline: A new class of corrosion inhibitors of mild steel in hydrochloric acid media

Directory of Open Access Journals (Sweden)

R. Karthikaiselvi

2017-02-01

Full Text Available In recent years poly methyl aniline has been reported as one of the efficient corrosion inhibitors of mild steel in acidic media. In view of the major limitation of the insolubility of polymethyl aniline PMA, we propose to convert PMA into a water soluble composite using supporting polymer polyvinylpyrrolidone to get higher solubility and corrosion inhibition efficiency. The water soluble composite poly(vinylpyrrolidone-methyl aniline was synthesized by chemical oxidative polymerization and its inhibitive effect on mild steel in 1 M HCl has been investigated using weight loss and electrochemical techniques (potentiodynamic polarization studies and impedance spectroscopy. SEM and EDX analyses are carried out to establish a protective film formation on the metal surface.

Corrosion Behaviour of Sn-based Lead-Free Solders in Acidic Solution

Science.gov (United States)

Nordarina, J.; Mohd, H. Z.; Ahmad, A. M.; Muhammad, F. M. N.

2018-03-01

The corrosion properties of Sn-9(5Al-Zn), Sn-Cu and SAC305 were studied via potentiodynamic polarization method in an acidic solution of 1 M hydrochloric acid (HCl). Sn-9(5Al-Zn) produced different polarization profile compared with Sn-Cu and SAC305. The morphological analysis showed that small, deep grooves shaped of corrosion product formed on top of Sn-9(5Al-Zn) solder while two distinctive structures of closely packed and loosely packed corrosion product formed on top of Sn-Cu and SAC305 solder alloys. Phase analysis revealed the formations of various corrosion products such as SnO and SnO2 mainly dominant on surface of solder alloys after potentiodynamic polarization in 1 M hydrochloric acid (HCl).

Enhanced corrosion resistance of carbon steel in normal sulfuric acid medium by some macrocyclic polyether compounds containing a 1,3,4-thiadiazole moiety: AC impedance and computational studies

International Nuclear Information System (INIS)

Bentiss, F.; Lebrini, M.; Vezin, H.; Chai, F.; Traisnel, M.; Lagrene, M.

2009-01-01

We report here the use of macrocyclic polyether compounds containing a 1,3,4-thiadiazole moiety (n-MCTH) in the corrosion inhibition of C38 carbon steel in 0.5 M H 2 SO 4 acid medium. The aim of this work is devoted to study the inhibition characteristics of these compounds for acid corrosion of C38 steel using electrochemical impedance spectroscopy (EIS). Data obtained from EIS show a frequency distribution and therefore a modeling element with frequency dispersion behaviour, a constant phase element (CPE) has been used. The experimental results obtained revealed that these compounds inhibited the steel corrosion in acid solution and the protection efficiency increased with increasing inhibitors concentration. The difference in their inhibitive action can be explained on the basis of the number of oxygen atoms present in the polyether ring which contribute to the chemisorption strength through the donor acceptor bond between the non bonding electron pair and the vacant orbital of metal surface. Adsorption of n-MCTH was found to follow the Langmuir's adsorption isotherm. The thermodynamic functions of adsorption process were calculated and the interpretation of the results is given. These results are complemented with quantum chemical study in order to provide an explanation of the differences between the probed inhibitors. Correlation between the inhibition efficiency and the structure of these compounds are presented.

Long-term corrosion inhibition mechanism of microarc oxidation coated AZ31 Mg alloys for biomedical applications

International Nuclear Information System (INIS)

Gu, Yanhong; Bandopadhyay, Sukumar; Chen, Cheng-fu; Ning, Chengyun; Guo, Yuanjun

2013-01-01

Highlights: ► The corrosion behavior is significantly affected by the long-term immersion. ► The degradation is inhibited due to the corrosion product layer. ► The corrosion resistance is enhanced by optimized MAO electrolyte concentrations. ► The corrosion inhibition mechanism is presented by a Flash animation. - Abstract: This paper addresses the long-term corrosion behavior of microarc oxidation coated Mg alloys immersed in simulated body fluid for 28 days. The coatings on AZ31 Mg alloys were produced in the electrolyte of sodium phosphate (Na 3 PO 4 ) at the concentration of 20 g/L, 30 g/L and 40 g/L, respectively. Scanning electron microscope (SEM) and optical micrograph were used to observe the microstructure of the samples before and after corrosion. The composition of the MAO coating and corrosion products were determined by X-Ray Diffraction (XRD). Corrosion product identification showed that hydroxyapatite (HA) was formed on the surface of the corroded samples. The ratio of Ca/P in HA determined by the X-ray Fluorescence (XRF) technique showed that HA is an acceptable biocompatible implant material. The potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) were employed to characterize the corrosion rate and the electrochemical impedance. The corrosion resistance of the coated Mg alloys can be enhanced by optimizing the electrolyte concentrations for fabricating samples, and is enhanced after immersing the coated samples in simulated body fluid for more than 14 days. The enhanced corrosion resistance after long-term immersion is attributed to a corrosion product layer formed on the sample surface. The inhibition mechanism of the corrosion process is discussed and presented with an animation

Experimental and quantum chemical simulations on the corrosion inhibition of mild steel by 3-((5-(3,5-dinitrophenyl)-1,3,4-thiadiazol-2-yl)imino)indolin-2-one

Science.gov (United States)

Al-Azawi, Khalida F.; Mohammed, Iman Mahdi; Al-Baghdadi, Shaimaa B.; Salman, Taghried A.; Issa, Hamsa A.; Al-Amiery, Ahmed A.; Gaaz, Tayser Sumer; Kadhum, Abdul Amir H.

2018-06-01

Iraq has been one of the most extensive oil and natural gas industries in the world. The corrosion of mild steel is costly and insufficiency process. It is responsible for great loss in manufacture and environment. Natural and organic inhibitors have been utilized for a long time to inhibit the corrosion. Selected thiadiazol derivative, namely 3-((5-(3,5-dinitrophenyl)-1,3,4-thiadiazol-2-yl)imino)indolin-2-one (TDIO) was investigated for it inhibitive impacts in 1 M HCl medium on corrosion of mild steel using weight loss and scanning electron microscope techniques. The maximum inhibition efficiency up to 90.7% at the maximum inhibitor concentration 0.5 mM. Surface morphology of results demonstrated that TDIO formed adsorbed film on surface of mild steel in hydrochloric acid solution. Give molecular based clarifications to the inhibitive impacts of the studied. The interactions between mild steel surface and the inhibitor molecules have been undertaken to further corroborate the methodological results.

Controlled Release from Core-Shell Nano porous Silica Particles for Corrosion Inhibition of Aluminum Alloys

International Nuclear Information System (INIS)

Jiang, X.; Rathod, Sh.; Shah, P.; Brinker, C.J.; Jiang, X.; Jiang, Y.; Liu, N.; Xu, H.; Brinker, C.J.

2011-01-01

Cerium (Ce) corrosion inhibitors were encapsulated into hexagonally ordered nanoporous silica particles via single-step aerosol-assisted self-assembly. The core/shell structured particles are effective for corrosion inhibition of aluminum alloy AA2024-T3. Numerical simulation proved that the core-shell nanostructure delays the release process. The effective diffusion coefficient elucidated from release data for monodisperse particles in water was 1.0x10-14 m 2 s for Ce 3+ compared to 2.5x10-13 m 2 s for NaCl. The pore size, pore surface chemistry, and the inhibitor solubility are crucial factors for the application. Microporous hydrophobic particles encapsulating a less soluble corrosion inhibitor are desirable for long-term corrosion inhibition.

In situ ellipsometric investigation of stainless steel corrosion behavior in buffered solutions with amino acids

International Nuclear Information System (INIS)

Vinnichenko, M.V.; Pham, M.T.; Chevolleau, T.; Poperenko, L.V.; Maitz, M.F.

2003-01-01

The corrosion of metals is associated both with a release of ions and changes in optical surface properties. In this study, these two effects were correlated by a potentiodynamic corrosion test and in situ probing of the surface by ellipsometry. The studies were carried out with stainless steel (SS) AISI 304 and 316 in phosphate buffered saline (PBS) and in Dulbecco's modified minimal essential medium (DMEM) at pH 7.4. In both media, 304 steel is more susceptible to corrosion than 316 grade. The 316 steel shows a higher corrosion potential and higher corrosion current density in PBS than in DMEM, for 304 steel this behavior is vice versa. Ellipsometry demonstrated a higher sensitivity than potentiodynamics to surface modification in the cathodic area. In DMEM the removal of a surface layer at negative potential and a further repassivation with increasing potential was characteristic. In PBS a surface layer started to grow immediately. X-ray photoelectron spectra of this layer formed in PBS are consistent with iron phosphate. Its formation is inhibited in DMEM; the presence of amino acids is discussed as the reason

Inhibition effect of tetradecylpyridinium bromide on the corrosion of cold rolled steel in 7.0 M H3PO4

Directory of Open Access Journals (Sweden)

Xianghong Li

2017-05-01

Full Text Available Inhibition effect of cationic surfactant of tetradecylpyridinium bromide (TDPB on the corrosion of cold rolled steel (CRS in phosphoric acid produced by dihydrate wet method process (7.0 M H3PO4 was investigated by weight loss and potentiodynamic polarization methods and electrochemical impedance spectroscopy (EIS and scanning electron microscopy (SEM. Quantum chemical calculation was applied to elucidate the adsorption mode of the inhibitor molecule on steel surface. The results show that TDPB acts as a good inhibitor, and its maximum inhibition efficiency is higher than 90% even at low concentration. The adsorption of TDPB obeys the Langmuir adsorption isotherm equation. Polarization curves indicate that TDPB behaves as a mixed-type inhibitor in H3PO4. EIS spectra exhibit one capacitive loop which indicates that the corrosion reaction is controlled by charge transfer process. The inhibition action of TDPB could also be evidenced by surface SEM images. Density functional theory (DFT calculations suggest that the pyridine ring is the active adsorption center. Depending on the results, the inhibitive mechanism is proposed from the viewpoint of adsorption theory.

Corrosion of Bronzes by Extended Wetting with Single versus Mixed Acidic Pollutants

Directory of Open Access Journals (Sweden)

Liliana Gianni

2014-04-01

Full Text Available The corrosion of bronzes was examined in the context of single-acid versus mixed-acid (as in urban acid rain solutions. Two bi-component bronzes (copper with either 3% Sn or 7% Sn that closely represent those of historic artifacts were immersed for five weeks in conditions designed to replicate those experienced by statues and ornaments in cities where rainfall and humidity constantly produce an electrolyte layer on the surfaces of bronzes. Ions, acids, and particles of pollutants can dissolve in this layer, resulting in a variety of harsh corrosion processes. The kinetics of corrosion and the properties of the resulting patinas were monitored weekly by electrochemical impedance spectroscopy and open-circuit potential measurements. The sizes and appearances of the corrosion products were monitored and used to estimate the progress of the corrosion, whose crystalline structures were visualized using scanning electron microscopy with energy dispersive spectroscopy, identified by X-ray diffraction, and characterized by spectrocolorimetry. The electrochemical measurements demonstrated that greater damage (in terms of color change and corrosion product formation did not correspond to deficiencies in protection. The mixed-acid solution did not corrode the bronzes, as would be expected from the additive effects of the single acids. The postulated mechanisms of metal dissolution appear to be specific to a particular bronze alloy, with the tin component playing an important role.

An interesting and efficient green corrosion inhibitor for aluminium ...

African Journals Online (AJOL)

An interesting and efficient green corrosion inhibitor for aluminium from extracts of ... Journal Home > Vol 13, No 1 (2014) > ... possible applications in metal surface anodizing and surface coating in industries. Keywords: Moringa oleifera, Aluminium, Hydrochloric acid, Langmuir isotherm, Plant extracts, Corrosion inhibition ...

Corrosion behaviour of 6063 aluminium alloy in acidic and in alkaline media

Directory of Open Access Journals (Sweden)

Prabhu Deepa

2017-05-01

Full Text Available The corrosion behaviour of 6063 aluminium alloy was investigated in different concentrations of phosphoric acid medium and sodium hydroxide medium at different temperatures. The study was done by electrochemical method, using Tafel polarization technique and electrochemical impedance spectroscopy (EIS technique. The surface morphology was investigated using scanning electron microscope (SEM with Energy-dispersive X-ray spectroscopy (EDX. The results showed that the 6063 aluminium alloy undergoes severe corrosion in sodium hydroxide medium than in phosphoric acid medium. The corrosion rate of 6063 aluminium alloy increased with an increase in the concentration of acid as well as with alkali. The corrosion rate was increased with an increase in temperature. The kinetic parameters and thermodynamic parameters were calculated using Arrhenius theory and transition state theory. Suitable mechanism was proposed for the corrosion of 6063 aluminium alloy in phosphoric acid medium and sodium hydroxide medium. The results obtained by Tafel polarization and electrochemical impedance spectroscopy (EIS techniques were in good agreement with each other.

Inhibition Effect of Deanol on Mild Steel Corrosion in Dilute ...

African Journals Online (AJOL)

NICOLAAS

2014-06-23

Jun 23, 2014 ... allows for extensive use as the material of construction in petro- leum industries .... steel specimens was investigated after mass-loss analysis ..... Ogbuliec, Inhibition of pseudo-anaerobic corrosion of oil pipeline steel in ...

Corrosion Inhibition of the Galvanic Couple Copper-Carbon Steel in Reverse Osmosis Water

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Irene Carrillo

2011-01-01

Full Text Available The purpose of this paper is to evaluate the electrochemical behaviour of corrosion inhibition of the copper-carbon steel galvanic couple (Cu-CS, exposed to reverse osmosis water (RO used for rinsing of heat exchangers for heavy duty machinery, during manufacture. Molybdate and nitrite salts were utilized to evaluate the inhibition behaviour under galvanic couple conditions. Cu-CS couple was used as working electrodes to measure open circuit potential (OCP, potentiodynamic polarization (PP, and electrochemical impedance spectroscopy (EIS. The surface conditions were characterized by scanning electron microscopy (SEM and electron dispersive X-ray spectroscopy (EDS. The most effective concentration ratio between molybdate and nitrite corrosion inhibitors was determined. The morphological study indicated molybdate deposition on the anodic sites of the galvanic couple. The design of molybdate-based corrosion inhibitor developed in the present work should be applied to control galvanic corrosion of the Cu-CS couple during cleaning in the manufacture of heat exchangers.

benzoic acid Schiff base and evaluation as corrosion

African Journals Online (AJOL)

user

acid Schiff base and evaluation as corrosion inhibitor of steel in 2.0 M H2SO4. *. 1. ECHEM .... adopted for this experiment was in accordance with .... Table 4: Kinetic data for mild steel corrosion in 2M H2SO4 containing SBDAB from weight loss measurement. inhibitor .... and anti-bacterial activity of Schiff base derived.

Synergistic effect of halide ions on the corrosion inhibition of aluminium in H{sub 2}SO{sub 4} using 2-acetylphenothiazine

Energy Technology Data Exchange (ETDEWEB)

Ebenso, E.E

2003-03-05

The corrosion inhibition of aluminium in H{sub 2}SO{sub 4} in the presence of 2-acetylphenothiazine (2APTZ) at temperature range of 30-60 deg. C was studied using the weight loss and thermometric techniques. The effect of addition of halides (KCl, KBr, KI) is also reported. The inhibition efficiency (I, %) increased with increase in concentration of 2APTZ. The addition of the halides increased the inhibition efficiency to a considerable extent. The temperature increased the corrosion rate and inhibition efficiency in the range 30-60 deg. C in the absence and presence of the inhibitor and halides. Phenomenon of chemical adsorption is proposed. Flory-Huggins adsorption isotherm equation was obeyed at all the concentrations studied. The decrease in inhibition efficiency (and surface coverage values) was found to be in the order I{sup -}>Br{sup -}>Cl{sup -} which clearly indicates that the radii and the electronegativity of halides play a significant role in the adsorption process. All the data acquired reveal that 2APTZ acts as an inhibitor in the acid environment from the two techniques used. The synergistic effect of 2APTZ and halide ions is discussed.

Herbs as new type of green inhibitors for acidic corrosion of steel

Energy Technology Data Exchange (ETDEWEB)

Khamis, E. [Faculty of Science, Chemistry Department, Alexandria University, P.O. Box 426 Ibrahimia Alexandria 21321 (Egypt); AlAndis, N. [College of Science, Chemistry Department, King Saud University (Saudi Arabia)

2002-09-01

Corrosion inhibition of steel in sulphuric acid by six different herb plants has been studied using a.c and d.c electrochemical techniques. The environmentally friendly investigated compounds are namely: thyme, coriander, hibiscus, anis, black cumin and Garden cress. Electrochemical impedance spectroscopy has been successfully used to evaluate the performance of these compounds. The ac measurements showed that the dissolution process is activation controlled. Bode and theta diagrams show only one time constant ({tau}). Potentiodynamic polarization curves indicate that the studied compounds are mixed-type inhibitors. The order of increasing inhibition efficiency was correlated with the change of the constituent active materials of the compounds. Thyme, which contains the powerful antiseptic thymol as the active ingredient, offers excellent protection for steel surface. (Abstract Copyright [2002], Wiley Periodicals, Inc.)

Inhibitive Behaviour of Corrosion of Aluminium Alloy in NaCl by Mangrove Tannin

International Nuclear Information System (INIS)

Solhan Yahya; Afidah Abdul Rahim; Affaizza Mohd Shah; Rohana Adnan

2011-01-01

Anticorrosion potential of mangrove tannins on aluminium alloys AA6061 in NaCl solution has been studied using potentiodynamic polarisation method and scanning electron microscopy (SEM). The study was carried out in different pH of corrosive medium in the absence and presence of various concentrations of tannin. The corrosion inhibition behaviour of the mangrove tannin on AA6061 aluminium alloy corrosion was found to be dependant on the pH of NaCl solution. Our results showed that the inhibition efficiency increased with increasing tannins concentration in chloride solution at pH 6. Treatment of aluminium alloy 6061 with all concentrations of mangrove tannins reduced the current density, thus decreased the corrosion rate. Tannins behaved as mixed inhibitors at pH 6 and reduction in current density predominantly affected in cathodic reaction. Meanwhile, at pH 12, addition of tannins shifted the corrosion potential to more cathodic potentials and a passivating effect was observed in anodic potentials. SEM studies have shown that the addition of tannins in chloride solution at pH 12 reduced the surface degradation and the formation of pits. (author)

Benzimidazole as corrosion inhibitor for heat treated 6061 Al- SiCp composite in acetic acid

International Nuclear Information System (INIS)

Chacko, Melby; Nayak, Jagannath

2015-01-01

6061 Al-SiCpcomposite was solutionizedat 350 °C for 30 minutes and water quenched. It was then underaged at 140 °C (T6 treatment). The aging behaviour of the composite was studied using Rockwell B hardness measurement. Corrosion behaviour of the underaged sample was studied in different concentrations of acetic acid and at different temperatures. Benzimidazole at different concentrations was used for the inhibition studies. Inhibition efficiency of benzimidazole was calculated for different experimental conditions. Thermodynamic parameters were found out which suggested benzimidazole is an efficient inhibitor and it adsorbed on to the surface of composite by mixed adsorption where chemisorption is predominant. (paper)

Fundamental studies of aluminum corrosion in acidic and basic environments: Theoretical predictions and experimental observations

International Nuclear Information System (INIS)

Lashgari, Mohsen; Malek, Ali M.

2010-01-01

Using quantum electrochemical approaches based on density functional theory and cluster/polarized continuum model, we investigated the corrosion behavior of aluminum in HCl and NaOH media containing phenol inhibitor. In this regard, we determined the geometry and electronic structure of the species at metal/solution interface. The investigations revealed that the interaction energies of hydroxide corrosive agents with aluminum surface should be more negative than those of chloride ones. The inhibitor adsorption in acid is more likely to have a physical nature while it appears as though to be chemical in basic media. To verify these predictions, using Tafel plots, we studied the phenomena from experimental viewpoint. The studies confirmed that the rate of corrosion in alkaline solution is substantially greater than in HCl media. Moreover, phenol is a potential-molecule having mixed-type inhibition mechanism. The relationship between inhibitory action and molecular parameters was discussed and the activity in alkaline media was also theoretically anticipated. This prediction was in accord with experiment.

Towards corrosion testing of unglazed solar absorber surfaces in simulated acid rain

International Nuclear Information System (INIS)

Salo, T.; Pehkonen, A.; Konttinen, P.; Lund, P.

2005-01-01

Electrochemical impedance spectroscopy and potentiodynamic polarization tests were utilized for determining corrosion probabilities of unglazed C/Al 2 O 3 /Al solar absorber surfaces in simulated acid rain. Previously, the main degradation mechanism found was exponentially temperature-related hydration of aluminium oxide. In acid rain tests the main corrosion determinant was the pH value of the rain. Results indicate that these methods measure corrosion characteristics of Al substrate instead of the C/Al 2 O 3 /Al surface, probably mainly due to the rough and non-uniform microstructure of the latter. Further analyses of the test methods are required in order to estimate their applicability on Al-based uniform sputtered absorber surfaces. (author) (C/Al 2 O 3 /Al solar absorber; Acid rain; Corrosion; Electrochemical tests)

Mortar fights acid corrosion

Energy Technology Data Exchange (ETDEWEB)

1982-05-14

The burning of coal or oil to produce heat required to operate a power boiler also generates a severe corrosion problem within the interior of the duct and stacks used to emit the flue gas into the atmosphere. How can concrete and steel be protected from the effects of acid attack, when the acids are carried in a gas form, or come into direct contact with the steel or concrete from spillage or immersion conditions. Industry in North America has found that the solution to this problem is to build an outside concrete column, in this case of Portland cement, and inside that column, build a totally independent brick liner bonded with Sauereisen mortar.

Experimental and theoretical studies of benzoxazines corrosion inhibitors

Directory of Open Access Journals (Sweden)

Abdulhadi Kadhim

Full Text Available 2-Methyl-4H-benzo[d][1,3]oxazin-4-one (BZ1 and 3-amino-2-methylquinazolin-4(3H-one (BZ2 were evaluated for their corrosion inhibition properties on mild steel (MS in hydrochloric acid solution by weight loss technique and scanning electron microscopy. Results show the inhibition efficiency values depend on the amount of nitrogen in the inhibitor, the inhibitor concentration and the inhibitor molecular weight with maximum inhibition efficiency of 89% and 65% for BZ2 and BZ1 at highest concentration of the compounds. Keywords: Methylquinazoline, Benzoxazines, Corrosion, Inhibitors

The Inhibitive Effect of 2-Phenyl-3-nitroso-imidazo [1, 2-a]pyridine on the Corrosion of Steel in 0.5 M HCl Acid Solution

Directory of Open Access Journals (Sweden)

K. Bouhrira

2010-01-01

Full Text Available The effect of 2-phenyl-3-nitroso-imidazo[1,2-a]pyridine (PNIP on the corrosion inhibition of carbon-steel in 0.5 M HCl was studied by weight loss and different electrochemical techniques such as electrochemical impedance spectroscopy (EIS, potentiodynamic polarization. The obtained results showed that PNIP effectively reduces the corrosion rate of carbon steel. Inhibition efficiency (E% increases with inhibitor concentration to attain 88% at 10-3 M. Adsorption of that PNIP on the carbon steel surface in 0.5 M HCl follows the Langmuir isotherm model. E% values obtained from various methods used are in good agreement. SEM characterization of the steel surface is made.

Corrosion inhibition of nickel in H2SO4 solution by alanine

International Nuclear Information System (INIS)

Hamed, E.; Abd El-REhim, S.S.; El-Shahat, M.F.; Shaltot, A.M.

2012-01-01

Highlights: ► Corrosion of Ni in 1 M H 2 SO 4 in the absence and the presence of alanine. ► Alanine acts as a moderate mixed type inhibitor. ► Physical adsorption of alanine and formation of protective film are on Ni surface. ► Addition of KI improves the inhibition efficiency (synergistic effect). ► EFM technique is in reasonably good agreement with the different techniques used. - Abstract: The effect of alanine, as a safe inhibitor, was studied by measuring the corrosion of Ni in aerated and stagnant 1 M H 2 SO 4 solution (pH ∼0.2). Measurements were performed under various conditions using potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and the new electrochemical frequency modulation (EFM) methods. The obtained results showed that the addition of alanine alone gives a moderate inhibition and acts as an anodic-type inhibitor. The inhibition is due to physical adsorption of alanine on the metal surface. The inhibition efficiency enhances with increasing alanine concentration and immersion time but decreases with rise in temperature. The apparent activation energy, E a , is higher in the presence than in the absence of alanine. Addition of I − ions greatly improves the inhibition efficiency of alanine. The synergistic effect is due to enhanced adsorption of alanine cations by chemisorbed I − anions on the metal surface. The results obtained from polarization, EIS and EFM techniques are in good agreement indicating that EFM method can be used successfully for monitoring corrosion rate of Ni in H 2 SO 4 solution with and without alanine.

Inhibition of salt precipitation, corrosion and corrosion fatigue of steel in neutral environments

International Nuclear Information System (INIS)

Mikhajlovskij, V.Ya.; Slobodyan, Z.V.; Soprunyuk, N.G.; Ivanov, A.M.

1983-01-01

Processes of salt precipitation, corrosion under dynamic and static conditions, are studied as well as corrosion fatigue of 20 and 40Kh steels in neutral aqueous media without and with the addition of compounds of several classes. The solution of calcium bicarbonate with the initial concentration [Ca(HCO 3 ) 2 ]=1.3 g/l and 3% NaCl solution in distilled water are used for investigation. The effectiveness index of salt precipitation inhibitor is determined by the change in the rate of calcium bicarbonate transformation into carbonate. The combination of results obtained permits to make the conclusion that tripolyphosphate and pyrophosphoric acid are rather perspective inhibitors of complex effect with low protective concentrations

Characterizing Corrosion Effects of Weak Organic Acids Using a Modified Bono Test

Science.gov (United States)

Zhou, Yuqin; Turbini, Laura J.; Ramjattan, Deepchand; Christian, Bev; Pritzker, Mark

2013-12-01

To meet environmental requirements and achieve benefits of cost-effective manufacturing, no-clean fluxes (NCFs) or low-solids fluxes have become popular in present electronic manufacturing processes. Weak organic acids (WOAs) as the activation ingredients in NCFs play an important role, especially in the current lead-free and halogen-free soldering technology era. However, no standard or uniform method exists to characterize the corrosion effects of WOAs on actual metallic circuits of printed wiring boards (PWBs). Hence, the development of an effective quantitative test method for evaluating the corrosion effects of WOAs on the PWB's metallic circuits is imperative. In this paper, the modified Bono test, which was developed to quantitatively examine the corrosion properties of flux residues, is used to characterize the corrosion effects of five WOAs (i.e., abietic acid, succinic acid, glutaric acid, adipic acid, and malic acid) on PWB metallic circuits. Experiments were performed under three temperature/humidity conditions (85°C/85% RH, 60°C/93% RH, and 40°C/93% RH) using two WOA solution concentrations. The different corrosion effects among the various WOAs were best reflected in the testing results at 40°C and 60°C. Optical microscopy was used to observe the morphology of the corroded copper tracks, and scanning electron microscopy (SEM) energy-dispersive x-ray (EDX) characterization was performed to determine the dendrite composition.

Control and monitoring of the localized corrosion of zirconium in acidic chloride solutions

International Nuclear Information System (INIS)

Fahey, J.; Holmes, D.; Yau, T.L.

1995-01-01

Zirconium in acidic chloride solutions which are contaminated with ferric or cupric cations is prone to localized corrosion. This tendency can be reduced by ensuring that the zirconium surface is clean and smooth. In this paper, the effect of surface condition on the localized corrosion of zirconium in acidic chloride solutions is predicted with potentiodynamic scans. These predictions are confirmed by weight loss tests on various combinations of surface finish and acid concentrations. A real time indication of localized corrosion is seen by monitoring the electrochemical noise produced between two similar electrodes immersed in an acidic chloride solutions. Electrochemical noise monitoring correlates well with the predictions from potentiodynamic and weight loss experiments. The electrochemical noise results show that while an elevated (more anodic) potential caused by ferric ion contamination may be a necessary condition for localized corrosion, it is not a sufficient condition: A smooth, clean zirconium surface reduces the localized corrosion of zirconium

Novel package for inhibition of aluminium corrosion in alkaline solutions

Energy Technology Data Exchange (ETDEWEB)

Abdel-Gaber, A.M., E-mail: ashrafmoustafa@yahoo.com [Chemistry Department, Faculty of Science, Alexandria University, Ibrahimia, P.O. Box 426, Alexandria 21321 (Egypt); Khamis, E.; Abo-Eldahab, H.; Adeel, Sh. [Chemistry Department, Faculty of Science, Alexandria University, Ibrahimia, P.O. Box 426, Alexandria 21321 (Egypt)

2010-11-01

Inhibition of aluminium corrosion in 2 M sodium hydroxide solution by a package composed of the cationic surfactant cetyl trimethyl ammonium bromide (CTAB) and lupine seed extract has been investigated employing different electrochemical techniques and chemical gasometry measurements. Potentiodynamic polarization curve measurements showed that lupine seed extract controls both the anodic dissolution of aluminium and the hydrogen gas evolved at the cathodic sites of aluminium surface. Nyquist plots showed two capacitive semicircles in the high and low frequency regions separated by an inductive loop at intermediate frequencies. The inductive loop may be explained by the occurrence of adsorbed intermediates on the surface. A proposed equivalent circuit was used to analyse the impedance spectra for aluminium in NaOH solutions. The corrosion inhibition data have been analysed using different isotherms. The results showed excellent agreement between the kinetic-thermodynamic model and Flory-Huggins isotherm. Gasometry measurements showed that the Inhibitive effect of the surfactant increases at a composition around its critical micelle concentration (cmc). The presence of both the surfactant and lupine seed extract did not indicate synergistic action between them. The mode of adsorption of the surfactant molecules corresponding to their structure is also discussed.

Novel package for inhibition of aluminium corrosion in alkaline solutions

International Nuclear Information System (INIS)

Abdel-Gaber, A.M.; Khamis, E.; Abo-Eldahab, H.; Adeel, Sh.

2010-01-01

Inhibition of aluminium corrosion in 2 M sodium hydroxide solution by a package composed of the cationic surfactant cetyl trimethyl ammonium bromide (CTAB) and lupine seed extract has been investigated employing different electrochemical techniques and chemical gasometry measurements. Potentiodynamic polarization curve measurements showed that lupine seed extract controls both the anodic dissolution of aluminium and the hydrogen gas evolved at the cathodic sites of aluminium surface. Nyquist plots showed two capacitive semicircles in the high and low frequency regions separated by an inductive loop at intermediate frequencies. The inductive loop may be explained by the occurrence of adsorbed intermediates on the surface. A proposed equivalent circuit was used to analyse the impedance spectra for aluminium in NaOH solutions. The corrosion inhibition data have been analysed using different isotherms. The results showed excellent agreement between the kinetic-thermodynamic model and Flory-Huggins isotherm. Gasometry measurements showed that the Inhibitive effect of the surfactant increases at a composition around its critical micelle concentration (cmc). The presence of both the surfactant and lupine seed extract did not indicate synergistic action between them. The mode of adsorption of the surfactant molecules corresponding to their structure is also discussed.

Thermodynamic and Kinetic Study of Zinc bis-(Dipalmithyl Dithiophosphate Activity as Anti-Corrosion Additive-Fatty Acid Based Through Potentiodynamic Polarization Technique

Directory of Open Access Journals (Sweden)

Komar Sutriah

2016-08-01

Full Text Available Zinc bis-(dipalmithyl dithiophosphate (ZDTP16 is one product variant of zinc dialkyl dithiophosphate (ZDTP-fatty acid based having function as corrosion inhibitor. By using 3% of effective dose for the application, its effectiveness of ZDTP16 corrosion inhibition will achieve 97% and it will be able to decrease Cu metal corrosion rate from 0.152 to 0.004 mm per year. Thermodynamic and kinetic parameter verification indicates the decreasing of spontaneity and corrosion rate by existence of ZDTP16 inhibitor. Gibbs free energy transition corrosion of Cu metal in electrolyte medium is measured in corrosion simulator increased from +85.22 to +91.77 kJ mol-1, while its activation energy increased from +16.66 to +33.68 kJ mol-1. Morphology observation of Cu metal substrate surface using SEM-EDX shows that the adsorption of ZDTP16 at substrate surface is able to protect surface from corrosion indicated by the existence of Zn, P, S, and C constituents representing composer atoms of ZDTP16, and the decreasing of Cl- corrosive constituent at substrate surface.

A new insight into resource recovery of excess sewage sludge: Feasibility of extracting mixed amino acids as an environment-friendly corrosion inhibitor for industrial pickling

Energy Technology Data Exchange (ETDEWEB)

Su, Wen; Tang, Bing, E-mail: renytang@163.com; Fu, Fenglian; Huang, Shaosong; Zhao, Shiyuan; Bin, Liying; Ding, Jiewei; Chen, Cuiqun

2014-08-30

Graphical abstract: - Highlights: • A value-added product was extracted from the municipal excess sludge. • The effective components contained in the product were mixed amino acids. • The product could provide a reliable protection to the steel from the acid medium. • A new insight into the resource recovery of excess sewage sludge was provided. - Abstract: The work mainly presented a laboratory-scale investigation on an effective process to extract a value-added product from municipal excess sludge. The functional groups in the hydrolysate were characterized with Fourier transform infrared spectrum, and the contained amino acids were measured by means of an automatic amino acid analyzer. The corrosion-inhibition characteristics of the hydrolysate were determined with weight-loss measurement, electrochemical polarization and scanning electron microscopy. Results indicated that the hydrolysate contained 15 kinds of amino acid, and their adsorption on the surface could effectively inhibit the corrosion reaction of the steel from the acid medium. Polarization curves indicated that the obtained hydrolysate was a mixed-type inhibitor, but mainly restricted metal dissolution on the anode. The adsorption accorded well with the Langmuir adsorption isotherm, involved an increase in entropy, and was a spontaneous, exothermic process.

A new insight into resource recovery of excess sewage sludge: Feasibility of extracting mixed amino acids as an environment-friendly corrosion inhibitor for industrial pickling

International Nuclear Information System (INIS)

Su, Wen; Tang, Bing; Fu, Fenglian; Huang, Shaosong; Zhao, Shiyuan; Bin, Liying; Ding, Jiewei; Chen, Cuiqun

2014-01-01

Graphical abstract: - Highlights: • A value-added product was extracted from the municipal excess sludge. • The effective components contained in the product were mixed amino acids. • The product could provide a reliable protection to the steel from the acid medium. • A new insight into the resource recovery of excess sewage sludge was provided. - Abstract: The work mainly presented a laboratory-scale investigation on an effective process to extract a value-added product from municipal excess sludge. The functional groups in the hydrolysate were characterized with Fourier transform infrared spectrum, and the contained amino acids were measured by means of an automatic amino acid analyzer. The corrosion-inhibition characteristics of the hydrolysate were determined with weight-loss measurement, electrochemical polarization and scanning electron microscopy. Results indicated that the hydrolysate contained 15 kinds of amino acid, and their adsorption on the surface could effectively inhibit the corrosion reaction of the steel from the acid medium. Polarization curves indicated that the obtained hydrolysate was a mixed-type inhibitor, but mainly restricted metal dissolution on the anode. The adsorption accorded well with the Langmuir adsorption isotherm, involved an increase in entropy, and was a spontaneous, exothermic process

Alkanediyl-α, ω-bis (dimethyl cetylammonium bromide gemini surfactants as novel corrosion inhibitors for mild steel in formic acid

Directory of Open Access Journals (Sweden)

Mohammad Mobin

2012-12-01

Full Text Available Gemini surfactants, butanediyl 1,4-bis(dimethyl cetylammonium bromide, pentanediyl 1,5 - bis (dimethyl cetylammonium bromide and hexanediyl 1,6 - bis (dimethyl cetylammonium bromide from Alkanediyl-α, ω-bis (dimethyl cetylammonium bromide series were synthesized in laboratory and were characterized by using Nuclear Magnetic Resonance (NMR spectroscopy. The surfactants were tested as corrosion inhibitors for mild steel in 20% formic acid. The influence of surfactants on mild steel corrosion inhibition was investigated by measuring the corrosion rate of mild steel in their absence and presence by weight loss measurements, solvent analysis of iron ions into the test solution and potentiodynamic polarization measurements. The surface morphology of the corroded steel samples in presence and absence of surfactants was evaluated by using Scanning Electron Microscopy (SEM. The synthesized gemini surfactants performed as excellent corrosion inhibitor, the inhibition efficiency (IE being in the range of 76.66-97.41%. The IE of surfactants is slightly affected by the spacer length. The IE increased with increase in surfactant concentration and temperature. The adsorption of gemini surfactants on the steel surface was found to obey Langmuir adsorption isotherm. The results of the potentiodynamic polarization studies are consistent with the results of weight loss studies.

Experimental and quantum chemical studies on two triazole derivatives as corrosion inhibitors for mild steel in acid media

Energy Technology Data Exchange (ETDEWEB)

Li, W.; Tian, H.; Hou, B. [Key Laboratory of Corrosion Science, Shandong, Institute of Oceanology, Chinese Academy of Sciences, Qingdao (China); Hu, L.; Tao, Z. [College of Chemistry and Chemical Engineering, Chongqing University, Chongqing (China)

2011-11-15

Two triazole derivatives [1-phenyl-2-(5-(1,2,4) triazol-1-ylmethyl-(1,3,4) oxadizaol-2-ylsulphanyl)-ethanone (PTOE) and 2-(4-tert-butyl-benzylsulphanyl)-5-(1,2,4) triazol-1-ylmethyl-(1,3,4) oxadiazole (TBTO)] were synthesized as new corrosion inhibitors for the corrosion of mild steel in 1 M hydrochloric acid solutions. The inhibiting efficiency of the different inhibitors was evaluated by means of weight loss and electrochemical techniques such as electrochemical impedance spectroscopy (EIS) and polarization curves. The electrochemical investigation results indicate that these compounds act as mixed-type inhibitors retarding the anodic and cathodic corrosion reactions and do not change the mechanism of either hydrogen evolution reaction or mild steel dissolution. The studied compounds followed the Langmuir adsorption isotherm, and the thermodynamic parameters were determined and discussed. The effect of molecular structure on the inhibition efficiency has been investigated with ab initio calculations. The electronic properties such as highest occupied molecular orbital (HOMO) energy level, lowest unoccupied molecular orbital (LUMO) energy level, dipole moment ({mu}) and molecular orbital densities were calculated. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Contradictory effect of chromate inhibitor on corrosive wear of aluminium alloy

International Nuclear Information System (INIS)

Pokhmurskii, V.I.; Zin, I.M.; Vynar, V.A.; Bily, L.M.

2011-01-01

Research highlights: → Corrosive wear of aluminium alloy in inhibited artificial acid rain was studied. → Tribometer with linear reciprocating ball-on-flat geometry was used.→ Corrosion potential, polarization current and friction coefficient were measured. → Chromate decreases corrosion of aluminium alloy under wear conditions. → Chromate in general accelerates corrosive wear of the alloy in acid rain. - Abstract: The corrosive wear of D16T aluminium alloy in artificial acid rain was studied. A special tribometer with the linear reciprocating ball-on-flat geometry was used. The setup allows to measure simultaneously an open circuit potential, to carry out potentiostatic and potentiodynamic polarization studies of the alloy corrosion and to record the friction coefficient. It was established that the addition of strontium chromate inhibitor to the working environment decreases an electrochemical corrosion of the aluminium alloy under wear conditions, but in general accelerates its destruction due to insufficient wear resistance of a formed surface film.

Inorganic Corrosion-Inhibitive Pigments for High-Temperature Alkali-activated Well Casing Foam Cement

Energy Technology Data Exchange (ETDEWEB)

Sugama, T. [Brookhaven National Lab. (BNL), Upton, NY (United States); Pyatina, T. [Brookhaven National Lab. (BNL), Upton, NY (United States)

2014-11-14

This study evaluates inorganic pigments for improving carbon steel (CS) brine-corrosion protection by the sodium metasilicate-activated calcium aluminate cement/Fly Ash blend at 300°C. Calcium borosilicate (CBS) and zinc phosphate, significantly improved CS corrosion-protection by decreasing cement’s permeability for corrosive ions and inhibiting anodic corrosion. An amorphous Na₂O-Al₂O₃-SiO₂-H₂O phase tightly attached to CS surface formed at 300oC in CBS-modified cement pore solution. The corrosion rate of the CS covered with this phase was nearly 4-fold lower than in the case of nonmodified cement pore solution where the major phase formed on the surface of CS was crystalline analcime.

Inorganic Corrosion-Inhibitive Pigments for High-Temperature Alkali-activated Well Casing Foam Cement

Energy Technology Data Exchange (ETDEWEB)

Sugama, T. [Brookhaven National Lab. (BNL), Upton, NY (United States); Pyatina, T. [Brookhaven National Lab. (BNL), Upton, NY (United States)

2014-11-01

This study evaluates inorganic pigments for improving carbon steel (CS) brine-corrosion protection by the sodium metasilicate-activated calcium aluminate cement/Fly Ash blend at 300°C. Calcium borosilicate (CBS) and zinc phosphate, significantly improved CS corrosion-protection by decreasing cement’s permeability for corrosive ions and inhibiting anodic corrosion. An amorphous Na₂O-Al₂O₃-SiO₂-H₂O phase tightly attached to CS surface formed at 300oC in CBS-modified cement pore solution. The corrosion rate of the CS covered with this phase was nearly 4-fold lower than in the case of nonmodified cement pore solution where the major phase formed on the surface of CS was crystalline analcime.

Galvanic corrosion between carbon steel 1018 and Alloy 600 in crevice with boric acid solution

International Nuclear Information System (INIS)

Kim, Dong Jin; Kim, Hong Pyo; Kim, Joung Soo; Machonald, Digby D.

2005-01-01

This work dealt with the evaluation of galvanic corrosion rate in a corrosion cell having annular gap of 0.5 mm between carbon steel 1018 and alloy 600 as a function of temperature and boron concentration. Temperature and boron concentration were ranged from 110 to 300 .deg. C and 2000∼10000 ppm, respectively. After the operating temperature of the corrosion cell where the electrolyte was injected was attained at setting temperature, galvanic coupling was made and at the same time galvanic current was measured. The galvanic corrosion rate decreased with time, which was described by corrosion product such as protective film as well as boric acid deposit formed on the carbon steel with time. From the galvanic current obtained as a function of temperature and boron concentration, it was found that the galvanic corrosion rate decreased with temperature while the corrosion rate increased with boron concentration. The experimental results obtained from galvanic corrosion measurement were explained by adhesive property of corrosion product such as protective film, boric acid deposit formed on the carbon steel wall and dehydration of boric acid to be slightly soluble boric acid phase. Moreover the galvanic corrosion rate calculated using initial galvanic coupling current instead of steady state coupling current was remarked, which could give us relatively closer galvanic corrosion rate to real pressurized water reactor

Corrosion inhibition of aluminum 6063 using some pharmaceutical compounds

International Nuclear Information System (INIS)

Fouda, A.S.; Al-Sarawy, A.A.; Ahmed, F.Sh.; El-Abbasy, H.M.

2009-01-01

The corrosion inhibition characteristics of some pharmaceutical compounds on aluminum 6063 in 0.5 mol l -1 H 3 PO 4 has been studied using weight loss and galvanostatic polarization techniques. Results showed that the inhibition occurs through adsorption of the inhibitor molecules on the metal surface. The inhibition efficiency increased with increasing inhibitor concentration, but decreased with increasing temperature. The adsorption of first group pharmaceutical compounds on the metal surface is found to obey Frumkin's adsorption isotherm, but the adsorption of second group pharmaceutical compounds is found to obey Temkin's adsorption isotherm. Thermodynamic parameters for adsorption process were determined. Galvanostatic polarization studies showed that first and second groups' pharmaceutical compounds are mixed-type inhibitors and the results obtained from the two techniques are in good agreement

Ultrasonic Measurement of Corrosion Depth Development in Concrete Exposed to Acidic Environment

Directory of Open Access Journals (Sweden)

Fan Yingfang

2012-01-01

Full Text Available Corrosion depth of concrete can reflect the damage state of the load-carrying capacity and durability of the concrete structures servicing in severe environment. Ultrasonic technology was studied to evaluate the corrosion depth quantitatively. Three acidic environments with the pH level of 3.5, 2.5, and 1.5 were simulated by the mixture of sulfate and nitric acid solutions in the laboratory. 354 prism specimens with the dimension of 150 mm × 150 mm × 300 mm were prepared. The prepared specimens were first immersed in the acidic mixture for certain periods, followed by physical, mechanical, computerized tomography (CT and ultrasonic test. Damage depths of the concrete specimen under different corrosion states were obtained from both CT and ultrasonic test. Based on the ultrasonic test, a bilinear regression model is proposed to estimate the corrosion depth. It is shown that the results achieved by ultrasonic and CT test are in good agreement with each other. Relation between the corrosion depth of concrete specimen and the mechanical indices such as mass loss, compressive strength, and elastic modulus is discussed in detail. It can be drawn that the ultrasonic test is a reliable nondestructive way to measure the damage depth of concrete exposed to acidic environment.

Corrosion inhibition of powder metallurgy Mg by fluoride treatments.

Science.gov (United States)

Pereda, M D; Alonso, C; Burgos-Asperilla, L; del Valle, J A; Ruano, O A; Perez, P; Fernández Lorenzo de Mele, M A

2010-05-01

Pure Mg has been proposed as a potential degradable biomaterial to avoid both the disadvantages of non-degradable internal fixation implants and the use of alloying elements that may be toxic. However, it shows excessively high corrosion rate and insufficient yield strength. The effects of reinforcing Mg by a powder metallurgy (PM) route and the application of biocompatible corrosion inhibitors (immersion in 0.1 and 1M KF solution treatments, 0.1M FST and 1M FST, respectively) were analyzed in order to improve Mg mechanical and corrosion resistance, respectively. Open circuit potential measurements, polarization techniques (PT), scanning electrochemical microscopy (SECM) and electrochemical impedance spectroscopy (EIS) were performed to evaluate its corrosion behavior. SECM showed that the local current of attacked areas decreased during the F(-) treatments. The corrosion inhibitory action of 0.1M FST and 1M FST in phosphate buffered solution was assessed by PT and EIS. Under the experimental conditions assayed, 0.1M FST revealed better performance. X-ray photoelectron spectroscopy, energy dispersive X-ray and X-ray diffraction analyses of Mg(PM) with 0.1M FST showed the presence of KMgF(3) crystals on the surface while a MgF(2) film was detected for 1M FST. After fluoride inhibition treatments, promising results were observed for Mg(PM) as degradable metallic biomaterial due to its higher yield strength and lower initial corrosion rate than untreated Mg, as well as a progressive loss of the protective characteristics of the F(-)-containing film which ensures the gradual degradation process. Copyright (c) 2009 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Electrochemical evaluation of under-deposit corrosion and its inhibition using the wire beam electrode method

Energy Technology Data Exchange (ETDEWEB)

Tan Yongjun, E-mail: yj.tan@curtin.edu.a [Western Australian Corrosion Research Group, Department of Chemistry, Curtin University, GPO Box U1987, Perth (Australia); Fwu, Young; Bhardwaj, Kriti [Western Australian Corrosion Research Group, Department of Chemistry, Curtin University, GPO Box U1987, Perth (Australia)

2011-04-15

Research highlights: A new experiment method for evaluating under-deposit corrosion and its inhibitors. Under-deposit corrosion did not occur in a CO{sub 2} saturated pure brine solution. Inhibitor imidazoline addition and O{sub 2} contamination initiated under-deposit corrosion. Inhibitor imidazoline reduced general corrosion but enhanced localised corrosion. - Abstract: A new experimental method has been applied to evaluate under-deposit corrosion and its inhibition by means of an electrochemically integrated multi-electrode array, namely the wire beam electrode (WBE). Maps showing galvanic current and corrosion potential distributions were measured from a WBE surface that was partially covered by sand. Under-deposit corrosion did not occur during the exposure of the WBE to carbon dioxide saturated brine under ambient temperature. The introduction of corrosion inhibitor imidazoline and oxygen into the brine was found to significantly affect the patterns and rates of corrosion, leading to the initiation of under-deposit corrosion over the WBE.

ELECTROCHEMICAL STUDIES FOR CORROSION INHIBITION OF MILD STEEL BY CHRYSOPHYLLUM ALBIDUM EXTRACT

OpenAIRE

Akoma Chigozie S.; Osarolube Eziaku; Abumere O. E.

2018-01-01

The corrosion behavior of mild steel in carbonated drinks produced by Nigerian Breweries (Fanta, Sprite and Coke) was studied in the presence and absence of an eco-friendly inhibitor, Chrysophyllum albidum using Potentiodynamic polarization technique at 25 °C. Results showed that Chrysophyllum albidum reduced the current density (icorr), which in turn means that the corrosion rate was reduced significantly. The inhibition efficiency was found to be 93%, 78.6% and 87.5% for Fanta, Sprite and C...

Effects of organic acid pickling on the corrosion resistance of magnesium alloy AZ31 sheet

DEFF Research Database (Denmark)

Nwaogu, Ugochukwu Chibuzoh; Blawert, C.; Scharnagl, N.

2010-01-01

mu m of the contaminated surface was required to reach corrosion rates less than 1 mm/year in salt spray condition. Among the three organic acids examined, acetic acid is the best choice. Oxalic acid can be an alternative while citric acid is not suitable for cleaning AZ31 sheet, because......Organic acids were used to clean AZ31 magnesium alloy sheet and the effect of the cleaning processes on the surface condition and corrosion performance of the alloy was investigated. Organic acid cleanings reduced the surface impurities and enhanced the corrosion resistance. Removal of at least 4...

Inhibitory effect of some carbazides on corrosion of aluminium in hydrochloric acid and sodium hydroxide solutions

Energy Technology Data Exchange (ETDEWEB)

Fouda, A.S. [El-Mansoura Univ. (Egypt). Dept. of Chemistry; Madkour, L.H. [Tanta Univ. (Egypt). Dept. of Chemistry; Elshafei, A.A. [El-Mansoura Univ. (Egypt). Dept. of Chemistry; Elasklany, A.H. [El-Mansoura Univ. (Egypt). Dept. of Chemistry

1995-06-01

The dissolution of aluminium in hydrochloric acid and sodium hydroxide solutions in the presence of semicarbazide, thiosemicarbazide and sym.diphenylcarbazide as corrosion inhibitors has been studied using thermometric, weight-loss and polarization methods. The three methods gave consistent results. The higher inhibition efficiency of these compounds in acidic than in alkaline madia may be due to the less negative potential of aluminium in hydrochloric acid solution, favouring adsorption of the additive. The adsorption of these compounds were found to obey Frumkin adsorption isotherm. Cathodic polarization measurements showed that these compounds are cathodic inhibitors and their adsorption in the double layer does not change the mechanism of the hydrogen evolution reaction. The results are analysed in terms of both molecular and cationic adsorption. (orig.)

Characterization of the corrosion products formed on mild steel in acidic medium with N-octadecylpyridinium bromide as corrosion inhibitor

Energy Technology Data Exchange (ETDEWEB)

Nava, N., E-mail: tnava@imp.mx; Likhanova, N. V. [Direccion de Investigacion y Posgrado, Instituto Mexicano del Petroleo (Mexico); Olivares-Xometl, O. [Benemerita Universidad Autonoma de Puebla, Facultad de Ingenieria Quimica (Mexico); Flores, E. A. [Direccion de Investigacion y Posgrado, Instituto Mexicano del Petroleo (Mexico); Lijanova, I. V. [CIITEC, Instituto Politecnico Nacional (Mexico)

2011-11-15

The characterization of the corrosion products formed on mild steel SAE 1018 after 2 months exposure in aqueous sulfuric acid with and without corrosion inhibitor N-octadecylpyridinium bromide has been carried out by means of transmission {sup 57}Fe Moessbauer spectroscopy and X-ray powder diffraction (XRD). The major constituent of the rust formed in this environment without corrosion inhibitor is goethite ({alpha}-FeOOH). The samples with N-octadecylpyridinium bromide contain rozenite and large amounts of melanterite in the corrosion layers.

Evaluation of some phenothiazine derivatives as corrosion inhibitors for bronze in weakly acidic solution

International Nuclear Information System (INIS)

Bostan, Roxana; Varvara, Simona; Găină, Luiza; Mureşan, Liana Maria

2012-01-01

Highlights: ► Phenothiazine derivatives are efficient inhibitors for bronze corrosion. ► Potentiodynamic polarization and EIS were used to elucidate inhibition mechanism. ► Adsorption of phenothiazine derivatives on bronze surface obeys Langmuir isotherm. ► A correlation between energy gaps and inhibition efficiencies values was obtained. - Abstract: Four phenothiazine derivatives have been tested as inhibitors for bronze corrosion in a solution containing Na 2 SO 4 and NaHCO 3 (pH 5). Electrochemical investigations (potentiodynamic polarisation and impedance measurements) revealed that all phenothiazine derivatives exert a protective effect against bronze corrosion and, in some cases their inhibition efficiency exceeds 90% at concentration level as low as 75 μM. An adherent layer of organic molecules chemisorbed on bronze surface is responsible for the protective effect of the investigated compounds. Adsorption of phenothiazine derivatives on bronze obeys Langmuir isotherm. Correlation between quantum chemical calculations and inhibition efficiency of the investigated compounds was discussed using DFT method.

Study of corrosion-erosion behaviour of stainless alloys in industrial phosphoric acid medium

Energy Technology Data Exchange (ETDEWEB)

Guenbour, Abdellah [Laboratory of Electrochemistry-Corrosion, Av. Ibn Batouta, BP1014-Faculty of Science, Rabat (Morocco)]. E-mail: guenbour@fsr.ac.ma; Hajji, Mohamed-Adil [Group Corrosion and Protection of Materials, ENIM, Rabat (Morocco); Jallouli, El Miloudi [Group Corrosion and Protection of Materials, ENIM, Rabat (Morocco); Bachir, Ali Ben [Laboratory of Electrochemistry-Corrosion, Av. Ibn Batouta, BP1014-Faculty of Science, Rabat (Morocco)

2006-12-30

The corrosion and corrosion-abrasion resistance of some stainless steels in industrial phosphoric acid 30% P{sub 2}O{sub 5} has been studied using electrochemical techniques. The corrosion rate of materials increases with the increase of temperature. Alloys which contain chromium, molybdenum and nitrogen in sufficient quantities present the best behaviour. In the abrasion-corrosion conditions, the experimental device set up allowed to follow continually samples electrochemical behaviour. Under dynamic conditions and without solid particles, the increase of acid projection speed has no effect on the alloys corrosion behaviour. The adding of abrasive leads to a general increase of corrosion rate and to a decrease of material resistance. Under these conditions, materials attack is controlled by synergistic effect between the abrasion and the impurities. The cast 30% Cr shows good resistance according to his high chromium content.

Study of corrosion-erosion behaviour of stainless alloys in industrial phosphoric acid medium

International Nuclear Information System (INIS)

Guenbour, Abdellah; Hajji, Mohamed-Adil; Jallouli, El Miloudi; Bachir, Ali Ben

2006-01-01

The corrosion and corrosion-abrasion resistance of some stainless steels in industrial phosphoric acid 30% P 2 O 5 has been studied using electrochemical techniques. The corrosion rate of materials increases with the increase of temperature. Alloys which contain chromium, molybdenum and nitrogen in sufficient quantities present the best behaviour. In the abrasion-corrosion conditions, the experimental device set up allowed to follow continually samples electrochemical behaviour. Under dynamic conditions and without solid particles, the increase of acid projection speed has no effect on the alloys corrosion behaviour. The adding of abrasive leads to a general increase of corrosion rate and to a decrease of material resistance. Under these conditions, materials attack is controlled by synergistic effect between the abrasion and the impurities. The cast 30% Cr shows good resistance according to his high chromium content

Corrosion-Activated Micro-Containers for Environmentally Friendly Corrosion Protective Coatings

Science.gov (United States)

Li, Wenyan; Buhrow, J. W.; Zhang, X.; Johnsey, M. N.; Pearman, B. P.; Jolley, S. T.; Calle, L. M.

2016-01-01

This work concerns the development of environmentally friendly encapsulation technology, specifically designed to incorporate corrosion indicators, inhibitors, and self-healing agents into a coating, in such a way that the delivery of the indicators and inhibitors is triggered by the corrosion process, and the delivery of self-healing agents is triggered by mechanical damage to the coating. Encapsulation of the active corrosion control ingredients allows the incorporation of desired autonomous corrosion control functions such as: early corrosion detection, hidden corrosion detection, corrosion inhibition, and self-healing of mechanical damage into a coating. The technology offers the versatility needed to include one or several corrosion control functions into the same coating.The development of the encapsulation technology has progressed from the initial proof-of-concept work, in which a corrosion indicator was encapsulated into an oil-core (hydrophobic) microcapsule and shown to be delivered autonomously, under simulated corrosion conditions, to a sophisticated portfolio of micro carriers (organic, inorganic, and hybrid) that can be used to deliver a wide range of active corrosion ingredients at a rate that can be adjusted to offer immediate as well as long-term corrosion control. The micro carriers have been incorporated into different coating formulas to test and optimize the autonomous corrosion detection, inhibition, and self-healing functions of the coatings. This paper provides an overview of progress made to date and highlights recent technical developments, such as improved corrosion detection sensitivity, inhibitor test results in various types of coatings, and highly effective self-healing coatings based on green chemistry. The NASA Kennedy Space Centers Corrosion Technology Lab at the Kennedy Space Center in Florida, U.S.A. has been developing multifunctional smart coatings based on the microencapsulation of environmentally friendly corrosion

Inhibition properties of self-assembled corrosion inhibitor talloil diethylenetriamine imidazoline for mild steel corrosion in chloride solution saturated with carbon dioxide

International Nuclear Information System (INIS)

Jevremović, Ivana; Singer, Marc; Nešić, Srđan; Mišković-Stanković, Vesna

2013-01-01

Highlights: •Corrosion inhibitor talloil diethylenetriamine imidazoline effectively protects mild steel from CO 2 corrosion. •Quartz crystal microbalance measurements were used to the investigate kinetics of corrosion inhibitor adsorption. •Adsorption of talloil diethylenetriamine imidazoline can be described by Langmuir adsorption isotherm. -- Abstract: The inhibition effect of talloil diethylenetriamine imidazoline (TOFA/DETA imidazoline) on corrosion of mild steel in chloride solutions saturated with CO 2 was investigated by weight loss measurements (WL) and atomic force microscopy (AFM). Adsorption mechanism and kinetics of self-assembled (TOFA/DETA imidazoline) monolayers formation on gold were studied using the quartz crystal microbalance measurements (QCM). WL and AFM results demonstrated that TOFA/DETA imidazoline can effectively protect mild steel surface from corrosion. QCM measurements shown that the adsorption of TOFA/DETA imidazoline onto gold follows Langmuir adsorption isotherm and further investigation of the adsorption process will be carried out on a corroding metal surface

On the use of triazines as inhibitors of steel corrosion

International Nuclear Information System (INIS)

Sizaya, O.I.; Andrushko, A.P.

2004-01-01

A possibility of using substandard pesticides as a raw materials for synthesis of a set of triazines and also using them as a inhibitors of acidic corrosion of steel 20, as well as additions to epoxy powder coatings is considered. It is shown that triazines studied are inhibitors of acidic corrosion of steel 20. 2,4-di(ethylamino)-6-phenylhydrazono-1,3,5-triazine (In 4) has a maximum inhibiting effect among the studied compounds [ru

Effect of Surface Precipitate on the Crevice Corrosion in HYBRID and Oxalic Acid Solution

International Nuclear Information System (INIS)

Park, S. Y.; Jung, J. Y.; Won, H. J.; Kim, S. B.; Choi, W. K.; Moon, J. K.; Park, S. J.

2015-01-01

In this study, we investigated the characteristics of the crevice corrosion for Inconel-600 and 304SS in OA solution according to the change in pH. The evaluation of the crevice corrosion with the chemical thermodynamic analysis identified the effect of the residual chemicals such as iron-oxalate and nickeloxalate to the crevice corrosion behavior. Test results were compared with those of HYBRID (HYdrizine Base Reductive metal Ion Decontamination). The crevice corrosion properties of 304 SS and Inconel-600 in HYBRID and oxalic acid solution were evaluated. In case of oxalic acid solution, the corrosion rate on 304SS was rapidly increased with a pH decrease of around 2, but there was no increase in the corrosion rate on Inconel-600

Effect of Ethanolamines on Corrosion Inhibition of Ductile Cast Iron in Nitrite Containing Solutions

International Nuclear Information System (INIS)

Kim, K. T.; Kim, Y. S.; Chang, H. Y.; Lim, B. T.; Park, H. B.

2016-01-01

In this work, synergistic corrosion inhibition effect of nitrite and 3 kinds of ethanolamines on ductile cast iron using chemical and electrochemical methods was evaluated. This work attempts to clarify the synergistic effect of nitrite and ethanolamines. The effects of single addition of TEA, DEA, and MEA, and mixed addition of nitrite plus TEA, DEA or MEA on the corrosion inhibition of ductile cast iron in a tap water were evaluated. A huge amount of single addition of ethanolamine was needed. However, the synergistic effect by mixed addition was observed regardless of the combination of nitrite and triethanolamines, but their effects increased in a series of MEA + nitrite > DEA + nitrite > TEA + nitrite. This tendency of synergistic effect was attributed to the film properties and polar effect; TEA addition couldn't form the film showing high film resistance and semiconductive properties, but DEA or MEA could build the film having relatively high film resistance and n-type semiconductive properties. Moreover, it can be explained that this behaviour was closely related to electron attractive group within the ethanolamines, and thus corrosion inhibition power depends upon the number of the electron attractive group of MEA, DEA, and TEA.

Effect of Ethanolamines on Corrosion Inhibition of Ductile Cast Iron in Nitrite Containing Solutions

Energy Technology Data Exchange (ETDEWEB)

Kim, K. T.; Kim, Y. S. [Andong National University, Andong (Korea, Republic of); Chang, H. Y.; Lim, B. T.; Park, H. B. [KEPCO Engineering and Construction Company, Gimcheon (Korea, Republic of)

2016-08-15

In this work, synergistic corrosion inhibition effect of nitrite and 3 kinds of ethanolamines on ductile cast iron using chemical and electrochemical methods was evaluated. This work attempts to clarify the synergistic effect of nitrite and ethanolamines. The effects of single addition of TEA, DEA, and MEA, and mixed addition of nitrite plus TEA, DEA or MEA on the corrosion inhibition of ductile cast iron in a tap water were evaluated. A huge amount of single addition of ethanolamine was needed. However, the synergistic effect by mixed addition was observed regardless of the combination of nitrite and triethanolamines, but their effects increased in a series of MEA + nitrite > DEA + nitrite > TEA + nitrite. This tendency of synergistic effect was attributed to the film properties and polar effect; TEA addition couldn't form the film showing high film resistance and semiconductive properties, but DEA or MEA could build the film having relatively high film resistance and n-type semiconductive properties. Moreover, it can be explained that this behaviour was closely related to electron attractive group within the ethanolamines, and thus corrosion inhibition power depends upon the number of the electron attractive group of MEA, DEA, and TEA.

Corrosion behavior of ODS steels with several chromium contents in hot nitric acid solutions

Science.gov (United States)

Tanno, Takashi; Takeuchi, Masayuki; Ohtsuka, Satoshi; Kaito, Takeji

2017-10-01

Oxide dispersion strengthened (ODS) steel cladding tubes have been developed for fast reactors. Tempered martensitic ODS steels with 9 and 11 wt% of chromium (9Cr-, 11Cr-ODS steel) are the candidate material in research being carried out at JAEA. In this work, fundamental immersion tests and electrochemical tests of 9 to 12Cr-ODS steels were systematically conducted in various nitric acid solutions at 95 °C. The corrosion rate decreased exponentially with effective solute chromium concentration (Creff) and nitric acid concentration. Addition of vanadium (V) and ruthenium (Ru) also decreased the corrosion rate. The combination of low Creff and dilute nitric acid could not avoid the active mass dissolution during active domain at the beginning of immersion, and the corrosion rate was high. Higher Creff decreased the partial anodic current during the active domain and assisted the passivation of the surface of the steel. Concentrated nitric acid and addition of Ru and V increased partial cathodic current and shifted the corrosion potential to noble side. These effects should have prevented the active mass dissolution and decreased the corrosion rate.

Effect of boric acid on intergranular corrosion and on hideout return efficiency of sodium in the tube support plate crevices

International Nuclear Information System (INIS)

Paine, J.P.N.; Shoemaker, C.E.; Campan, J.L.; Brunet, J.P.; Schindler, P.; Stutzmann, A.

1995-01-01

Sodium hydroxide is one of the main causes of intergranular attack/stress corrosion cracking (IGA/SCC) of alloy 600 steam generator (S.G.) tubes. Boric acid appears to be one of the possible remedies for intergranular corrosion process inhibition. In order to obtain data on boric acid injection efficiency, an experimental program was performed on previously corroded tubes. To prevent premature tube wall cracking, samples were sleeved on alloy 690 tubes. The objective of the tests was to evaluate, on a statistically valid number of samples, the effectiveness of boric acid and tube sleeving as possible remedies for IGA/SCC extension. Another independent experimental program was initiated to determine the hideout return efficiency in the tube support plate (TSP) and tubesheet (TS) crevices after a significant duration (≤ 180 hours) of sodium hideout. The main objective of the first tests being a statistical evaluation of the efficiency of boric acid treatment, was not achieved. The tests did demonstrate that sleeving effectively reduces IGA/SCC growth. In an additional program, cracks were obtained on highly susceptible tubes when specimens were not sleeved. The companion tests performed in the same conditions but with an addition of boric acid did not show any IGA or cracks. These results seem to demonstrate the possible effect of boric acid in preventing the corrosion process. Results of the second tests did not demonstrate any difference in the amount of sodium piled up in the crevices before and after boric acid injection. They however showed an increase of the hideout return efficiency at the tube support plate level from 78 % without boric acid to 95 % when boric acid is present in the feed water

Corrosion Study of Mild Steel in Aqueous Sulfuric Acid Solution Using 4-Methyl-4H-1,2,4-Triazole-3-Thiol and 2-Mercaptonicotinic Acid—An Experimental and Theoretical Study

Directory of Open Access Journals (Sweden)

Valbonë V. Mehmeti

2017-08-01

Full Text Available The corrosion behavior of mild steel in 0.1 M aqueous sulfuric acid medium has been studied using weight loss, potentiodynamic polarization measurements, quantum chemical calculations, and molecular dynamic simulations in the presence and absence of 4-methyl-4H-1,2,4-triazole-3-thiol and 2-mercaptonicotinic acid. Potentiodynamic measurements indicate that these compounds mostly act as mixed inhibitors due to their adsorption on the mild steel surface. The goal of the study was to use theoretical calculations to better understand the inhibition. Monte Carlo simulation was used to calculate the adsorption behavior of the studied molecules onto Fe (1 1 1 and Fe2O3 (1 1 1 surface. The molecules were also studied with the density functional theory (DFT, using the B3LYP functional in order to determine the relationship between the molecular structure and the corrosion inhibition behavior. More accurate adsorption energies between the studied molecules and iron or iron oxide were calculated by using DFT with periodic boundary conditions. The calculated theoretical parameters gave important assistance into the understanding the corrosion inhibition mechanism expressed by the molecules and are in full agreement with the experimental results.

Studying titanium-molybdenum-zirconium alloys of increased corrosion resistance in acid solutions

International Nuclear Information System (INIS)

Tomashov, N.D.; Kazarin, V.I.; Mikheev, V.S.; Goncharenko, B.A.; Sigalovskaya, T.M.; Kalyanova, M.P.

1977-01-01

New promising Ti-Mo-Nb-Zr system alloys, possessing good workability and a high corrosion resistance in non-oxidizing solutions of acids, have been developed. The alloys may be recommended as structural materials for equipment operating in severely agressive acid media, such as hydrochloric, sulphuric and phosphoric acids. The corrosion resistance of alloys of the above system in solutions of H 2 SO 4 , HCl and H 3 PO 4 acids may be maximized by increasing the overall alloying to 42% (keeping the ratio of the alloying components Mo/Nb/Zr=4/1/1 unchanged), while retaining sufficiently good plasticity and workability

Corrosion

Science.gov (United States)

Slabaugh, W. H.

1974-01-01

Presents some materials for use in demonstration and experimentation of corrosion processes, including corrosion stimulation and inhibition. Indicates that basic concepts of electrochemistry, crystal structure, and kinetics can be extended to practical chemistry through corrosion explanation. (CC)

Inhibiting properties and adsorption of an amine based fatty acid corrosion inhibitor on carbon steel in aqueous carbon dioxide solutions

Energy Technology Data Exchange (ETDEWEB)

Buchweishaija, Joseph

1997-12-31

Carbon dioxide corrosion is a major corrosion problem in oil and gas production systems and many organic inhibitors have been tested and used to protect the substrate from corrosion. This thesis studies the mechanism of interaction of the inhibitor molecule with the metallic substrate and how this affects the dissolution rate of the metal. The performance of a commercial amine based fatty acid corrosion inhibitor has been investigated using rotating cylinder electrodes and carbon steel electrodes in CO{sub 2} saturated formation water in the temperature range between 35 to 80{sup o}C. The corrosion process was monitored by electrochemical impedance measurements, and at the end of each experiment full polarization curves were recorded. When the inhibitor was applied on noncorroded electrodes, high inhibitor performance, over 99.7%, was observed independent of temperature. On precorroded electrodes inhibitor performance was found to depend on temperature and time of precorrosion. Above 60{sup o}C, the inhibitor performance decreased with increasing time of precorrosion, presumably because of the formation of a corrosion film of either iron carbonate or a combination of iron carbonate and iron carbide which prevent the inhibitor from reaching the surface. The inhibitor protection efficiency was assumed to be associated with the degree of inhibitor coverage at the material surface, and adsorption isotherms have been calculated in the concentration range between 0.1 ppm and 100 ppm. A Langmuir isotherm was found to give the best fit. The inhibitor performance on a 2 days precorroded rotating electrode was investigated at different solution pH ranging between 4.5 and 6.5 at 35{sup o}C. 130 refs., 80 figs., 22 tabs.

Passive films and corrosion protection due to phosphonic acid inhibitors

Energy Technology Data Exchange (ETDEWEB)

Fang, J.L.; Liu, Q. (Nanjing Univ. (China)); Li, Y.; Wang, Z.W. (Nanjing Inst. of Chemical Tech. (China))

1993-04-01

For protecting mild steel from corrosion, aminotrimethylidenephosphonic acid (ATMP) was more effective than 1-hydroxyethylidene diphosphonic acid (HEDP), N.N-dimethylidenediphosphonic acid (EEDP), and ethylenediaminetetramethylidenephosphonic acid (EDTMP). A 20-min treatment in 1.0 mol/l of ATMP with a pH 0.23 at 45 C formed an anti-corrosive complex film that was composed of 48.4% O, 28.6% P, 7.0% Fe, 4.3% N, and 11.7% C, based on x-ray photoelectron spectroscopy and Auger electron spectroscopy. From differences in binding energies of Fe, N, and O, in the shift of C-N and P-O vibration, in the reflection FTIR spectra, and in the change of P-OH and Fe-N vibration before and after film formation, it was deduced that N and O in ATMP were coordinated with Fe[sub 2+] in the film.

Corrosion inhibition by inorganic cationic inhibitors on the high strength alumunium alloy, 2024-T3

Science.gov (United States)

Chilukuri, Anusha

The toxicity and carcinogenic nature of chromates has led to the investigation of environmentally friendly compounds that offer good corrosion resistance to AA 2024-T3. Among the candidate inhibitors are rare earth metal cationic (REM) and zinc compounds, which have received much of attention over the past two decades. A comparative study on the corrosion inhibition caused by rare earth metal cations, Ce3+, Pr3+, La3+ and Zn2+ cations on the alloy was done. Cathodic polarization showed that these inhibitor ions suppress the oxygen reduction reaction (ORR) to varying extents with Zn2+ providing the best inhibition. Pr3+ exhibited windows of concentration (100-300 ppm) in which the corrosion rate is minimum; similar to the Ce3+ cation. Scanning Electron Microscopy (SEM) studies showed that the mechanism of inhibition of the Pr3+ ion is also similar to that of the Ce3+ ion. Potentiodynamic polarization experiments after 30 min immersion time showed greatest suppression of oxygen reduction reaction in neutral chloride solutions (pH 7), which reached a maximum at a Zn2+ ion concentration of 5 mM. Anodic polarization experiments after 30 min immersion time, showed no anodic inhibition by the inhibitor in any concentration (0.1 mM - 10 mM) and at any pH. However, anodic polarization of samples immersed after longer immersion times (upto 4 days) in mildly acidic Zn2+ (pH 4) solutions showed significant reduction in anodic kinetics indicating that zinc also acts as a “slow anodic inhibitor”. In contrast to the polarization experiments, coupons exposed to inhibited acidic solutions at pH 4 showed complete suppression of dissolution of Al2CuMg particles compared to zinc-free solutions in the SEM studies. Samples exposed in pH 4 Zn2+-bearing solution exhibited highest polarization resistance which was also observed to increase with time. In deaerated solutions, the inhibition by Zn2+ at pH 4 is not observed as strongly. The ability to make the interfacial electrolyte

Note: Inhibiting bottleneck corrosion in electrical calcium tests for ultra-barrier measurements

Energy Technology Data Exchange (ETDEWEB)

Nehm, F., E-mail: frederik.nehm@iapp.de; Müller-Meskamp, L.; Klumbies, H.; Leo, K. [Institut für Angewandte Photophysik, Technische Universität Dresden, George-Bähr-Straße 1, 01069 Dresden (Germany)

2015-12-15

A major failure mechanism is identified in electrical calcium corrosion tests for quality assessment of high-end application moisture barriers. Accelerated calcium corrosion is found at the calcium/electrode junction, leading to an electrical bottleneck. This causes test failure not related to overall calcium loss. The likely cause is a difference in electrochemical potential between the aluminum electrodes and the calcium sensor, resulting in a corrosion element. As a solution, a thin, full-area copper layer is introduced below the calcium, shifting the corrosion element to the calcium/copper junction and inhibiting bottleneck degradation. Using the copper layer improves the level of sensitivity for the water vapor transmission rate (WVTR) by over one order of magnitude. Thin-film encapsulated samples with 20 nm of atomic layer deposited alumina barriers this way exhibit WVTRs of 6 × 10{sup −5} g(H{sub 2}O)/m{sup 2}/d at 38 °C, 90% relative humidity.

Inhibition of anodic corrosion of aluminium cathode current collector on recharging in lithium imide electrolytes

Energy Technology Data Exchange (ETDEWEB)

Wang, Xianming; Yasukawa, Eiki; Mori, Shoichiro [Tsukuba Research Center, Mitsubishi Chemical Corp., Ibaraki (Japan)

2000-07-01

Pitting corrosion of aluminum as cathode current collector for lithium rechargeable batteries was found to take place at potential positive of 3.5 V in 1 mol dm {sup -3} LiN(SO{sub 2}CF{sub 3}){sub 2} /EC + DME (1:1) electrolyte. The corrosion mechanism of aluminum in the presence of LiN(SO{sub 2}CF{sub 3}){sub 2} was proposed, and three methods were deduced to inhibit the aluminum corrosion based on this mechanism. As a result, an additive of lithium salts based on perfluorinated inorganic anions, especially LiPF{sub 6}, was found to inhibit the aluminum corrosion to a certain extent by forming a protective film on aluminum surface. The oxidation stability of aluminum in LiN(SO{sub 2}CF{sub 3}){sub 2} -containing electrolytes depended strongly on the solvent structure. The ether solvents such as tetrahydrofuran (THF) and dimethoxyethane (DME) were effective in preventing aluminum corrosion due to their low dielectric constants. Furthermore, LiN(SO{sub 2}C{sub 2}F{sub 5}){sub 2} salt with a larger anion than that of LiN(SO{sub 2}CF{sub 3}){sub 2} was evaluated and good oxidation stability of aluminum was obtained regardless of the kind of solvents. (Author)

Inhibition effect of fatty amides with secondary compound on carbon steel corrosion in hydrodynamic condition

Science.gov (United States)

Ibrahim, I. M.; Jai, J.; Daud, M.; Hashim, Md A.

2018-03-01

The inhibition effect demonstrates an increase in the inhibition performance in presence of a secondary compound in the inhibited solution. This study introduces fatty amides as corrosion inhibitor and oxygen scavenger, namely, sodium sulphite as a secondary compound. The main objective is to determine the synergistic inhibition effect of a system by using fatty amides together with sodium sulphite in hydrodynamic condition. The synergistic inhibition of fatty amides and sodium sulphite on corrosion of carbon steel in 3.5 wt% sodium chloride solution had been studied using linear polarization resistance method and scanning electron microscope (SEM) with energy dispersive X-ray spectroscopy (EDX). Electrochemical measurement was carried out using rotating cylinder electrode at different flow regimes (static, laminar, transition and turbulent). Linear polarization resistance experiments showed the changes in polarization resistance when the rotation speed increased. It found that, by addition of fatty amides together with sodium sulphite in test solution, the inhibition efficiency increased when rotation speed increased. The results collected from LPR experiment correlated with results from SEM-EDX. The results showed inhibition efficiency of system was enhanced when fatty amides and oxygen scavengers were present together.

Inhibition Effect of Deanol on Mild Steel Corrosion in Dilute ...

African Journals Online (AJOL)

The influence of deanol on the corrosion behaviour of mild steel in dilute sulphuric acid with sodium chloride addition was studied by means of mass-loss, potentiodynamic polarization, electrode potential monitoring, scanning electron microscopy and statistical analysis. Results show that deanol performed excellently with ...

Corrosion rate of construction materials in hot phosphoric acid with the contribution of anodic polarization

Energy Technology Data Exchange (ETDEWEB)

Kouril, M. [Institute of Chemical Technology, Technicka 5, 166 28 Prague (Czech Republic); Christensen, E. [Technical University of Denmark, Kemitorvet, 2800 Kgs. Lyngby (Denmark); Eriksen, S.; Gillesberg, B. [Tantaline A/S, Nordborgvej 81, 6430 Nordborg (Denmark)

2012-04-15

The paper is focused on selection of a proper material for construction elements of water electrolysers, which make use of a 85% phosphoric acid as an electrolyte at temperature of 150 C and which might be loaded with anodic polarization up to 2.5 V versus a saturated Ag/AgCl electrode (SSCE). Several grades of stainless steels were tested as well as tantalum, niobium, titanium, nickel alloys and silicon carbide. The corrosion rate was evaluated by means of mass loss at free corrosion potential as well as under various levels of polarization. The only corrosion resistant material in 85% phosphoric acid at 150 C and at polarization of 2.5 V/SSCE is tantalum. In that case, even a gentle cathodic polarization is harmful in such an acidic environment. Hydrogen reduction leads to tantalum hydride formation, to loss of mechanical properties and to complete disintegration of the metal. Contrary to tantalum, titanium is free of any corrosion resistance in hot phosphoric acid. Its corrosion rate ranges from tens of millimetres to metres per year depending on temperature of the acid. Alloy bonded tantalum coating was recognized as an effective corrosion protection for both titanium and stainless steel. Its serviceability might be limited by slow dissolution of tantalum that is in order of units of mm/year. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Development of corrosion testing equipment under heat transfer and irradiation conditions to evaluate corrosion resistance of materials used in acid recovery evaporator. Contract research

International Nuclear Information System (INIS)

Motooka, Takafumi; Numata, Masami; Kiuchi, Kiyoshi

2002-01-01

We have been evaluated the safety for corrosion of various metals applied to acid recovery evaporators by the mock-up tests using small scaled equipment and the reference tests in laboratories with small specimens. These tests have been conducted under-radioactive environment. The environment in practical reprocessing plants has many radioactive species. Therefore, the effect of irradiation on corrosion should be evaluated in detail. In this study, we have developed the corrosion testing equipment, which is employed to simulate environments in the acid recovery evaporators. This report describes the specification of corrosion testing equipment and the results of primary, reference and hot tests. Using the equipment, the corrosion test under heat transfer and irradiation conditions have been carried out for 930 hours in safety. It is expectable that useful corrosion test data in radioactive environment are accumulated with this equipment in future, and help the adequate choice of corrosion test condition in laboratories. (author)

The application of ion-exchanged clay as corrosion inhibiting pigments in organic coatings

Science.gov (United States)

Chrisanti, Santi

High strength aluminum alloys are used in aerospace industry and are normally coated to prevent corrosion. The corrosion protection of the coatings is mainly provided by pigmented-primer layer. Strontium chromate pigments are widely used, but they are toxic and carcinogenic. The objective of the current study is to develop and characterize the ion exchange compounds bentonite and hydrotalcite as corrosion inhibiting pigments. These compounds were synthesized with different cations and anions, and were used either alone or in mixtures as particulate additive in organic coatings. In coating applications as well as bulk solution, the inhibitor release mechanism is based on ion exchange. To evaluate corrosion inhibition, pigments extract solutions were used in potentiodynamic polarization as well as electrochemical impedance spectroscopy (EIS) experiments on bare aluminum alloy 2024-T3. Cathodic polarization showed that zinc- and cerium-containing filtrate solutions modestly inhibited cathodic current density. These solutions also decreased the extent of pitting damage formed on the surface, as compared to uninhibited 0.5 M NaCl solution. Pigments were also added as primer additives, and painted on AA2024-T3. The coated panels were then subjected to salt spray exposure testing. The possibility of sensing inhibitor exhaustion by means of X-ray diffraction interrogation of the pigment in a coating is demonstrated and discussed on cerium bentonite-pigmented coatings. Although cerium bentonite-pigmented coatings did not show behavior indicative of self-healing, the combination of bentonite and hydrotalcite that released Ce3+, Zn 2+, and PO43- showed potent scribe protection even after 3000 h exposure in salt spray. Promising self-healing was also demonstrated by pigments that consisted of decavanadate-hydrotalcite and zinc pyrovanadate, as indicated by a shiny scribed area after 1000h exposure in salt spray. When these pigments are used, blistering is minimized.

Antifungal drugs as corrosion inhibitors for aluminium in 0.1 M HCl

Energy Technology Data Exchange (ETDEWEB)

Obot, I.B. [Department of Chemistry, Faculty of Science, University of Uyo, Uyo (Nigeria)], E-mail: proffoime@yahoo.com; Obi-Egbedi, N.O. [Department of Chemistry, University of Ibadan, Ibadan (Nigeria); Umoren, S.A. [Department of Chemistry, Faculty of Science, University of Uyo, Uyo (Nigeria)

2009-08-15

The inhibitive capabilities of Clotrimazole (CTM) and Fluconazole (FLC), two antifungal drugs, on the electrochemical corrosion of aluminium in 0.1 M HCl solution has been studied using weight loss measurements at 30 and 50 deg. C. The results indicate that both compound act as inhibitors in the acidic corrodent. At constant acid concentration, the inhibition efficiency (%I) increased with increase in the concentration of the inhibitors. Increase in temperature increased the corrosion rate in the absence and presence of the inhibitors but decreased the inhibition efficiency. CTM and FLC adsorbed on the surface of aluminium according to the Langmuir adsorption isotherm model at all the concentrations and temperatures studied. Phenomenon of physical adsorption is proposed from the activation parameter obtained. Thermodynamic parameters reveal that the adsorption process is spontaneous. The reactivity of these compounds was analyzed through theoretical calculations based on AM1 semi-empirical method to explain the different efficiencies of these compounds as corrosion inhibitors. CTM was found to be a better inhibitor than FLC.

Synergistic effect of iodide ion addition on the inhibition of mild steel corrosion in 1 M HCl by 3-amino-2-methylbenzylalcohol

Energy Technology Data Exchange (ETDEWEB)

Obot, I.B., E-mail: obot@kfupm.edu.sa; Madhankumar, A.

2016-07-01

The inhibition of mild steel corrosion in 1 M HCl aqueous solution by 3-amino-2-methylbenzylalcohol (AMBA) was investigated using weight loss, electrochemical impedance spectroscopy (EIS), potentiodynamic polarization (PDP) and cyclic voltammametry (CV) techniques. Attenuated total reflectance infrared spectroscopy (ATR-IR), contact angle (CA) and scanning electron microscopy (SEM) measurements were carried out to confirm the adsorption of AMBA on mild steel surface. Computer simulations using density functional theory (DFT) and Monte Carlo methodologies were further employed to provide insights into the mechanism of interaction between the inhibitor and the steel surface. All the results confirmed that AMBA is a good corrosion inhibitor for mild steel in 1 M HCl. The addition of NaI was found to increase the inhibition effect of AMBA on mild steel to a considerable extent. DFT results reveal that the N atom together with the π-systems in the aromatic ring were the active sites for the interaction of AMBA with steel surface. Furthermore, the negative value of the adsorption energy obtained from the Monte Carlo simulation indicates the stability of the adsorbed inhibitor film on the steel surface. - Graphical abstract: EIS spectra and adsorption configuration of AMBA on Fe (110). - Highlights: • 3-amino-2-methylbenzylalcohol inhibit mild steel corrosion in acid medium. • ATR-IR, contact angle, SEM, were used for steel surface characterization. • DFT and Monte Carlo simulations provide atomic and molecular level insights. • The theoretical data clearly support the experimental results obtained.

Anion embedded sol-gel films on Al for corrosion protection

International Nuclear Information System (INIS)

Sheffer, Mari; Groysman, Alec; Starosvetsky, David; Savchenko, Natali; Mandler, Daniel

2004-01-01

We report here on the successful incorporation of organic anions into a sol-gel film on Al as a means of enhancing the protection against corrosion. Following our previous study where we showed that hydrophobic sol-gel films provided pronounced corrosion inhibition, we studied the corrosion inhibition that phenylphosphonic acid (PPA) has when embedded inside a thin sol-gel coating on Al. The anion of this organic anion tends to stay inside a phenyltrimethoxysilane (PTMOS) based sol-gel film due to π-interactions. Our findings, which are derived primarily from potentiodynamic polarization measurements, electrochemical noise, scanning electron microscopy measurements and Auger electron spectroscopy (AES), clearly show that the organic phosphonate adds to the protection efficiency of the sol-gel film

Corrosion inhibition performance of 2,5-bis(4-dimethylaminophenyl)-1,3,4-oxadiazole for carbon steel in HCl solution: Gravimetric, electrochemical and XPS studies

Energy Technology Data Exchange (ETDEWEB)

Bouanis, M.; Tourabi, M.; Nyassi, A. [Laboratoire de Catalyse et de Corrosion des Matériaux (LCCM), Faculté des Sciences, Université Chouaib Doukkali, B.P. 20, M-24000 El Jadida (Morocco); Zarrouk, A. [LCAE-URAC 18, Faculty of Science, First Mohammed University, PO Box 717, M-60 000 Oujda (Morocco); Jama, C. [UMET-ISP, CNRS UMR 8207, ENSCL, Université Lille Nord de France, CS 90108, F-59652 Villeneuve d' Ascq Cedex (France); Bentiss, F., E-mail: fbentiss@gmail.com [Laboratoire de Catalyse et de Corrosion des Matériaux (LCCM), Faculté des Sciences, Université Chouaib Doukkali, B.P. 20, M-24000 El Jadida (Morocco); UMET-ISP, CNRS UMR 8207, ENSCL, Université Lille Nord de France, CS 90108, F-59652 Villeneuve d' Ascq Cedex (France)

2016-12-15

Highlights: • 2,5-Bis(4-dimethylaminophenyl)-1,3,4-oxadiazole is good corrosion inhibitor for carbon steel in 1 M HCl. • XPS analysis has provided the composition of adsorbed protective layer on the steel surface. • The adsorption of the investigated 1,3,4-oxadiazole is mainly due to chemisorption. - Abstract: Corrosion inhibition of carbon steel in normal hydrochloric acid solution at 30 °C by 2,5-bis(4-dimethylaminophenyl)-1,3,4-oxadiazole (DAPO) has been studied by weight loss measurements and electrochemical techniques (polarization and AC impedance). The experimental results showed that DAPO acted as an efficient inhibitor against the carbon steel corrosion in 1 M HCl, and its inhibition efficiency increased with the inhibitor concentration reaching a value up to 93% at 1 mM. Polarization studies showed that the DAPO was a mixed-type inhibitor. The adsorption of this 1,3,4-oxadiazole derivative on the carbon steel surface in 1 M HCl solution followed the Langmuir adsorption isotherm and the corresponding value of the standard Gibbs free energy of adsorption (ΔG°{sub ads}) is associated to a chemisorption mechanism. Scanning Electron Microscopy (SEM) and X-Ray Photoelectron Spectroscopy (XPS) analyses were carried out to characterize the chemical composition of the inhibitive film formed on the steel surface. The surfaces studies showed that the inhibitive layer is composed of an iron oxide/hydroxide mixture where DAPO molecules are incorporated. The cytotoxicity of DAPO was also determined using cell culture system.

Superhydrophobic and superoleophobic surface by electrodeposition on magnesium alloy substrate: Wettability and corrosion inhibition.

Science.gov (United States)

Liu, Yan; Li, Shuyi; Wang, Yaming; Wang, Huiyuan; Gao, Ke; Han, Zhiwu; Ren, Luquan

2016-09-15

Superamphiphobic (both superhydrophobic and superoleophobic) surfaces have attracted great interests in the fundamental research and practical application. This research successfully fabricated the superamphiphobic surfaces by combining the nickel plating process and modification with perfluorocaprylic acid. The cooperation of hierarchical micro-nano structures and perfluorocaprylic acid with low surface energy plays an important role in the formation of superamphiphobic surfaces. The contact angles of water/oil have reached up to 160.2±1°/152.4±1°, respectively. Contrast with bare substrate, the electrochemical measurements of superamphiphobic surfaces, not only the EIS measurement, but also potentiodynamic polarization curves, all revealed that, the surface corrosion inhibition was improved significantly. Moreover, superamphiphobic surfaces exhibited superior stability in the solutions with a large pH range, also could maintain excellent performance after storing for a long time in the air. This method is easy, feasible and effective, and could be used to fabricate large-area mutli-functional surface. Such a technique will develop a new approach to fabricate superamphiphobic surfaces on different engineering materials. Copyright © 2016 Elsevier Inc. All rights reserved.

Corrosion resistance of zirconium: general mechanisms, behaviour in nitric acid

International Nuclear Information System (INIS)

Pinard Legry, G.

1990-01-01

Corrosion resistance of zirconium results from the strong affinity of this metal for oxygen; as a result a thin protective oxide film is spontaneously formed in air or aqueous media, its thickness and properties depending on the physicochemical conditions at the interface. This film passivates the underlying metal but obviously if the passive film is partially or completely removed, localised or generalised corrosion phenomena will occur. In nitric acid, this depassivation may be chemical (fluorides) or mechanical (straining, creep, fretting). In these cases it is useful to determine the physicochemical conditions (concentration, temperature, potential, stress) which will have to be observed to use safely zirconium and its alloys in nitric acid solutions [fr

Inhibiting mild steel corrosion from sulfate-reducing bacteria using antimicrobial-producing biofilms in Three-Mile-Island process water.

Science.gov (United States)

Zuo, R; Ornek, D; Syrett, B C; Green, R M; Hsu, C-H; Mansfeld, F B; Wood, T K

2004-04-01

Biofilms were used to produce gramicidin S (a cyclic decapeptide) to inhibit corrosion-causing, sulfate-reducing bacteria (SRB). In laboratory studies these biofilms protected mild steel 1010 continuously from corrosion in the aggressive, cooling service water of the AmerGen Three-Mile-Island (TMI) nuclear plant, which was augmented with reference SRB. The growth of both reference SRB (Gram-positive Desulfosporosinus orientis and Gram-negative Desulfovibrio vulgaris) was shown to be inhibited by supernatants of the gramicidin-S-producing bacteria as well as by purified gramicidin S. Electrochemical impedance spectroscopy and mass loss measurements showed that the protective biofilms decreased the corrosion rate of mild steel by 2- to 10-fold when challenged with the natural SRB of the TMI process water supplemented with D. orientis or D. vulgaris. The relative corrosion inhibition efficiency was 50-90% in continuous reactors, compared to a biofilm control which did not produce the antimicrobial gramicidin S. Scanning electron microscope and reactor images also revealed that SRB attack was thwarted by protective biofilms that secrete gramicidin S. A consortium of beneficial bacteria (GGPST consortium, producing gramicidin S and other antimicrobials) also protected the mild steel.

Eco-Friendly Inhibitors for Copper Corrosion in Nitric Acid: Experimental and Theoretical Evaluation

Science.gov (United States)

Savita; Mourya, Punita; Chaubey, Namrata; Singh, V. K.; Singh, M. M.

2016-02-01

The inhibitive performance of Vitex negundo, Adhatoda vasica, and Saraka asoka leaf extracts on corrosion of copper in 3M HNO3 solution was investigated using gravimetric, potentiodynamic polarization, and electrochemical impedance spectroscopic techniques. Potentiodynamic polarization studies indicated that these extracts act as efficient and predominantly cathodic mixed inhibitor. Thermodynamic parameters revealed that the adsorption of these inhibitors on copper surface was spontaneous, controlled by physiochemical processes and occurred according to the Langmuir adsorption isotherm. AFM examination of copper surface confirmed that the inhibitor prevented corrosion by forming protective layer on its surface. The correlation between inhibitive effect and molecular structure was ascertained by density functional theory data.

Inhibition of copper corrosion in sodium chloride solution by the self-assembled monolayer of sodium diethyldithiocarbamate

Energy Technology Data Exchange (ETDEWEB)

Liao, Q.Q., E-mail: liaoqq1971@yahoo.com.c [Key Lab of Shanghai Colleges and Universities for Electric Power Corrosion Control and Applied Electrochemistry, Shanghai Engineering Research Center of Energy - Saving in Heat Exchange Systems, Shanghai University of Electric Power, Shanghai 200090 (China); Yue, Z.W.; Yang, D. [Key Lab of Shanghai Colleges and Universities for Electric Power Corrosion Control and Applied Electrochemistry, Shanghai Engineering Research Center of Energy - Saving in Heat Exchange Systems, Shanghai University of Electric Power, Shanghai 200090 (China); Wang, Z.H. [Department of Chemistry, Tongji University, Shanghai 200092 (China); Li, Z.H. [Department of Chemistry, Fudan University, Shanghai 200433 (China); Ge, H.H. [Key Lab of Shanghai Colleges and Universities for Electric Power Corrosion Control and Applied Electrochemistry, Shanghai Engineering Research Center of Energy - Saving in Heat Exchange Systems, Shanghai University of Electric Power, Shanghai 200090 (China); Li, Y.J. [Department of Chemistry, Tongji University, Shanghai 200092 (China)

2011-05-15

Research highlights: DDTC is of low toxicity. DDTC SAM had good corrosion inhibition effects on copper in 3% NaCl solution. DDTC SAM was chemisorbed on copper surface by its S atoms. - Abstract: Sodium diethyldithiocarbamate (DDTC) self-assembled monolayer (SAM) on copper surface has been investigated by SERS and EDS and the results show that DDTC SAM is chemisorbed on copper surface by its S atoms with tilted orientation. Corrosion inhibition ability of DDTC SAM was measured in 3% NaCl solution using electrochemical methods. The impedance results indicate that the maximum inhibition efficiency of DDTC SAM can reach 99%. Quantum chemical calculations show that DDTC has relatively small {Delta}E between HOMO and LUMO and large negative charge in its two sulfur atoms, which facilitates the formation of a DDTC SAM on copper surface.

Corrosion Inhibition of Copper-nickel Alloy: Experimental and Theoretical Studies

Energy Technology Data Exchange (ETDEWEB)

Khadom, Anees A. [Univ. of Daiyla, Baquba (Iran, Islamic Republic of); Yaro, Aprael S. [Univ. of Baghdad, Aljadreaa (Iran, Islamic Republic of); Musa, Ahmed Y.; Mohamad, Abu Bakar; Kadhum, Abdul Amir H. [UniversitiKebangsaan Malaysia, Bangi (Malaysia)

2012-08-15

The corrosion inhibition of copper-nickel alloy by Ethylenediamine (EDA) and Diethylenetriamine (DETA) in 1.5M HCl has been investigated by weight loss technique at different temperatures. Maximum value of inhibitor efficiency was 75% at 35 .deg. C and 0.2 M inhibitor concentration EDA, while the lower value was 4% at 35 .deg. C and 0.01 M inhibitor concentration DETA. Two mathematical models were used to represent the corrosion rate data, second order polynomial model and exponential model respectively. Nonlinear regression analysis showed that the first model was better than the second model with high correlation coefficient. The reactivity of studied inhibitors was analyzed through theoretical calculations based on density functional theory (DFT). The results showed that the reactive sites were located on the nitrogen (N1, N2 and N4) atoms.

Enhancement of the Inhibitor Efficiency of Atropine Methochloride in Corrosion Control of Mild Steel in Sulphuric Acid

Directory of Open Access Journals (Sweden)

Abida Begum

2008-01-01

Full Text Available The inhibition efficiency and synergistic behaviour of 10-4 M Atropine methochloride was carried out using mass loss and polarisation methods in the presence of (i metal ions, Ni2+ and Cu2+ between 10-2 M to 10-6 M concentrations, (ii different concentrations of metal ions and 10-3 M I-, 10-3 M Cl- and 10-3 M Br- solutions and (iii different metal ions, 10-3M I- and at three different temperatures. The analysis reveals that the inhibition efficiency of Atropine methochloride was maximum at 10-2 M in 5 hours of immersion period. Halides decreased the corrosion rate of mild steel in Sulphuric acid. The decrease is maximum with 10-3 M I-. As the temperature increased from 298K to 308K, the inhibition efficiency gradually decreased. The inhibitor was found to be effective up to 303K

Standard test method for initial screening of corrosion inhibiting admixtures for steel in concrete

CERN Document Server

American Society for Testing and Materials. Philadelphia

2007-01-01

1.1 This test method covers a procedure for determining the effects of chemical admixtures on the corrosion of metals in concrete. This test method can be used to evaluate materials intended to inhibit chloride-induced corrosion of steel in concrete. It can also be used to evaluate the corrosivity of admixtures by themselves or in a chloride environment. This test is not applicable for emulsions. 1.2 &solely-SI-units; 1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

Corrosion resistance of nickel alloys with chromium and silicon to the red fuming nitric acid

International Nuclear Information System (INIS)

Gurvich, L.Ya.; Zhirnov, A.D.

1994-01-01

Corrosion and electrochemical behaviour of binary Ni-Cr, Ni-Si nickel and ternary Ni-Cr-Si alloys in the red fuming nitric acid (RFNA) (8-% of HNO 3 +20% of N 2 O 4 ) is studied. It is shown that nickel alloying with chromium improves its corrosion resistance to the red fuming nitric acid. Nickel alloying with silicon in quantities of up to 5 % reduces, and up to 10%-increases abruptly the corrosion resistance with subsequent decrease of the latter after the further increase of concentration. Ni-15% of Cr alloy alloying with silicon increases monotonously the corrosion resistance. 10 refs., 7 figs., 3 tabs

Corrosion mechanism of Z3 CN18.10 stainless steel in the presence of nitric acid condensates

International Nuclear Information System (INIS)

Balbaud, Fanny

1998-01-01

In installations handling concentrated boiling nitric acid, a severe intergranular corrosion can sometimes occur in condensation zones constituted of non-sensitized Z3 CN 18.10 stainless steel. Corrosion tests in reactors and in a specific loop, CIRCE, allowed to specify the conditions of occurrence of this type of corrosion and showed the similitude with the corrosion in non-renewed liquid nitric acid: the specific parameters linked to the condensate phase are the high ratio metallic surface area to volume of condensate and the low renewing rate which induce a concentration of oxidation products of the metal and of reduction products of nitric acid. The initiation of the intergranular corrosion is attributed to the increase in the reduction rate of nitric acid by an autocatalytic mechanism which was demonstrated by electrochemical measurements on platinum and on stainless steel. The reduction mechanism involves a charge transfer step where nitrous acid, the electro-active species, is reduced into nitrogen monoxide and a chemical regeneration reaction of nitrous acid. The thermodynamic study led to a representation of the chemical and electrochemical properties of nitric acid. This study allowed also to determine the Gibbs free energy of formation of nitrous acid in solution in concentrated nitric acid at 100 deg. C. The diagram, constructed in coordinates log(P O 2 ) / [-log(P HNO 3 )] or E eXperimental / [-log(P HNO 3 )], shows that the final reduction product of nitric acid depends on the concentration of nitric acid: at 100 deg. C, NO is obtained for concentrations lower than 8 mol.L -1 and NO 2 is obtained for higher concentrations. All these results allowed to propose a corrosion mechanism of Z3 CN 18.10 stainless steel in the presence of nitric acid condensates. [fr

The effect of temperature and concentration on the corrosion inhibition mechanism of an amphiphilic amido-amine in CO2 saturated solution

International Nuclear Information System (INIS)

Desimone, M.P.; Gordillo, G.; Simison, S.N.

2011-01-01

Highlights: → Behaviour of N-[2-[(2-aminoethyl)amino]ethyl]-9-octadecenamide (AAOA) as CO 2 corrosion inhibitor. → The adsorption of the AAOA corrosion inhibitor obeys a Frumkin adsorption isotherm. → The inhibition efficiency of the AAOA depends on temperature and concentration. → There is a change in the adsorption mode of the inhibitor with concentration. → AAOA is mainly physi- or chemisorbed for low or high concentrations, respectively. - Abstract: The corrosion inhibition mechanism of the N-[2-[(2-aminoethyl)amino]ethyl]-9-octadecenamide on mild steel surface in CO 2 -saturated 5% NaCl solution has been studied. The inhibition efficiency decreases with increasing temperature. Adsorption of the inhibitor studied is found to follow the Frumkin adsorption isotherm. EIS results show that the mechanism of its corrosion inhibition at concentrations higher than critical micelle concentration is by forming a protective porous bi-layer. The activation energy, thermodynamic parameters and electrochemical results reveal a change in the adsorption mode of the inhibitor studied: the inhibitor could primarily be physically adsorbed at low concentrations, while chemisorption is favoured as concentration increases.

A comparative study of leaves extracts for corrosion inhibition effect on aluminium alloy in alkaline medium

Directory of Open Access Journals (Sweden)

Namrata Chaubey

2017-12-01

Full Text Available This paper deals with the comparative inhibition study of some plants leaves extract namely Cannabis sativa (CS, Rauwolfia serpentina (RS, Cymbopogon citratus (CC, Annona squamosa (AS and Adhatoda vasica (AV on the corrosion of aluminium alloy (AA in 1 M NaOH. The corrosion tests were performance by using gravimetric, electrochemical impedance spectroscopy (EIS, potentiodynamic polarization and linear polarization resistance (LPR techniques. RS showed maximum inhibition efficiency (η%, 97% at 0.2 g L−1. Potentiodynamic polarization curves justified that all the inhibitors are mixed-type. Surface morphology of AA is carried by scanning electron microscopy (SEM and atomic force microscopy (AFM.

The effect of temperature and concentration on the corrosion inhibition mechanism of an amphiphilic amido-amine in CO2 saturated solution

OpenAIRE

Desimone, Paula Mariela; Gordillo, Gabriel Jorge; Simison, Silvia Noemi

2017-01-01

The corrosion inhibition mechanism of the N-[2-[(2-aminoethyl)amino]ethyl]-9-octadecenamide on mild steel surface in CO2-saturated 5% NaCl solution has been studied. The inhibition efficiency decreases with increasing temperature. Adsorption of the inhibitor studied is found to follow the Frumkin adsorption isotherm. EIS results show that the mechanism of its corrosion inhibition at concentrations higher than critical micelle concentration is by forming a protective porous bi-layer. The a...

Inhibition of pH fronts in corrosion cells due to the formation of cerium hydroxide

NARCIS (Netherlands)

Soestbergen, M. van; Erich, S.J.F.; Huinink, H.P.; Adan, O.C.G.

2013-01-01

The effect of cerium-based corrosion inhibitors on the pH front between the alkaline cathode and acidic anode in corrosion cells has been studied. The cerium component of these inhibitors can affect the pH front since it precipitates in an alkaline environment as cerium hydroxide, which is important

Inhibitory effect of non-ionic surfactants of the TRITON-X series on the corrosion of carbon steel in sulphuric acid

International Nuclear Information System (INIS)

Fuchs-Godec, R.

2007-01-01

The corrosion inhibition characteristics of non-ionic surfactants of the TRITON-X series, known as TRITON-X-100 and TRITON-X-405, on stainless steel (SS) type X4Cr13 in sulphuric acid were investigated by potentiodynamic polarisation measurements. It was found that these surfactants act as good inhibitors of the corrosion of stainless steel in 2 mol L -1 H 2 SO 4 solution, but the inhibition efficiency strongly depends on the electrode potential. The polarisation data showed that the non-ionic surfactants used in this study acted as mixed-type inhibitors and adsorb on the stainless steel surface, in agreement with the Flory-Huggins adsorption isotherm. Calculated ΔG ads values are -57.79 kJ mol -1 for TRITON-X-100, and -87.5 kJ mol -1 for TRITON-X-405. From the molecular structure it can be supposed that these surfactants adsorb on the metal surface through two lone pairs of electrons on the oxygen atoms of the hydrophilic head group, suggesting a chemisorption mechanism

An AFM and XPS study of corrosion caused by micro-liquid of dilute sulfuric acid on stainless steel

International Nuclear Information System (INIS)

Wang Rongguang

2004-01-01

Micro-liquid of dilute sulfuric acid deposited on SUS304 steel surface were observed with the ac non-contact mode of an atomic force microscopy (AFM), and the detail of the corrosion process caused by them was investigated with the contact mode of the AFM, X-ray photoelectron spectroscopy (XPS) and wavelength dispersive X-ray spectroscopy (WDXS). As a result, even not applying bias voltages between the tip of the cantilever and the specimen, micro-liquid of sulfuric acid can be successfully imaged using the ac non-contact mode of AFM. Two shapes of micro-acid, i.e., micro-droplets and micro-films, were found to co-exist on the specimen surface. On areas covered by micro-films of acid, only small corrosion product particles appeared and no corrosion pits were found. Beneath micro-droplets, corrosion reaction continue to produce pits until they were all consumed to form a corrosion product (mainly iron oxides) with almost the same shape with the droplet. The total corrosion reaction time was speculated to be between 690 and 1500 ks. The corrosion product formed from micro-droplets was believed to be a process of accumulating small corrosion product particles from the liquid/substrate interface to the surface of the formerly produced corrosion product. The XPS and WDXS analysis also supports the above results

Corrosion behavior of stainless steel and zirconium in nitric acid containing highly oxidizing species

International Nuclear Information System (INIS)

Mayuzumi, Masami; Fujita, Tomonari

1994-01-01

Corrosion behavior of 304ELC, 310Nb stainless steels and Zirconium was investigated in the simulated dissolver solution of a reprocessing plant to obtain fundamental data for life prediction. Corrosion of heat transfer surface was also investigated in nitric acid solutions containing Ce ion. The results obtained are as follows: (1) Stainless steels showed intergranular corrosion in the simulated dissolver solution. The corrosion rate increased with time and reached to a constant value after several hundred hours of immersing time. The constant corrosion rate changed depending on potential suggesting that corrosion potential dominates the corrosion process. 310Nb showed superior corrosion resistance to 304ELC. (2) Corrosion rate of stainless steels increased in the heat transfer condition. The causes of corrosion enhancement are estimated to be higher corrosion potential and higher temperature of heat transfer surface. (3) Zirconium showed perfect passivity in all the test conditions employed. (author)

A Revisit to the Corrosion Inhibition of Aluminum in Aqueous Alkaline Solutions by Water-Soluble Alginates and Pectates as Anionic Polyelectrolyte Inhibitors

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Refat Hassan

2013-01-01

Full Text Available The corrosion behavior of aluminum (Al in alkaline media in presence of some natural polymer inhibitors has been reinvestigated. The inhibition action of the tested inhibitors was found to obey both Langmuir and Freundlich isotherms models. The inhibition efficiency was found to increase with increasing the inhibitors concentration and decrease with increasing the temperature, suggesting physical adsorption mechanism. Factors such as the concentration and geometrical structure of the inhibitor, concentration of the corrosive medium, and temperature affecting the corrosion rates were examined. The kinetic parameters were evaluated, and a suitable corrosion mechanism consistent with the kinetic results obtained is suggested and discussed.

Novel dispersed magnetite core-shell nanogel polymers as corrosion inhibitors for carbon steel in acidic medium

International Nuclear Information System (INIS)

Atta, Ayman M.; El-Azabawy, Olfat E.; Ismail, H.S.; Hegazy, M.A.

2011-01-01

Graphical abstract: Display Omitted Research highlights: → Through a one-step thermal reaction, magnetite nanoparticles were synthesized, and self-assembled mixed films of modified cross-linked ionic polymer magnetite nanoparticles were prepared on iron surface. → The size distribution and shape of magnetite nanoparticles were examined using transmission electron microscopy (TEM). → The corrosion inhibition efficiency of carbon steel in 1 M HCl by the synthesized Fe 3 O 4 nanogel polymers has been studied using potentiodynamic polarization and EIS. → Scanning electron microscopy (SEM) measurements were applied to study the morphology of the carbon steel surface. - Abstract: Novel core-shell preparing poly(2-acrylamido-2-methylpropane sulfonic acid) (PAMPS) and copolymers with acrylic acid (AA) or acrylamide (AM) magnetic nanogels with controllable particle size produced via free aqueous polymerization at room temperature have been developed for the first time. The crosslinking polymerization was carried out in the presence of N,N'-methylenebisacrylamide (MBA) as a crosslinker, N,N,N',N'-tetramethylethylenediamine (TEMED) and potassium peroxydisulfate (KPS) as redox initiator system. The structure and morphology of the magnetic nanogels were characterized by Fourier transform infrared spectroscopy (FTIR), transmission and scanning electron microscopy (TEM and SEM). The effectiveness of the synthesized compounds as corrosion inhibitors for carbon steel in 1 M HCl was investigated by various electrochemical techniques such as potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). The results showed enhancement in inhibition efficiencies with increasing the inhibitor concentrations and temperatures. The results showed the nanogel particles act as mixed inhibitors. Adsorption of nanogel particles was found to fit the Langmuir isotherm and was chemisorption.

Sodium phthalamates as corrosion inhibitors for carbon steel in aqueous hydrochloric acid solution

International Nuclear Information System (INIS)

Flores, Eugenio A.; Olivares, Octavio; Likhanova, Natalya V.; Dominguez-Aguilar, Marco A.; Nava, Noel; Guzman-Lucero, Diego; Corrales, Monica

2011-01-01

Highlights: → N-Alkyl-sodium phthalamates as corrosion inhibitors for industry in acidic medium. → Compounds behaved as mixed type inhibitors and followed Langmuir adsorption isotherm. → Efficiencies were proportional to aliphatic chain length and inhibitor concentration. → Iron complexes and chelates with phthalamates contributed to carbon steel protection. - Abstract: Three compounds of N-alkyl-sodium phthalamates were synthesized and tested as corrosion inhibitors for carbon steel in 0.5 M aqueous hydrochloric acid. Tests showed that inhibitor efficiencies were related to aliphatic chain length and dependent on concentration. N-1-n-tetradecyl-sodium phthalamate displayed moderate efficiency against uniform corrosion, 42-86% at 25 deg. C and 25-60% at 40 o C. Tests indicated that compounds behave as mixed type inhibitors where molecular adsorption on steel followed Langmuir isotherm, whereas thermodynamic suggested that a physisorption process occurred. XPS analysis confirmed film formation on surface, where Fe +2 complexes and Fe +2 chelates with phthalamates prevented steel from further corrosion.

Corrosion control of galvanized steel using a phosphate/calcium ion inhibitor mixture

International Nuclear Information System (INIS)

Zin, I.M.; Lyon, S.B.; Pokhmurskii, V.I.

2003-01-01

The corrosion inhibition of galvanized steel was studied in artificial acid rain solution using extracts of pigments normally used in organic coatings for corrosion control. It was established that a combination of zinc phosphate/molybdate and calcium ion exchange silica has a significant synergetic anticorrosion effect in the acid rain solution compared to the pigments used alone. Further, the charge transfer resistance of galvanized steel in acid rain solution saturated by the above pigment blend approaches that of strontium chromate in artificial acid rain solution. Use of the pigment blend was found to lead to development of a protective film, which is thought to be a complex mixture of calcium phosphates and zinc phosphate

Binary Mixtures of Nonyl Phenol with Alkyl Substituted Anilines as Corrosion Inhibitors for Mild Steel in Acidic Medium

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H. S. Shukla

2012-01-01

Full Text Available The present study deals with the evaluation of the corrosion inhibition effectiveness of the two binary mixtures of nonyl phenol (NPH with 2, 4 dimethyl aniline (DMA and 2 ethyl aniline (EA at different concentration ratios (from 1:7 to 7:1 for mild steel in H2SO4 (pH=1 solution by weight loss and potentiodynamic polarization method. Corrosion inhibition ability of the compounds has been tested at different exposure periods (6 h to 24 h and at different temperatures (303 K to 333 K. The binary mixture of NPH and EA (at 7:1 concentration ratio has afforded maximum inhibition (IE% 93.5% at 6 h exposure period and at room temperature. The adsorption of both the inhibitors is found to accord with Temkin adsorption isotherm. Potentiodynamic polarization study reveals that the tested inhibitors are mixed type inhibitor and preferentially act on cathodic areas. Electrochemical impedance study suggests formation of an inhibition layer by the adsorption of the inhibitors on the metal surface. An adsorption model of the inhibitor molecules on the metal surface has been proposed after immersion test in the inhibited acid showed characteristic shift of N-H and O-H bond frequencies towards lower side compared to that of the respective pure samples which indicated the donation of electron pair through N and O atom of the inhibitor molecule in the surface adsorption phenomena. SEM study has revealed formation of semi globular inhibitor products on the metal surface. The comparisons of the protection efficiencies of these compounds according to their relative electron density on the adsorption centre and projected molecular area of the inhibitor molecules have been made.

Effect of some pyrimidinic Schiff bases on the corrosion of mild steel in hydrochloric acid solution

International Nuclear Information System (INIS)

Ashassi-Sorkhabi, H.; Shaabani, B.; Seifzadeh, D.

2005-01-01

The efficiency of benzylidene-pyrimidin-2-yl-amine (A) (4-methyl-benzylidene)-pyrimidine-2-yl-amine (B) and (4-chloro-benzylidene)-pyrimidine-2-yl-amine, as corrosion inhibitors for mild steel in 1 M HCl have been determined by weight loss measurements and electrochemical polarization method. The results showed that these inhibitors revealed a good corrosion inhibition even at very low concentrations. Polarization curves indicate that all compounds are mixed type inhibitors. The effect of various parameters such as temperature and inhibitor concentration on the efficiency of the inhibitors has been studied. Activation energies of corrosion reaction in the presence and absence of inhibitors have been calculated. The adsorption of used compounds on the steel surface obeys Langmuir's isotherm. It appears that an efficient inhibition is characterized by a relatively greater decrease in free energy of adsorption. Significant correlations are obtained between inhibition efficiency and quantum chemical parameters using quantitative structure-activity relationship (QSAR) method

Corrosion of Selected Materials in Boiling Sulfuric Acid for the Nuclear Power Industries

International Nuclear Information System (INIS)

Kim, Dong Jin; Lee, Han Hee; Kwon, Hyuk Chul; Kim, Hong Pyo; Hwang, Seong Sik

2007-01-01

Iodine sulfur (IS) process is one of the promising processes for a hydrogen production by using a high temperature heat generated by a very high temperature gas cooled reactor(VHTR) in the nuclear power industries. Even though the IS process is very efficient for a hydrogen production and it is not accompanied by a carbon dioxide evolution, the highly corrosive environment of the process limits its application in the industry. Corrosion tests of selected materials were performed in sulfuric acid to select appropriate materials compatible with the IS process. The materials used in this work were Fe-Cr alloys, Fe-Ni-Cr alloys, Fe-Si alloys, Ni base alloys, Ta, Ti, Zr, SiC, Fe-Si, etc. The test environments were 50 wt% sulfuric acid at 120 .deg. C and 98 wt% at 320 .deg. C. Corrosion rates were measured by using a weight change after an immersion. The surface morphologies and cross sectional areas of the corroded materials were examined by using SEM equipped with EDS. Corrosion behaviors of the materials were discussed in terms of the chemical composition of the materials, a weight loss, the corrosion morphology, the precipitates in the microstructure and the surface layer composition

Corrosion inhibition studies in support of the long term storage of AGR fuel

Energy Technology Data Exchange (ETDEWEB)

Standring, P [Sellafield Limited (United Kingdom)

2012-07-01

Thorp Receipt and Storage (at Sellafield, UK) is currently being investigated as a bridging solution for the storage of AGR fuel pending the out-come of a national review into spent fuel management. AGR spent fuel is known to be susceptible to corrosion through inter-granular attack. To avoid this, the chosen storage regime for AGR fuel is sodium hydroxide dosed pond water to pH 11.4; now 22 years of operating experience. The conversion of TR and S will require a phased transition. During this transition sodium hydroxide cannot be used due to materials compatibility issues. Alternative corrosion inhibitors have been investigated as an interim measure and sodium nitrate has been selected as a suitable candidate. The efficiency of sodium nitrate to inhibit propagating inter-granular attack of active AGR materials has yet to be established. In the longer term sodium hydroxide will be deployed along with a move to a closed loop pond water management system. Given that carbon dioxide is known to be absorbed by sodium hydroxide dosed water and can affect fuel integrity, in the case of Magnox fuel, there is a need to establish its impact on AGR fuel. The objectives are: To establish the impact of carbonate on AGR fuel corrosion; To establish the efficiency of sodium nitrate to inhibit propagating inter-granular attack of irradiated AGR materials.

Inhibition of filiform corrosion on organic-coated AA2024-T3 by smart-release cation and anion-exchange pigments

International Nuclear Information System (INIS)

Williams, G.; McMurray, H.N.

2012-01-01

Highlights: ► Filiform corrosion (FFC) inhibition by various smart-release pigments was evaluated by SKP. ► Rare earth cation-containing pigments were ineffective at halting FFC propagation. ► Metal oxo-anions and organic copper-specific agents were exchanged into hydrotalcite. ► Effective inhibition of FFC was demonstrated by anions which stopped copper re-plating. - Abstract: In-coating cation and anion exchange pigments are studied with respect to their ability to inhibit chloride-induced filiform corrosion (FFC) on organic-coated AA2024-T3 aluminium alloy substrates. In-situ scanning Kelvin probe potentiometry is used to quantify both underfilm potentials associated with populations of propagating corrosion filaments and the kinetics of coating disbondment. Smart-release bentonite pigments containing exchangeable cerium (III) and yttrium (III) cations are shown to be largely ineffective in reducing rates of FFC propagation. The reasons for this are discussed in terms of the chemistry of the electrolyte-filled corrosion filament head. In contrast, anion-exchange hydrotalcite (HT) based pigments are highly effective inhibitors of FFC. A comparison of the extent of FFC observed for various inorganic exchangeable anions is made with as-received HT comprising carbonate anions. Of the anions evaluated, exchangeable chromate unsurprisingly provides the highest FFC inhibition efficiency. It is also demonstrated that exchanging the native carbonate ions for certain organic species which act as complexing agents for copper ions, gives rise to an equivalent level of FFC inhibition. The implication of these findings with respect to the mechanism of FFC on copper containing aluminium alloys is considered.

Evaluation of Plants and Weeds Extract on the Corrosion Inhibition of Mild Steel in Sulphuric Acid

Directory of Open Access Journals (Sweden)

Abida Begum

2011-01-01

Full Text Available Experiments were performed in order to determine the inhibitive effects of extracts of plants and weeds namely Parthenium hysterophorus, Dathura stromonium, Azadirachta indica, Helianthus annuus leaves extract for mild steel in sulphuric acid by using weight loss and thermometric technique. Results demonstrated that, all the experimental inhibitors show an adsorption on steel surface according to Langmuir’s isotherm. The inhibition efficiency increased with increase in the concentration of all tested inhibitors to attain a maximum value at 1.0%. Free energy values for adsorption process show that the process is spontaneous. The kinetic treatment of the results shows first order kinetics.

Interaction of inhibitors with corrosion scale formed on N80 steel in CO{sub 2}-saturated NaCl solution

Energy Technology Data Exchange (ETDEWEB)

Liu, D. [School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Hubei Key Laboratory of Materials Chemistry and Service Failure, Wuhan (China); School of Chemical Engineering and Pharmacy, Key Laboratory for Green Chemical Process of Ministry of Education, Wuhan Institute of Technology, Wuhan (China); Qiu, Y.B.; Guo, X.P. [School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Hubei Key Laboratory of Materials Chemistry and Service Failure, Wuhan (China); Tomoe, Y.; Bando, K. [Japan Oil, Gas and Metals National Corporation, The Former Japan National Oil Corporation, Hamada, Mihama-ku, Chiba-City, Chiba (Japan)

2011-12-15

The performance of the selected inhibitors, including thioglycolic acid (TGA), diethylenetriamine (DETA), and naphthene acid imidazolines (IM), on the bare surface of N80 steel and its scaled surface pre-corroded in CO{sub 2}-saturated 1%NaCl solution was investigated by weight-loss method, electrochemical measurements using rotating cylinder electrode and surface analytical methods (SEM, XRD, and EPMA). The results indicate that there is a remarkable difference in inhibition efficiency of inhibitors on the N80 steel with and without pre-corrosion scale. The synergistic effect between inhibitors and corrosion scale not only depends on the size of inhibitor molecules, but also depends on the interaction of the inhibitor with the corrosion scale. It shows that IM and DETA have a good positive synergistic effect with the corrosion scale formed on N80 steel, although DETA has no inhibition efficiency for bare N80 steel, which can easily enter into the apertures of the corrosion scale, and block the active sites on the metal surface and the diffusion routeways of the reactant so as to depress the corrosion of the substrate metal. While TGA shows excellent inhibition efficiency on bare N80 steel, but it has an antagonistic effect with the corrosion scale although it has a small molecular weight as well as DETA, because TGA can dissolve corrosion scale and break its integrality and protectiveness performance. (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Corrosion resistance of Ultra-Low-Carbon 19% Cr-11% Ni stainless steel for nuclear fuel reprocessing plants in nitric acid

International Nuclear Information System (INIS)

Ariga, Tamako; Takagi, Yoshio; Inazumi, Toru; Masamura, Katsumi; Sukekawa, M.

1995-01-01

An Ultra-Low-Carbon 19% Cr-11% Ni Stainless Steels used in nuclear fuel reprocessing plants where highly corrosion resistance in nitric acid is required has been developed. This steel has optimized the chemistry composition to decrease inclusions and deformation-induced martensitic transformation. The formation of deformation-induced martensite has the potential danger of accelerating corrosion in nitric acid. In this paper, effects of cold reduction and martensitic transformation on corrosion resistance of Ultra-Low-Carbon Stainless Steels in nitric acid are discussed. The developed steel showed excellent corrosion resistance during long-term exposure to nitric acid. (author)

Localized corrosion of high performance metal alloys in an acid/salt environment

Science.gov (United States)

Macdowell, L. G.; Ontiveros, C.

1991-01-01

Various vacuum jacketed cryogenic supply lines at the Space Shuttle launch site at Kennedy Space Center use convoluted flexible expansion joints. The atmosphere at the launch site has a very high salt content, and during a launch, fuel combustion products include hydrochloric acid. This extremely corrosive environment has caused pitting corrosion failure in the thin walled 304L stainless steel flex hoses. A search was done to find a more corrosion resistant replacement material. The study focussed on 19 metal alloys. Tests which were performed include electrochemical corrosion testing, accelerated corrosion testing in a salt fog chamber, and long term exposure at a beach corrosion testing site. Based on the results of these tests, several nickel based alloys were found to have very high resistance to this corrosive environment. Also, there was excellent agreement between the electrochemical tests and the actual beach exposure tests. This suggests that electrochemical testing may be useful for narrowing the field of potential candidate alloys before subjecting samples to long term beach exposure.

The inhibition performance of long-chain alkyl-substituted benzimidazole derivatives for corrosion of mild steel in HCl

International Nuclear Information System (INIS)

Zhang, Dongqin; Tang, Yongming; Qi, Sijun; Dong, Dawei; Cang, Hui; Lu, Gang

2016-01-01

Highlights: • Inhibition performance of long-chain alkyl-substituted benzimidazole. • Benzimidazole segment donating electrons to metal surface. • Non-polar long chain enhancing inhibition by the barrier effect. • Molecular form of DBI more tightly adsorbs on the steel than its protonated form. - Abstract: The corrosion inhibition of a new benzimidazole derivative, 6-(dodecyloxy)-1H-benzo[d]imidazole (DBI), for mild steel in 1 M HCl was investigated in this paper. Computational chemistry was performed to explore the adsorption of DBI on metal surface. Inhibition performance of DBI is attributed to both the direct interaction of benzimidazole segment with iron surface and the barrier effect of the non-polar long chain against aggressive solution. Compared to the protonated form, the molecular form of DBI could more tightly interact with iron surface. These results show that the long-chain alkyl-substituted benzimidazole derivative is of great potential application as corrosion inhibitor.

Intergranular corrosion testing of austenitic stainless steels in nitric acid solutions

Energy Technology Data Exchange (ETDEWEB)

Whillock, G.O.H.; Dunnett, B. F. [British Nuclear Fuels plc, BNFL, B170, Sellafield, Seascale, Cumbria CA20 1PG (United Kingdom)

2004-07-01

In hot strong nitric acid solutions, stainless steels exhibit intergranular corrosion. Corrosion rates are often measured from immersion testing of specimens manufactured from the relevant material (e.g. plate or pipe). The corrosion rates, measured from weight loss, are found to increase with time prior to reaching steady state, which can take thousands of hours to achieve. The apparent increase in corrosion rate as a function of time was found to be an artefact due to the surface area of the specimen's being used in the corrosion rate calculations, rather than that of the true area undergoing active corrosion i.e. the grain boundaries. The steady state corrosion rate coincided with the onset of stable grain dropping, where the use of the surface area of the specimen to convert the weight loss measurements to corrosion rates was found to be appropriate. This was confirmed by sectioning of the specimens and measuring the penetration depths. The rate of penetration was found to be independent of time and no induction period was observed. A method was developed to shorten considerably the testing time to reach the steady state corrosion rate by use of a pre-treatment that induces grain dropping. The long-term corrosion rates from specimens which were pre-treated was similar to that achieved after prolonged testing of untreated (i.e. initially ground) specimens. The presence of cut surfaces is generally unavoidable in the simple immersion testing of specimens in test solutions. However, inaccuracy in the results may occur as the measured corrosion rate is often influenced by the orientation of the microstructure, the highest rates typically being observed on the cut surfaces. Two methods are presented which allow deconvolution of the corrosion rates from immersion testing of specimens containing cut surfaces, thus allowing reliable prediction of the long-term corrosion rate of plate surfaces. (authors)

Corrosion Inhibition Study of Al-Cu-Ni Alloy in Simulated Sea-Water ...

African Journals Online (AJOL)

A study on the inhibition of Al-Cu-Ni alloy in simulated sea-water environment was investigated using Sodium Chromate as inhibitor. The inhibitor concentration was varied as control, 0.25, 0.5, 1.0, 1.5 and 2.0 Molar. Al-Cu-Ni alloy was sand cast into cylindrical bars of 20 mm x 300 mm dimension. The corrosion of the ...

ac impedance, X-ray photoelectron spectroscopy and density functional theory studies of 3,5-bis(n-pyridyl)-1,2,4-oxadiazoles as efficient corrosion inhibitors for carbon steel surface in hydrochloric acid solution

Energy Technology Data Exchange (ETDEWEB)

Outirite, Moha; Lagrenee, Michel; Lebrini, Mounim [Unite de Catalyse et de Chimie du Solide, UMR-CNRS 8181, ENSCL, B.P. 90108, F-59652 Villeneuve d' Ascq Cedex (France); Traisnel, Michel; Jama, Charafeddine [Laboratoire des Procedes d' Elaboration des Revetements Fonctionnels, PERF UMR-CNRS 8008, ENSCL, B.P. 90108, F-59652 Villeneuve d' Ascq Cedex (France); Vezin, Herve [Laboratoire de Chimie Organique et Macromoleculaire, UMR-CNRS 8009, USTL Bat C4, F-59655 Villeneuve d' Ascq Cedex (France); Bentiss, Fouad, E-mail: fbentiss@enscl.f [Laboratoire de Chimie de Coordination et d' Analytique, Faculte des Sciences, Universite Chouaib Doukkali, B.P. 20, M-24000 El Jadida (Morocco)

2010-02-01

The corrosion inhibition properties of a new class of oxadiazole derivatives, namely 3,5-bis(n-pyridyl)-1,2,4-oxadiazoles (n-DPOX) for C38 carbon steel corrosion in 1 M HCl medium were analysed by electrochemical impedance spectroscopy (EIS). An adequate structural model of the interface was used and the values of the corresponding parameters were calculated and discussed. The experimental results showed that these compounds are excellent inhibitors for the C38 steel corrosion in acid solution and that the protection efficiency increased with increasing the inhibitors concentration. Electrochemical impedance data demonstrate that the addition of the n-DPOX derivatives in the corrosive solution decreases the charge capacitance and simultaneously increases the function of the charge/discharge of the interface, facilitating the formation of an adsorbed layer over the steel surface. Adsorption of these inhibitors on the steel surface obeys to the Langmuir adsorption isotherm. X-ray photoelectron spectroscopy (XPS) and the thermodynamic data of adsorption showed that inhibition of steel corrosion in normal hydrochloric solution by n-DPOX is due to the formation of a chemisorbed film on the steel surface. Quantum chemical calculations using the Density Functional Theory (DFT) and the Quantitative Structure Activity Relationship (QSAR) approach were performed on n-DPOX derivatives to determine the relationship between molecular structure and their inhibition efficiencies. The results of the quantum chemical calculations and experimental inhibition efficiency were subjected to correlation analysis and indicate that their inhibition effect is closely related to E{sub HOMO}, E{sub LUMO}, and dipole moment (mu).

Electropolymerization of camphorsulfonic acid doped conductive polypyrrole anti-corrosive coating for 304SS bipolar plates

Science.gov (United States)

Jiang, Li; Syed, Junaid Ali; Gao, Yangzhi; Zhang, Qiuxiang; Zhao, Junfeng; Lu, Hongbin; Meng, Xiangkang

2017-12-01

Conductive polymer coating doped with large molecular organic acid is an alternative method used to protect stainless steel (SS) bipolar plates in proton exchange membrane fuel cells (PEMFCs). However, it is difficult to select the proper doping acid, which improves the corrosion resistance of the coating without affecting its conductivity. In this study, large spatial molecular group camphorsulfonic acid (CSA) doped polypyrrole (PPY) conductive coating was prepared by galvanostatic electropolymerization on 304SS. The electrochemical properties of the coating were evaluated in 0.1 M H2SO4 solution in order to simulate the PEMFC service environment. The results indicate that the coating increased the corrosion potential and shifted Ecorr towards more positive value, particularly the jcorr value of PPY-CSA coated 304SS was dropped from 97.3 to 0.00187 μA cm-2. The long-term immersion tests (660 h) show that the PPY-CSA coating exhibits better corrosion resistance in comparison with the small acid (SO42-) doped PPY-SO42- or PPY/PPY-SO42- coatings. Moreover, the PPY-CSA coating presents low contact resistance and maintains strong corrosion resistance during the prolonged exposure time due to barrier effect and anodic protection.

The effect of functionalized polycarboxylate structures as corrosion inhibitors in a simulated concrete pore solution

Science.gov (United States)

Fazayel, A. S.; Khorasani, M.; Sarabi, A. A.

2018-05-01

In this study, the effects of polycarboxylate derivatives with different comonomers and functional groups on the control or reduction of corrosion in steel specimens were evaluated through electrochemical impedance spectroscopy (EIS) and potentiodynamic analysis. A highly alkaline contaminated concrete pore solution (CPS) containing chlorides was used to simulate the pitting corrosion, and according to the results, the mechanism of inhibitive action was determined. Both the inhibition efficiency and pitting corrosion inhibition of methacrylate-copolymers were in the order of poly methacrylate-co acrylamide > poly methacrylate-co-2-acrylamido-2 methylpropane sulfonic acid > poly methacrylate-co-hydroxyethyl methacrylate. In addition, the corrosion potential of steel specimens in all studied concentrations of NaCl with different concentrations of polymethacrylate-co acrylamide (as the best inhibitor in this study) in saturated Ca(OH)2 solution showed almost an identical trend. Polymethacrylic acid-co-acrylamide showed a 92.35% inhibitor efficiency in the saturated Ca(OH)2 solution containing 1.8 wt.% chlorides and could effectively reduce the corrosion rate. Even at 3.5 wt.% of NaCl, this inhibitor could remarkably reduce the destructive effect of chloride ion attacks on the steel surface and passive film. The inhibition effect of these polymeric inhibitors seemed to be due to the formation of a barrier layer on the metal surface, approved by the well-known adsorption mechanism of organic molecules at the metal/solution interface. The results of SEM, EDS and AFM investigations were also in agreement with the outcomes of electrochemical studies.

Electrochemical and spectroscopic evidences of corrosion inhibition of bronze by a triazole derivative

International Nuclear Information System (INIS)

Dermaj, A.; Hajjaji, N.; Joiret, S.; Rahmouni, K.; Srhiri, A.; Takenouti, H.; Vivier, V.

2007-01-01

The electrochemical behavior of the bronze (Cu-8Sn in wt%) was investigated in 3% NaCl aqueous solution, in presence and in absence of a corrosion inhibitor, the 3-phenyl-1,2,4-triazole-5-thione (PTS). The inhibiting effect of the PTS was evidenced for concentrations higher than 1 mM for the cathodic process whereas its effect was clearly seen with a concentration as low as 0.1 mM for the anodic process. A significant positive shift of the corrosion potential was also observed, and its inhibiting effect increased with both its concentration and the immersion time of the sample. From voltammetry and electrochemical impedance spectroscopy experiments, the inhibiting efficiency of the PTS was found to be in the 94-99% range for 1 mM concentration. Scanning electron microscopy and X-ray energy dispersion analysis of the specimen surface show the presence of sulphur on the surface. Raman micro-spectrometry study confirms the protective effect of the PTS in aqueous solution through three types of interactions with the electrode, namely the adsorption of the inhibitor in a flat configuration, the formation of copper-thiol molecules, and when copper is released, the formation of a polymeric complex

Corrosion resistance of stainless steels and high Ni-Cr alloys to acid fluoride wastes

International Nuclear Information System (INIS)

Smith, H.D.; Mackey, D.B.; Pool, K.H.; Schwenk, E.B.

1992-04-01

TRUEX processing of Hanford Site waste will utilize potentially corrosive acid fluoride processing solutions. Appropriate construction materials for such a processing facility need to be identified. Toward this objective, candidate stainless steels and high Ni-Cr alloys have been corrosion tested in simulated acid fluoride process solutions at 333K. The high Ni-Cr alloys exhibited corrosion rates as low as 0.14 mm/y in a solution with an HF activity of about 1.2 M, much lower than the 19 to 94 mm/y observed for austenitic stainless steels. At a lower HF activity (about 0.008 M), stainless steels display delayed passivation while high Ni-Cr alloys display essentially no reaction

Choice of corrosion-resistant metal for fluotitanic acid

International Nuclear Information System (INIS)

Reingeverts, M.D.; Lapchenko, E.P.; Semenyuk, E.Y.

1986-01-01

The authors investigate the corrosion and anodic behavior of steels 12Kh18N10T, 08Kh21N6M2T, and 06KhN28MDT, nickel, and molybdenum in 10-40% naturally aerated solutions of H 2 TiF 6 at 20 and 50 degrees C. The authors found that in solutions of fluotitanic acid, as also in tetrafluoroboric and hydrofluoric acids, the most stable alloys are chromium-nickel-molybdenum alloy of type 06KhN28MDT and (for acid concentrations above 20%) copper-nickel-alloys of the monel metal type. Steels 12Kh18N10T and 08Kh21N6M2T can be used in acid concentrations of less than 10% and temperatures up to 20 degrees C with anodic protection

Corrosion behaviour of alloy Ti-35 in boiling nitric acid solution

International Nuclear Information System (INIS)

Lan Cui; Qiu Shaoyu

2005-01-01

This report states the corrosion behaviors of alloy Ti-35 in boiling nitric acid solution. The results show that its general corrosion rate is by far superior to high-purity austenitic stainless steel with super-low carbon content, the stress corrosion and crevice corrosion have been not discovered in its samples, and oxide film can be quickly reproduced in scratch. The microstructural analysis on samples shows that there is a thin compact TiO 2 film on the sample surface of alloy Ti-35, and most of the film possess the crystal structure of rutile type, the other has the crystal structure of anatase type. This oxide layer plays a role in hindering corrosion development, so the corrosion resistance of alloy Ti-35 is raised. In contrast with it, the oxide film on the sample surface of austenitic stainless steel is not found. It is evident that alloy Ti-35 can become the prime candidate structural material for dissolver of reprocessing facility of spent fuel and be substituted for high-purity austenitic stainless steel with super-low carbon content which is used now. (authors)

Nickel Inhibits Mitochondrial Fatty Acid Oxidation

Science.gov (United States)

Uppala, Radha; McKinney, Richard W.; Brant, Kelly A.; Fabisiak, James P.; Goetzman, Eric S.

2015-01-01

Nickel exposure is associated with changes in cellular energy metabolism which may contribute to its carcinogenic properties. Here, we demonstrate that nickel strongly represses mitochondrial fatty acid oxidation—the pathway by which fatty acids are catabolized for energy—in both primary human lung fibroblasts and mouse embryonic fibroblasts. At the concentrations used, nickel suppresses fatty acid oxidation without globally suppressing mitochondrial function as evidenced by increased glucose oxidation to CO2. Pre-treatment with L-carnitine, previously shown to prevent nickel-induced mitochondrial dysfunction in neuroblastoma cells, did not prevent the inhibition of fatty acid oxidation. The effect of nickel on fatty acid oxidation occurred only with prolonged exposure (>5 hr), suggesting that direct inhibition of the active sites of metabolic enzymes is not the mechanism of action. Nickel is a known hypoxia-mimetic that activates hypoxia inducible factor-1α (HIF1α). Nickel-induced inhibition of fatty acid oxidation was blunted in HIF1α knockout fibroblasts, implicating HIF1α as one contributor to the mechanism. Additionally, nickel down-regulated the protein levels of the key fatty acid oxidation enzyme very long-chain acyl-CoA dehydrogenase (VLCAD) in a dose-dependent fashion. In conclusion, inhibition of fatty acid oxidation by nickel, concurrent with increased glucose metabolism, represents a form of metabolic reprogramming that may contribute to nickel-induced carcinogenesis. PMID:26051273

Phosphate ions as inhibiting agents for copper corrosion in chlorinated tap water

International Nuclear Information System (INIS)

Yohai, L.; Schreiner, W.H.; Vázquez, M.; Valcarce, M.B.

2013-01-01

PO 4 3− ions as corrosion inhibitor were investigated on copper in tap water in the presence of NaClO. The inhibitor was evaluated by electrochemical techniques and weight loss tests. Raman spectroscopy and X-ray photoelectron spectroscopy were used to study the passive layer. In inhibited tap water, the passive layer is thick and compact if NaClO is present. Weight-loss tests showed the inhibition of uniform dissolution and no pitting attack. When adding NaClO, Cu 3 (PO 4 ) 2 is incorporated to the passive film. Thus, phosphate ions are effective as inhibitors for copper in tap water, even when using high dosages of biocides. - Highlights: ► Changes in the copper corrosion after adding phosphate to tap water were analyzed. ► When NaClO and phosphates are present, Cu 3 (PO 4 ) 2 participates of the surface film. ► In the absence of biocide the surface film contains a mixture of Cu 2 O, CuO and Cu(OH) 2 . ► PO 4 3− is an effective inhibitor for Cu in tap water containing high NaClO dosages

Study on tea leaves extract as green corrosion inhibitor of mild steel in hydrochloric acid solution

Science.gov (United States)

Hamdan, A. B.; Suryanto; Haider, F. I.

2018-01-01

Corrosion inhibitor from extraction of plant has been considered as the most preferable and most chosen technique to prevent corrosion of metal in acidic medium because of the environmental friendly factor. In this study, black tea leaves extraction was tested as corrosion inhibitor for mild steel in 0.1M of hydrochloric acid (HCl) with the absence and presence of corrosion inhibitor. The efficiency and effectiveness of black tea as corrosion inhibitor was tested by using corrosion weight loss measurement experiment was carried out with varies parameters which with different concentration of black tea extract solution. The extraction of black tea solution was done by using aqueous solvent method. The FT-IR result shows that black tea extract containing compounds such as catechin, caffeine and tannins that act as anti-corrosive reagents and responsible to enhance the effectiveness of black tea extract as corrosion inhibitor by forming the hydrophobic thin film through absorption process. As a result of weight loss measurement, it shows that loss in weight of mild steel reduces as the concentration of inhibitor increases. The surface analysis was done on the mild steel samples by using SEM.

Effects of noble-metal ion implantation on corrosion inhibition and charge injection capability of surgical Ti and Ti-6Al-4V

International Nuclear Information System (INIS)

Lee, I.S.

1989-01-01

Studies are described involving effects of noble-metal ion implantation on corrosion inhibition and charge injection capabilities of surgical Ti and Ti-6Al-4V. With surgical alloys, harmful biological responses are principally due to the type and quantity of metal ions released by the corrosion process. One approach to improve long-term biological performance involves surface modifications to significantly reduce degradation rates. With regard to surface-modifications, one of the most effective methods is through ion implantation. Results are presented for ion-implanted Au, Rh, and Ir. For the static in vitro corrosion properties, the noble-metal ion implanted Ti-6Al-4V and commercially-pure (CP) Ti were investigated in non-passivating acid and passivating saline solutions. It was postulated that during the early stages of corrosion (or during a corrosion pretreatment) the implanted noble-metal would enrich at the surface and significantly reduce subsequent corrosion rates. The observed behavior for the Ir and Rh implanted materials appeared to follow the postulated mechanism, with both initial and time-dependent improvements in corrosion resistance. However, the Au implanted material yielded early benefits, but the enhanced corrosion resistance deteriorated with time. X-ray photoelectron spectroscopy (XPS) analysis indicated that the implanted Au atoms remained as pure metallic Au, while the Ir and Rh atoms were in some oxide state, which gave the good adhesion of the Ir or Rh enriched surface to the Ti substrate. For a stimulating neural electrode, the charge density should be as large as possible to provide adequate stimulation of the nervous system while allowing for miniaturization of the electrode. Activated Ir has been known as having the highest charge injection capability of any material known

Inhibition of hepatic lipogenesis by 2-tetradecylglycidic acid.

Science.gov (United States)

McCune, S A; Nomura, T; Harris, R A

1979-10-01

2-Tetradecylglycidic acid (TDGA), a hypoglycemic agent, has been found to be a very effective inhibitor of de novo fatty acid synthesis by isolated hepatocytes. A comparison was made between the effectiveness of TDGA and 5-(tetradecyloxy)-2-furoic acid (TOFA), a hypolipidemic agent, on the metabolic processes of isolated hepatocytes. These compounds are structurally related and both inhibit fatty acid synthesis; however, they have opposite effects from each other on the oxidation and esterification of fatty acids. TDGA inhibits whereas TOFA stimulates fatty acid oxidation. TDGA stimulates whereas TOFA inhibits fatty acid esterification.

INHIBITION EFFECT OF FLAVONOID EXTRACT OF Euphorbia Guyoniana ON THE CORROSION OF MILD STEEL IN H2SO4 MEDIUM

OpenAIRE

S. Chihi; N. Gherraf; B. Alabed; S. Hameurlain

2009-01-01

The influence of flavonoids extracts of three parts of Euphorbia Guyoniana towards the corrosion of type API 5L X52 steel in 15% H2SO4 has been evaluated by weight loss method and polarization technique. The results showed that extracts are a good inhibitors for API 5L X52 steel in this medium. The corrosion inhibition efficiency increases on increasing plant extracts concentration. The inhibition is attributed to the adsorption of the surface of the metal. Potentiodynamic polarization result...

Inhibiting effects of imidazole on copper corrosion in 1 M HNO3 solution

International Nuclear Information System (INIS)

Lee, Woo-Jin

2003-01-01

The present work deals with the inhibiting effects of imidazole on the pure copper (Cu) corrosion in 1 M HNO 3 solution analysing potentiodynamic polarisation curves, potentiostatic anodic current transient, AC impedance spectra and X-ray photoelectron spectra (XPS). By adding imidazole to HNO 3 solution, the polarisation curves showed decrease in the corrosion current and the cathodic current, suggesting that imidazole acts as an effective cathodic inhibitor to Cu corrosion. From the measured anodic current transients, it is inferred that the protective Cu-imidazole complex film is simultaneously formed with the Cu oxide in the presence of imidazole during the early stage of the anodic polarisation. Analysis of the AC impedance spectra revealed that the values of the charge transfer resistance R ct obtained in imidazole-containing HNO 3 solution were greater than that value in imidazole-free one and at the same time steadily increased with immersion time to the constant value. Contrarily, the capacitance value was abruptly lowered from the double layer capacitance C dl to the complex film capacitance C cf in the progress of immersion time. Furthermore, the Warburg coefficient σ value for the ion diffusion through the complex film was observed to increase with immersion time. This means that the Cu(N-OH) complex film becomes thicker during immersion in the HNO 3 solution with imidazole through the inward growth of the N-rich outer layer to the O-rich inner layer, as well validated by XPS. Based upon the experimental results, it is suggested that the Cu corrosion in 1 M HNO 3 solution is efficiently inhibited with the addition of imidazole by retarding both the charge transfer on cathodic sites of the Cu surface in the early stage of immersion time and the subsequent ion diffusion through the steadily growing complex film

The corrosion inhibition of pure zinc in NH{sub 4}Cl aqueous solutions by N-Alkyl quaternary ammonium bromides

Energy Technology Data Exchange (ETDEWEB)

Branzoi, V.; Pilan, Luisa; Pruna, Alina [University ' Politehnica' of Bucharest, Faculty of Industrial Chemistry, Department of Physical Chemistry and Electrochemistry, Calea Grivitei, 132, Bucharest (Romania); Branzoi, Florina [Institute of Physical Chemistry Bucharest, Splaiul Independentei, 202, Bucharest (Romania)

2004-07-01

The corrosion of zinc in NH{sub 4}Cl solutions of different concentrations has been studied by potentiostatic and potentiodynamic methods and by impedance measurements. The results obtained in a potential region near the zinc corrosion potential showed that the cathodic reaction of hydrogen discharge does not fit a simple exponential law because the Tafel coefficient appears to be electrode potential dependent. At low overvoltages, in the anodic region, the corrosion process is under activation control, while at high overvoltages the process is under diffusion control. N-dodecyl, n-tetra-decyl and n-hexa-decyl ammonium bromides were used as organic inhibitors. The potentiostatic and potentiodynamic polarization studies and EIS measurements showed that each quaternary ammonium salt inhibits the corrosion of pure zinc in 1M NH{sub 4}Cl at 30 deg. C. The inhibition efficiency of the cations was discussed on the basis of Coulomb adsorption behaviour, using molecular coverage areas and polar substituent constant. The inhibition efficiency obtained from the corrosion currents was found to increase linearly with an increase in the molecular coverage area (A) for the series of tetra-alkyl ammonium ions. The efficiency of the cations increased with an increase in the positive charge of the nitrogen atom, which was due to the inductive effect of the electron-attractive groups. This effect on the Coulomb adsorption of the cations was, however, far less than that of the electron donating groups on the chemisorption of un-protonated amines. The steric requirements for the adsorption of the quaternaries with branched alkyl chains were small. Each organic compound exhibits Langmuir behaviour and inhibition increases with increasing alkyl chain length. This is attributed to cohesive Van der Waals forces between the positive head groups co-adsorbed with bromide ions on the positively charged zinc surface. (authors)

Corrosion control of carbon steel using inhibitor of banana peel extract in acid diluted solutions

Science.gov (United States)

Komalasari; Utami, S. P.; Fermi, M. I.; Aziz, Y.; Irianti, R. S.

2018-04-01

Issues of corrosion happened in pipes, it was used as fluid transportation in the chemical industry. Corrosion cannot be preventing, however it could be controlled or blocked. Inhibitor addition is one of the method to control the corrosion inside the pipe. Corrosion inhibitors consisted of inorganic and organic compound inhibitors. Organic inhibitor is composed from synthetic and natural material. This study focused to evaluate the inhibition’s efficiency from banana peel to carbon steel in different concentration of inhibitor and immersing time in acid solution variation. The research employed inhibitor concentration of 0 gram/liter, 2 gram/liter, 4 gram/liter and 6 gram/liter, immersed time of carbon steel for 2, 4, 6, 8 and 10 hours. It was immersed in chloride acid solution of 0.5 M and 1.5 M. Carbon Steel AISI 4041 was used as specimen steel. Results were analyzed using corrosion rate evaluation for each specimens and inhibitor efficiencies determination. It was found that the specimen without inhibitor yielded fast corrosion rate in long immersing time and high concentration of HCl. However, the specimens with inhibitor gave lowest corrosion rate which was 78.59% for 6 gram/litre and 10 hours in 0.5 M HCl.

DEVELOPMENT OF AN ENVIRONMENTALLY BENIGN MICROBIAL INHIBITOR TO CONTROL INTERNAL PIPELINE CORROSION

Energy Technology Data Exchange (ETDEWEB)

Bill W. Bogan; Brigid M. Lamb; Gemma Husmillo; Kristine Lowe; J. Robert Paterek; John J. Kilbane II

2004-12-01

The overall program objective is to develop and evaluate environmentally benign agents or products that are effective in the prevention, inhibition, and mitigation of microbially influenced corrosion (MIC) in the internal surfaces of metallic natural gas pipelines. The goal is to develop one or more environmentally benign (a.k.a. ''green'') products that can be applied to maintain the structure and dependability of the natural gas infrastructure. Various chemicals that inhibit the growth and/or the metabolism of corrosion-associated microbes such as sulfate reducing bacteria, denitrifying bacteria, and methanogenic bacteria were evaluated to determine their ability to inhibit corrosion in experiments utilizing pure and mixed bacterial cultures, and planktonic cultures as well as mature biofilms. Planktonic cultures are easier to inhibit than mature biofilms but several compounds were shown to be effective in decreasing the amount of metal corrosion. Of the compounds tested hexane extracts of Capsicum pepper plants and molybdate were the most effective inhibitors of sulfate reducing bacteria, bismuth nitrate was the most effective inhibitor of nitrate reducing bacteria, and 4-((pyridine-2-yl)methylamino)benzoic acid (PMBA) was the most effective inhibitor of methanogenic bacteria. All of these compounds were demonstrated to minimize corrosion due to MIC, at least in some circumstances. The results obtained in this project are consistent with the hypothesis that any compound that disrupts the metabolism of any of the major microbial groups present in corrosion-associated biofilms shows promise in limiting the amount/rate of corrosion. This approach of controlling MIC by controlling the metabolism of biofilms is more environmentally benign than the current approach involving the use of potent biocides, and warrants further investigation.

Corrosion of high purity Fe-Cr-Ni alloys in 13 N boiling nitric acid

International Nuclear Information System (INIS)

Ohta, Joji; Mayuzumi, Masami; Kusanagi, Hideo; Takaku, Hiroshi

1998-01-01

Corrosion in boiling nitric acid was investigated for high purity Fe-18%Cr-12%Ni alloys and type 304L stainless steels (SS). Owing to very low impurity concentration, the solution treated high purity alloys show almost no intergranular corrosion while the type 304L SS show severe intergranular corrosion. Both in the high purity alloys and type 304L SS, aging treatments ranging from 873 K to 1073 K for 1 h enhance intergranular corrosion. During the aging treatments, impurities should be segregated to the grain boundaries. The corrosion behaviors were discussed from a standpoint of impurity segregation to grain boundaries. This study is of importance for purex reprocessing of spent fuels

Corrosion behaviour of WC-VC-Co hardmetals in acidic media

CSIR Research Space (South Africa)

Konadu, DS

2010-09-01

Full Text Available The effect of increasing vanadium carbide (VC) content on the corrosion behaviour of tungsten carbide – 10 wt% cobalt hard metals was investigated in 1 M hydrochloric (HCl), and sulphuric (H2SO4) acids solutions. Increasing VC content makes the open...

Studies on inhibition characteristics of corn steep liquor and black sulphite liquor on corrosion of mild steel in acid media

Energy Technology Data Exchange (ETDEWEB)

Deb, P C; Mukherjea, R N

1968-06-01

The purpose of this study was to economically reduce the attack by acid on the parent metal, during the process of removing mill scale by acid pickling. Two inhibitors, by-products of the starch industry and pulp industry, were studied due to their cheapness and availability in India. The inhibition efficiency of the corn steep liquor and black sulfite liquor was found to be below that of thiourea. For example, in 6.2% (w/w) H/sub 2/SO/sub 4/ (at 50/sup 0/C), an inhibition efficiency of 90.5% and 84.5% is reached for inhibitor concentrations of 10 g per liter in the case of corn steep liquor and black sulfite liquor, respectively, while a concentration of 0.25 g per liter of thiourea was required to reach an inhibition efficiency of 98.6%.

Preparation and corrosion resistance of magnesium phytic acid/hydroxyapatite composite coatings on biodegradable AZ31 magnesium alloy.

Science.gov (United States)

Zhang, Min; Cai, Shu; Zhang, Feiyang; Xu, Guohua; Wang, Fengwu; Yu, Nian; Wu, Xiaodong

2017-06-01

In this work, a magnesium phytic acid/hydroxyapatite composite coating was successfully prepared on AZ31 magnesium alloy substrate by chemical conversion deposition technology with the aim of improving its corrosion resistance and bioactivity. The influence of hydroxyapatite (HA) content on the microstructure and corrosion resistance of the coatings was investigated. The results showed that with the increase of HA content in phytic acid solution, the cracks on the surface of the coatings gradually reduced, which subsequently improved the corrosion resistance of these coated magnesium alloy. Electrochemical measurements in simulated body fluid (SBF) revealed that the composite coating with 45 wt.% HA addition exhibited superior surface integrity and significantly improved corrosion resistance compared with the single phytic acid conversion coating. The results of the immersion test in SBF showed that the composite coating could provide more effective protection for magnesium alloy substrate than that of the single phytic acid coating and showed good bioactivity. Magnesium phytic acid/hydroxyapatite composite, with the desired bioactivity, can be synthesized through chemical conversion deposition technology as protective coatings for surface modification of the biodegradable magnesium alloy implants. The design idea of the new type of biomaterial is belong to the concept of "third generation biomaterial". Corrosion behavior and bioactivity of coated magnesium alloy are the key issues during implantation. In this study, preparation and corrosion behavior of magnesium phytic acid/hydroxyapatite composite coatings on magnesium alloy were studied. The basic findings and significance of this paper are as follows: 1. A novel environmentally friendly, homogenous and crack-free magnesium phytic acid/hydroxyapatite composite coating was fabricated on AZ31 magnesium alloy via chemical conversion deposition technology with the aim of enhancing its corrosion resistance and

Synthesis and inhibition of N-alkyl-2-(4-hydroxybut-2-ynyl) pyridinium bromide for mild steel in acid solution: Box–Behnken design optimization and mechanism probe

International Nuclear Information System (INIS)

Gu, Tianbin; Chen, Zhengjun; Jiang, Xiaohui; Zhou, Limei; Liao, Yunwen; Duan, Ming; Wang, Hu; Pu, Qiang

2015-01-01

Highlights: • N-alkyl-2-(4-hydroxybut-2-ynyl) pyridinium bromide prepared is new type of inhibitor. • Box–Behnken experiment design-based optimization model is used to maximize inhibition efficiency. • O-n adsorbing on X70 steel surface enhances the resistance of the steel to acid corrosion. • O-n acts as mix-type inhibitor to suppress both the anodic and cathodic reaction of X70 steel. - Abstract: N-alkyl-2-(4-hydroxybut-2-ynyl) pyridinium bromides (designated as O-n) was synthesized and characterized by 1 H and 13 C NMR and FTIR. Box–Behnken design (BBD)-based optimization was engaged to analyze the factors and the interaction of the factors that influence the corrosion inhibition efficiency of O-n for X70 steel. The inhibition mechanism was also probed by means of X-ray photoelectron spectroscopy (XPS), Tafel polarization and electrochemical impedance spectroscopy (EIS) techniques

Corrosion inhibition of carbon steel XC70 in H 2 SO 4 solution by ...

African Journals Online (AJOL)

In this work, we studied the efficiency of corrosion inhibition of carbon steel XC70 in H2SO4 0.5 M aqueous solution using ferrocenyl derivatives synthesized in our laboratory, this compound is: 3-(ferrocenylmethylamine)benzonitrile. The inhibitory potential of this compound was determined by electrochemical techniques ...

Enhanced Biodegradability, Lubricity and Corrosiveness of Lubricating Oil by Oleic Acid Diethanolamide Phosphate

Directory of Open Access Journals (Sweden)

Fang Jianhua

2012-09-01

Full Text Available Impacts of oleic acid diethanolamide phosphate (abbreviated as ODAP as an additive on biodegradability, anti-wear capacity, friction-reducing ability and corrosiveness of an unreadily biodegradable HVI 350 mineral lubricating oil was studied. The biodegradabilities of neat lubricating oil and its formulations with ODAP were evaluated on a biodegradation tester. Furthermore, the anti-wear and friction-reducing abilities and the corrosiveness of neat oil and the formulated oils were determined on a four-ball tribotester and a copper strip corrosion tester, respectively. The results indicated that ODAP markedly enhanced biodegradability as well as anti-wear and friction-reducing abilities of the lubricating oil. On the other hand, excellent color ratings of copper strips for both neat oil and the ODAP-doped oil were obtained in the corrosion tests, demonstrating that the corrosiveness of neat oil and the doped oil was negligible, although the latter seemed to provide slightly better anti-corrosion ability.

Anticorrosion potential of hydralazine for corrosion of mild steel in ...

African Journals Online (AJOL)

Anticorrosion potential of mild steel by Hydralazine as corrosion inhibitor for mild steel in 1M hydrochloric acid was investigated by chemical and electrochemical measurements at 303-333 K temperature. The maximum inhibition efficiency of inhibitor by Weight loss method is around 90%, Tafel polarization method is ...

Phosphate ions as inhibiting agents for copper corrosion in chlorinated tap water

Energy Technology Data Exchange (ETDEWEB)

Yohai, L. [División Electroquímica y Corrosión, INTEMA, CONICET, UNMdP, Juan B. Justo 4302, B7608FDQ Mar del Plata (Argentina); Schreiner, W.H. [Laboratório de Superfícies e Interfases, Departamento de Física, Universidade Federal do Paraná, 81531-990 Curitiba, PR (Brazil); Vázquez, M., E-mail: mvazquez@fi.mdp.edu.ar [División Electroquímica y Corrosión, INTEMA, CONICET, UNMdP, Juan B. Justo 4302, B7608FDQ Mar del Plata (Argentina); Valcarce, M.B. [División Electroquímica y Corrosión, INTEMA, CONICET, UNMdP, Juan B. Justo 4302, B7608FDQ Mar del Plata (Argentina)

2013-05-15

PO{sub 4}{sup 3−} ions as corrosion inhibitor were investigated on copper in tap water in the presence of NaClO. The inhibitor was evaluated by electrochemical techniques and weight loss tests. Raman spectroscopy and X-ray photoelectron spectroscopy were used to study the passive layer. In inhibited tap water, the passive layer is thick and compact if NaClO is present. Weight-loss tests showed the inhibition of uniform dissolution and no pitting attack. When adding NaClO, Cu{sub 3}(PO{sub 4}){sub 2} is incorporated to the passive film. Thus, phosphate ions are effective as inhibitors for copper in tap water, even when using high dosages of biocides. - Highlights: ► Changes in the copper corrosion after adding phosphate to tap water were analyzed. ► When NaClO and phosphates are present, Cu{sub 3}(PO{sub 4}){sub 2} participates of the surface film. ► In the absence of biocide the surface film contains a mixture of Cu{sub 2}O, CuO and Cu(OH){sub 2}. ► PO{sub 4}{sup 3−} is an effective inhibitor for Cu in tap water containing high NaClO dosages.

Moessbauer study of corrosion induced by acid rain

International Nuclear Information System (INIS)

Arshed, M.; Hussain, N.; Siddiqui, M.; Anwar-ul-Islam, M.; Rehman, S.; Butt, N.M.

1997-01-01

Strictly speaking acid rain refers to wet precipitation of pollutants S0/sub 2/SO/sub 3/ and NO/sub x/HNO/sub 3/ which have dissolved in cloud and rain droplets to from sulphuric and nitric acids. Acid rain has seriously damaged pine and spruce forests in Canada, USA and Europe. In these areas it has caused damage to buildings, reduced fish population due to acidification of lakes and rivers, and affected health of human beings as a result of poor water quality. The corrosion products formed in a simulated acid rain environment have been identified with transmission Moessbauer spectroscopy using a /sup 57/Co source. They were found to be gamma-FeOOH, alpha-FeOOH, gamma-Fe/sub 2/O/sub 3/ and a phase with unfamiliar parameters which seems to be amorphous in nature and can be considered as an intermediate phase. (author)

Influence of molecular packing on the corrosion inhibition properties of self-assembled octadecyltrichlorosilane monolayers on silicon

International Nuclear Information System (INIS)

Hsieh, Shuchen; Chao, Wei-Jay; Lin, Pei-Ying; Hsieh, Chiung-Wen

2014-01-01

Highlights: •Molecular packing plays an important role in determining SAM film properties. •Loose-packed OTS monolayers on silicon were corroded by exposure to KMnO 4 . •Dense-packed OTS SAM films exhibited excellent corrosion protection efficacy. -- Abstract: The corrosion inhibition properties of octadecyltrichlorosilane (OTS) self-assembled monolayers (SAMs) on silicon were investigated. Atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS), contact angle (CA), and lateral force microscopy (LFM) were used to determine the OTS film formation time, packing density, and corrosion protection efficacy. The OTS films reached adsorption saturation after 15 s; however, the molecular density continued to increase up to 24 h. The films were exposed to the strong oxidant KMnO 4 , and while 15-s film samples exhibited corrosion after a 1 min exposure, samples with films grown for 24 h were protected even after 24 h

Hydrodynamic Effect on the Inhibition for the Flow Accelerated Corrosion of an Elbow

Energy Technology Data Exchange (ETDEWEB)

Zeng, L.; Zhang, G. A.; Guo, X. P. [Huazhong University of Science and Technology, Wuhan (China)

2017-02-15

The inhibition effect of thioureido imidazoline inhibitor (TAI) for flow accelerated corrosion (FAC) at different locations for an X65 carbon steel elbow was studied by array electrode and computational fluid dynamics (CFD) simulations. The distribution of the inhibition efficiency measured by electrochemical impedance spectroscopy (EIS) is in good accordance with the distribution of the hydrodynamic parameters at the elbow. The inhibition efficiencies at the outer wall are higher than those at the inner wall meaning that the lower inhibition efficiency is associated with a higher flow velocity, shear stress, and turbulent kinetic energy at the inner wall of the elbow, as well as secondary flow at the elbow rather than the mass transport of inhibitor molecules. Compared to the static condition, the inhibition efficiency of TAI for FAC was relatively low. It is also due to a drastic turbulence flow and high wall shear stress during the FAC test, which prevents the adsorption of inhibitor and/or damages the adsorbed inhibitor film.

Corrosion inhibition of iron in 0.5 mol L-1 H2SO4 by halide ions

Directory of Open Access Journals (Sweden)

Jeyaprabha C.

2006-01-01

Full Text Available The inhibition effect of halide ions such as iodide, bromide and chloride ions on the corrosion of iron in 0.5 mol L-1 H2SO4 and the adsorption behaviour of these ions on the electrode surface have been studied by polarization and impedance methods. It has been found that the inhibition of nearly 90% has been observed for iodide ions at 2.5 10-3 mol L-1, for bromide ions at 10 10-3 mol L-1 and 80% for chloride ions at 2.5 10-3 mol L-1. The inhibition effect is increased with increase of halide ions concentration in the case of I- and Br- ions, whereas it has decreased in the case of Cl- ion at concentrations higher than 5 10-3 mol L-1. The double layer capacitance values have decreased considerably in the presence of halide ions which indicate that these anions are adsorbed on iron at the corrosion potential.

DFT theoretical study of 7-R-3methylquinoxalin-2(1H)-thiones (R=H; CH3; Cl) as corrosion inhibitors in hydrochloric acid

International Nuclear Information System (INIS)

El Adnani, Z.; Mcharfi, M.

2013-01-01

Highlights: ► A theoretical study of three quinoxaline derivatives. ► We try to explain their experimental mild steel corrosion inhibition efficiencies. ► The solvent effect was also depicted using the PCM model. ► Most of the global reactivity descriptors agree well with the experimental results. ► The results show that the sulphur atom is probably the main adsorption site. - Abstract: Quantum chemical approach at B3LYP/6-31G(d,p) level of theory, was used to calculate some structural and electronic properties of three quinoxaline derivatives, recently reported as mild steel corrosion inhibitors in acidic media, to ascertain the correlation between their experimental inhibitive efficiencies and some of the computed parameters. The results of most of the global reactivity descriptors show that the experimental and theoretical studies agree well and confirm that Me-Q=S is a better inhibitor than Q=S and Cl-Q=S, respectively. In addition, the local reactivity, analyzed through Fukui functions, show that the sulphur atom will be the main adsorption site.

Inhibition Effect of 1-Butyl-4-Methylpyridinium Tetrafluoroborate on the Corrosion of Copper in Phosphate Solutions

OpenAIRE

Scendo, M.; Uznanska, J.

2011-01-01

The influence of the concentration of 1-Butyl-4-methylpyridinium tetrafluoroborate (4MBPBF4) as ionic liquid (IL) on the corrosion of copper in 0.5 M P O 4 3 − solutions of pH 2 and 4 was studied. The research involved electrochemical polarization method, and scanning electron microscopy (SEM) technique. The results obtained showed that the inhibition efficiency of corrosion of copper increases with an increase in the concentration of 4MBPBF4 but decreases with increasing temperature. The the...

A New Multichelating Acid System for High-Temperature Sandstone Reservoirs

Directory of Open Access Journals (Sweden)

Nianyin Li

2015-01-01

Full Text Available Sandstone reservoir acidizing is a complex and heterogeneous acid-rock reaction process. If improper acid treatment is implemented, further damage can be induced instead of removing the initial plug, particularly in high-temperature sandstone reservoirs. An efficient acid system is the key to successful acid treatment. High-temperature sandstone treatment with conventional mud acid system faces problems including high acid-rock reaction rate, short acid effective distance, susceptibility to secondary damage, and serious corrosion to pipelines. In this paper, a new multichelating acid system has been developed to overcome these shortcomings. The acid system is composed of ternary weak acid, organic phosphonic chelating agent, anionic polycarboxylic acid chelating dispersant, fluoride, and other assisted additives. Hydrogen ion slowly released by multistage ionization in ternary weak acid and organic phosphonic within the system decreases the concentration of HF to achieve retardation. Chelating agent and chelating dispersant within the system inhibited anodic and cathodic reaction, respectively, to protect the metal from corrosion, while chelating dispersant has great chelating ability on iron ions, restricting the depolarization reaction of ferric ion and metal. The synergic effect of chelating agent and chelating dispersant removes sulfate scale precipitation and inhibits or decreases potential precipitation such as CaF2, silica gel, and fluosilicate. Mechanisms of retardation, corrosion-inhibition, and scale-removing features have been discussed and evaluated with laboratory tests. Test results indicate that this novel acid system has good overall performance, addressing the technical problems and improving the acidizing effect as well for high-temperature sandstone.

Corrosion by concentrated sulfuric acid in carbon steel pipes and tanks: state of the art

Energy Technology Data Exchange (ETDEWEB)

Panossian, Zehbour; Almeida, Neusvaldo Lira de; Sousa, Raquel Maria Ferreira de [Instituto de Pesquisas Tecnologicas (IPT), Sao Paulo, SP (Brazil); Pimenta, Gutemberg de Souza [PETROBRAS S.A., Rio de Janeiro, RJ (Brazil). Centro de Pesquisas e Desenvolvimento (CENPES); Marques, Leandro Bordalo Schmidt [PETROBRAS Engenharia, Rio de Janeiro, RJ (Brazil)

2009-07-01

PETROBRAS, allied to the policy of reduction of emission of pollutants, has been adjusting the processes of the new refineries to obtain products with lower sulfur content. Thus, the sulfur dioxide, extracted from the process gases of a new refinery to be built in the Northeast, will be used to produce sulfuric acid with concentration between (94-96) %. This acid will be stored in carbon steel tanks and transported through a buried 8-km carbon steel pipe from the refinery to a pier, where it will be loaded onto ships and sent to the consumer markets. Therefore, the corrosion resistance of carbon steel by concentrated acid will become a great concern for the mentioned storage and transportation. When the carbon steel comes into contact with concentrated sulfuric acid, there is an immediate acid attack with the formation of hydrogen gas and ferrous ions which, in turn, forms a protective layer of FeSO{sub 4} on the metallic surface. The durability of the tanks and pipes made of carbon steel will depend on the preservation of this protective layer. This work presents a review of the carbon steel corrosion in concentrated sulfuric acid and discusses the preventive methods against this corrosion, including anodic protection. (author)

In situ synthesis, electrochemical and quantum chemical analysis of an amino acid-derived ionic liquid inhibitor for corrosion protection of mild steel in 1M HCl solution

International Nuclear Information System (INIS)

Kowsari, E.; Arman, S.Y.; Shahini, M.H.; Zandi, H.; Ehsani, A.; Naderi, R.; PourghasemiHanza, A.; Mehdipour, M.

2016-01-01

Highlights: • Electrochemical analysis of effectiveness of an amino acid-derived ionic liquid inhibitor. • Quantum chemical analysis of effectiveness of an amino acid-derived ionic liquid inhibitor. • Finding correlation between electrochemical analysis and quantum chemical analysis. - Abstract: In this study, an amino acid-derived ionic liquid inhibitor, namely tetra-n-butyl ammonium methioninate, was synthesized and the role this inhibitor for corrosion protection of mild steel exposed to 1.0 M HCl was investigated using electrochemical, quantum and surface analysis. By taking advantage of potentiodynamic polarization, the inhibitory action of tetra-n-butyl ammonium methioninate was found to be mainly mixed-type with dominant anodic inhibition. The effectiveness of the inhibitor was also indicated using electrochemical impedance spectroscopy (EIS). Moreover, to provide further insight into the mechanism of inhibition, electrochemical noise (EN) and quantum chemical calculations of the inhibitor were performed.

Development of sulfuric acid dew point corrosion resistant stainless steel for smokestacks and its ducts. Entotsu endoyo tairyusan roten fushoku stainless ko no kaihatsu

Energy Technology Data Exchange (ETDEWEB)

Sato, E.; Matsuhashi, R.; Koseki, T. (Nippon Steel Corp., Tokyo (Japan)); Ebara, R.; Nakamoto, H. (Mitsubishi Heavy Industries, Ltd., Tokyo (Japan))

1993-05-20

A new corrosion resistant steel was developed as a metal system lining material to prevent sulfuric acid dew point corrosion in smokestacks and ducts. SO3 in stack gas turns to sulfuric acid as a result of reacting with coexistent moisture in non-steady conditions during boiler actuation and shutdown when smokestack walls have low temperatures. When sulfuric acid thus generated contacts with metallic materials at temperatures lower than the sulfuric acid dew point temperature, sulfuric acid dew point corrosion occurs. During boiler steady operation, localized corrosion develops at clearance between salt deposits and the metallic materials. In order to improve the corrosion resistance, Mo, Cu and N were added in a reasonable range of amount. Entire surface corrosion resistance and local corrosion resistance were experimented in aqueous solutions simulating the smokestack environments to derive relational formulas with steel compositions. The new corrosion resistant steel met the the entire surface and local corrosion resistance requirements and was found economical. Low torsional velocity tensile and U-bend tests proved the steel satisfying the stress corrosion resistance requirement. Semi-automatic CO2 welding and shielded are welding provided good workability with no cracking, and impact strength and corrosion resistance in joints equivalent to those in the base material. 3 refs., 4 figs., 4 tabs.