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)

Characterization of Encapsulated Corrosion Inhibitors Containing Microparticles for Environmentally Friendly Smart Coatings

Science.gov (United States)

Pearman, Benjamin Pieter; Calle, Luz M.

2015-01-01

This poster presents the results obtained from experiments designed to evaluate the release properties, as well as the corrosion inhibition effectiveness, of several encapsulated corrosion inhibitors. Microencapsulation has been used in the development of environmentally friendly multifunctional smart coatings. This technique enables the incorporation of autonomous corrosion detection, inhibition and self-healing functionalities into many commercially available coating systems. Select environmentally friendly corrosion inhibitors were encapsulated in organic and inorganic pH-sensitive microparticles and their release in basic solutions was studied. The release rate results showed that the encapsulation can be tailored from fast, for immediate corrosion protection, to slow, which will provide continued long-term corrosion protection. The incorporation of several corrosion inhibitor release profiles into a coating provides effective corrosion protection properties. To investigate the corrosion inhibition efficiency of the encapsulated inhibitors, electrochemical techniques were used to obtain corrosion potential, polarization curve and polarization resistance data. These measurements were performed using the free as well as the encapsulated inhibitors singly or in combinations. Results from these electrochemical tests will be compared to those obtained from weight loss and other accelerated corrosion experiments.

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

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...

Fatty Amides from Crude Rice Bran Oil as Green Corrosion Inhibitors

Directory of Open Access Journals (Sweden)

E. Reyes-Dorantes

2017-01-01

Full Text Available Due to its high oil content, this research proposes the use of an agroindustrial byproduct (rice bran as a sustainable option for the synthesis of corrosion inhibitors. From the crude rice bran oil, the synthesis of fatty amide-type corrosion inhibitors was carried out. The corrosion inhibitory capacity of the fatty amides was evaluated on an API X-70 steel using electrochemical techniques such as real-time corrosion monitoring and potentiodynamic polarization curves. As a corrosive medium, a CO2-saturated solution (3.5% NaCl was used at three temperatures (30, 50, and 70°C and different concentrations of inhibitor (0, 5, 10, 25, 50, and 100 ppm. The results demonstrate that the sustainable use of agroindustrial byproducts is a good alternative to the synthesis of environmentally friendly inhibitors with high corrosion inhibition efficiencies.

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.

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

The efficiency of a corrosion inhibitor on steel in a simulated concrete environment

Energy Technology Data Exchange (ETDEWEB)

Gartner, Nina; Kosec, Tadeja, E-mail: tadeja.kosec@zag.si; Legat, Andraž

2016-12-01

The aim of the present work was to characterize the efficiency of a corrosion inhibitor on steel in a simulated concrete pore solution. Laboratory measurements were performed at various chloride and inhibitor concentrations in order to simulate different applications of the inhibitor when used for the protection or rehabilitation of steel reinforcement in concrete. Two electrochemical techniques, i.e. potentiodynamic polarization scans and electrochemical impedance spectroscopy, were used for this study. The exposed surfaces of the steel specimens were subsequently investigated by Raman spectroscopy and scanning electron microscopy. It was found that the inhibitor can efficiently retard the corrosion of steel in a simulated concrete pore solution at concentrations of the inhibitor >2.0% and of chlorides <0.3% at a pH 10.5. On the other hand, when these conditions are not fulfilled, localized corrosion was observed. The results of the Raman and SEM/EDS analysis showed various morphologies of corrosion products and different types of corrosion attack depending on the pH of the pore solution, and the applied concentrations of the chlorides and the inhibitor. - Highlights: • Electrochemical studies performed at various Cl{sup −} and inhibitor concentrations. • Exposed steel surfaces investigated by Raman spectroscopy and SEM. • Cl{sup −}/inhibitor ratio is important parameter for the inhibitor's efficiency. • The corrosion can re-occur if the concentration of the inhibitor is reduced. • Different corrosion behaviour and oxides in the presence of inhibitor and/or Cl{sup −}.

Natural compounds as corrosion inhibitors for highly cycled systems

Energy Technology Data Exchange (ETDEWEB)

Quraishi, M.A.; Farooqi, I.H.; Saini, P.A. [Corrosion Research Lab., Aligarh (India)

1999-11-01

Strict environmental legislations have led to the development of green inhibitors in recent years. In continuation of the authors` research work on development of green inhibitors, they have investigated the aqueous extracts of three plants namely: Azadirachta indica, Punica Granatum and Momordica charantia as corrosion inhibitors for mild steel in 3% NaCl using weight loss and electrochemical methods. All the investigated compounds exhibited excellent corrosion inhibition properties comparable to that of HEDP. Azadirachta showed better scale inhibition effect than HEDP.

Release Properties and Electrochemical Characterization of Encapsulated Corrosion Inhibitors for Environmentally Friendly Smart Coatings

Science.gov (United States)

Pearman, B. P.; Calle, L. M.; Zhang, X.; Li, W.; Buhrow, J. W.; Johnsey, M. N.; Montgomery, E. L.; Fitzpatrick, L.; Surma, J. M.

2015-01-01

The NASA Kennedy Space Center's 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 indicators, inhibitors and self-healing agents. This allows for the incorporation of autonomous corrosion control functionalities, such as corrosion detection and inhibition as well as the self-healing of mechanical damage, into coatings. This paper presents technical details on the characterization of inhibitor-containing particles and their corrosion inhibitive effects using electrochemical and mass loss methods. Three organic environmentally friendly corrosion inhibitors were encapsulated in organic microparticles that are compatible with desired coatings. The total inhibitor content and the release of one of the inhibitors from the microparticles in basic solution was measured. Particles with inhibitor contents of up 60 wt% were synthesized. Fast release, for immediate corrosion protection, as well as long-term release for continued protection, was observed. The inhibition efficacy of the inhibitors, both as the pure materials and in microparticles, on carbon steel was evaluated. Polarization curves and mass loss measurements showed that, in the case of 2MBT, its corrosion inhibition effectiveness was greater when it was delivered from microparticles.

Natural Corrosion Inhibitors for Steel Reinforcement in Concrete — a Review

Science.gov (United States)

Raja, Pandian Bothi; Ghoreishiamiri, Seyedmojtaba; Ismail, Mohammad

2015-04-01

Reinforced concrete is one of the widely used construction materials for bridges, buildings, platforms and tunnels. Though reinforced concrete is capable of withstanding a large range of severe environments including marine, industrial and alpine conditions, there are still a large number of failures in concrete structures for many reasons. Either carbonation or chloride attack is the main culprit which is due to depassivation of reinforced steel and subsequently leads to rapid steel corrosion. Among many corrosion prevention measures, application of corrosion inhibitors play a vital role in metal protection. Numerous range of corrosion inhibitors were reported for concrete protection that were also used commercially in industries. This review summarizes the application of natural products as corrosion inhibitors for concrete protection and also scrutinizes various factors influencing its applicability.

Potassium sorbate-A new aqueous copper corrosion inhibitor

International Nuclear Information System (INIS)

Abelev, Esta; Starosvetsky, David; Ein-Eli, Yair

2007-01-01

This work presents the novel nature of 2,4-hexadienoic acid potassium salt (potassium sorbate (KCH 3 CH=CHCH=CHCO 2 )) as an effective copper aqueous corrosion inhibitor. The influence of pH and potassium sorbate concentration on copper corrosion in aerated sulfate and chloride solutions is reported. Degree of copper protection was found to increase with an increase in potassium sorbate concentration; an optimum concentration of this inhibitor in sulfate solutions was found to be 10 g/L. Copper is highly resistant to corrosion attacks by chloride ions in the presence of potassium sorbate. X-ray photoelectron spectroscopy (XPS) studies suggest that copper protection is achieved via the formation of a mixed layer of cuprous oxide, cupric hydroxide and copper(II)-sorbate at the metal surface

Performance investigation of low-toxic organic corrosion inhibitors in amine treating unit

International Nuclear Information System (INIS)

Veawab, A.; Tanthapanichakoon, W.

2003-01-01

Amine treating unit is constantly subject to severe corrosion problems leading to extra expenditure and operational limitations. Heavy-metal vanadium compounds are extensively used as corrosion inhibitors to suppress the severe corrosion to an acceptable level. In recent years, the fact that these vanadium compounds are inherently toxic and can potentially pose adverse impacts on the human health and the environment has brought about environmental awareness that causes their uses costly due to the difficulty in waste disposal. To respond to the environmental concern and reduce cost of waste disposal as well as prepare for more stringent regulations for chemical uses, the development of low-toxic corrosion inhibitors is necessary. This work therefore focuses on an investigation of inhibition performance of a number of organic and inorganic compounds that have relatively low toxicity in comparison with conventional inhibitors. The performance evaluation was carried out through corrosion experiments using carbon steel specimens. The experiments were done in 3 and 5 kmol/m 3 monoethanolamine (MEA) solution saturated with CO 2 at 80 o C. It was found that several tested compounds have potential to be effective low-toxic corrosion inhibitors. The promising compounds provide reasonable and in some cases comparable protection performance to the conventional inhibitor. (author)

Corrosion Inhibitor of Carbon Steel from Onion Peel Extract

Directory of Open Access Journals (Sweden)

Muhammad Samsudin Asep

2018-01-01

Full Text Available Carbon steels composed by two main elements, they are iron (Fe and carbon (C elements which widely used in industrial because of its resistance and more affordable than stainless steel, but their weakness is they have low corrosion resistance. One way to modify carbon steel is by coating them with antioxidant compounds that can delay, slow down, and prevent lipid oxidation process, which obtained from onion peel extract. Several studies on corrosion inhibitors have been performed. However, the efficiency was not reach the optimum. This study aims to examine the effect of onion peel extract concentration on the efficiency of corrosion inhibitor and characterization of the green corrosion inhibitor from onion peel extract. This research method begins by extracting onion peel to 200 ml solvent which we use aquadest and methanol and mixed with 5 grams of crushed onion peel, then let them be extracted for 60 minutes with room temperature. Once it was filtered and the solution obtained, followed by evaporating process with rotary evaporator to decrease the content of solvent. The product is ready to be used as a green corrosion inhibitor of carbon steel in 1 mol/L HCl. While the analysis used is HPLC qualitative analysis, and electroplatting process. The impedance is measured at a frequency of 100 kHz to 4 mHz with an AC current of 10mV. Inhibitor concentrations are vary between 2 ml and 4 ml of onion peel extract. Electroplatting is done within 30 minutes with 10 minutes each checking time. Furthermore, quantitative analysis was done for the analysis of corrosion rate and weight loss. Based on HPLC analysis, it is known that the extract of onion peel contains 1mg/L of quercetin, which is belong to flavonoid group as green inhibitor. While electroplatting process, aquadest solvent having average efficiency of 99,57% for 2 ml of extract, and 99,60% for 4 ml of extract. Methanol solvent having average efficiency of 99,52% for 2 ml of extract and 99

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.

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.

Corrosion inhibitor development for slightly sour environments with oxygen intrusion

Energy Technology Data Exchange (ETDEWEB)

Wylde, J.; Wang, H.; Li, J. [Clariant Oil Services North America, Calgary, AB (Canada)

2009-07-01

This presentation reported on a study that examined the effect of oxygen on the inhibition of carbon steel in slightly sour corrosion, and the initiation and propagation of localized attack. Oxygen can enter sour water injection systems through the vapor space in storage tanks and process system. Oxygen aggravates the corrosion attack by participating in the cathodic reaction under full or partial diffusion control. Laboratory testing results were reported in this presentation along with the development of corrosion inhibitors for such a slightly sour system. Bubble testing cells were used with continuous H{sub 2}/CO{sub 2} mixture gas sparging and occasional oxygen intrusion of 2 to 4 hours during a week long test. Linear polarization resistance (LPR) measurements and weight loss corrosion coupons were used to quantify the corrosion attack. The findings were presented in terms of the magnitude of localized attacks at different oxygen concentrations and intrusion periods, with and without the presence of corrosion inhibitors. tabs., figs.

The corrosion behaviour of galvanized steel in cooling tower water containing a biocide and a corrosion inhibitor.

Science.gov (United States)

Minnoş, Bihter; Ilhan-Sungur, Esra; Çotuk, Ayşın; Güngör, Nihal Doğruöz; Cansever, Nurhan

2013-01-01

The corrosion behaviour of galvanized steel in cooling tower water containing a biocide and a corrosion inhibitor was investigated over a 10-month period in a hotel. Planktonic and sessile numbers of sulphate reducing bacteria (SRB) and heterotrophic bacteria were monitored. The corrosion rate was determined by the weight loss method. The corrosion products were analyzed by energy dispersive X-ray spectroscopy and X-ray diffraction. A mineralized, heterogeneous biofilm was observed on the coupons. Although a biocide and a corrosion inhibitor were regularly added to the cooling water, the results showed that microorganisms, such as SRB in the mixed species biofilm, caused corrosion of galvanized steel. It was observed that Zn layers on the test coupons were completely depleted after 3 months. The Fe concentrations in the biofilm showed significant correlations with the weight loss and carbohydrate concentration (respectively, p < 0.01 and p < 0.01).

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 ...

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.

Improvement of Corrosion Inhibitors of Primary and Secondary Closed Cooling Water System

International Nuclear Information System (INIS)

Choi, Byung Seon; Kim, K. M.; Kim, K. H.

2010-08-01

In nuclear power plants, the Closed Cooling Water (CCW) system provide cooling to both safety-related and non-safety-related heat exchange equipment. Various chemicals are used to mitigate corrosion, fouling, and microbiological growth in the CCW systems. In nuclear plants, these inhibitors have included chromates, nitrites, molybdates, hydrazine, and silicate. In the case of the CCW of some domestic nuclear power plants, there is during the overhaul period, a saturation of ion exchange resin caused by an inhibitor which has high conductivity for an increase in radiation exposure and radioactive waste. The objective of this study is to evaluate the corrosion behavior of structural materials with various corrosion inhibitors. In the present study, more than 50 ppm hydrazine concentration is needed to reduce the corrosion rate of carbon steel to satisfy the CCW operational guidelines. However, if hydrazine is continuously injected into the CCW system, the critical concentration of hydrazine will be lower. Hydrazine might be an alternative corrosion inhibitor for nitrite in the CCW system of nuclear power plant

Tannin bark Melalauca cajuputi powell (gelam) as green corrosion inhibitor of mild steel

Energy Technology Data Exchange (ETDEWEB)

Talib, Nur Atiqah Abu; Zakaria, Sarani; Hua, Chia Chin; Othman, Norinsan Kamil [School of Applied Physic, Faculty Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor (Malaysia)

2014-09-03

Tannin was extracted from gelam bark and used to produce corrosion inhibitor for mild steel. Tannin was extracted from gelam bark using 70% aqueous acetone for 6 hour. Tannin powder was characterization using fourier transform infrared spectroscopy to analyse chemical component in tannin and Scanning electron microscope (SEM) for tannin physical structure. The tannin effect on the corrosion inhibition of mild steel has been investigated in 1Mol HCl solution for 6 hour followed ASTM. The weight loss method were applied to study the mild steel corrosion behavior in the present and absend of different concentration of tannin (250, 300, 350)ppm. Tannin act good inhibitor as corrosion inhibitor for mild steel in acid medium. Surface morphology of carbon steel with and without inhibitor was investigated by scanning electron microscopy.

Astrakhan-Mangyshlak water main (pipeline): corrosion state of the inner surface, and methods for its corrosion protection. Part III. The effects of KW2353 inhibitor. Part IV. Microbiological corrosion

International Nuclear Information System (INIS)

Reformatskaya, I.I.; Ashcheulova, I.I.; Barinova, M.A.; Kostin, D.V.; Prutchenko, S.G.; Ivleva, G.A.; Taubaldiev, T.S.; Murinov, K.S.; Tastanov, K.Kh.

2003-01-01

The effect of the KW2353 corrosion inhibitor, applied on the Astrakhan-Mangyshlak water main (pipeline) since 1997, on the corrosion processes, occurring on the 17G1S steel surface, is considered. The properties of the surface sediments are also considered. The role of the microbiological processes in the corrosion behavior of the water main (pipeline) inner surface is studied. It is shown, that application of the polyphosphate-type inhibitors, including the KW2353 one, for the anticorrosive protection of the inner surface of the extended water main (pipelines) is inadmissible: at the temperature of ∼20 deg C this corrosion inhibitor facilitates the development of the local corrosion processes on the water main (pipeline) inner surface. At the temperature of ∼8 deg C the above inhibitor discontinues to effect the corrosive stability of the 17G1S steel. The optimal way of the anticorrosive protection of the steel equipment, contacting with the water media, is the increase in the oxygen content therein [ru

Evaluation of corrosion inhibitors for high temperature decontamination applications

International Nuclear Information System (INIS)

Sathyaseelan, V.S.; Rufus, A.L.; Velmurugan, S.

2015-01-01

Normally, chemical decontamination of coolant systems of nuclear power reactors is carried out at temperatures less than 90 °C. At these temperatures, though magnetite dissolves effectively, the rate of dissolution of chromium and nickel containing oxides formed over stainless steel and other non-carbon steel coolant system surfaces is not that appreciable. A high temperature dissolution process using 5 mM NTA at 160 °C developed earlier by us was very effective in dissolving the oxides such as ferrites and chromites. However, the corrosion of structural materials such as carbon steel (CS) and stainless steel (SS) also increased beyond the acceptable limits at elevated temperatures. Hence, the control of base metal corrosion during the high temperature decontamination process is very important. In view of this, it was felt essential to investigate and develop a suitable inhibitor to reduce the corrosion that can take place on coolant structural material surfaces during the high temperature decontamination applications with weak organic acids. Three commercial inhibitors viz., Philmplus 5K655, Prosel PC 2116 and Ferroqest were evaluated at ambient and at 160 °C temperature in NTA formulation. Preliminary evaluation of these corrosion inhibitors carried out using electrochemical techniques showed maximum corrosion inhibition efficiency for Philmplus. Hence, it was used for high temperature applications. A concentration of 500 ppm was found to be optimum at 160 °C and at this concentration it showed an inhibition efficiency of 62% for CS. High temperature dissolution of oxides such as Fe 3 O 4 and NiFe 2 O 4 , which are relevant to nuclear reactors, was also carried out and the rate of dissolution observed was less in the presence of Philmplus. Studies were also carried out to evaluate hydrazine as a corrosion inhibitor for high temperature applications. The results revealed that for CS inhibition efficiency of hydrazine is comparable to that of Philmplus, while

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

Protective effect of KhOSP-10 inhibitor during corrosion, hydrogenadsorption and corrosion cracking of a steel in sulfuric acid

Energy Technology Data Exchange (ETDEWEB)

Mindyuk, A K; Svist, E I; Savitskaya, O P; Goyan, E B; Gopanenko, A N [AN Ukrainskoj SSR, Lvov. Fiziko-Mekhanicheskij Inst.

1975-01-01

The protective propeties of inhibitor KhOSP-10 in the time of corrosion and corrosive cracking of steel 40Kh are higher then those of inhibitors KPI-1, KI-1, I-I-V etc. Its ability to reduce steel hydrogenation is the same as in the case of KPI-1 inhibitor i.e. below that of KI-1. HCl additives enhance the efficiency of inhibitors KPI-1, KI-1, I-1-V etc. up to the protective ability of KhOSP-10. Kinetics of the electrode processes was estimated from polarization curves.

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

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.

Effect of Inhibitors on Weld Corrosion under Sweet Conditions Using Flow Channel

OpenAIRE

Khaled Alawadhi; Abdulkareem Aloraier; Suraj Joshi; Jalal Alsarraf

2014-01-01

The aim of this paper is to compare the effectiveness and electrochemical behavior of typical oilfield corrosion inhibitors with previous oilfield corrosion inhibitors under the same electrochemical techniques to control preferential weld corrosion of X65 pipeline steel in artificial seawater saturated with carbon dioxide at a pressure of one bar. A secondary aim is to investigate the conditions under which current reversal takes place. A flow channel apparatus was used in the laboratory to s...

Evaluation of mechanically treated cerium (IV) oxides as corrosion inhibitors for galvanized steel

Energy Technology Data Exchange (ETDEWEB)

Deflorian, F., E-mail: flavio.deflorian@ing.unitn.it [Department of Materials Engineering and Industrial Technology, University of Trento, Via Mesiano 77, 38123 Trento (Italy); Fedel, M.; Rossi, S. [Department of Materials Engineering and Industrial Technology, University of Trento, Via Mesiano 77, 38123 Trento (Italy); Kamarchik, P. [PPG Industries, Coatings Innovation Center, 4325 Rosanna Drive, Allison Park, PA 15101 (United States)

2011-09-30

The use of cerium salts as corrosion inhibitors for hot dip galvanized steel has been object of a numerous studies in the last few years. The role of cerium ions as corrosion inhibitors was proved: cerium is able to block the cathodic sites of the metal, forming insoluble hydroxides and oxides on the zinc surface. This fact leads to a dramatic decrease of the cathodic current densities and, therefore, to a reduction the overall corrosion processes. On the other hand, the potential of cerium oxides as corrosion inhibitors was also proposed. However, the real effectiveness of this kind of anticorrosive pigments has not been clarified yet. In this work cerium (IV) oxides are considered as corrosion inhibitors for galvanized steel. The corrosion inhibition mechanism of mechanically treated (milled) CeO{sub 2} alone and in combination with milled SiO{sub 2} nanoparticles was investigated. For this purpose milled CeO{sub 2}, CeO{sub 2} and SiO{sub 2} milled together and milled SiO{sub 2} particles were studied as corrosion inhibitors in water solution. Therefore, the different mechanically treated particles were dispersed in 0.1 M NaCl solution to test their effectiveness as corrosion inhibitors for galvanized steel. The galvanized steel was immersed in the different solutions and the corrosion inhibition efficiency of the different particles was measured by means of electrochemical techniques. For this purpose, electrochemical impedance spectroscopy (EIS) measurements were carried out, monitoring the evolution of the corrosion processes occurring at the metal surface with the immersion time in the solution. The effect of the different pigments was also investigated by carrying out anodic and cathodic polarization measurements. The polarization curves were acquired under conditions of varied pH. The experimental measurements suggest that the mechanical treatment performed on the SiO{sub 2} and CeO{sub 2} particles promote the formation of an effective corrosion pigment

Adsorption and performance of the 2-mercaptobenzimidazole as a carbon steel corrosion inhibitor in EDTA solutions

International Nuclear Information System (INIS)

Calderón, J.A.; Vásquez, F.A.; Carreño, J.A.

2017-01-01

This study presents a thermodynamic analysis of the adsorption and anti-corrosion performance of 2-mercaptobenzimidazole (2-MBI) on carbon steel in EDTA-Na2 solutions. The adsorption of the inhibitor on the metal surface was studied as a function of the concentration of the inhibiting species and the temperature of the system. The corrosion inhibition efficiency was studied by electrochemical impedance spectroscopy and mass loss tests. The results show that the adsorption of the inhibitor onto the metal surface behaves according to the Langmuir model, following an endothermic process. The inhibitor is chemically adsorbed onto the carbon steel surface. The efficiency of corrosion inhibition was above 93%, which was confirmed by both mass loss tests and the electrochemical impedance technique. The good performance of the corrosion inhibitor was maintained up to 24 h after the inhibitor was added to the corrosive EDTA-Na2 solutions. When the ratio of the volume of solution/exposed area was reduced, a decrease in the area covered by the inhibitor was observed. The best cost/benefit ratio for the corrosion protection of carbon steel was obtained when the number of moles of the inhibitor per surface area was maintained at 2.68 mmol cm"−"2. - Highlights: • Adsorption of the inhibitor on the metal surface is confirmed by thermodynamic data. • Adsorption of the inhibitor onto the metal behaves according to the Langmuir model. • Endothermic adsorption process indicates that the inhibitor is chemically adsorbed. • The efficiency of corrosion inhibition was above 93%. • The good performance of the corrosion inhibitor was maintained up to 24 h.

Adsorption and performance of the 2-mercaptobenzimidazole as a carbon steel corrosion inhibitor in EDTA solutions

Energy Technology Data Exchange (ETDEWEB)

Calderón, J.A., E-mail: andres.calderon@udea.edu.co [Centro de Investigación, Innovación y Desarrollo de Materiales –CIDEMAT, Universidad de Antioquia UdeA, Calle 70 No. 52-21, Medellín (Colombia); Vásquez, F.A. [Centro de Investigación, Innovación y Desarrollo de Materiales –CIDEMAT, Universidad de Antioquia UdeA, Calle 70 No. 52-21, Medellín (Colombia); Carreño, J.A. [Laboratório de H2S, CO2 e Corrosividade, Instituto Nacional De Tecnologia (INT), Av. Venezuela, 82 – Térreo, Anexo 01, Sala 101A, Saúde, Rio de Janeiro, RJ (Brazil)

2017-01-01

This study presents a thermodynamic analysis of the adsorption and anti-corrosion performance of 2-mercaptobenzimidazole (2-MBI) on carbon steel in EDTA-Na2 solutions. The adsorption of the inhibitor on the metal surface was studied as a function of the concentration of the inhibiting species and the temperature of the system. The corrosion inhibition efficiency was studied by electrochemical impedance spectroscopy and mass loss tests. The results show that the adsorption of the inhibitor onto the metal surface behaves according to the Langmuir model, following an endothermic process. The inhibitor is chemically adsorbed onto the carbon steel surface. The efficiency of corrosion inhibition was above 93%, which was confirmed by both mass loss tests and the electrochemical impedance technique. The good performance of the corrosion inhibitor was maintained up to 24 h after the inhibitor was added to the corrosive EDTA-Na2 solutions. When the ratio of the volume of solution/exposed area was reduced, a decrease in the area covered by the inhibitor was observed. The best cost/benefit ratio for the corrosion protection of carbon steel was obtained when the number of moles of the inhibitor per surface area was maintained at 2.68 mmol cm{sup −2}. - Highlights: • Adsorption of the inhibitor on the metal surface is confirmed by thermodynamic data. • Adsorption of the inhibitor onto the metal behaves according to the Langmuir model. • Endothermic adsorption process indicates that the inhibitor is chemically adsorbed. • The efficiency of corrosion inhibition was above 93%. • The good performance of the corrosion inhibitor was maintained up to 24 h.

Development of new corrosion inhibitor tested on mild steel supported by electrochemical study

Science.gov (United States)

Habeeb, Hussein Jwad; Luaibi, Hasan Mohammed; Dakhil, Rifaat Mohammed; Kadhum, Abdul Amir H.; Al-Amiery, Ahmed A.; Gaaz, Tayser Sumer

2018-03-01

Mild steel is a metal which is commonly used in industrials and manufacturing of equipment for most industries round the world. It is cheaper cost compared with the other metals and its durable, hard and easy-to-wear physical properties make it a major choice in the manufacture of equipment parts. The main problem through the uses of mild steel in industry is its resistance against corrosion, especially in acidic solutions. This case led to raise the cost of maintenance of equipment that used mild steel and as a result increased costs for the company. Organic corrosive inhibitors that also act as green chemicals, 4-hydroxybenzylideneaminomethyl-5-ethyl-1,3,4-thiadiazol have been synthesized. This inhibitor is tested as corrosion inhibitor on a mild steel sample MS in 1 M hydrochloric acid solution (HCl) using electrochemical measurements test includes PD (Potentiodynamic), EIS (Electrochemical impedance spectroscopy), OCP (Open circuit potential) and EFM (electrochemical frequency modulation). The obtained results indicate that 4-hydroxybenzylideneaminomethyl-5-ethyl-1,3,4-thiadiazol acts as a good corrosion inhibitor for mild steel sample in HCl solution with efficiency above 90%. Changes in the impedance parameters postulated adsorption on the mild steel specimens' surfaces of, which it going to the formation of protective coating layer. It also shows that 4-hydroxybenzylideneaminomethyl-5-ethyl-1,3,4-thiadiazol corrosion inhibitors are effective in helping to reduce and slow down the corrosion process that occurs on mild steel surface in hydrochloric acid solution. Increase of corrosion inhibitor concentration provides a protective layer of mild steel. However, this protective layer becomes weak when the temperature of the solution increases.

Corrosion Protection Of Mild Steel In Sea Water Using Chemical Inhibitor

Science.gov (United States)

Araoyinbo, Alaba O.; Salleh, Mohd Arif Anuar Mohd; Zulerwan Jusof, Muhammad

2018-03-01

The effect of sodium nitrite as a corrosion inhibitor of mild steel in sea water (i.e ASTM standard prepared sea water and sea water obtained from a local river) was investigated, using the weight loss technique. Different amount of sodium nitrite were prepared (i.e 2 % to 10 %) in the inhibition of the mild steel corrosion in sea water exposed to irradiation condition from sunlight exposure. The cut samples of mild steel were exposed to these corrosive media and the corresponding weight loss subsequently obtained was recorded at intervals of 1 to 4 weeks. It was observed that corrosion rate increases with the time of exposure to the corrosive medium exposed to sunlight and that sodium nitrite that was used at the chemical inhibitor was able to retard the corrosion rate of mild steel if the appropriate concentration is applied. The results obtained from the weight loss analysis shows that the optimum percentage of sodium nitrate in sea water that gives the optimum corrosion inhibition of mild steel is 4 %.

Using high throughput experimental data and in silico models to discover alternatives to toxic chromate corrosion inhibitors

International Nuclear Information System (INIS)

Winkler, D.A.; Breedon, M.; White, P.; Hughes, A.E.; Sapper, E.D.; Cole, I.

2016-01-01

Highlights: • We screened a large library of organic compounds as replacements for toxic chromates. • High throughput automated corrosion testing was used to assess inhibitor performance. • Robust, predictive machine learning models of corrosion inhibition were developed. • Models indicated molecular features contributing to performance of organic inhibitors. • We also showed that quantum chemistry descriptors do not correlate with performance. - Abstract: Restrictions on the use of toxic chromate-based corrosion inhibitors have created important issues for the aerospace and other industries. Benign alternatives that offer similar or superior performance are needed. We used high throughput experiments to assess 100 small organic molecules as potential inhibitors of corrosion in aerospace aluminium alloys AA2024 and AA7075. We generated robust, predictive, quantitative computational models of inhibitor efficiency at two pH values using these data. The models identified molecular features of inhibitor molecules that had the greatest impact on corrosion inhibition. Models can be used to discover better corrosion inhibitors by screening libraries of organic compounds for candidates with high corrosion inhibition.

Development of new corrosion inhibitor tested on mild steel supported by electrochemical study

Directory of Open Access Journals (Sweden)

Hussein Jwad Habeeb

2018-03-01

Full Text Available Mild steel is a metal which is commonly used in industrials and manufacturing of equipment for most industries round the world. It is cheaper cost compared with the other metals and its durable, hard and easy-to-wear physical properties make it a major choice in the manufacture of equipment parts. The main problem through the uses of mild steel in industry is its resistance against corrosion, especially in acidic solutions. This case led to raise the cost of maintenance of equipment that used mild steel and as a result increased costs for the company. Organic corrosive inhibitors that also act as green chemicals, 4-hydroxybenzylideneaminomethyl-5-ethyl-1,3,4-thiadiazol have been synthesized. This inhibitor is tested as corrosion inhibitor on a mild steel sample MS in 1 M hydrochloric acid solution (HCl using electrochemical measurements test includes PD (Potentiodynamic, EIS (Electrochemical impedance spectroscopy, OCP (Open circuit potential and EFM (electrochemical frequency modulation. The obtained results indicate that 4-hydroxybenzylideneaminomethyl-5-ethyl-1,3,4-thiadiazol acts as a good corrosion inhibitor for mild steel sample in HCl solution with efficiency above 90%. Changes in the impedance parameters postulated adsorption on the mild steel specimens' surfaces of, which it going to the formation of protective coating layer. It also shows that 4-hydroxybenzylideneaminomethyl-5-ethyl-1,3,4-thiadiazol corrosion inhibitors are effective in helping to reduce and slow down the corrosion process that occurs on mild steel surface in hydrochloric acid solution. Increase of corrosion inhibitor concentration provides a protective layer of mild steel. However, this protective layer becomes weak when the temperature of the solution increases. Keywords: Hydroxybenzylideneaminomethy, Potentiodynamic, Electrochemical frequency modulation, Impedance

Additives as corrosion inhibitors in reinforced concrete

International Nuclear Information System (INIS)

Venegas, Ricardo; Vera, Rosa; Carvajal, Ana Maria; Villarroel, Maria; Vera, Enrique; Ortiz, Cesar

2008-01-01

This work studies the behavior of two additives as inhibitors of corrosion in reinforced concrete. The presence of Microsilica, a physical inhibitor, in the mixture decreases pore size in structures and improves compression. Calcium Nitrite, a chemical inhibitor, is an oxidizing agent and allows a more homogenous film to form over the steel that becomes more resistant to attacks from aggressive ions like anion chloride and others. Three pairs of concrete test pieces were used without additives and with additives with a/c ration of 0.55. The samples were exposed to an accelerated attack of chlorides, submerging them in a 4.27 M solution of NaCl for 24 hours and then drying them at room temperature for another 24 hours, completing a cycle every 48 hours. The tests were carried out at 1 cycle and 5 cycles of partial moistening and drying. The steel corrosion was evaluated with corrosion potential measurements. Conductivity, pH, chlorides and sulfate profiles were defined depending on the depth of the concrete. The composition of the corrosion products was determined using X-ray diffraction and the morphology of the film by scanning electron microscopy. The results show that for 1 test cycle, the corrosion potential of the steel in the sample with calcium nitrite was -54mV, which was a higher value than that measured in the sample with microsilica (-217.3mV) and without an additive (-159.1mV), corroborating its inhibitory power. The content of the free chlorides in the sample with micros ice allows greater capillary suction by adding high amounts of chloride to the structure (2.6% on the outside up to 2.20% near the steel); while the test pieces with calcium nitrite and without an additive had concentrations lower than 2% in all the evaluated points. After five cycles of exposing the samples to the saline solution the behavior is inverted. The measures of conductivity agreed with the previous results. Meanwhile, the pH of the solutions obtained from the powder from the

Studies on plant extracts as corrosion inhibitors for mild steel in air saturated water

International Nuclear Information System (INIS)

Mohamad Daud; Abdul Razak Daud; Zainal Abidin Sidi

1988-01-01

The effectiveness in inhibiting corrosion by garlic, soya bean, and tobacco extracts and their combinations in air saturated water at ambient temperature were studied by using electrochemical corrosion test. The range of inhibitor concentration studied was from 0.1 to 1.0 g/l. The variations of corrosion potential and corrosion current density was recorded and the results showed that the extracts have inhibitive properties in the corrosion of mild stee. The effectiveness of the inhibitors is in the following order: extract mixture > tobacco > garlic > soya bean extracts. (author)

Density functional theory (DFT) as a powerful tool for designing new organic corrosion inhibitors. Part 1: An overview

International Nuclear Information System (INIS)

Obot, I.B.; Macdonald, D.D.; Gasem, Z.M.

2015-01-01

The use of computational chemistry as a tool in the design and development of organic corrosion inhibitors has been greatly enhanced by the development of density functional theory (DFT). Whereas, traditionally, corrosion scientists have identified new corrosion inhibitor molecules either by incrementally changing the structures of existing inhibitors or by testing hundreds of compounds in the laboratory, these experimental means are often very expensive and time-consuming. Thus, ongoing hardware and software advances have opened the door for powerful use of theoretical chemistry in corrosion inhibition research at a reduced cost. DFT has enabled corrosion scientist to accurately predict the inhibition efficacies of organic corrosion inhibitors based on electronic/molecular properties and reactivity indices. This review summarizes the main features of DFT, giving a brief background to selected DFT-based chemical reactivity concepts, calculations and their applications to organic corrosion inhibitor design. The paper also reviews the principles upon which modern corrosion science is based with emphasis on corrosion in the oil and gas industry and with the goal of identifying important issues in the design of new, more effective inhibitors in this field. The impact of this review is to illustrate the enormous power of DFT and to identify shortcomings in past work, including the assumption that inhibitors only interact with bare metal surfaces.

Corrosion prevention of iron with novel organic inhibitor of hydroxamic acid and UV irradiation

International Nuclear Information System (INIS)

Deng Huihua; Nanjo, Hiroshi; Qian, Pu; Xia Zhengbin; Ishikawa, Ikuo; Suzuki, Toshishige M.

2008-01-01

Corrosion prevention by self-assembled monolayers (SAM) of monomer and polymer inhibitor on iron covered with air-formed oxide films was investigated by cyclic voltammetry in borate buffer solution. Anti-corrosion efficiency of the SAM-coated Fe electrodes depends on UV irradiation duration on Fe electrodes prior to coating and inhibitor concentration to form SAM. The 1-h UV-irradiated Fe electrodes coated with SAM exhibits the most effective corrosion resistance despite the anti-corrosion efficiency of air-formed films on Fe was linearly increased with UV irradiation. The addition of monomer in polymer solution improves the stability and corrosion resistance of SAM

Use of a free-jet expansion, molecular beam mass spectrometer to understand processes involving volatile corrosion products

International Nuclear Information System (INIS)

Jacobson, N.S.

1997-01-01

Many high-temperature corrosion processes generate volatile products in addition to condensed phase products. Examples of these volatile products are chlorides, oxychlorides, and certain oxides and hydroxyl species. One of the best techniques to identify high temperature vapor molecules is mass spectrometry. Most mass spectrometers operate in high vacuum and are generally used to examine processes ocurring at greatly reduced pressures. However, a free-jet expansion, molecular beam mass spectrometer system allows direct sampling of volatile corrosion products. This instrument is described. Several examples from our studies on chlorination/oxidation of metals and ceramics are discussed. In addition, reactions of Cr 2 O 3 , SiO 2 , and Al 2 O 3 with water vapor, which produce volatile hydroxyl species are discussed. (orig.)

Corrosion of steels in saline mediums with CO2, efficiency of inhibitors as a function of the degree of pre-corrosion and microstructure

International Nuclear Information System (INIS)

Paolinelli, LD; Perez, T; Simison, S.N

2004-01-01

Despite the big influence of the microstructure and chemical composition of plain carbon steels and low alloy steels on corrosion in saline mediums with CO 2 , the results found in the literature are contradictory. An aspect that is less studied is the effect of these variables on the formation and characteristics of the films as products of corrosion and on the efficiency of the inhibitors used in oil production. Previous works have shown that the efficiency of the inhibitors is affected by the microstructure and that this effect depends on the inhibitor's molecular structure. This work aims to further define the relationship between the films of corrosion products, the steel microstructure and the efficiency of the inhibitors. A plain carbon steel was studied with two different microstructures in a 5% NaCl deoxygenated solution at 40 o C, pH 6, saturated with CO 2 under laminar flow conditions. The efficiency of an imidazoline-based commercial inhibitor commonly used in oil production was characterized. The inhibitor was added after different periods of pre-corrosion: 24, 48 and 72 hours. The characteristics of the surface films were analyzed by SEM. Electrochemical tests were carried out (electrochemical impedance, resistance to lineal polarization every 24 h.) and the corrosion potentials were also recorded. The results show that the properties of the surface films and the inhibitor's efficiency depend on the microstructure with higher values for the quenched and tempered samples than for the annealed samples. While the inhibitor's efficiency diminishes in all cases along with the degree of pre-corrosion, the amount of this decrease is different for each microstructural condition (CW)

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.

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

The Effect of Adding Corrosion Inhibitors into an Electroless Nickel Plating Bath for Magnesium Alloys

Science.gov (United States)

Hu, Rong; Su, Yongyao; Liu, Hongdong; Cheng, Jiang; Yang, Xin; Shao, Zhongcai

2016-10-01

In this work, corrosion inhibitors were added into an electroless nickel plating bath to realize nickel-phosphorus (Ni-P) coating deposition on magnesium alloy directly. The performance of five corrosion inhibitors was evaluated by inhibition efficiency. The results showed that only ammonium hydrogen fluoride (NH4HF2) and ammonium molybdate ((NH4)2MoO4) could be used as corrosion inhibitors for magnesium alloy in the bath. Moreover, compounding NH4HF2 and (NH4)2MoO4, the optimal concentrations were both at 1.5 ~ 2%. The deposition process of Ni-P coating was observed by using a scanning electron microscope (SEM). It showed corrosion inhibitors inhibited undesired dissolution of magnesium substrate during the electroless plating process. In addition, SEM observation indicated that the corrosion inhibition reaction and the Ni2+ replacement reaction were competitive at the initial deposition time. Both electrochemical analysis and thermal shock test revealed that the Ni-P coating exhibited excellent corrosion resistance and adhesion properties in protecting the magnesium alloy.

On the protective effect of KhOSP-10 inhibitor during corrosion, hydrogenadsorption and corrosion cracking of a steel in sulfuric acid

International Nuclear Information System (INIS)

Mindyuk, A.K.; Svist, E.I.; Savitskaya, O.P.; Goyan, E.B.; Gopanenko, A.N.

1975-01-01

The protective propeties of inhibitor KhOSP-10 in the time of corrosion and corrosive cracking of steel 40Kh are higher then those of inhibitors KPI-1, KI-1, I-I-V etc. Its ability to reduce steel hydrogenation is the same as in the case of KPI-1 inhibitor i.e. below that of KI-1. HCl additives enhance the efficiency of inhibitors KPI-1, KI-1, I-1-V etc. up to the protective ability of KhOSP-10. Kinetics of the electrode processes was estimated from polarization curves

Assessment of high performance concrete containing fly ash and calcium nitrite based corrosion inhibitor as a mean to prevent the corrosion of reinforcing steel

International Nuclear Information System (INIS)

Montes-García, P; Jiménez-Quero, V; López-Calvo, H

2015-01-01

This research analyses the effectiveness of the water-to-cement ratio (w/c), fly ash and a calcium nitrite based corrosion inhibitor to prevent the corrosion of reinforcing steel embedded in high performance concrete. The interactive effect between the inhibitor and fly ash was evaluated because the occurrence of a negative effect when both ingredients are added together in a concrete mixture has been reported. All the concrete mixtures studied in this investigation had 8.2% of silica fume. Twenty seven prismatic concrete specimens were fabricated with dimensions of 55 × 230 × 300 mm each containing two steel rods embedded for the purpose of corrosion monitoring. The specimens were exposed to a simulated marine environment with two daily cycles of wetting and drying for one year. To evaluate the deterioration of the specimens corrosion potentials and linear polarization resistance tests were carried out. The results indicate that the use of a low w/c, the addition of fly ash and the addition of the corrosion inhibitor contributed to the reduction of the corrosion of steel in the concrete specimens. The results further suggest that the combination of fly ash and corrosion inhibitor does not promote the deterioration of the concrete matrix

Inhibitors for the corrosion of reactive metals: titanium and zirconium and their alloys in acid media

International Nuclear Information System (INIS)

Petit, J.A.; Chatainier, G.; Dabosi, F.

1981-01-01

The search for effective corrosion inhibitors for titanium and zirconium in acid media is growing because of the considerable increase in the use of these materials in chemical process equipment. It still remains limited, as appears from this review, because of the exceptionally high corrosion resistance of the metals. Titanium has received the greater attention. Its corrosion rate can be lowered by introduction in the medium of multivalent ions, inorganic and organic oxidants. Care should be taken to hold the concentration at a level exceeding some critical value, otherwise the corrosion rate increases. Complexing organic agents do not show such hazardous behaviour. The very rapid corrosion of titanium and zirconium in fluoride media may be lessened by complexing the fluoride ions. Though rarely encountered, localized corrosion may be avoided by using inhibitors. In some cases good corrosion inhibitors for titanium are dissolution accelerators for zirconium. (author)

Use of Extracted Green Inhibitors as a Friendly Choice in Corrosion Protection of Low Alloy Carbon Steel

Directory of Open Access Journals (Sweden)

Jano, A.

2012-11-01

Full Text Available Mitigation of corrosion impact on environment is an important step in environmental protection. Use of environmentally friendly corrosion protection methods is very important. It is smart to choose cheap and safe to handle compounds as corrosion inhibitors. The use of green inhibitors (extracted inexpensively, from the seed endosperm of some Leguminosae plants, and investigation of their efficiency in corrosion protection is the aim of this study. As green inhibitor one kind of polysaccharides (galactomannan from locust bean gum (also known as carob gum, carob bean gum extracted from the seed of carob tree is used. Corrosion protection efficiency of these extracted green inhibitors was tested for carbon steel marked as: steel 39, steel 44, and iron B 500 (usually applied as reinforcing bars to concrete. Sulfuric acid solution in the presence of chloride ions was used as corrosion media. The composition of corrosion acid media used was 1 mol L-1 H2SO4 and 10-3 mol L-1 Cl- (in the form of NaCl. Electrochemical techniques such as potentiodynamic polarization methods were used for inhibitor efficiency testing.

The application of neutron reflectometry and atomic force microscopy in the study of corrosion inhibitor films

International Nuclear Information System (INIS)

John, Douglas; Blom, Annabelle; Bailey, Stuart; Nelson, Andrew; Schulz, Jamie; De Marco, Roland; Kinsella, Brian

2006-01-01

Corrosion inhibitor molecules function by adsorbing to a steel surface and thus prevent oxidation of the metal. The interfacial structures formed by a range of corrosion inhibitor molecules have been investigated by in situ measurements based on atomic force microscopy and neutron reflectometry. Inhibitors investigated include molecules cetyl pyridinium chloride (CPC), dodecyl pyridinium chloride (DPC), 1-hydroxyethyl-2-oleic imidazoline (OHEI) and cetyl dimethyl benzyl ammonium chloride (CDMBAC). This has shown that the inhibitor molecules adsorb onto a surface in micellar structures. Corrosion measurements confirmed that maximum inhibition efficiency coincides with the solution critical micelle concentration

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)

Benzotriazole (BTA), A Promising Corrosion Inhibitor for WC-Co Hardmetal

Energy Technology Data Exchange (ETDEWEB)

Schnyder, B.; Stoessel-Sittig, C.; Koetz, R.; Hochstrasser-Kurz, S. [ETH Zuerich (Switzerland); Virtanen, S. [ETH Zuerich (Switzerland); Jaeggi, Ch. [University of Bern (Switzerland); Eichenberger, N. [University of Bern (Switzerland); Szoecs, E. [University of Bern (Switzerland); Siegenthaler, H. [University of Bern (Switzerland); Ziegler, P. [AGIE SA (Switzerland); Beltrami, I. [AGIE SA (Switzerland)

2004-03-01

Wire Electro-Discharge Machining (W-EDM) of tungsten carbide with Co-binder may lead to corrosion and discolouration at the surface. The corrosion behaviour of WC-Co based hardmetal was investigated in different aqueous solutions (acidic, neutral, and alkaline solutions). At open-circuit potential WC-Co based hardmetals show rather high dissolution rates in all types of electrolyte. An efficient corrosion inhibitor (benzotriazole, C{sub 6}H{sub 5}N{sub 3}) could be found for a borate buffer solution, pH = 8.4. (author)

Electrochemical techniques for practical evaluation of corrosion inhibitor effectiveness. Performance of cerium nitrate as corrosion inhibitor for AA2024T3 alloy

International Nuclear Information System (INIS)

Rosero-Navarro, N.C.; Curioni, M.; Bingham, R.; Duran, A.; Aparicio, M.; Cottis, R.A.; Thompson, G.E.

2010-01-01

In this work, a split-cell technique and image-assisted electrochemical noise analysis, which provide minimal perturbation of the freely corroding system and good time resolution, are proposed as a tool for simultaneous investigation of the corrosion inhibition mechanism and assessment of performance. The results obtained are compared with results from traditional electrochemical impedance spectroscopy, disclosing the advantages of these techniques in the evaluation of inhibitor performance. Specific attention is also given to the investigation of corrosion inhibition by cerium nitrate.

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.

Corrosion of X65 Pipeline Steel Under Deposit and Effect of Corrosion Inhibitor

Directory of Open Access Journals (Sweden)

XU Yun-ze

2016-10-01

Full Text Available Effect of the deposit on the electrochemical parameters of X65 pipeline steel in oxygen contained sodium chloride solution was studied by EIS and PDS methods. The galvanic corrosion behavior under deposit and effect of different concentration of corrosion inhibitor PBTCA were studied by electrical resistance (ER method combined with ZRA. The results show that the corrosion potential of X65 steel shifts negatively as SiO2 covering its surface and the corrosion rate becomes lower. When the galvanic couple specimen with deposit is electrically connected with the specimen without deposit, anodic polarization occurs on X65 steel under deposit and the galvanic current density decreases from 120μA/cm2 to 50μA/cm2 and keeps stable. As 5×10-5, 8×10-5 and 3×10-4 PBTCA were introduced into the solution, the galvanic current density reaches the highest 1300μA/cm2 and then decreases to 610μA/cm2 keeping stable around 610μA/cm2, corrosion rate of X65 steel under deposit reaches 6.11mm/a. PBTCA accelerates the corrosion of X65 steel under deposit in oxygen contained solution. Through the investigation on the surface of the specimens, serious local corrosion occurs on the X65 steel surface under deposit.

Pullulan as a potent green inhibitor for corrosion mitigation of aluminum composite: Electrochemical and surface studies.

Science.gov (United States)

B P, Charitha; Rao, Padmalatha

2018-06-01

This work emphasizes the corrosion inhibition ability of pullulan, an environmentally benign fungal polysaccharide on acid corrosion of 6061Aluminum-15% (v) SiC (P) composite material (Al-CM). The electrochemical measurements such as potentiodynamic polarization (PDP) and electrochemical impedance spectroscopy (EIS) studies were carried out for the corrosion inhibition studies. Conditions were optimized to obtain maximum inhibition efficiency, by performing the experiment at varying concentrations of inhibitor, in the temperature range of 308K- 323K. Surface morphology studies were done to reaffirm the adsorption of inhibitor on the surface of composite material. Pullulan acted as mixed type of inhibitor with a maximum efficiency of 89% at 303K for the addition of 1.0 gL -1 of inhibitor. Evaluation of kinetic and thermodynamic parameters revealed that inhibitor underwent physical adsorption onto the surface of Al-CM and obeyed Freundlich adsorption isotherm. The surface characterization like SEM-EDX, AFM confirmed the adsorption of pullulan molecule. Pullulan can be considered as effective, eco friendly green inhibitor for the corrosion control of Al-CM. Copyright © 2018 Elsevier B.V. All rights reserved.

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

Directory of Open Access Journals (Sweden)

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

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.

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

Benzimidazole and its derivatives as corrosion inhibitors for mild steel in 1M HCl solution

International Nuclear Information System (INIS)

Aljourani, J.; Raeissi, K.; Golozar, M.A.

2009-01-01

In this paper, the inhibition ability of benzimidazole and its derivatives against the corrosion of mild steel in 1M HCl solution was studied. The change of impedance parameters observed by variation of inhibitors concentration within the range of 50-250 ppm was an indication of their adsorption. The thermodynamic adsorption parameters proposed that these inhibitors retard both cathodic and anodic processes through physical adsorption and blocking the active corrosion sites. The adsorption of these compounds obeyed the Langmuir's adsorption isotherm. The inhibition efficiency was increased with inhibitor concentration in the order of 2-mercaptobenzimidazole > 2-methylbenzimidazole > benzimidazole, which is in accordance with the variation of apparent activation energy of corrosion.

Safe corrosion inhibitor for treating cooling water on heat power engineering plants

Science.gov (United States)

Nikolaeva, L. A.; Khasanova, D. I.; Mukhutdinova, E. R.; Safin, D. Kh.; Sharifullin, I. G.

2017-08-01

Heat power engineering (HPE) consumes significant volumes of water. There are, therefore, problems associated with corrosion, biological fouling, salt deposits, and sludge formation on functional surfaces of heat power equipment. One of the effective ways to solve these problems is the use of inhibitory protection. The development of new Russian import-substituting environmentally friendly inhibitors is very relevant. This work describes experimental results on the OPC-800 inhibitor (TU 2415-092-00206 457-2013), which was produced at Karpov Chemical Plant and designed to remove mineral deposits, scale, and biological fouling from the surfaces of water-rotation node systems on HPE objects. This reagent is successfully used as an effective corrosion inhibitor in the water recycling systems of Tatarstan petrochemical enterprises. To save fresh make-up water, the circulating system is operated in a no-blow mode, which is characterized by high evaporation and salt content coefficients. It was experimentally found that corrosion rate upon treatment of recycled water with the OPC-800 inhibitor is 0.08-0.10 mm/year. HPE mainly uses inhibitors based on oxyethylidene diphosphonic (OEDPA) and nitrilotrimethylphosphonic (NTMPA) acids. The comparative characteristic of inhibition efficiency for OPC-800 and OEDF-Zn-U2 is given. The results obtained indicate that OPC-800 can be used as an inhibitor for treatment of cooling water in HPE plants. In this case, it is necessary to take into account the features of water rotation of a thermal power plant.

Green chemistry applied to corrosion and scale inhibitors

Energy Technology Data Exchange (ETDEWEB)

Darling, D.; Rakshpal, R. [Environmental Protection Agency, Washington, DC (United States)

1998-12-31

Numerous breakthroughs in environmental protection and pollution prevention have been realized in recent years by both industry and academia through the application of green chemistry principles. Green chemistry, or pollution prevention at the molecular level, is chemistry designed to reduce or eliminate the use or generation of hazardous materials associated with the manufacture and application of chemicals. The application of the green chemistry principles to the areas of corrosion and scale inhibitors has resulted in the reduction/elimination of many of the more toxic inhibitors and the development of newer, more environmentally friendly ones.

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.

Effect of caffeine inhibitor in corrosion rate and microstructure of KS01 carbon steel and AISI 1045 at media sea water

International Nuclear Information System (INIS)

Sulistioso Giat S; Setyo Purwanto; Deswita; Ari Handayani; Berta Vidyananda

2013-01-01

Many synthetic materials are good inhibitors for the prevention of corrosion . Many inhibitors are toxic, because of the influence of these toxic properties, recently use organic materials as corrosion inhibitors, that are not hazardous and environmentally friendly. In this study caffeine compounds used as corrosion inhibitors. This compound could be used as corrosion inhibitor because of the existence of their chemical groups that containing free electron pair, that is nitrogen. Corrosion rate testing conducted in sea water medium taken from the Northern region of Indramayu with variations of the concentration of caffeine 0, 50, 100, 150, and 200 ppm to determine the optimum concentration of caffeine in corrosion rate of carbon steel AISI 1045 and KS01 that a widely used on the cooling system in the industry. Corrosion rate of KS-01 steel before used in inhibitor media is 25,07 mpy that less than corrosion rate of carbon steel AISI 1045, is 45,82 mpy . The results of this study indicate that caffeine is able to inhibit the corrosion rate of both of samples with optimum efficiency KS01 for 64.38%, and AISI 1045 of 66.63%. The optimum concentration of caffeine to inhibited AISI 1045 is 150 ppm and for KS01 is 100 ppm,. Beside that analysis of microstructure for both samples have done, for media before and after inhibitor addition. (author)

Investigation of thermally sensitised stainless steels as analogues for spent AGR fuel cladding to test a corrosion inhibitor for intergranular stress corrosion cracking

Science.gov (United States)

Whillock, Guy O. H.; Hands, Brian J.; Majchrowski, Tom P.; Hambley, David I.

2018-01-01

A small proportion of irradiated Advanced Gas-cooled Reactor (AGR) fuel cladding can be susceptible to intergranular stress corrosion cracking (IGSCC) when stored in pond water containing low chloride concentrations, but corrosion is known to be prevented by an inhibitor at the storage temperatures that have applied so far. It may be necessary in the future to increase the storage temperature by up to ∼20 °C and to demonstrate the impact of higher temperatures for safety case purposes. Accordingly, corrosion testing is needed to establish the effect of temperature increases on the efficacy of the inhibitor. This paper presents the results of studies carried out on thermally sensitised 304 and 20Cr-25Ni-Nb stainless steels, investigating their grain boundary compositions and their IGSCC behaviour over a range of test temperatures (30-60 °C) and chloride concentrations (0.3-10 mg/L). Monitoring of crack initiation and propagation is presented along with preliminary results as to the effect of the corrosion inhibitor. 304 stainless steel aged for 72 h at 600 °C provided a close match to the known pond storage corrosion behaviour of spent AGR fuel cladding.

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.

Adsorption behavior of caffeine as a green corrosion inhibitor for copper

International Nuclear Information System (INIS)

Souza, Fernando Sílvio de; Giacomelli, Cristiano; Gonçalves, Reinaldo Simões; Spinelli, Almir

2012-01-01

Electrochemical and impedance experiments were carried out to evaluate the corrosion behavior of copper in aerated 0.1 mol L −1 H 2 SO 4 solutions in the presence of three xanthine derivatives with similar chemical structures. The corrosion rate of copper was found to increase in the presence of theophylline and theobromine and decrease in the presence of caffeine. The adsorption and inhibitory effect of caffeine on copper surfaces in aerated 0.1 mol L −1 H 2 SO 4 solutions were then investigated in detail by potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), contact angle measurements, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and fluorescence experiments. The data obtained indicate that caffeine behaves as a cathodic-type inhibitor adsorbing onto the copper surface according to the Temkin isotherm, with the negative ∆G° ads value of − 31.1 kJ mol −1 signifying a spontaneous adsorption process. The corrosion inhibition efficiency increased with caffeine concentration in the range of 1.0–10.0 mmol L −1 . Furthermore, the EIS results obtained at the open-circuit potential and surface analysis (SEM, EDS and fluorescence) clearly demonstrated the adsorption of the organic compound onto the copper electrode. The contact angle measurements revealed the formation of a hydrophobic protective film. This film covers up to 72% of the total active surface, acts as a protective barrier and prevents interaction between the metal, water and oxygen molecules. - Highlights: ► We have investigated the adsorption and corrosion inhibition of caffeine on copper surfaces. ► Caffeine behaves as a cathodic-type inhibitor. ► Caffeine adsorbs onto copper surface according to Temkin isotherm. ► There exists the formation of a hydrophobic film that acts as a protective barrier. ► This corrosion inhibitor covers up to 72% of the total active surface of copper.

Effects of chitosan inhibitor on the electrochemical corrosion behavior of 2205 duplex stainless steel

Science.gov (United States)

Yang, Se-fei; Wen, Ying; Yi, Pan; Xiao, Kui; Dong, Chao-fang

2017-11-01

The effects of chitosan inhibitor on the corrosion behavior of 2205 duplex stainless steel were studied by electrochemical measurements, immersion tests, and stereology microscopy. The influences of immersion time, temperature, and chitosan concentration on the corrosion inhibition performance of chitosan were investigated. The optimum parameters of water-soluble chitosan on the corrosion inhibition performance of 2205 duplex stainless steel were also determined. The water-soluble chitosan showed excellent corrosion inhibition performance on the 2205 duplex stainless steel. Polarization curves demonstrated that chitosan acted as a mixed-type inhibitor. When the stainless steel specimen was immersed in the 0.2 g/L chitosan solution for 4 h, a dense and uniform adsorption film covered the sample surface and the inhibition efficiency (IE) reached its maximum value. Moreover, temperature was found to strongly influence the corrosion inhibition of chitosan; the inhibition efficiency gradually decreased with increasing temperature. The 2205 duplex stainless steel specimen immersed in 0.4 g/L water-soluble chitosan at 30°C displayed the best corrosion inhibition among the investigated specimens. Moreover, chitosan decreased the corrosion rate of the 2205 duplex stainless steel in an FeCl3 solution.

Corrosion/95 conference papers

International Nuclear Information System (INIS)

Anon.

1995-01-01

The papers in this conference represent the latest technological advances in corrosion control and prevention. The following subject areas are covered: cathodic protection in natural waters; materials for fossil fuel combustion and conversion systems; modern problems in atmospheric corrosion; innovative ideas for controlling the decaying infrastructure; deposits and their effects on corrosion in industry; volatile high temperature and non aqueous corrosion inhibitors; corrosion of light-weight and precoated metals for automotive application; refining industry corrosion; corrosion in pulp and paper industry; arctic/cold weather corrosion; materials selection for waste incinerators and associated equipment; corrosion measurement technology; environmental cracking of materials; advancing technology in the coating industry; corrosion in gas treating; green inhibition; recent advances in corrosion control of rail equipment; velocity effects and erosion corrosion in oil and gas production; marine corrosion; corrosion of materials in nuclear systems; underground corrosion control; corrosion in potable and industrial water systems in buildings and its impact on environmental compliance; deposit related boiler tube failures; boiler systems monitoring and control; recent developments and experiences in reactive metals; microbiologically influenced corrosion; corrosion and corrosion control for steel reinforced concrete; international symposium on the use of 12 and 13 Cr stainless steels in oil and gas production environments; subsea corrosion /erosion monitoring in production facilities; fiberglass reinforced pipe and tubulars in oilfield service; corrosion control technology in power transmission and distribution; mechanisms and methods of scale and deposit control; closing the loop -- results oriented cooling system monitoring and control; and minimization of aqueous discharge

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.

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.

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

Directory of Open Access Journals (Sweden)

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.

Electrochemical study of galvanic corrosion inhibitors in water-based and ethylene glycol-based heat transfer circuits

International Nuclear Information System (INIS)

Netter, Pierre

1981-01-01

This research thesis reports the search for and the efficiency assessment of mixes of inhibitors for coolant circuits of motor cars. After a discussion of the general properties of water-alcohol solvents (chemical properties, acid-base equilibriums) and of parameters affecting corrosion in coolant circuits, the author proposes an overview of the main inhibitors which are used to protect these circuits against corrosion, and discusses their action mechanism and efficiency. The different methods used to study the corrosion of these circuits are described, and the advantages and drawbacks of test methods are commented. The second part proposes a synthesis of the different corrosion electromechanical mechanisms which may occur with respect to the used metallic materials and to possible galvanic couplings. The next part describes the experimental installations. The last part focuses on the different protections obtained with the different used inhibitor class in terms of results obtained by gravimetric tests and visual examination of samples, current-voltage curves in hydrodynamic regime, and galvanic corrosion tests performed in laboratory or in situ in motor cars [fr

Corrosion '98: 53. annual conference and exposition, proceedings

International Nuclear Information System (INIS)

Anon.

1998-01-01

This conference was divided into the following sections: Corrosion in Gas Treating; Problems and Solutions in Commercial Building Water Systems; Green Corrosion/Scale Inhibitors; Atmospheric Corrosion; AIRPOL Update/98; Rubber Lining--Answers to Many Problems; Interference Problems; Environmental Assisted Cracking: Fundamental Research and Industrial Applications; Corrosion in Nuclear Systems; New Developments in Scale and Deposit Control; Corrosion and Corrosion Protection in the Transportation Industries; What's All the Noise About--Electrochemical That Is; Refining Industry Corrosion; Corrosion Problems in Military Hardware: Case Histories, Fixes and Lessons Learned; Cathodic Protection Test Methods and Instrumentation for Underground and On-grade Pipelines and Tanks; Recent Developments in Volatile Corrosion Inhibitors; Corrosion in Supercritical Fluids; Microbiologically Influenced Corrosion; Advances in Understanding and Controlling CO 2 Corrosion; Managing Corrosion with Plastics; Material Developments for Use in Exploration and Production Environments; Corrosion in Cold Regions; The Effect of Downsizing and Outsourcing on Cooling System Monitoring and Control Practices; New Developments in Mechanical and Chemical Industrial Cleaning; Mineral Scale Deposit Control in Oilfield Related Operations; Biocides in Cooling Water; Corrosion and Corrosion Control of Reinforced Concrete Structures; Materials Performance for Fossil Energy Conversion Systems; Marine corrosion; Thermal Spray--Coating and Corrosion Control; Flow Effects on Corrosion in Oil and Gas Production; Corrosion Measurement Technologies; Internal Pipeline Monitoring--Corrosion Monitoring, Intelligent Pigging and Leak Detection; Cathodic Protection in Natural Waters; Corrosion in Radioactive Liquid Waste Systems; On-line Hydrogen Permeation Monitoring Equipment and Techniques, State of the Art; Water Reuse and Recovery; Performance of Materials in High Temperature Environments; Advances in Motor

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)

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.

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.

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

Directory of Open Access Journals (Sweden)

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

The use of morinda citrifolia as a green corrosion inhibitor for low carbon steel in 3.5% NaCl solution

Science.gov (United States)

Kusumastuti, Rahayu; Pramana, Rakhmad Indra; Soedarsono, Johny W.

2017-03-01

The effect and mechanism of green corrosion inhibitor of Morinda Citrifolia (Noni) toward low carbon steel material has been researched. The general background is to develop the cheap and eco-friendly corrosion inhibitor based on components taken from tropical plants that grow +in Indonesia. This research aims to determine the effectiveness of the use of the extracts of noni as green corrosion inhibitor of carbon steel material in aggressive environment. The medium applied for this experiment is 3.5% natrium chloride solution. The variation of the concentration and immersion time duration has been applied as the experimental parameters. All the work was done at room temperature. The corrosion rate was measured by electrochemical polarization method with CMS 600-Gamry instruments and weight loss. The adsorption of inhibitor into the metal surface, which induced bonding formation after immersion was observed by using FTIR method. Inhibition mechanism was observed by polarization curves and fitted by the Langmuir adsorption models. The experimental results show that the higher concentration of inhibitor increasing the inhibition effect. The optimum inhibition is obtained at 3 ppm noni fruit extract, after immersion for about 288 hours. The corrosion rates obtained was 1.385 mpy, with the inhibitor efficiency of 76.92%. The monolayer film is formed coating the surface material as a result of mixed type corrosion inhibitor behavior of Noni. It can be concluded that this green inhibitor is effective to be used for low carbon steel material.

Multiscale numerical modeling of Ce3+-inhibitor release from novel corrosion protection coatings

International Nuclear Information System (INIS)

Trenado, Carlos; Wittmar, Matthias; Veith, Michael; Strauss, Daniel J; Rosero-Navarro, Nataly C; Aparicio, Mario; Durán, Alicia; Castro, Yolanda

2011-01-01

A novel hybrid sol–gel coating has recently been introduced as an alternative to high toxic chromate-based corrosion protection systems. In this paper, we propose a multiscale computational model to estimate the amount and time scale of inhibitor release of the active corrosion protection coating. Moreover, we study the release rate under the influence of parameters such as porosity and viscosity, which have recently been implicated in the stability of the coating. Numerical simulations obtained with the model predicted experimental release tests and recent findings on the compromise between inhibitor concentration and the stability of the coating

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

Directory of Open Access Journals (Sweden)

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

The use of Euphorbia falcata extract as eco-friendly corrosion inhibitor of carbon steel in hydrochloric acid solution

International Nuclear Information System (INIS)

El Bribri, A.; Tabyaoui, M.; Tabyaoui, B.; El Attari, H.; Bentiss, F.

2013-01-01

Euphorbia falcata L. extract (EFE) was investigated as eco-friendly corrosion inhibitor of carbon steel in 1 M HCl using gravimetric, ac impedance, polarization and scanning electron microscopy (SEM) techniques. The experimental results show that EFE is good corrosion inhibitor and the protection efficiency is increased with the EEF concentration. The results obtained from weight loss and ac impedance studies were in reasonable agreement. Impedance experimental data revealed a frequency distribution of the capacitance, simulated as constant phase element. Polarization curves indicated that EFE is a mixed inhibitor. The corrosion inhibition was assumed to occur via adsorption of EFE molecules on the metal surface. The adsorption of the E. falcata extract was well described by the Langmuir adsorption isotherm. The calculated ΔG ads o value showed that the corrosion inhibition of the carbon steel in 1 M HCl is mainly controlled by a physisorption process. - Graphical abstract: Display Omitted - Highlights: • EFE is a good eco-friendly inhibitor for the corrosion of carbon steel in 1 M HCl. • EFE acts as mixed-type inhibitor in 1 M HCl medium. • Weight loss, ac impedance and polarization methods are in reasonable agreement. • The adsorption of EFE is well described by the Langmuir adsorption isotherm

Evaluation of the potential of additives as corrosion inhibitors of CA-50 carbon steel used as reinforcement in concretes

International Nuclear Information System (INIS)

Mennucci, Marina Martins

2006-01-01

In this work, various compounds were tested to evaluate their potential capability for their use as corrosion inhibitors of carbon steel reinforcement in concretes. The additives tested were sodium benzoate, polyethylene glycol, hexamethylenetetramine, benzotriazole and yttrium carbonate. Initially, exploratory tests were carried out to select the ones to be used as corrosion inhibitors, based on the inhibit ion efficiency determined from electrochemical tests, specifically polarization tests and electrochemical impedance spectroscopy. These tests were carried out in a solution composed of 0.01 N sodium hydroxide (NaOH) and 0.05 N potassium hydroxide (KOH) to simulate the composition of the solution inside the pores in concretes. The additive that presented the most promising potential to be used as corrosion inhibitor was benzotriazole (BTA). After the elimination of some compounds and selection of the additive with higher corrosion inhibit ion efficiency in the test medium, the effect of its concentration on the corrosion inhibition efficiency was evaluated. Sodium nitrite solutions with the same concentrations as those solutions with BTA were tested for comparison reasons. Sodium nitrite is a well established corrosion inhibitor for carbon steel reinforcement in concretes but it has been related to toxic effects. The BTA was associated to higher corrosion inhibition efficiencies than that of sodium nitrite in similar concentrations. A blackish adherent film was formed on the steel surface exposed to BTA solutions during long periods of immersion in the alkaline medium. The results suggest that BTA is a potential candidate for substitution of nitrites as corrosion inhibitor of reinforcements in concrete. (author)

Adsorption behavior of caffeine as a green corrosion inhibitor for copper

Energy Technology Data Exchange (ETDEWEB)

Souza, Fernando Silvio de [Grupo de Estudos de Processos Eletroquimicos e Eletroanaliticos, Departamento de Quimica, Universidade Federal de Santa Catarina, 88040-900, Florianopolis, SC (Brazil); Giacomelli, Cristiano [Departamento de Quimica, Universidade Federal de Santa Maria, Av. Roraima 1000, 97119-900, Santa Maria, RS (Brazil); Goncalves, Reinaldo Simoes [Universidade Federal do Rio Grande do Sul, Av. Bento Goncalves 9500, 91501-970, Porto Alegre, RS (Brazil); Spinelli, Almir, E-mail: almir.spinelli@ufsc.br [Grupo de Estudos de Processos Eletroquimicos e Eletroanaliticos, Departamento de Quimica, Universidade Federal de Santa Catarina, 88040-900, Florianopolis, SC (Brazil)

2012-12-01

Electrochemical and impedance experiments were carried out to evaluate the corrosion behavior of copper in aerated 0.1 mol L{sup -1} H{sub 2}SO{sub 4} solutions in the presence of three xanthine derivatives with similar chemical structures. The corrosion rate of copper was found to increase in the presence of theophylline and theobromine and decrease in the presence of caffeine. The adsorption and inhibitory effect of caffeine on copper surfaces in aerated 0.1 mol L{sup -1} H{sub 2}SO{sub 4} solutions were then investigated in detail by potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), contact angle measurements, scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and fluorescence experiments. The data obtained indicate that caffeine behaves as a cathodic-type inhibitor adsorbing onto the copper surface according to the Temkin isotherm, with the negative Increment G Degree-Sign {sub ads} value of - 31.1 kJ mol{sup -1} signifying a spontaneous adsorption process. The corrosion inhibition efficiency increased with caffeine concentration in the range of 1.0-10.0 mmol L{sup -1}. Furthermore, the EIS results obtained at the open-circuit potential and surface analysis (SEM, EDS and fluorescence) clearly demonstrated the adsorption of the organic compound onto the copper electrode. The contact angle measurements revealed the formation of a hydrophobic protective film. This film covers up to 72% of the total active surface, acts as a protective barrier and prevents interaction between the metal, water and oxygen molecules. - Highlights: Black-Right-Pointing-Pointer We have investigated the adsorption and corrosion inhibition of caffeine on copper surfaces. Black-Right-Pointing-Pointer Caffeine behaves as a cathodic-type inhibitor. Black-Right-Pointing-Pointer Caffeine adsorbs onto copper surface according to Temkin isotherm. Black-Right-Pointing-Pointer There exists the formation of a hydrophobic film that acts as a

Study on the Effects of Corrosion Inhibitor According to the Functional Groups for Cu Chemical Mechanical Polishing in Neutral Environment

Energy Technology Data Exchange (ETDEWEB)

Lee, Sang Won; Kim, Jae Jeong [Institute of Chemical Process, Seoul National University, Seoul (Korea, Republic of)

2015-08-15

As the aluminum (Al) metallization process was replaced with copper (Cu), the damascene process was introduced, which required the planarization step to eliminate over-deposited Cu with Chemical Mechanical Polishing (CMP) process. In this study, the verification of the corrosion inhibitors, one of the Cu CMP slurry components, was conducted to find out the tendency regarding the carboxyl and amino functional group in neutral environment. Through the results of etch rate, removal rate, and chemical ability of corrosion inhibitors based on 1H-1,2,4-triazole as the base corrosion inhibitor, while the amine functional group presents high Cu etching ability, carboxyl functional group shows lower Cu etching ability than base-corrosion inhibitor which means that it increases passivation effect by making strong passivation layer. It implies that the corrosion inhibitor with amine functional group was proper to apply for 1st Cu CMP slurry owing to the high etch rate and with carboxyl functional group was favorable for the 2nd Cu CMP slurry due to the high Cu removal rate/dissolution rate ratio.

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.

Inhibitor selection for internal corrosion control of pipelines. 1: Laboratory methodologies

Energy Technology Data Exchange (ETDEWEB)

Papavinasam, S.; Revie, R.W.; Attard, M. [CANMET, Ottawa, Ontario (Canada). Materials Technology Lab.; Demoz, A.; Sun, H.; Donini, J.C.; Michaelian, K. [CANMET, Devon, Alberta (Canada). Western Research Centre

1999-11-01

Various laboratory methodologies to evaluate corrosion inhibitors are reviewed. Two new methodologies, high-temperature, high-pressure jet impingement (HTHPJI) and high-temperature, high-pressure rotating electrode (HTHPRE), are presented. Flow patterns and hydrodynamic parameters of rotating cage are presented.

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

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

Directory of Open Access Journals (Sweden)

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.

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.

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

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.

Studies on corrosion inhibitors for the cooling water system at the Heavy Water Project, Kota

International Nuclear Information System (INIS)

Pillai, B.P.; Mehta, C.T.; Abubacker, K.M.

1986-01-01

The Heavy Water Project at Kota uses the water from the Rana Pratap Sagar Lake as coolant in the open recirculation system. In order to find suitable corrosion inhibitors for the above system, a series of laboratory experiments on corrosion inhibitors were carried out using the constructional materials of the cooling water system and a number of proprietary formulations and the results are tabulated. From the data thus generated through various laboratory experiments, the most useful ones have been recommended for application in practice. (author)

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

Directory of Open Access Journals (Sweden)

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.

Novel environment friendly corrosion inhibitor pigments based on naturally occurring clay minerals

Energy Technology Data Exchange (ETDEWEB)

Bohm, S.; McMurray, H.N.; Worsley, D.A. [University of Wales, Swansea (United Kingdom). Dept. of Materials Engineering; Powell, S.M. [University of Wales, Swansea (United Kingdom). Engineering Doktorate Centre

2001-12-01

Novel, ceramic, corrosion inhibitor pigments consisting of cerium (III) and calcium (II) cation exchanged bentonites have been shown to provide effective cut-edge corrosion resistance in organic coated galvanised steel. The bentonite pigments were prepared from a naturally occurring (Wyoming) bentonite with a cation-exchange-capacity of 0.7 milli-equivalents per gram. Cation exchange was carried out by repeated washing with aqueous solutions of cerium (III) chloride and calcium (II) chloride to produce bentonites containing 31500 ppm exchangeable cerium (III) and 13500 ppm exchangeable calcium (II) respectively. The resulting bentonite pigments were dispersed in a polyester-resin based primer paint system to give a pigment volume concentration of 19%. For comparison, two similar primer systems were prepared containing a commercial calcium (II) exchanged silica pigment Shieldex: 60 000 ppm calcium (II) and a strontium chromate dispersion, both with a 19% pigment volume concentration. All three primer systems were applied (5 {mu}m) to the zinc surface of galvanised 0.7 mm gauge sheet steel and overcoated with an architectural polyester topcoat (18 {mu}m). The performance of the inhibitor pigments was compared by measuring the rate of corrosion-driven organic coating delamination from the cut edge of samples during 1000 h of salt-spray testing. The calcium (II) bentonite pigment exhibited an anti-delamination performance similar to that of strontium chromate but superior to that of Shieldex. However, the cerium (III) bentonite pigment was superior in performance to both strontium chromate and Shieldex. Thus, the bentonite pigments represent promising, environmentally friendly, ion-exchange corrosion inhibitors which exhibit good anti-delamination performance by comparison with current commercial systems. (orig.)

Yttrium 3-(4-nitrophenyl)-2-propenoate used as inhibitor against copper alloy corrosion in 0.1 M NaCl solution

International Nuclear Information System (INIS)

Nam, Nguyen Dang; Thang, Vo Quoc; Hoai, Nguyen To; Hien, Pham Van

2016-01-01

Highlights: • Yttrium 3-(4-nitrophenyl)-2-propenoate has been studied as an effective corrosion inhibitor for copper. • A high inhibition performance is attributed to the forming protective inhibiting deposits. • Yttrium 3-(4-nitrophenyl)-2-propenoate mitigates corrosion by promoting random distribution of minor anodes. - Abstract: Yttrium 3-(4-nitrophenyl)-2-propenoate has been studied as an effective corrosion inhibitor for copper alloy in 0.1 M chloride solution. The results show that the surface of copper alloy coupons exposed to solutions containing 0.45 mM yttrium 3-(4-nitrophenyl)-2-propenoate had no signs of corrosion attack due to protective film formation, whereas the surface of copper alloy coupons exposed to non-inhibitor and lower concentrations of yttrium 3-(4-nitrophenyl)-2-propenoate containing solutions were severely corroded. A high inhibition performance is attributed to the forming protective inhibiting deposits that slow down the electrochemical corrosion reactions and mitigate corrosion by promoting random distribution of minor anodes.

The influence of Desulfovibrio vulgaris on the efficiency of imidazoline as a corrosion inhibitor on low-carbon steel in seawater

Energy Technology Data Exchange (ETDEWEB)

Gonzalez-Rodriguez, Carlos A. [Facultad de Quimica UNAM, Ciudad Universitaria, C.P. 04510 Mexico, D.F. (Mexico)], E-mail: gorc74@yahoo.com; Rodriguez-Gomez, Francisco J.; Genesca-Llongueras, Joan [Facultad de Quimica UNAM, Ciudad Universitaria, C.P. 04510 Mexico, D.F. (Mexico)

2008-12-01

The action of Desulfovibrio vulgaris (Dv) during a corrosion process has been reported in literature, but the influence of imidazoline in the formation of biofilms is not clear, as well as the effect of bacteria on the efficiency of the corrosion inhibitors. The aim of this work is to determine the behavior of bacteria in the presence of imidazoline. Therefore, the growth of Dv, isolated and characterized from a morphological point of view, was monitored during 21 days, during which synthetic seawater was used as the culture medium, according to the ASTM D665-98 standard. Electrochemical noise (EN) was employed to establish the corrosion type generated by the microorganism on an AISI 1018 steel cylinder. The attack was observed using scanning electron microscopy (SEM). In order to evaluate the efficiency of the corrosion inhibitor, Tafel extrapolation was used; the optimum concentration of the inhibitor was used in the presence of sulphate-reducing bacteria (SRB). In general, two forms of corrosion were observed: localized corrosion (in the LAG phase) and mixed corrosion (in the LOG phase)

The influence of Desulfovibrio vulgaris on the efficiency of imidazoline as a corrosion inhibitor on low-carbon steel in seawater

International Nuclear Information System (INIS)

Gonzalez-Rodriguez, Carlos A.; Rodriguez-Gomez, Francisco J.; Genesca-Llongueras, Joan

2008-01-01

The action of Desulfovibrio vulgaris (Dv) during a corrosion process has been reported in literature, but the influence of imidazoline in the formation of biofilms is not clear, as well as the effect of bacteria on the efficiency of the corrosion inhibitors. The aim of this work is to determine the behavior of bacteria in the presence of imidazoline. Therefore, the growth of Dv, isolated and characterized from a morphological point of view, was monitored during 21 days, during which synthetic seawater was used as the culture medium, according to the ASTM D665-98 standard. Electrochemical noise (EN) was employed to establish the corrosion type generated by the microorganism on an AISI 1018 steel cylinder. The attack was observed using scanning electron microscopy (SEM). In order to evaluate the efficiency of the corrosion inhibitor, Tafel extrapolation was used; the optimum concentration of the inhibitor was used in the presence of sulphate-reducing bacteria (SRB). In general, two forms of corrosion were observed: localized corrosion (in the LAG phase) and mixed corrosion (in the LOG phase)

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.

Evolution of the corrosion process of AA 2024-T3 in an alkaline NaCl solution with sodium dodecylbenzenesulfonate and lanthanum chloride inhibitors

International Nuclear Information System (INIS)

Zhou, Biner; Wang, Yishan; Zuo, Yu

2015-01-01

Highlights: • Inhibition effect of LaCl 3 and SDBS for AA 2024 in NaCl solution (pH 10) was studied. • At the beginning the active polarization behavior of the alloy changed to passivation. • The passive behavior gradually disappeared with time and pitting happened at S-phases. • The compounded inhibitors showed good inhibition but cannot totally inhibit pitting. • The adsorption of SDBS played the key role for inhibition to the corrosion process. - Abstract: The evolution of the corrosion process of AA 2024-T3 in 0.58 g L −1 NaCl solution (pH 10) with sodium dodecylbenzenesulfonate (SDBS) and lanthanum chloride inhibitors was studied with electrochemical and surface analysis methods. With the addition of the compounded LaCl 3 and SDBS inhibitors, in the early stage the polarization behavior of AA 2024-T3 changed from active corrosion to passivation, and both the general corrosion and pitting corrosion were inhibited. However, with the immersion time extended, the passive behavior gradually disappeared and pitting happened at the Cu-rich phases. After 24 h immersion, the compounded inhibitors still showed good inhibition for general corrosion, but the polarization curve again presented the characteristic similar to active polarization. The compounded inhibitors also inhibited the pitting corrosion to some extent. The acting mechanism of the inhibitors SDBS and La 3 Cl on the corrosion process of AA 2024-T3 in the test solution was discussed.

Screening and Quantification of Aliphatic Primary Alkyl Corrosion Inhibitor Amines in Water Samples by Paper Spray Mass Spectrometry.

Science.gov (United States)

Jjunju, Fred P M; Maher, Simon; Damon, Deidre E; Barrett, Richard M; Syed, S U; Heeren, Ron M A; Taylor, Stephen; Badu-Tawiah, Abraham K

2016-01-19

Direct analysis and identification of long chain aliphatic primary diamine Duomeen O (n-oleyl-1,3-diaminopropane), corrosion inhibitor in raw water samples taken from a large medium pressure water tube boiler plant water samples at low LODs (corrosion inhibitors in an industrial water boiler plant and other related samples in the water treatment industry. This approach was applied for the analysis of three complex water samples including feedwater, condensate water, and boiler water, all collected from large medium pressure (MP) water tube boiler plants, known to be dosed with varying amounts of polyamine and amine corrosion inhibitor components. Polyamine chemistry is widely used for example in large high pressure (HP) boilers operating in municipal waste and recycling facilities to prevent corrosion of metals. The samples used in this study are from such a facility in Coventry waste treatment facility, U.K., which has 3 × 40 tonne/hour boilers operating at 17.5 bar.

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

Directory of Open Access Journals (Sweden)

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.

Active corrosion protection performance of an epoxy coating applied on the mild steel modified with an eco-friendly sol-gel film impregnated with green corrosion inhibitor loaded nanocontainers

Science.gov (United States)

Izadi, M.; Shahrabi, T.; Ramezanzadeh, B.

2018-05-01

In this study the corrosion resistance, active protection, and cathodic disbonding performance of an epoxy coating were improved through surface modification of steel by a hybrid sol-gel system filled with green corrosion inhibitors loaded nanocontainer as intermediate layer on mild steel substrate. The green inhibitor loaded nanocontainers (GIN) were used to induce active inhibition performance in the protective coating system. The corrosion protection performance of the coated panels was investigated by electrochemical impedance spectroscopy (EIS), salt spray, and cathodic disbonding tests. It was observed that the corrosion inhibition performance of the coated mild steel panels was significantly improved by utilization of active multilayer coating system. The inhibitor release from nanocontainers at the epoxy-silane film/steel interface resulted in the anodic and cathodic reactions restriction, leading to the lower coating delamination from the substrate and corrosion products progress. Also, the active inhibition performance of the coating system was approved by electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM), and energy dispersive X-ray (EDS) analysis on the panels with artificial defects. The inhibitive agents were released to the scratch region and blocked the active sites on the metal surface.

Application of calculated NMR parameters, aromaticity indices and wavefunction properties for evaluation of corrosion inhibition efficiency of pyrazine inhibitors

Science.gov (United States)

Behzadi, Hadi; Manzetti, Sergio; Dargahi, Maryam; Roonasi, Payman; Khalilnia, Zahra

2018-01-01

In light of the importance of developing novel corrosion inhibitors, a series of quantum chemical calculations were carried out to evaluate 15N chemical shielding CS tensors as well as aromaticity indexes including NICS, HOMA, FLU, and PDI of three pyrazine derivatives, 2-methylpyrazine (MP), 2-aminopyrazine (AP) and 2-amino-5-bromopyrazine (ABP). The NICS parameters have been shown in previous studies to be paramount to the prediction of anti-corrosion properties, and have been combined here with HOMA, FLU and PDI and detailed wavefunction analysis to determine the effects from bromination and methylation on pyrazine. The results show that the electron density around the nitrogens, represented by CS tensors, can be good indicators of anti-corrosion efficiency. Additionally, the NICS, FLU and PDI, as aromaticity indicators of molecule, are well correlated with experimental corrosion inhibition efficiencies of the studied inhibitors. Bader sampling and detailed wavefunction analysis shows that the major effects from bromination on the pyrazine derivatives affect the Laplacian of the electron density of the ring, delocalizing the aromatic electrons of the carbon atoms into lone pairs and increasing polarization of the Laplacian values. This feature is well agreement with empirical studies, which show that ABP is the most efficient anti-corrosion compound followed by AP and MP, a property which can be attributed and predicted by derivation of the Laplacian of the electron density of the ring nuclei. This study shows the importance of devising DFT methods for development of new corrosion inhibitors, and the strength of electronic and nuclear analysis, and depicts most importantly how corrosion inhibitors composed of aromatic moieties may be modified to increase anti-corrosive properties.

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.

Opuntia ficus-indica Extract as Green Corrosion Inhibitor for Carbon Steel in 1 M HCl Solution

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J. P. Flores-De los Ríos

2015-01-01

Full Text Available The effect of Opuntia ficus-indica (Nopal as green corrosion inhibitor for carbon steel in 1 M HCl solution has been investigated by using weight loss tests, potentiodynamic polarization curves, and electrochemical impedance spectroscopy measurements. Also, scanning electron microscopy (SEM and Fourier transform infrared spectroscopy (FT-IR analysis were performed. The inhibitor concentrations used ranged from 0 to 300 ppm at 25, 40, and 60°C. Results indicated the inhibition efficiency increases with increasing extract concentration and decreases with the temperature, and the inhibitor acted as a cathodic-type inhibitor which is physically absorbed onto the steel surface. In fact, the adsorption of the inhibitor on the steel surface follows the Langmuir adsorption isotherm, indicating monolayer adsorption. The presence of heteroatoms such as C, N, and O and OH groups were responsible for the corrosion inhibition.

Electrochemical evaluation of antibacterial drugs as environment-friendly inhibitors for corrosion of carbon steel in HCl solution

Energy Technology Data Exchange (ETDEWEB)

Golestani, Gh.; Shahidi, M., E-mail: shahidi1965@gmail.com; Ghazanfari, D.

2014-07-01

The effect of penicillin G, ampicillin and amoxicillin drugs on the corrosion behavior of carbon steel (ASTM 1015) in 1.0 mol L⁻¹ hydrochloric acid solution was investigated using potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and electrochemical noise (EN) techniques. The inhibition efficiency was found to increase with increasing inhibitor concentration. The effect of temperature on the rate of corrosion in the absence and presence of these drugs was also studied. Some thermodynamic parameters were computed from the effect of temperature on corrosion and inhibition processes. Adsorption of these inhibitors was found to obey Langmuir adsorption isotherm. There was a case of mixed mode of adsorption here but while penicillin was adsorbed mainly through chemisorption, two other drugs were adsorbed mainly through physisorption. Potentiodynamic polarization measurements indicated that the inhibitors were of mixed type. In addition, this paper suggests that the electrochemical noise (EN) technique under open circuit conditions as the truly noninvasive electrochemical method can be employed for the quantitative evaluation of corrosion inhibition. This was done by using the standard deviation of partial signal (SDPS) for calculation of the amount of noise charges at the particular interval of frequency, thereby obtaining the inhibition efficiency (IE) of an inhibitor. These IE values showed a reasonable agreement with those obtained from potentiodynamic polarization and EIS measurements.

Electrochemical evaluation of antibacterial drugs as environment-friendly inhibitors for corrosion of carbon steel in HCl solution

International Nuclear Information System (INIS)

Golestani, Gh.; Shahidi, M.; Ghazanfari, D.

2014-01-01

The effect of penicillin G, ampicillin and amoxicillin drugs on the corrosion behavior of carbon steel (ASTM 1015) in 1.0 mol L −1 hydrochloric acid solution was investigated using potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and electrochemical noise (EN) techniques. The inhibition efficiency was found to increase with increasing inhibitor concentration. The effect of temperature on the rate of corrosion in the absence and presence of these drugs was also studied. Some thermodynamic parameters were computed from the effect of temperature on corrosion and inhibition processes. Adsorption of these inhibitors was found to obey Langmuir adsorption isotherm. There was a case of mixed mode of adsorption here but while penicillin was adsorbed mainly through chemisorption, two other drugs were adsorbed mainly through physisorption. Potentiodynamic polarization measurements indicated that the inhibitors were of mixed type. In addition, this paper suggests that the electrochemical noise (EN) technique under open circuit conditions as the truly noninvasive electrochemical method can be employed for the quantitative evaluation of corrosion inhibition. This was done by using the standard deviation of partial signal (SDPS) for calculation of the amount of noise charges at the particular interval of frequency, thereby obtaining the inhibition efficiency (IE) of an inhibitor. These IE values showed a reasonable agreement with those obtained from potentiodynamic polarization and EIS measurements.

18th national meeting for energy saving promotion (prize winning case awarded by Ministry of International Trade and Industry). ; Saving energy in annealed coil cooling equipment by using volatile corrosion inhibitor. Dai 18 kai sho energy suishin zenkoku taikai (tsusho sangyo daijinsho jusho jirei); Kikasei boseizai ni yoru shodon coil reikyaku setsubi no sho energy

Energy Technology Data Exchange (ETDEWEB)

1993-01-30

A method and a device for preventing rust in annealed coils using volatile corrosion inhibitor (VCI) were put into practical use. Air cooling using dehumidified air and corrosion inhibiting air cooling have been used to prevent rusting caused by condensation on surfaces of coils being cooled, but these methods consume a very large amount of energy. As a result of discussing new corrosion inhibiting methods, cyclohexylamine carbonate (CHC) showed a highest corrosion prohibition capability as a VCI. Because CHC has a strong odor, new deodorants have been searched by combining it with special metallic salts. It was found that the range where a deodorant can be added without impeding the corrosion prohibiting effect is from 20% to 30%. A test for practical application indicated that rusting could be suppressed even using a VCI with concentration as low as 0.4 ppm to 0.8 ppm if the velocity of cooling air on coil surfaces is held from 0.2 m/s to 0.4 m/s. A high-accuracy continuous CHC analyzing method was established that uses a nitrogen oxide analyzer. The required installation space was reduced to 1/15 to 1/20 and the running cost to 1/8 to 1/10 of conventional methods. 11 figs., 4 tabs.

Determination of the Optimum Conditions in Evaluation of Kiwi Juice as Green Corrosion Inhibitor of Steel in Hydrochloric Acid

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Khalid Hamid Rasheed

2018-08-01

Full Text Available The corrosion protection of low carbon steel in 2.5 M HCl solution by kiwi juice was studied at different temperatures and immersion times by weight loss technique. To study the determination of the optimum conditions from statistical design in evaluation of a corrosion inhibitor, three variables, were considered as the most dominant variables. These variables are: temperature, inhibitor concentration (extracted kiwi juice and immersion time at static conditions. These three variables are manipulated through the experimental work using central composite rotatable Box – Wilson Experimental Design (BWED where second order polynomial model was proposed to correlate the studied variables with the corrosion rate of low carbon steel alloy to estimate the coefficients by nonlinear regression analysis method based on Rosenbrock and Quasi-Newton estimation method in as few experiments as possible to determinate of the optimum conditions of the proposed polynomial adopted via STATISTICA software. The parametric study on corrosion inhibition process using response surface methodology (RSM is presented in this paper. The study shows that the immersion time and temperature of corroding medium had shown negative dependence of great significance in increase the corrosion rate while the other studied variable (i.e. inhibitor concentration had shown large positive dependence in reduce the corrosion rate of low carbon steel alloy. Optimum conditions for achieving the minimum corrosion rate are obtained from optimizing the above correlation and are found as follow: 42.86 °C temperature of corroding medium, 29.29 cm3/L inhibitor concentration and 2.65 h immersion time. In these circumstances, the value of inhibition efficiency obtained was 96.09 %. It could be concluded that Box-Wilson experimental design was adequately applicable in the optimization of process variables and that kiwi juice sufficiently inhibited the corrosion for low carbon steel at the

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

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.

Benzotriazole as an inhibitor of brass corrosion in chloride solution

International Nuclear Information System (INIS)

Kosec, Tadeja; Milosev, Ingrid; Pihlar, Boris

2007-01-01

The current research explores the formation of protective layers on copper, zinc and copper-zinc (Cu-10Zn and Cu-40Zn) alloys in chloride solution containing benzotriazole (BTAH), by use of electrochemical techniques, atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). Electrochemical reactions and surface products formed at the open circuit potential and as a function of the potential range are discussed. The addition of benzotriazole to aerated, near neutral 0.5 M NaCl solution affects the dissolution of copper, zinc, Cu-10Zn and Cu-40Zn alloys. The research also compares the inhibition efficiency and Gibbs adsorption energies of the investigated process. Benzotriazole, generally known as an inhibitor of copper corrosion is also shown to be an efficient inhibitor for copper-zinc alloys and zinc metal. The surface layer formed on alloys in BTAH-inhibited solution comprised both oxide and polymer components, namely Cu 2 O and ZnO oxides, and Cu(I)-BTA and Zn(II)-BTA polymers. The formation of this mixed copper-zinc oxide polymer surface film provides an effective barrier against corrosion of both metal components in chloride solution

Stress corrosion cracking susceptibility of steam generator tube materials in AVT (all volatile treatment) chemistry contaminated with lead

International Nuclear Information System (INIS)

Gomez Briceno, D.; Castano, M.L.; Garcia, M.S.

1996-01-01

Alloy 600 steam generator tubing has shown a high susceptibility to stress corrosion degradation at the operation conditions of pressurized water reactors. Several contaminants, such as lead, have been postulated as being responsible for producing the secondary side stress corrosion cracking that has occurred mainly at the location where these contaminants can concentrate. An extensive experimental work has been carried out in order to better understand the effects of lead on the stress corrosion cracking susceptibility of steam generator tube materials, namely Alloys 600, 690 and 800. This paper presents the experimental work conducted with a view to determining the influence of lead oxide concentration in AVT (all volatile treatment) conditions on the stress corrosion resistance of nickel alloys used in the fabrication of steam generator tubing. (orig.)

Investigation on the Effect of Green Inhibitors for Corrosion Protection of Mild Steel in 1 M NaOH Solution

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Premjith Jayakumar Ramakrishnan

2014-01-01

Full Text Available Alkaline corrosion is one of the main issues faced by the industries. The main chemicals abundantly used in industries are NaOH, H3PO4, HCl, and H2SO4. Corrosion control of metals has technical, economical, environmental, and aesthetical importance. The use of inhibitors is one of the best options to protect metals and alloys against corrosion. The corrosion protection of mild steel in 1 M NaOH solution by mix of Henna/Zeolite powder was studied at different temperatures by weight loss technique. Adsorption, activation, and statistical studies were addressed in this work. Adsorption studies showed that inhibitor adsorbed on metal surface according to Langmuir isotherm. Surface studies were performed by using UV-spectra and SEM. The adsorption of inhibitor on the steel surface was found to obey Langmuir’s adsorption isotherm. The inhibition efficiency increased with increasing concentration of the inhibitor in NaOH medium. Inhibition mechanism is deduced from the concentration and temperature dependence of the inhibition efficiency, Langmuir’s adsorption isotherm, SEM, and UV spectroscopic results.

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.

Utilization of Tahongai stem bark (Kleinhovia hospita Linn.) extract as corrosion inhibitor on API 5L steel

Science.gov (United States)

Rizky, Yoel; Novita, Eli; Rinda, Shaimah; Sulistijono, Triana, Yunita

2018-04-01

Tahongai (Kleinhovia hospita Linn.) is one of herbal plant cultivated in Kalimantan. Tahongai stem bark extract (Kleinhovia hospita Linn.) is known containing antioxidant to prevent cancer cell growing, therefore it is expected to become a good organic corrosion inhibitor. Tests conducted in this study were: DPPH to prove the content of antioxidant compounds in Tahongai woods (Kleinhovia hospita Linn.) from which IC50 number is found to be 153.78 µg/mL, indicating intermediate power, Fourier Transform Infrared Specroscopy (FTIR) to determine the functional groups and compounds in Tahongai stem bark extract (Kleinhovia hospita Linn.) and suspected that flavonoid compound contained in extract, Open Circuit Potential (OCP) to obtain corrosion rate data and found that the slowest corrosion occurred on 400 ppm (30 days) with corrosion rate 8,74 × 10-4 mm/year. The most efficient inhibitor found in 400 ppm (30 days) with 92,063%.

Application of a cosmetic additive as an eco-friendly inhibitor for mild steel corrosion in HCl solution.

Science.gov (United States)

Liao, Liu Li; Mo, Shi; Lei, Jing Lei; Luo, Hong Qun; Li, Nian Bing

2016-07-15

The use of the cosmetic ingredient cocamidopropylamine oxide (CAO) to inhibit the corrosion of steel in 0.5mol/LHCl is investigated. Electrochemical and weight loss methods were used to evaluate the inhibiting effect of CAO and the influences of inhibitor concentration and temperature were determined. It was found that CAO acted as a mix-type inhibitor and was adsorbed chemically onto the steel in HCl solution, and the maximum inhibition efficiency was found at critical micelle concentration (CMC) of CAO in tested corrosive media. Moreover, it was speculated that relationships of the two adsorption sites of the inhibitor and steel surface were different. Copyright © 2016 Elsevier Inc. All rights reserved.

Quantum chemical studies on the some inorganic corrosion inhibitors

International Nuclear Information System (INIS)

Sayin, Koray; Karakaş, Duran

2013-01-01

Highlights: •Some quantum chemical parameters are important to determine inhibition efficiency. •Quantum chemical calculations were performed on six inorganic inhibitors. •Five experimental reports were used to explain the theoretical results. •Atomic charges and %contributions were used to determine the atom at protonation process. •For inorganic inhibitors, the best method and basis set were investigated. -- Abstract: Some quantum chemical parameters were calculated by using Hartree–Fock (HF) approximation, Density Functional Theory (DFT/B3LYP) and Møller Plesset perturbation theory (MP3) methods at LANL2DZ, LANL2MB and SDD levels in gas phase and water for dichromate (Cr 2 O 7 2- ), chromate (CrO 4 2- ), tungstate (WO 4 2- ), molybdate (MoO 4 2- ), nitrite (NO 2 - ) and nitrate (NO 3 - ) which are used as inorganic corrosion inhibitors. All theoretical results and experimental inhibition efficiencies of inhibitors were subjected to correlation analyses. In a summary, MP3/SDD level in water was found as the best level. In this level, the inhibition efficiency ranking was found as CrO 4 2- >WO 4 2- >MoO 4 2- >Cr 2 O 7 2- >NO 2 - ≈NO 3 -

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

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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.

Effect of fluid flow, pH and tobacco extracts concentration as organic inhibitors to corrosion characteristics of AISI 1045 steel in 3.5% NaCl environment containing CO2 gas

Science.gov (United States)

Kurniawan, Budi Agung; Pratiwi, Vania Mitha; Ahmadi, Nafi'ul Fikri

2018-04-01

Corrosion become major problem in most industries. In the oil and gas company, corrosion occurs because of reaction between steel and chemical species inside crude oil. Crude oil or nature gas provide corrosive species, such as CO2, O2, H2S and so on. Fluid containing CO2 gas causes CO2 corrosion which attack steel as well as other corrosion phenomena. This CO2 corrosion commonly called as sweet environment and produce FeCO3 as corrosion products. Fluid flow factor in pipelines during the oil and gas transportation might increase the rate of corrosion itself. Inhibitor commonly use used as corrosion protection because its simplicity in usage. Nowadays, organic inhibitor become main issue in corrosion protection because of biodegradable, low cost, and environmental friendly. This research tried to use tobacco leaf extract as organic inhibitor to control corrosion in CO2 environment. The electrolyte solution used was 3.5% NaCl at pH 4 and pH 7. Weight loss test results showed that the lowest corrosion rate was reach at 132.5 ppm inhibitor, pH 7 and rotational speed of 150 rpm with corrosion rate of 0.091 mm/y. While at pH 4, the lowest corrosion rate was found at rotational speed of 150 rpm with inhibitor concentration of 265 ppm and corrosion rate of 0.327 mm/y. FTIR results indicate the presence of nicotine functional groups on the steel surface. However, based on corrosion rate, it is believed that corrosion occurs, and FeCO3 was soluble in electrolyte. Tobacco leaf extract inhibitors worked by a physisorption mechanism, where tobacco inhibitors formed thin layer on the steel surface.

Wet-gas transport in the Mediterranean Sea. Selection of a combined kinetic hydrate/corrosion inhibitor system

Energy Technology Data Exchange (ETDEWEB)

Zettlitzer, M. [RWE Dea AG, Wietze (Germany); Rozengard, N.; Koeckritz, V. [Technical Univ. Freiberg (Germany); Malt, E. [RWE Dea AG (Egypt)

2007-09-13

Raw gas will be collected on a platform in the centre of the field. Due to volume and weight constraints, condensing fluids will not be separated from the gas on the platform so that the raw gas will be transported in three-phase mode (gas, water, and condensate) via a 33 km long pipeline to a gas treatment plant. Under the calculated pipeline pressure of about 100 barg, hydrate formation is - according to the outcome of thermodynamic simulations - to be expected at temperatures of 19 C and below while the pipeline may cool down to about 15 C in winter conditions. Due to logistical, environmental and economic reasons, RWE Dea decided to inhibit hydrate formation with kinetic hydrate inhibitors (KHI). As the gas also contains carbon dioxide, certain corrosivity was forecasted and addition of a corrosion inhibitor turned out to be necessary. Laboratory tests were carried out to confirm the feasibility of the concept and to define the required dosage of KHI. Service companies were contacted and several kinetic hydrate and corrosion inhibitors were screened. Experiments with the different chemicals were performed at the University of Freiberg in a high-pressure cell at the pipeline pressure of 100 barg. Hydrate formation was detected by continuous pressure registration during temperature changes and by observation through a glass window. In order to preselect the chemicals, first tests were performed with pure methane. These tests also served for calibration of the equipment with literature data and especially as an indication for the minimum chemical concentration required. A second test series was performed with synthetic gas in a composition close to that of the field gas under consideration in order to verify the results obtained with methane. Finally, the optimum kinetic hydrate inhibitor was identified as well as the required dosage concentration. Compatibility of KHI and corrosion inhibitor was experimentally proven. A further set of kinetic inhibitor tests with

Development of an Alternative Corrosion Inhibitor for the Storage of Advanced Gas-Cooled Reactor Fuel

International Nuclear Information System (INIS)

Standring, P.N.; Hands, B.J.; Morgan, S.; Brooks, A.

2015-01-01

Sellafield Lt. currently stores AGR fuel in sodium hyrodxide dosed pool water to pH 11.5 to prevent susceptible AGR fuel from failing due to inter-granular attack. The exception to the above storage practice is Thorp Receipt and Storage (TR&S) where an AGR reprocessing buffer is stored in demineralised water as the expected storage durations were short term (up to 5 years). With the extended shut-down of Thorp, storage durations have increased and this has prompted a re-evaluation of the AGR storage regime in TR&S. The use of sodium hydroxide is not feasible due to a compatibility issue with aluminum components used in LWR storage furniture. The implementation process adopted by Sellafield Ltd in developing an alternative corrosion inhibitor for spent AGR fuel is outlined. The two stranded approach evaluates the impact of candidate corrosion inhibitors on fuel integrity and on plant and processes. The development studies in support of the fuel integrity strand are reported. Candidate inhibitors were first evaluated inactively in terms of their ability to arrest propagating corrosion, radiation stability, compatibility with aluminium and environmental impact. Sodium Nitrate was concluded to be the most promising inhibitor. Sodium nitrate was subsequently tested with active AGR brace material. These studies involved the use of bespoke test equipment and techniques. The studies demonstrated that propagating corrosion could be arrested using 10 ppm nitrate and showed that the resultant nitrate film required relatively high chloride concentrations to break it down over the study duration of 60 days. The development studies to date have provided the confidence that sodium nitrate has the potential to be an effective inhibitor for AGR fuel. The final phase of the fuel integrity strand involves a Lead Container Study using whole AGR pins. A staged approach is being adopted in the study programme where proceeding to a more onerous study is not progressed until positive

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.

Di-n-butylamine as an inhibitor for the corrosion of aluminium alloys in hydrochloric acid solutions

Energy Technology Data Exchange (ETDEWEB)

Unni, V K.V.; Rama Char, T L

1965-01-01

Di-n-butylamine is a satisfactory inhibitor for the corrosion of aluminum-manganese alloy in hydrochloric acid solutions. Polarization studies indicate that the anode polarization is negligible, whereas the cathode polarization is appreciable and is increased by the inhibitor. The Tafel plot holds good in this case. The dissolution of the metal is electrochemical in character; the corrosion process appears to be under cathodic control. The efficiency increases with time, the effect being quite significant up to about 3 hr. It increases with increases in concentration of the inhibitor up to a certain value beyond which it is constant. The values increase with acid concentration up to 1.25 N., and remain practically unchanged thereafter. An acid concentration of 1.25 N. and an inhibitor concentration of 0.5 g per liter of nitrogen can be regarded as the optimum from the viewpoint of efficiency, the value being in the range 57-84%. The efficiency of the inhibitor for the aluminum-manganese alloy is about the same order as for pure aluminum. (10 refs.)

Semiempirical Theoretical Studies of 1,3-Benzodioxole Derivatives as Corrosion Inhibitors

Directory of Open Access Journals (Sweden)

Omnia A. A. El-Shamy

2017-01-01

Full Text Available The efficiency of 1,3-benzodioxole derivatives as corrosion inhibitors is theoretically studied using quantum chemical calculation and Quantitative Structure Activity Relationship (QSAR. Different semiempirical methods (AM1, PM3, MNDO, MINDO/3, and INDO are applied in order to determine the relationship between molecular structure and their corrosion protection efficiencies. Different quantum parameters are obtained as the energy of highest occupied molecular orbital EHOMO, the energy of the lowest unoccupied molecular orbital ELUMO, energy gap ΔEg, dipole moment μ, and Mulliken charge on the atom. QSAR approach is applied to elucidate some important parameters as the hydrophobicity (Log P, surface area (S.A, polarization (P, and hydration energy (EHyd.

Marjoram Extract as Corrosion Inhibitor for Dissolution of Zinc in 1.0 M HCl

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M. Sobhi

2013-01-01

Full Text Available In this study, water marjoram (Origanum marjorana L. extract was evaluated as corrosion inhibitor for zinc in 1.0 M HCl solution. The polarization measurements showed that this inhibitor is acting as mixed inhibitors for both anodic and cathodic reactions. The results showed that the inhibition efficiency was increased by increasing the inhibitor doses and reached the maximum at 500 ppm. The adsorption of marjoram extract on zinc surface was found to obey Langmuir type isotherm. The efficiency obtained from the impedance measurements was in good agreement with those obtained from the gravimetrical, thermometric, and polarization techniques which prove the validity of these tolls in the measurements of the tested inhibitor.

Study of caffeine as corrosion inhibitors of carbon steel in chloride solution containing hydrogen sulfide using electrochemical impedance spectroscopy (EIS)

Science.gov (United States)

Solehudin, Agus; Berman, Ega Taqwali; Nurdin, Isdiriayani

2015-09-01

The corrosion behaviour of steel surface in the absence and presence of caffeine in 3.5% NaCl solution containing dissolved H2S gas is studied using electrochemical impedance spectroscopy (EIS). The experimental results of carbon steel corrosion in 3.5% NaCl solution containing 500 mg/l H2S at different caffeine concentrations showed that corrosion rate of carbon steel decreases with increasing of caffeine concentrations from 0 to 0,1 mmol/l. Whereas, the corrosion rate increase with increasing of caffeine concentrations from 1 to 10 mmol/l. It is clear that no inhibition efficiency increases with increasing inhibitor concentration. The optimum value of inhibition efficiency was 90% at a caffeine concentration of 0.1 mmol/l. This suggests that caffeine's performance as a corrosion inhibitor is more effective at a concentration of 0.1 mmol/l.

Assessment of multi-phase movements in a gas-gathering pipeline and the relevance to on-line, real-time corrosion monitoring and inhibitor injection

Energy Technology Data Exchange (ETDEWEB)

Baker, M.A.; Asperger, R.G.

1988-01-01

A study was conducted to determine the time required for aqueous fluid to travel 100 miles (160 km) from an offshore platform in the Gulf of Mexico to landfill. If this time is short, the corrosivity of the water at landfall may be used as the basis for setting the offshore corrosion inhibitor injection rates. But, for this particular system, the traveling time was found to be long, greater than 65 days. Therefore, the corrosivity as measured on-shore can not be used for online, real-time adjustments of the offshore, corrosion inhibitor chemical pumps.

Effect of Corrosion Inhibitors on In Situ Leak Repair by Precipitation of Calcium Carbonate in Potable Water Pipelines.

Science.gov (United States)

Wang, Fei; Devine, Christina L; Edwards, Marc A

2017-08-01

Corrosion inhibitors can affect calcium carbonate precipitation and associated in situ and in-service water distribution pipeline leak repair via clogging. Clogging of 150 μm diameter leak holes represented by glass capillary tubes, in recirculating solutions that are supersaturated with calcite (Ω calcite = 13), demonstrated that Zn, orthophosphate, tripolyphosphate, and hexametaphosphate corrosion/scaling inhibitors hinder clogging but natural organic matter (NOM) has relatively little impact. Critical concentrations of phosphates that could inhibit leak repair over the short-term in one water tested were: tripolyphophate (0.05 mg/L as P) water systems.

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

Study of benzotriazole as corrosion inhibitors of carbon steel in chloride solution containing hydrogen sulfide using electrochemical impedance spectroscopy (EIS)

Energy Technology Data Exchange (ETDEWEB)

Solehudin, Agus, E-mail: asolehudin@upi.edu [Department of Mechanical Engineering Education, Indonesia University of Education (UPI), Bandung, West Java (Indonesia); Nurdin, Isdiriayani [Department of Chemical Engineering, Bandung Institute of Technology, Bandung, West Java (Indonesia)

2014-03-24

Corrosion and inhibition studies on API 5LX65 carbon steel in chloride solution containing various concentrations of benzotriazole has been conducted at temperature of 70°C using Electrochemical Impedance Spectroscopy (EIS). Corroded carbon steel surface with and without inhibitor have been observed using X-ray Diffraction (XRD), Scanning Electron Microscope (SEM), and Energy Dispersive Spectroscopy (EDS). The objectives of this research are to study the performance of benzotriazole as corrosion inhibitors. The experimental results of carbon steel corrosion in 3.5% NaCl solution containing 500 mg/l H{sub 2}S at different BTAH concentrations showed that corrosion rate of carbon steel decreases with increasing of BTAH concentrations from 0 to 10 mmol/l. The inhibition efficiency of BTAH was found to be affected by its concentration. The optimum efficiency obtained of BTAH is 93% at concentration of 5 mmol/l. The result of XRD and EDS analysis reveal the iron sulfide (FeS) formation on corroded carbon steel surface without inhibitor. The EDS spectrum show the Nitrogen (N) bond on carbon steel surface inhibited by BTAH.

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 ...

Water-base acrylic terpolymer as a corrosion inhibitor for SAE1018 in simulated sour petroleum solution in stagnant and hydrodynamic conditions

International Nuclear Information System (INIS)

Vakili Azghandi, M.; Davoodi, A.; Farzi, G.A.; Kosari, A.

2012-01-01

Highlights: ► Corrosion inhibition of a water-base copolymer, ATP, was studied. ► Efficiency more than 90% was obtained with 0.8 mmol/L ATP in 2000 rpm. ► ATP obeys Langmuir isotherm in static and hydrodynamic conditions. ► With the presence of ATP, OM images showed a decrease in surface attack. - Abstract: The effect of static and hydrodynamic conditions (0–2000 rpm) on corrosion inhibition of a water-base acrylic terpolymer (ATP), methyl methacrylate/butyl acrylate/acrylic acid, for SAE1018 steel in simulated sour petroleum corrosive solution (NACE 1D196) were investigated by AC/DC electrochemical tests. Increase in rotation speed accelerates the corrosion rate; however the corrosion inhibitor efficiency increases. This was attributed to the enhanced mass transport of inhibitor molecules to the metal surface. OM examinations also demonstrate that in presence of ATP, a decrease in corrosion attacks is observed. Thermodynamic calculations also showed that ATP obeys Langmuir adsorption isotherm and adsorbs chemically into the surface.

Effect of inorganic inhibitors on the corrosion behavior of 1018 carbon steel in the LiBr + ethylene glycol + H2O mixture

International Nuclear Information System (INIS)

Samiento-Bustos, E.; Rodriguez, J.G. Gonzalez; Uruchurtu, J.; Dominguez-Patino, G.; Salinas-Bravo, V.M.

2008-01-01

The effect of inorganic inhibitors on the corrosion behavior of 1018 carbon steel in the mixture LiBr (55%) + ethylene glycol + H 2 O at room temperature has been evaluated. Used inhibitors included LiNO 3 (Lithium Nitrate), Li 2 MoO 4 (Lithium Molybdate) and Li 2 CrO 4 (Lithium Chromate) at concentrations of 5, 20 and 50 ppm. Electrochemical techniques included potentiodynamic polarization curves, electrochemical noise resistance (EN) and electrochemical impedance spectroscopy (EIS) measurements. Additionally, adsorption isotherms were calculated. The results obtained showed that both, the corrosion rate and the passive current density decreased with inhibitors, and, in general terms, inhibitors efficiency increased with inhibitor concentration, except in the case of Li 2 CrO 4, where the highest efficiency was obtained with 20 ppm of inhibitor. Pitting potential with 5 ppm of inhibitor, regardless its chemical composition, was more active than in absence of inhibitor, increased at 20 ppm, especially with Li 2 CrO 4 , and remained unaltered with 50 ppm. EN measurements showed that at 5 ppm of inhibitor, the number of film rupture/repassivation events was higher than that obtained at 20 or 50 ppm. Adsorption isotherms suggested a different adsorption mechanism for each inhibitor, whereas EIS results suggested that the corrosion process when nitrates were added was under charge transfer control, but in the case of molybdates or chromates was under diffusion control

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.

Efficiency and corrosion rate analysis of organic inhibitor utilization from bawang dayak leaves (EleutherineamericanaMerr.) on API 5L steel

Science.gov (United States)

Sari, Shaimah Rinda; Sari, Eli Novita; Rizky, Yoel; Sulistijono, Triana, Yunita

2018-05-01

This research studied the inhibition of corrosion by bawang dayak leaves extract (EleutherineamericanaMerr.) on API 5L steel in brine water environment (3.5% NaCl). The inhibitor was extracted using maceration process from bawang dayak leaves that was cultivated in Paser District, East Kalimantan. The test of antioxidant activity showed that bawang dayak leaves extract is a very powerful antioxidant with IC50 value of 27.30204. The results from FTIR test show the presence of electronegative atoms and double bonds of the alkenes groups that provide the potential of the extract as a corrosion inhibitor. Efficiency of inhibition reached up to 93.158% for the addition of inhibitor with 300 ppm concentration and 20 days of immersion time. This inhibitory behavior is also supported by polarization measurements where the lowest corrosion rate of 0.00128 mm/year is obtained at the same concentration and immersion time.

Microencapsulation Technology for Corrosion Mitigation by Smart Coatings

Science.gov (United States)

Buhrow, Jerry; Li, Wenyan; Jolley, Scott; Calle, Luz M.

2011-01-01

A multifunctional, smart coating for the autonomous control of corrosion is being developed based on micro-encapsulation technology. Corrosion indicators as well as corrosion inhibitors have been incorporated into microcapsules, blended into several paint systems, and tested for corrosion detection and protection effectiveness. This paper summarizes the development, optimization, and testing of microcapsules specifically designed to be incorporated into a smart coating that will deliver corrosion inhibitors to mitigate corrosion autonomously. Key words: smart coating, corrosion inhibition, microencapsulation, microcapsule, pH sensitive microcapsule, corrosion inhibitor, corrosion protection pain

Corrosion and corrosion control

International Nuclear Information System (INIS)

Khanna, A.S.; Totlani, M.K.

1995-01-01

Corrosion has always been associated with structures, plants, installations and equipment exposed to aggressive environments. It effects economy, safety and product reliability. Monitoring of component corrosion has thus become an essential requirement for the plant health and safety. Protection methods such as appropriate coatings, cathodic protection and use of inhibitors have become essential design parameters. High temperature corrosion, especially hot corrosion, is still a difficult concept to accommodate in corrosion allowance; there is a lack of harmonized system of performance testing of materials at high temperatures. In order to discuss and deliberate on these aspects, National Association for Corrosion Engineers International organised a National Conference on Corrosion and its Control in Bombay during November 28-30, 1995. This volume contains papers presented at the symposium. Paper relevant to INIS is indexed separately. refs., figs., tabs

Electrochemical Study on Newly Synthesized Chlorocurcumin as an Inhibitor for Mild Steel Corrosion in Hydrochloric Acid

Directory of Open Access Journals (Sweden)

Ahmed A. Al-Amiery

2013-11-01

Full Text Available A new curcumin derivative, i.e., (1E,4Z,6E-5-chloro-1,7-bis(4-hydroxy-3-methoxyphenylhepta-1,4,6-trien-3-one (chlorocurcumin, was prepared starting with the natural compound curcumin. The newly synthesized compound was characterized by elemental analysis and spectral studies (IR, 1H-NMR and 13C-NMR. The corrosion inhibition of mild steel in 1 M HCl by chlorocurcumin has been studied using potentiodynamic polarization (PDP measurements and electrochemical impedance spectroscopy (EIS. The inhibition efficiency increases with the concentration of the inhibitor but decreases with increases in temperature. The potentiodynamic polarization reveals that chlorocurcumin is a mixed-type inhibitor. The kinetic parameters for mild steel corrosion were determined and discussed.

Electrochemical Study on Newly Synthesized Chlorocurcumin as an Inhibitor for Mild Steel Corrosion in Hydrochloric Acid

Science.gov (United States)

Al-Amiery, Ahmed A.; Kadhum, Abdul Amir H.; Mohamad, Abu Bakar; Musa, Ahmed Y.; Li, Cheong Jiun

2013-01-01

A new curcumin derivative, i.e., (1E,4Z,6E)-5-chloro-1,7-bis(4-hydroxy-3-methoxyphenyl)hepta-1,4,6-trien-3-one (chlorocurcumin), was prepared starting with the natural compound curcumin. The newly synthesized compound was characterized by elemental analysis and spectral studies (IR, 1H-NMR and 13C-NMR). The corrosion inhibition of mild steel in 1 M HCl by chlorocurcumin has been studied using potentiodynamic polarization (PDP) measurements and electrochemical impedance spectroscopy (EIS). The inhibition efficiency increases with the concentration of the inhibitor but decreases with increases in temperature. The potentiodynamic polarization reveals that chlorocurcumin is a mixed-type inhibitor. The kinetic parameters for mild steel corrosion were determined and discussed. PMID:28788402

Corrosion/96 conference papers

International Nuclear Information System (INIS)

Anon.

1996-01-01

Topics covered by this conference include: cathodic protection in natural waters; cleaning and repassivation of building HVAC systems; worldwide opportunities in flue gas desulfurization; advancements in materials technology for use in oil and gas service; fossil fuel combustion and conversion; technology of corrosion inhibitors; computers in corrosion control--modeling and information processing; recent experiences and advances of austenitic alloys; managing corrosion with plastics; corrosion measurement technology; corrosion inhibitors for concrete; refining industry; advances in corrosion control for rail and tank trailer equipment; CO 2 corrosion--mechanisms and control; microbiologically influenced corrosion; corrosion in nuclear systems; role of corrosion in boiler failures; effects of water reuse on monitoring and control technology in cooling water applications; methods and mechanisms of scale and deposit control; corrosion detection in petroleum production lines; underground corrosion control; environmental cracking--relating laboratory results and field behavior; corrosion control in reinforced concrete structures; corrosion and its control in aerospace and military hardware; injection and process addition facilities; progress reports on the results of reinspection of deaerators inspected or repaired per RP0590 criteria; near 100% volume solids coating technology and application methods; materials performance in high temperature environments containing halides; impact of toxicity studies on use of corrosion/scale inhibitors; mineral scale deposit control in oilfield related operations; corrosion in gas treating; marine corrosion; cold climate corrosion; corrosion in the pulp and paper industry; gaseous chlorine alternatives in cooling water systems; practical applications of ozone in recirculating cooling water systems; and water reuse in industry. Over 400 papers from this conference have been processed separately for inclusion on the data base

Holographic interferometry as electrochemical emission spectroscopy of carbon steel in seawater with low concentration of RA-41 corrosion inhibitor

International Nuclear Information System (INIS)

Habib, K.; Al-Muhana, K.; Habib, A.

2009-01-01

In the present investigation, holographic interferometry was utilized for the first time to determine the rate change of the number of the fringe evolutions during the corrosion test of carbon steel in blank seawater and with seawater with different concentrations of a corrosion inhibitor. In other words, the anodic dissolution behaviors (corrosion) of the carbon steel were determined simultaneously by holographic interferometry, an electromagnetic method, and by the electrochemical impedance (EI) spectroscopy, an electronic method. So, the abrupt rate change of the number of the fringe evolutions during corrosion test (EI) spectroscopy, of the carbon steel is called electrochemical emission spectroscopy. The corrosion process of the steel samples was carried out in blank seawater and seawater with different concentrations, 5-20 ppm, of RA-41 corrosion inhibitor using the EI spectroscopy method, at room temperature. The electrochemical emission spectra of the carbon steel in different solutions represent a detailed picture of the rate change of the anodic dissolution of the steel throughout the corrosion processes. Furthermore, the optical interferometry data of the carbon steel were compared to the data, which were obtained from the EI spectroscopy. Consequently, holographic interferometric is found very useful for monitoring the anodic dissolution behaviors of metals, in which the number of the fringe evolutions of the steel samples can be determined in situ. (Author)

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

Directory of Open Access Journals (Sweden)

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.

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

Bio-testing integral toxicity of corrosion inhibitors, biocides and oil hydrocarbons in oil-and gas-processing industry

Energy Technology Data Exchange (ETDEWEB)

Chugunov, V.A.; Kholodenko, V.P.; Irkhina, I.A.; Fomchenkov, V.M.; Novikov, I.A. [State Research Center for Applied Microbiology, Obolensk, Moscow (Russian Federation)

2004-07-01

In recent years bioassays have been widely used for assessing levels of contamination of the environment. This is due to the fact that test-organisms provide a general response to toxicants present in samples. Based on microorganisms as test objects, it is possible to develop cheap, sensitive and rapid assays to identify environmental xenobiotics and toxicants. The objective of the research was to develop different microbiological assays for assessing integral toxicity of water environments polluted with corrosion inhibitors, biocides and hydrocarbons in oil- and gas-processing industry. Bio-luminescent, electro-orientational, osmo-optic and microorganism reducing activity assays were used for express evaluation of integral toxicity. They are found to determine promptly integral toxicity of water environments containing various pollutants (oil, oil products, corrosion inhibitors, biocides). Results conclude that the assays may be used for analyzing integral toxicity of water polluted with hydrocarbons, as well as for monitoring of water changes as a result of biodegradation of pollutants by microorganisms and their associations. Using a kit of different assays, it is also possible to evaluate ecological safety of biocides, corrosion inhibitors, and their compositions. Bioassays used as a kit are more effective than each assay individually, allowing one to get complete characterization of a reaction of bacterial test organisms to different environments. (authors)

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)

Corrosion inhibitors for neutral aqueous media based on the products on sugar cane processing. 1.Furfural derivatives as inhibitors

International Nuclear Information System (INIS)

Ledovskikh, V.M.; Kamekho Khinnebra, Kh.Kh.

1993-01-01

A series of carboxy-, nitrogen- and nitroderivaties of furfural - the main product of sugar cane processing (furancasboxylic acid, 5-nitrofurancarboxylic acid and its salts, furfurine, furfurylamine) was studied as inhibitors of iron and copper, corrosion in aqueous-salt media. Nitrofuroates of sodium and ammonium, which decelerate anode process, intensity cathode one and provide the stable passive state, are considered to be the most effective

Moessbauer and ESCA investigations on the formation of oxidic iron phases in aqueous solution under the influence of organic corrosion inhibitors

International Nuclear Information System (INIS)

Guetlich, P.; Meisel, W.; Mohs, E.

1982-01-01

Corrosions layers on steel grown in water of well defined hardness and chloride concentration were studied by Moessbauer and ESCA spectroscopy with particular emphasis on the influence of added organic inhibitors. Relatively thick layers were found with an unexpectedly small iron content (as FeOOH). The layers contain a remarkable amount of constituent ions from the solution and fragments of the inhibitors. The latter seem to be decomposed by the corrosive medium. It is assumed that the whole organic molecule determines the kind of transportation of the inhibitor to the iron metal, but that the inhibition itself is due to functional groups only. (orig.) [de

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

Directory of Open Access Journals (Sweden)

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.

Inhibitor for the Corrosion of Mild Steel in H 2 SO 4 | Patel | South ...

African Journals Online (AJOL)

An extract of Terminalia chebula fruits was investigated as a corrosion inhibitor of mild steel in 0.5 M H2SO4 by means of conventional mass loss, electrochemical polarization, electrochemical impedance spectroscopy and scanning electron microscopy. The mass loss results showed that the extract of Terminalia chebula is ...

Portable electrochemical system using screen-printed electrodes for monitoring corrosion inhibitors.

Science.gov (United States)

Squissato, André L; Silva, Weberson P; Del Claro, Augusto T S; Rocha, Diego P; Dornellas, Rafael M; Richter, Eduardo M; Foster, Christopher W; Banks, Craig E; Munoz, Rodrigo A A

2017-11-01

This work presents a portable electrochemical system for the continuous monitoring of corrosion inhibitors in a wide range of matrices including ethanol, seawater and mineral oil following simple dilution of the samples. Proof-of-concept is demonstrated for the sensing of 2,5-dimercapto-1,3,5-thiadiazole (DMCT), an important corrosion inhibitor. Disposable screen-printed graphitic electrodes (SPGEs) associated with a portable batch-injection cell are proposed for the amperometric determination of DMCT following sample dilution with electrolyte (95% v/v ethanol + 5% v/v 0.1molL -1 H 2 SO 4 solution). This electrolyte was compatible with all samples and the organic-resistant SPGE could be used continuously for more than 200 injections (100µL injected at 193µLs -1 ) free from effects of adsorption of DMCT, which have a great affinity for metallic surfaces, and dissolution of the other reported SPGE inks which has hampered prior research efforts. Fast (180h -1 ) and precise responses (RSD < 3% n = 10) with a detection limit of 0.3µmolL -1 was obtained. The accuracy of the proposed method was attested through recovery tests (93-106%) and the reasonable agreement of results of DMCT concentrations in samples analyzed by both proposed and spectrophotometric (comparative) methods. Copyright © 2017 Elsevier B.V. All rights reserved.

EFFECTIVENESS OF INHIBITORS OF METAL CORROSION IN AQUEOUS ENVIRONMENTS WITH VARYING SALINITY

OpenAIRE

Носачова, Юлія Вікторівна; Макаренко, Ірина Миколаївна; Шаблій, Тетяна Олександрівна

2015-01-01

EFFECTIVENESS OF INHIBITORS OF METAL CORROSION IN AQUEOUS ENVIRONMENTS WITH VARYING SALINITYThe main reason for the growing problem of water quality in Ukraine is the increase of anthropogenic impacts on water resources caused by intense chemical, biological and radiation contamination of existing and potential sources for industrial and communal water supply. Especially polluted rivers in Donbass and Krivbas area, that turned into collectors of saline wastewater. Especially hard environment...

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

Directory of Open Access Journals (Sweden)

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.

Lithium salts as leachable corrosion inhibitors and potential replacement for hexavalent chromium in organic coatings for the protection of aluminum alloys

NARCIS (Netherlands)

Visser, P; Liu, Y; Terryn, H.A.; Mol, J.M.C.

2016-01-01

Lithium salts are being investigated as leachable corrosion inhibitor and potential replacement for hexavalent chromium in organic coatings. Model coatings loaded with lithium carbonate or lithium oxalate demonstrated active corrosion inhibition and the formation of a protective layer in a

Effect of inorganic inhibitors on the corrosion behavior of 1018 carbon steel in the LiBr + ethylene glycol + H{sub 2}O mixture

Energy Technology Data Exchange (ETDEWEB)

Samiento-Bustos, E. [Centro de Investigacion en Ingenieria y Ciencias Aplicadas, Universidad Autonoma del Estado de Morelos. Av. Universidad 1001, Col. Chamilpa, CP 62210, Cuernavaca, Morelos (Mexico); Rodriguez, J.G. Gonzalez [Centro de Investigacion en Ingenieria y Ciencias Aplicadas, Universidad Autonoma del Estado de Morelos. Av. Universidad 1001, Col. Chamilpa, CP 62210, Cuernavaca, Morelos (Mexico)], E-mail: ggonzalez@uaem.mx; Uruchurtu, J. [Centro de Investigacion en Ingenieria y Ciencias Aplicadas, Universidad Autonoma del Estado de Morelos. Av. Universidad 1001, Col. Chamilpa, CP 62210, Cuernavaca, Morelos (Mexico); Dominguez-Patino, G. [Centro de Investigacion en Ingenieria y Ciencias Aplicadas, Universidad Autonoma del Estado de Morelos. Av. Universidad 1001, Col. Chamilpa, CP 62210, Cuernavaca, Morelos (Mexico); U.A.E.M. Facultad de Ciencias Quimicas e Ingenieria, Av. Universidad 1001, 62209, Cuernavaca, Morelos (Mexico); Salinas-Bravo, V.M. [Instituto de Investigaciones Electricas, Gerencia de Materiales y Proceso Quimicos, Av. Reforma 113, Col. Palmira, CP 62490, Cuernavaca, Morelos (Mexico)

2008-08-15

The effect of inorganic inhibitors on the corrosion behavior of 1018 carbon steel in the mixture LiBr (55%) + ethylene glycol + H{sub 2}O at room temperature has been evaluated. Used inhibitors included LiNO{sub 3} (Lithium Nitrate), Li{sub 2}MoO{sub 4} (Lithium Molybdate) and Li{sub 2}CrO{sub 4} (Lithium Chromate) at concentrations of 5, 20 and 50 ppm. Electrochemical techniques included potentiodynamic polarization curves, electrochemical noise resistance (EN) and electrochemical impedance spectroscopy (EIS) measurements. Additionally, adsorption isotherms were calculated. The results obtained showed that both, the corrosion rate and the passive current density decreased with inhibitors, and, in general terms, inhibitors efficiency increased with inhibitor concentration, except in the case of Li{sub 2}CrO{sub 4,} where the highest efficiency was obtained with 20 ppm of inhibitor. Pitting potential with 5 ppm of inhibitor, regardless its chemical composition, was more active than in absence of inhibitor, increased at 20 ppm, especially with Li{sub 2}CrO{sub 4}, and remained unaltered with 50 ppm. EN measurements showed that at 5 ppm of inhibitor, the number of film rupture/repassivation events was higher than that obtained at 20 or 50 ppm. Adsorption isotherms suggested a different adsorption mechanism for each inhibitor, whereas EIS results suggested that the corrosion process when nitrates were added was under charge transfer control, but in the case of molybdates or chromates was under diffusion control.

2-Butyne-1,4-diol as a novel corrosion inhibitor for API X65 steel pipeline in carbonate/bicarbonate solution

International Nuclear Information System (INIS)

Sadeghi Meresht, E.; Shahrabi Farahani, T.; Neshati, J.

2012-01-01

Highlights: ► Corrosion of API 5L X65 is effectively reduced by the addition of the inhibitor. ► The techniques include weight loss, potentiodynamic polarization, EIS and AFM. ► 2-Butyne-1,4-diol acts as a mixed-type inhibitor. ► The adsorption of 2-butyne-1,4-diol obeys Langmuir adsorption isotherm. - Abstract: The inhibition effects of 2-butyne-1,4-diol on the corrosion susceptibility of grade API 5L X65 steel pipeline in 2 M Na 2 CO 3 /1 M NaHCO 3 solution were studied by electrochemical techniques and weight loss measurements. The results indicated that this inhibitor was a mixed-type inhibitor, with a maximum percentage inhibition efficiency of approximately 92% in the presence of 5 mM inhibitor. Atomic force microscopy revealed that a protective film was formed on the surface of the inhibited sample. The adsorption of the inhibitor was found to conform to the Langmuir isotherm with the standard adsorption free energy of −21.08 kJ mol −1 .

Corrosion probe. Innovative technology summary report

International Nuclear Information System (INIS)

1999-05-01

Over 253 million liters of high-level waste (HLW) generated from plutonium production is stored in mild steel tanks at the Department of Energy (DOE) Hanford Site. Corrosion monitoring of double-shell storage tanks (DSTs) is currently performed at Hanford using a combination of process knowledge and tank waste sampling and analysis. Available technologies for corrosion monitoring have progressed to a point where it is feasible to monitor and control corrosion by on-line monitoring of the corrosion process and direct addition of corrosion inhibitors. The electrochemical noise (EN) technique deploys EN-based corrosion monitoring probes into storage tanks. This system is specifically designed to measure corrosion rates and detect changes in waste chemistry that trigger the onset of pitting and cracking. These on-line probes can determine whether additional corrosion inhibitor is required and, if so, provide information on an effective end point to the corrosion inhibitor addition procedure. This report describes the technology, its performance, its application, costs, regulatory and policy issues, and lessons learned

Investigation of some green compounds as corrosion and scale inhibitors for cooling systems

Energy Technology Data Exchange (ETDEWEB)

Quraishi, M.A.; Farooqi, I.H.; Saini, P.A. (Aligarh Muslim Univ. (India))

1999-05-01

The performance of an open-recirculating cooling system, an important component in most industries, is affected by corrosion and scale formation. Numerous additives have been used in the past for the control of corrosion and scale formation. Effects of the naturally occurring compounds azadirachta indica (leaves), punica granatum (shell), and momordica charantia (fruits), on corrosion of mild steel in 3% sodium chloride (NaCl) were assessed using weight loss, electrochemical polarization, and impedance techniques. Extracts of the compounds exhibited excellent inhibition efficiencies comparable to that of hydroxyethylidine diphosphonic acid (HEDP), the most preferred cooling water inhibitor. The compounds were found effective under static and flowing conditions. Extracts were quite effective in retarding formation of scales, and the maximum antiscaling efficiency was exhibited by the extract of azadirachta indica (98%). The blowdown of the cooling system possessed color and chemical oxygen demand (COD). Concentrations of these parameters were reduced by an adsorption process using activated carbon as an adsorbent.

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...

Ceria nanoparticles vis-à-vis cerium nitrate as corrosion inhibitors for silica-alumina hybrid sol-gel coating

Energy Technology Data Exchange (ETDEWEB)

Lakshmi, R.V. [Surface Engineering Division, Council of Scientific and Industrial Research – National Aerospace Laboratories, HAL Airport Road, Kodihalli, Bengaluru 560017 (India); Aruna, S.T., E-mail: staruna194@gmail.com [Surface Engineering Division, Council of Scientific and Industrial Research – National Aerospace Laboratories, HAL Airport Road, Kodihalli, Bengaluru 560017 (India); Sampath, S. [Department of Inorganic and Physical Chemistry, Indian Institute of Science, Bengaluru 560012 (India)

2017-01-30

Highlights: • Corrosion protection efficiency comparison of ceria nanoparticles and cerium nitrate. • Silica-alumina hybrid coating exhibited good barrier protection. • Detailed XPS study confirm the hybrid structure and presence of Ce species in coating. • Loss of cerium ions not prevalent in ceria doped coating unlike that of cerium nitrate. • Ceria increased the coating integrity, corrosion inhibition and barrier protection. - Abstract: The present work provides a comparative study on the corrosion protection efficiency of defect free sol-gel hybrid coating containing ceria nanoparticles and cerium nitrate ions as corrosion inhibitors. Less explored organically modified alumina-silica hybrid sol-gel coatings are synthesized from 3-glycidoxypropyltrimethoxysilane and aluminium-tri-sec-butoxide. The microemulsion derived nanoparticles and the hybrid coatings are characterized and compared with coatings containing cerium nitrate. Corrosion inhibiting capability is assessed using electrochemical impedance spectroscopy. Scanning Kelvin probe measurements are also conducted on the coatings for identifying the apparent corrosion prone regions. Detailed X-ray photoelectron spectroscopy (XPS) analysis is carried out to comprehend the bonding and corrosion protection rendered by the hybrid coatings.

Evaluation of some non-toxic thiadiazole derivatives as bronze corrosion inhibitors in aqueous solution

International Nuclear Information System (INIS)

Varvara, Simona; Muresan, Liana Maria; Rahmouni, Kamal; Takenouti, Hisasi

2008-01-01

The inhibiting effect of four innoxious thiadiazole derivatives (2-mercapto-5-amino-1,3,4-thiadiazole (MAT), 2-mercapto-5-acetylamino-1,3,4-thiadiazole (MAcAT), 2-mercapto-5-methyl-1,3,4-thiadiazole (MMeT) and 2-mercapto-5-phenylamino-1,3,4-thiadiazole (MPhAT)) on bronze corrosion in an aerated solution of 0.2 g L -1 Na 2 SO 4 + 0.2 g L -1 NaHCO 3 at pH 5 was studied by potentiodynamic voltammetry and electrochemical impedance spectroscopy. The corrosion parameters determined from the polarisation curves indicate that the addition of the investigated thiadiazole derivatives decreases both cathodic and anodic current densities, due to an inhibition of the corrosion process, through the adsorption of thiadiazoles on the bronze surface. The inhibiting effect of the investigated organic compounds appears to be more pronounced on the anodic process than on the cathodic one and, except for the case MPhAT, it is enhanced by the increases of the inhibitors' concentration. The adsorption of the thiadiazole derivatives on bronze was confirmed by the presence of the nitrogen atoms in the EDX spectra of the bronze exposed to inhibitor-containing solutions. The magnitude of polarisation resistance values and, consequently, the inhibition efficiencies are influenced by the molecular structure of thiadiazole derivatives. The strongest inhibition was noticed in the presence of compounds with phenyl amino- or amino-functionalities in their molecules. The maximum protection efficiencies were obtained by addition of: 5 mM MAT (95.9%), 1 mM MAcAT (95.7%), 5 mM MMeT (92.6%) and 0.1 mM MPhAT (97%). EIS measurements also revealed that the inhibitor effectiveness of the optimal concentrations of thiadiazole is time-dependent

Evaluation of some non-toxic thiadiazole derivatives as bronze corrosion inhibitors in aqueous solution

Energy Technology Data Exchange (ETDEWEB)

Varvara, Simona [Department of Topography, ' 1 Decembrie 1918' University, 11-13 Nicolae Iorga Street, 510009 Alba Iulia (Romania); Muresan, Liana Maria [Department of Physical Chemistry, ' Babes-Bolyai' University, 11 Arany-Janos Street, 400028 Cluj-Napoca (Romania)], E-mail: limur@chem.ubbcluj.ro; Rahmouni, Kamal; Takenouti, Hisasi [UPMC LISE - UPR 15 of the CNRS, ' Pierre and Marie Curie' University, Paris (France)

2008-09-15

The inhibiting effect of four innoxious thiadiazole derivatives (2-mercapto-5-amino-1,3,4-thiadiazole (MAT), 2-mercapto-5-acetylamino-1,3,4-thiadiazole (MAcAT), 2-mercapto-5-methyl-1,3,4-thiadiazole (MMeT) and 2-mercapto-5-phenylamino-1,3,4-thiadiazole (MPhAT)) on bronze corrosion in an aerated solution of 0.2 g L{sup -1} Na{sub 2}SO{sub 4} + 0.2 g L{sup -1} NaHCO{sub 3} at pH 5 was studied by potentiodynamic voltammetry and electrochemical impedance spectroscopy. The corrosion parameters determined from the polarisation curves indicate that the addition of the investigated thiadiazole derivatives decreases both cathodic and anodic current densities, due to an inhibition of the corrosion process, through the adsorption of thiadiazoles on the bronze surface. The inhibiting effect of the investigated organic compounds appears to be more pronounced on the anodic process than on the cathodic one and, except for the case MPhAT, it is enhanced by the increases of the inhibitors' concentration. The adsorption of the thiadiazole derivatives on bronze was confirmed by the presence of the nitrogen atoms in the EDX spectra of the bronze exposed to inhibitor-containing solutions. The magnitude of polarisation resistance values and, consequently, the inhibition efficiencies are influenced by the molecular structure of thiadiazole derivatives. The strongest inhibition was noticed in the presence of compounds with phenyl amino- or amino-functionalities in their molecules. The maximum protection efficiencies were obtained by addition of: 5 mM MAT (95.9%), 1 mM MAcAT (95.7%), 5 mM MMeT (92.6%) and 0.1 mM MPhAT (97%). EIS measurements also revealed that the inhibitor effectiveness of the optimal concentrations of thiadiazole is time-dependent.

Alkaloids extract of Retama monosperma (L.) Boiss. seeds used as novel eco-friendly inhibitor for carbon steel corrosion in 1 M HCl solution: Electrochemical and surface studies

Energy Technology Data Exchange (ETDEWEB)

El Hamdani, Naoual; Fdil, Rabiaa [Laboratoire de Chimie Bioorganique, Faculté des Sciences, Université Chouaib Doukkali, B.P. 20, M-24000 El Jadida (Morocco); Tourabi, Mustapha [Laboratoire de Catalyse et de Corrosion des Matériaux (LCCM), Faculté des Sciences, Université Chouaib Doukkali, B.P. 20, M-24000 El Jadida (Morocco); Jama, Charafeddine [UMET-PSI, CNRS UMR 8207, ENSCL, Université Lille 1, CS 90108, F-59652 Villeneuve d’Ascq Cedex (France); Bentiss, Fouad, E-mail: fbentiss@enscl.fr [Laboratoire de Catalyse et de Corrosion des Matériaux (LCCM), Faculté des Sciences, Université Chouaib Doukkali, B.P. 20, M-24000 El Jadida (Morocco); UMET-PSI, CNRS UMR 8207, ENSCL, Université Lille 1, CS 90108, F-59652 Villeneuve d’Ascq Cedex (France)

2015-12-01

Graphical abstract: - Highlights: • AERS is good eco-friendly corrosion inhibitor for carbon steel in 1 M HCl. • AERS acts as mixed-type inhibitor in 1 M HCl medium. • AERS adsorption is well described by Langmuir isotherm. • Surface analyses were used to explain the AERS mechanism of carbon steel corrosion inhibition. - Abstract: Current research efforts now focus on the development of non-toxic, inexpensive and environmentally friendly corrosion inhibitors as alternatives to different organic and non-organic compounds. In this field, alkaloids extract of Retama monosperma (L.) Boiss. seeds (AERS) was tested for the first time as corrosion inhibitor for carbon steel in 1 M HCl medium using electrochemical and surface characterization techniques. The obtained results showed that this plant extract's acts as an efficient corrosion inhibitor for carbon steel in 1 M HCl and an inhibition efficiency of 94.4% was reached with 400 mg/L of AERS at 30 °C. Ac impedance experimental data revealed a frequency distribution of the capacitance, simulated as constant phase element. Impedance results demonstrated that the addition of the AERS 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. Polarization curves indicated that AERS is a mixed inhibitor. Adsorption of such alkaloid extract on the steel surface obeyed to the Langmuir adsorption isotherm. X-ray photoelectron spectroscopy (XPS) showed that the inhibition of steel corrosion in normal hydrochloric solution by AERS is mainly controlled by a physisorption process and the inhibitive layer is composed of an iron oxide/hydroxide mixture where AERS molecules are incorporated.

Substituted sodium phenylanthranylates as inhibitors of corrosion in chloride solutions

Energy Technology Data Exchange (ETDEWEB)

Kuznetsov, Yu.I.; Fialkov, Yu.A.; Popova, L.I.; Ehndel' man, E.S.; Kuznetsova, I.G. (AN SSSR, Moscow. Inst. Fizicheskoj Khimii)

The efficiency of corrosion protection of armco iron, zinc (Ts-O) aluminium (AB 000) and its alloys (.D16 and AMG6) with sodium phenylanthranylate derivatives in chloride buffer solutions (pH 7.4-8.08) are investigated. It has been ascertained that the introduction of sodium phenylanthranylate into phenyl radical in m- and p-position relative to the amino group of electron-seeking substitutes improves protective properties of an inhibitor. The inhibiting effect of phenylanthranylates and its dependence on electron structure enchances in zinc-aluminium-iron series and decreases in case of transition from pure aluminium to its alloys.

Substituted sodium phenylanthranylates as inhibitors of corrosion in chloride solutions

International Nuclear Information System (INIS)

Kuznetsov, Yu.I.; Fialkov, Yu.A.; Popova, L.I.; Ehndel'man, E.S.; Kuznetsova, I.G.

1982-01-01

The efficiency of corrosion protoction of armco iron, zinc (Ts-O) aluminium (AB 000) and its alloys (.D16 and AMG6) with sodium phenylanthranylate derivatives in clloride buffer solutions (pH 7.4-8.08) are investigated. It has been ascertained that the introduction of sodium phenylantiranylate into phenyl radical in m- and p-position relative to the amino group of electron-seeking substitutes improves protective properties of an inhibitor. The inhibiting effect of phenylanthranylates and its dependence on electron structure enchances in zinc-aluminium-iron series and decreases in case of transition from pure aluminium to its alloys

2-Butyne-1,4-diol as a novel corrosion inhibitor for API X65 steel pipeline in carbonate/bicarbonate solution

Energy Technology Data Exchange (ETDEWEB)

Sadeghi Meresht, E. [Materials Engineering Department, Faculty of Engineering, Tarbiat Modares University, 1411713114, Tehran (Iran, Islamic Republic of); Shahrabi Farahani, T., E-mail: tshahrabi34@modares.ac.ir [Materials Engineering Department, Faculty of Engineering, Tarbiat Modares University, 1411713114, Tehran (Iran, Islamic Republic of); Neshati, J. [Research Institute of Petroleum Industry, RIPI, 1485733111, Tehran (Iran, Islamic Republic of)

2012-01-15

Highlights: Black-Right-Pointing-Pointer Corrosion of API 5L X65 is effectively reduced by the addition of the inhibitor. Black-Right-Pointing-Pointer The techniques include weight loss, potentiodynamic polarization, EIS and AFM. Black-Right-Pointing-Pointer 2-Butyne-1,4-diol acts as a mixed-type inhibitor. Black-Right-Pointing-Pointer The adsorption of 2-butyne-1,4-diol obeys Langmuir adsorption isotherm. - Abstract: The inhibition effects of 2-butyne-1,4-diol on the corrosion susceptibility of grade API 5L X65 steel pipeline in 2 M Na{sub 2}CO{sub 3}/1 M NaHCO{sub 3} solution were studied by electrochemical techniques and weight loss measurements. The results indicated that this inhibitor was a mixed-type inhibitor, with a maximum percentage inhibition efficiency of approximately 92% in the presence of 5 mM inhibitor. Atomic force microscopy revealed that a protective film was formed on the surface of the inhibited sample. The adsorption of the inhibitor was found to conform to the Langmuir isotherm with the standard adsorption free energy of -21.08 kJ mol{sup -1}.

Corrosion studies on PREPP waste form

International Nuclear Information System (INIS)

Welch, J.M.; Neilson, R.M. Jr.

1984-05-01

Deformation or Failure Test and Accelerated Corrosion Test procedures were conducted to investigate the effect of formulation variables on the corrosion of oversize waste in Process Experimental Pilot Plant (PREPP) concrete waste forms. The Deformation or Failure Test did not indicate substantial waste form swelling from corrosion. The presence or absence of corrosion inhibitor was the most significant factor relative to measured half-cell potentials identified in the Accelerated Corrosion Test. However, corrosion inhibitor was determined to be only marginally beneficial. While this study produced no evidence that corrosion is of sufficient magnitude to produce serious degradation of PREPP waste forms, the need for corrosion rate testing is suggested. 11 references, 4 figures, 8 tables

Corrosion resistance of API 5L grade B steel with taro leaf (Colocasia esculenta) addition as corrosion inhibitor in HCl 0.1 M

Science.gov (United States)

Lestari, Yulinda; Priyotomo, Gadang

2018-05-01

Taro leaf (Colocasia esculenta) has the potential to be used as a corrosion inhibitor because it has a substance called polyphenol that binds to the hydroxyl group and essential amino acids. Taro leaf extract is taken by maceration method. In this study, the specimen was steel API 5L grade B that would measured the corosivity in 0.1 M HCl solution + taro leaf extract with a specific concentration (in ppm). Tests conducted by FTIR method taro leaves, potentiodynamic polarization (Tafel) and Electrochemical Impedance Spectroscopy (EIS). Based on the results revealed that there is a phenolic group in taro leaves, which has polyphenol content 0.053 % (mg/100 mg). The optimum composition of taro leaf extract is 4000 ppm which generate corrosion rate value of 30.22 mpy and efficiency inhibitor performance of 72.7 %. In this study, the Kads value of taro leaf extract ranged from 0.885 to greater than Kads value of ginger extract in hydrochloric acid solution. The high Kads values indicate a more efficient process of adsorption and better value of inhibition efficiency.

Study of low cost eco-friendly compounds as corrosion inhibitors for cooling systems

Energy Technology Data Exchange (ETDEWEB)

Farooqi, I H; Hussain, A; Saini, P A [AMU, Aligarh (India). Dept. of Civil Engineering; Quraishi, M A [AMU, Aligarh (India). Dept. of Applied Chemistry

1999-07-01

Attempts are made to utilize the aqueous extracts of natural compounds, namely cordia latifolia and curcumin, as corrosion inhibitors for mild steel in cooling systems, and their inhibition efficiencies are compared with that of Hydroxyethylidene 1-1 diphosphonic acid (HEDP). HEDP is also blended with aqueous extracts of natural compounds so as to improve their inhibition efficiency. The blowdown of the cooling system is also analysed for environmental factors. (author)

Evaluation of self-healing ability in protective coatings modified with combinations of layered double hydroxides and cerium molibdate nanocontainers filled with corrosion inhibitors

International Nuclear Information System (INIS)

Montemor, M.F.; Snihirova, D.V.; Taryba, M.G.; Lamaka, S.V.; Kartsonakis, I.A.; Balaskas, A.C.; Kordas, G.C.; Tedim, J.; Kuznetsova, A.; Zheludkevich, M.L.; Ferreira, M.G.S.

2012-01-01

Nowadays, there is a strong demand on the search of thinner, but more effective organic coatings for corrosion protection of metallic substrates, like galvanised steel, used in the automotive industry. In order to guarantee effective corrosion protection of these coatings, and because chromate-based pigments cannot be used, one of the most attractive strategies consists on the modification of the organic matrix with nano-additives filled with corrosion inhibitors, which can be released to the active sites. In this work, two different nano-additives are explored as potential self-healing materials for the development of active protective coatings. These additives are layered double hydroxides and cerium molybdate hollow nanospheres loaded with mercaptobenzothiazole, as a corrosion inhibitor. These additives were added to epoxy primers, individually, or combining the two nanoadditives in the same layer. The electrochemical behaviour and the potential of self-healing ability were studied by electrochemical impedance spectroscopy, scanning vibrating electrode technique and scanning ion-selective electrode technique. The results reveal that both types of nanocontainers can provide effective corrosion inhibition on artificial induced defects, at different stages of the degradation process. Moreover, the results also show that there is a synergistic effect concerning corrosion inhibition and self-healing potential when a mixture of the two nanocontainers is used. The mechanism of self healing is presented and discussed in terms of effect of organic inhibitor and role of the nanocontainers, including effect of cerium ions released from cerium molibdate nanoparticles.

Study on improvement of durability for reinforced concrete by surface-painting migrating corrosion inhibitor and engineering application

Science.gov (United States)

Song, Ning; WANG, Zixiao; LIU, Zhiyong; Zhou, Jiyuan; Zheng, Duo

2017-01-01

The corrosion currents of steel bar in concrete with three W/B and four chloride contents after surface-painting two migrating corrosion inhibitors (PCI-2015 and MCI-A) 14d to 150d in atmospheric condition were measured. The results showed that the corrosion current density (I corr) of steel bar reduced to 0.1 μA.cm-2 from the initial highest 3.833 μA.cm-2 (W/B=0.65, NaCl-1%) after surface-painting PCI-2015 14 d, and the I corr was still lower than 0.1 μA.cm-2 until 150d. The compressive strength and chloride migration coefficient of concrete specimens were tested. The possible reasons of the mechanisms of durability improvement for reinforced concrete by applying PCI-2015 inhibitor were PCI-2015 may be reacted with calcium hydroxide in cement concrete and lots of inhibitor particles may be adsorbed on the active sites first and then a stable protective layer may be formed. The I corr of steel bars in a hydraulic aqueduct concrete structure after painting PCI-2015, MCI-A (the United States) and MCI-B (Europe) during 6 months was monitored by Gecor 8 tester. The results showed that the average values of I corr of steel bars after painting the PCI-2015 150d fulfilled the specification requirements in “Design code for concrete structure strengthening (E.3) ”(GB 50367-2013).

Curcuminoid Compounds Isolated from Curcuma domestica Val. as Corrosion Inhibitor Towards Carbon Steel in 1 % NaCl Solution

International Nuclear Information System (INIS)

Kandias, D.; Bundjali, B.; Wahyuningrum, D.

2011-01-01

The corrosion inhibitor of carbon steel in 1 % NaCl solution by curcuminoids has been studied at 27 degree Celsius using weight loss and electrochemical method. The determination of corrosion inhibition efficiency (% eff) utilising weight loss method at the concentration of 80 ppm showed the best result of 78.70 % for third isolated fraction. Further determination utilising Tafel method showed the following results: raw pure extract of curcuminoid gave 89.88 % at 50 ppm; the first isolated fraction gave 46.50 % at 80 ppm; the second isolated fraction gave 44.83 % at 30 ppm; and the third isolated fraction gave 92.44 % at 70 ppm. Based on the analysis of Tafel extrapolation curve, the raw pure extract and the third fraction of curcuminoid acted as anodic inhibitor, whereas the first and the second fraction performed as cathodic inhibitors. The evaluations of synergism parameter (S θ ) indicate that the enhancement in inhibition efficiency towards raw pure extract was caused by the presence of second and third fractions as cathodic and anodic inhibitors. The contribution of steric hindrance of methoxy groups in curcuminoid structure causes the decrease in curcuminoid activity to be adsorbed on the electrode (carbon steel) surface. (author)

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

Directory of Open Access Journals (Sweden)

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.

A Multifunctional Smart Coating for Autonomous Corrosion Control

Science.gov (United States)

Calle, Luz Marina; Buhrow, Jerry W.; Jolley, Scott T.

2012-01-01

Corrosion is a destructive process that often causes failure in metallic components and structures. Protective coatings are the most commonly used method of corrosion control. However, progressively stricter environmental regulations have resulted in the ban of many commercially available corrosion protective coatings due to the harmful effects of their solvents or corrosion inhibitors. This work concerns the development of a multifunctional, smart coating for the autonomous control of corrosion. This coating is being developed to have the inherent ability to detect the chemical changes associated with the onset of corrosion and respond autonomously to control it. The multi-functionality of the coating is based on micro-encapsulation technology specifically designed for corrosion control applications. This design has, in addition to all the advantages of other existing microcapsules designs, the corrosion controlled release function that allows the delivery of corrosion indicators and inhibitors on demand only when and where needed. Corrosion indicators as well as corrosion inhibitors have been incorporated into microcapsules, blended into several paint systems, and tested for corrosion detection and protection efficacy. This

A Multifunctional Coating for Autonomous Corrosion Control

Science.gov (United States)

Calle, Luz M.; Li, Wenyan; Buhrow, Jerry W.; Jolley, Scott t.

2011-01-01

Nearly all metals and their alloys are subject to corrosion that causes them to lose their structural integrity or other critical functionality. Protective coatings are the most commonly used method of corrosion control. However, progressively stricter environmental regulations have resulted in the ban of many commercially available corrosion protective coatings due to the harmful effects of their solvents or corrosion inhibitors. This work concerns the development of a multifunctional smart coating for the autonomous control of corrosion. This coating is being developed to have the inherent ability to detect the chemical changes associated with the onset of corrosion and respond autonomously to indicate it and control it. The multi-functionality of the coating is based on microencapsulation technology specifically designed for corrosion control applications. This design has, in addition to all the advantages of existing microcapsulation designs, the corrosion controlled release function that triggers the delivery of corrosion indicators and inhibitors on demand, only when and where needed. Microencapsulation of self-healing agents for autonomous repair of mechanical damage to the coating is also being pursued. Corrosion indicators, corrosion inhibitors, as well as self-healing agents, have been encapsulated and dispersed into several paint systems to test the corrosion detection, inhibition, and self-healing properties of the coating. Key words: Corrosion, coating, autonomous corrosion control, corrosion indication, corrosion inhibition, self-healing coating, smart coating, multifunctional coating, microencapsulation.

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

Directory of Open Access Journals (Sweden)

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.

Electrochemical evaluation of sodium metabisulfite as environmentally friendly inhibitor for corrosion of aluminum alloy 6061 in a chloride solution

Energy Technology Data Exchange (ETDEWEB)

Zaid, B., E-mail: zaidbachir@yahoo.com [Département de métallurgie, Division de Technologie du Combustible, Centre de Recherche Nucléaire de Draria CRND, BP. 43 Draria, Alger (Algeria); Maddache, N.; Saidi, D. [Département de métallurgie, Division de Technologie du Combustible, Centre de Recherche Nucléaire de Draria CRND, BP. 43 Draria, Alger (Algeria); Souami, N. [Centre de Recherche Nucléaire d’Alger CRNA, 2 Bd. Frantz Fanon, Alger (Algeria); Bacha, N. [Département de Mécanique, Université SAAD Dahleb, Blida (Algeria); Si Ahmed, A. [Im2np, UMR 7334 CNRS, Aix-Marseille Université, 13397 Marseille Cedex 20 (France)

2015-04-25

Highlights: • Sodium metabisulfite acts as cathodic-type inhibitor. • The polarization resistance increases with the inhibitor concentration. • The pit nucleation rate decreases with increasing inhibitor concentration. • The current rise linked to pit propagation drops as inhibitor content increases. • The reactions involved in the inhibition actions are pointed out. - Abstract: Inhibition properties of sodium metabisulfite (Na{sub 2}S{sub 2}O{sub 5}) on pitting corrosion of 6061 aluminum alloy, in 5 × 10{sup −2} M NaCl solution of pH near 7.2 at 298 K, are characterized using open circuit potential, polarization resistance, cyclic and chrono-amperometric polarization measurements. In addition, scanning electron microscopy coupled with energy dispersive spectroscopy and X-ray photoelectrons are employed. Sodium metabisulfite, which is well compatible with environmental requirements, seems to act as a cathodic-type corrosion inhibitor. The passivation range and the polarization resistance increase with Na{sub 2}S{sub 2}O{sub 5} concentration. The inhibition effects are also reflected through the substantial reduction of both the rate of pit nucleation and the current rise characterizing the pit propagation progress. The SEM–EDS and XPS analyses reveal the formation of a passive film, which contains sulfur atoms.

Blue tetrazolium as a novel corrosion inhibitor for cold rolled steel in hydrochloric acid solution

International Nuclear Information System (INIS)

Li Xianghong; Deng Shuduan; Fu Hui

2010-01-01

The inhibition effect of blue tetrazolium (BT) on the corrosion of cold rolled steel (CRS) in 1.0 M HCl solution at 20 o C was investigated by weight loss, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), and scanning electron microscopy (SEM) methods. The results show that BT is a very good inhibitor, and the adsorption of BT on CRS surface obeys Langmuir adsorption isotherm. Polarization curves reveal that BT acts as a mixed-type inhibitor. EIS spectra exhibit one capacitive loop and confirm the inhibitive ability. The inhibition action of BT is also evidenced by SEM images.

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.

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.

The effect of inhibitor sodium nitrate on pitting corrosion of dissimilar material weldment joint of stainless steel AISI 304 and mild steel SS 400

Energy Technology Data Exchange (ETDEWEB)

Hilca, B. R., E-mail: bangkithilca@yahoo.com; Triyono, E-mail: triyonomesin@uns.ac.id [Mechanical Engineering Department, Sebelas Maret University, Surakarta 57126 (Indonesia)

2016-03-29

This study experimentally evaluated the effect of Sodium Nitrate inhibitor (NaNO{sub 3}) of 0.1%, 0.3%, and 0.5% on NaCl 3.5% toward pitting corrosion of dissimilar metal welding joint between stainless steel AISI 304 and mild steel SS 400. Electrochemical corrosion was tested using potentiodynamic polarization. Further the Scanning Electron Microscope (SEM) conducted to analyze the specimen. Chemical composition analysis used Energy Dispersive X-ray Spectrometry (EDS). The highest efficiency of sodium nitrate for ER 308 attained 63.8% and 64.89%for ER 309L. The specimen surface which observed through SEM showed decrease of pitting corrosion respectively with the addition of sodium nitrate content as inhibitor.

A novel imidazoline derivative as corrosion inhibitor for P110 carbon steel in hydrochloric acid environment

Directory of Open Access Journals (Sweden)

Lei Zhang

2015-09-01

Full Text Available A novel imidazoline derivative, 2-methyl-4-phenyl-1-tosyl-4, 5-dihydro-1H-imidazole (IMI, was prepared and investigated as corrosion inhibitor for P110 carbon steel in 1.0 M HCl solution by weight loss measurements, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS tests. The inhibition efficiency increased with the rising concentration of IMI inhibitor. The test results and fitting data indicated that the IMI behaved as a mixed-type inhibitor and obeys the Langmuir adsorption isotherm. Scanning electron microscopy (SEM was carried out to investigate the surface of carbon steel specimens, showing great protection from aggressive solution. Finally, inhibition mechanism of IMI on metal surface was further discussed.

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

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

The Corrosion Inhibition Characteristics of Sodium Nitrite Using an On-line Corrosion Rate Measurement System

International Nuclear Information System (INIS)

Park, Mal-Yong; Kang, Dae-Jin; Moon, Jeon-Soo

2015-01-01

An on-line corrosion rate measurement system was developed using a personal computer, a data acquisition board and program, and a 2-electrode corrosion probe. Reliability of the developed system was confirmed with through comparison test. With this system, the effect of sodium nitrite (NaNO 2 ) as a corrosion inhibitor were studied on iron and aluminum brass that were immersed in sodium chloride (NaCl) solution. Corrosion rate was measured based on the linear polarization resistance method. The corrosion rates of aluminum brass and iron in 1% NaCl solutions were measured to be 0.290 mm per year (mmpy) and 0.2134 mmpy, respectively. With the addition of 200 ppm of NO 2 - , the corrosion rates decreased to 0.0470 mmpy and 0.0254 mmpy. The addition of NO 2 - caused a decrease in corrosion rates of both aluminum brass and iron, yet the NO 2 - acted as a more effective corrosion inhibitor for iron. than aluminum brass

The microwave assisted synthesis of 1-alkyl-3-methylimidazolium bromide as potential corrosion inhibitor toward carbon steel in 1 M HCl solution saturated with carbon dioxide

Energy Technology Data Exchange (ETDEWEB)

Pasasa, Norman Vincent A., E-mail: npasasa@gmail.com; Bundjali, Bunbun; Wahyuningrum, Deana [Department of Chemistry, Faculty of Mathematics and Natural Sciences, Institut Teknologi Bandung, Jalan Ganesha No. 10 Bandung, Jawa Barat (Indonesia)

2015-09-30

Injection of corrosion inhibitor into the fluid current of oil and gas pipelines is an effective way to mitigate corrosion rate on the inner-surface parts of pipelines, especially carbon steel pipelines. In this research, two alkylimidazolium ionic liquids, 1-decyl-3-methylimidazolium bromide (IL1) and 1-dodecyl-3-methylimidazolium bromide (IL2) have been synthesized and studied as a potential corrosion inhibitor towards carbon steel in 1 M HCl solution saturated with carbon dioxide. IL1 and IL2 were synthesized using microwave assisted organic synthesis (MAOS) method. Mass Spectrometry analysis of IL1 and IL2 showed molecular mass [M-H+] peak at 223.2166 and 251.2484, respectively. The FTIR,{sup 1}H-NMR and {sup 13}C-NMR spectra confirmed that IL1 and IL2 were successfully synthesized. Corrosion inhibition activity of IL1 and IL2 were determined using weight loss method. The results showed that IL1 and IL2 have the potential as good corrosion inhibitors with corrosion inhibition efficiency of IL1 and IL2 are 96.00% at 100 ppm (343 K) and 95.60% at 50 ppm (343 K), respectively. The increase in the concentration of IL1 and IL2 tends to improve their corrosion inhibition activities. Analysis of the data obtained from the weight loss method shows that the adsorption of IL1 and IL2 on carbon steel is classified into chemisorption which obeys Langmuir’s adsorption isotherm.

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 Inhibitors for Aluminum.

Science.gov (United States)

Muller, Bodo

1995-01-01

Describes a simple and reliable test method used to investigate the corrosion-inhibiting effects of various chelating agents on aluminum pigments in aqueous alkaline media. The experiments that are presented require no complicated or expensive electronic equipment. (DDR)

Electrochemical Studies of Monoterpenic Thiosemicarbazones as Corrosion Inhibitor for Steel in 1 M HCl

Directory of Open Access Journals (Sweden)

R. Idouhli

2018-01-01

Full Text Available We have studied the inhibitory effect of some Monoterpenic Thiosemicarbazones on steel corrosion in 1 M HCl solution. The potentiodynamic polarization and electrochemical impedance spectroscopy were used. The Monoterpenic Thiosemicarbazones have inhibited significantly the dissolution of steel. The inhibition efficiency increased with increasing inhibitor concentration and also with the increase in temperature (293–323 K. Furthermore, the results obtained revealed that the adsorption of inhibitor on steel surface obeys Langmuir adsorption model and the thermodynamic parameters such as enthalpy and activation energy were determined. The scanning electron microscopy combined with dispersive X-ray spectroscopy examinations were used to see the shape of the surface morphology and to determine the elemental composition. Scanning electron microscope (SEM images show that the surface damage decreases when the inhibitor is added. The quantum chemical calculations using density functional theory (DFT were performed in order to provide some insights into the electronic density distribution as well as the nature of inhibitor-steel interaction.

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.

Stress corrosion inhibitors for type 18-10 stainless steels with low carbon content in hot and concentrated solutions of MgCl2. Study of some inorganic iodides

International Nuclear Information System (INIS)

Pinard, J.-L.

1974-01-01

Stress corrosion inhibitors for type Z2CN18-10 austenitic stainless steels with low carbon content in a solution of Cl 2 Mg at 105 deg C were investigated. It was established that iodides are the most adequate corrosion inhibitors because they react simultaneously upon the three main components of the alloy (Fe, Ni, Cr). A difference of behavior between I 2 Mg and the other iodides was observed (in electrochemistry and in simple stress corrosion experiments) and the influence of the metallic cation associated to I - was studied. The formation of the superficial film and the phenomena liable to occur at the interface film-corrosive solution were examined: film growth in MgCl 2 ; influence of certain substances added to the solution. A mechanism of inhibition by I - is suggested. It is similar to the mechanism proposed by BERGEN for the stress corrosion cracking by Cl - [fr

Reactivity of polyester aliphatic amine surfactants as corrosion inhibitors for carbon steel in formation water (deep well water)

International Nuclear Information System (INIS)

Alsabagh, A.M.; Migahed, M.A.; Awad, Hayam S.

2006-01-01

Effect of different concentrations, 40-200 ppm, of various polyester aliphatic amine surfactants on inhibition of the corrosion of carbon steel in the formation water (deep well water) was investigated. These surfactants exhibit different levels of inhibition particularly at high concentration (200 ppm). Inhibition efficiencies in the range 86-96% were determined by weight loss method. Comparable results were obtained from electrochemical measurements using Tafel extrapolation and polarisation resistance methods. It was shown that all the investigated surfactants act primarily as anodic inhibitors; however, they also affect the rate and mechanism of the cathodic reaction. These compounds function via adsorption on reactive sites on the corroding surface reducing the corrosion rate of the metal. It was revealed that the adsorption of these surfactants obey Langmuir adsorption isotherm. The inhibition effectiveness increases with the length of the aliphatic hydrocarbon chain, being a maximum in the presence of surfactant IV (∼96% efficiency). The corrosion inhibition feature of this compound is attributed to the presence of a long hydrocarbon chain that ensures large surface coverage as well as the presence of multiple active centers for adsorption. Scanning electron microscopy, SEM, has been applied to identify the surface morphology of carbon steel alloy in the absence and presence of the inhibitor molecules

Reactivity of polyester aliphatic amine surfactants as corrosion inhibitors for carbon steel in formation water (deep well water)

Energy Technology Data Exchange (ETDEWEB)

Alsabagh, A.M. [Department of Petroleum Applications, Egyptian Petroleum Research Institute (EPRI), Ahmed El-Zomor Street 1, Nasr City, Cairo 11727 (Egypt); Migahed, M.A. [Department of Petroleum Applications, Egyptian Petroleum Research Institute (EPRI), Ahmed El-Zomor Street 1, Nasr City, Cairo 11727 (Egypt)]. E-mail: mohamedatiyya707@hotmail.com; Awad, Hayam S. [Chemistry Department, Faculty of Girls for Science, Art and Education, Ain Shams University, Asmaa Fahmi Street, Helliopolis, Cairo (Egypt)

2006-04-15

Effect of different concentrations, 40-200 ppm, of various polyester aliphatic amine surfactants on inhibition of the corrosion of carbon steel in the formation water (deep well water) was investigated. These surfactants exhibit different levels of inhibition particularly at high concentration (200 ppm). Inhibition efficiencies in the range 86-96% were determined by weight loss method. Comparable results were obtained from electrochemical measurements using Tafel extrapolation and polarisation resistance methods. It was shown that all the investigated surfactants act primarily as anodic inhibitors; however, they also affect the rate and mechanism of the cathodic reaction. These compounds function via adsorption on reactive sites on the corroding surface reducing the corrosion rate of the metal. It was revealed that the adsorption of these surfactants obey Langmuir adsorption isotherm. The inhibition effectiveness increases with the length of the aliphatic hydrocarbon chain, being a maximum in the presence of surfactant IV ({approx}96% efficiency). The corrosion inhibition feature of this compound is attributed to the presence of a long hydrocarbon chain that ensures large surface coverage as well as the presence of multiple active centers for adsorption. Scanning electron microscopy, SEM, has been applied to identify the surface morphology of carbon steel alloy in the absence and presence of the inhibitor molecules.

Task-specific ionic liquid as a new green inhibitor of mild steel corrosion

Energy Technology Data Exchange (ETDEWEB)

Kowsari, E., E-mail: kowsarie@aut.ac.ir [Department of Chemistry, Amirkabir University of Technology, No. 424, Hafez Avenue, 1591634311 Tehran (Iran, Islamic Republic of); Payami, M. [Department of Chemistry, Amirkabir University of Technology, No. 424, Hafez Avenue, 1591634311 Tehran (Iran, Islamic Republic of); Amini, R.; Ramezanzadeh, B. [Department of Surface Coating and Corrosion, Institute for Color Science and Technology (ICST), PO 16765-654 Tehran (Iran, Islamic Republic of); Javanbakht, M. [Department of Chemistry, Amirkabir University of Technology, No. 424, Hafez Avenue, 1591634311 Tehran (Iran, Islamic Republic of)

2014-01-15

The corrosion inhibition effects of an imidazolium-based task specific ionic liquid (TSIL) were investigated on a low carbon steel in 1 M HCl solution. Samples were exposed to 1 M HCl solution without and with different concentrations of TSIL. Weight loss measurements, potentiodynamic polarization test, electrochemical impedance spectroscopy (EIS), scanning electron microscope (SEM), atomic force microscope (AFM) and contact angle measurements were utilized to investigate the inhibition effects of TSIL. The results obtained from the polarization studies revealed that both the anodic and cathodic branches slopes affected in the presence of TSIL. It was shown that TSIL behaved as a mixed type inhibitor with a dominant effect on the anodic reaction rate depression. It was shown that the increase in polarization resistance and the decrease in corrosion current density were more pronounced using 100 mg/L of TSIL after 2 h immersion time. It was also shown that the adsorption of TSIL followed a Langmuir adsorption isotherm.

Electrochemical and surface studies of some Porphines as corrosion inhibitor for J55 steel in sweet corrosion environment

Energy Technology Data Exchange (ETDEWEB)

Singh, Ambrish, E-mail: ambrish.16752@ipu.co.in [State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation (Southwest Petroleum University), Chengdu, Sichuan 610500 (China); Department of Chemistry, LFTS, Lovely Professional University, Phagwara, Punjab 144402 (India); Lin, Yuanhua, E-mail: yhlin28@163.com [State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation (Southwest Petroleum University), Chengdu, Sichuan 610500 (China); Ansari, K.R.; Quraishi, M.A. [Department of Applied Chemistry, Indian Institute of Technology, Banaras Hindu University, Varanasi, U.P. (India); Ebenso, Eno. E. [Department of Chemistry, School of Mathematical & Physical Sciences, North-West University(Mafikeng Campus), Private Bag X2046, Mmabatho 2735 (South Africa); Chen, Songsong; Liu, Wanying [CNPC Key Lab for Tubular Goods Engineering (Southwest Petroleum University), Chengdu, Sichuan 610500 (China)

2015-12-30

Graphical abstract: Corrosion inhibition of J55 steel in 3.5 wt.% NaCl solution saturated with CO2 by the three Porphines 5,10,15,20-Tetra(4-pyridyl)-21H,23H-porphine (P1), 5,10,15,20-Tetraphenyl-21H,23H-porphine (P2), 5,10,15,20-Tetrakis(4-hydroxyphenyl)-21H,23H-porphine (P3), electrochemical impedance spectroscopy (EIS), contact angle measurement, scanning electrochemical microscopy (SECM), and atomic force microscopy (AFM). - Highlights: • J55 steel protection in 3.5% NaCl solution saturated with CO2 by Porphines. • Weight loss and impedance results are in good agreement. • The adsorption of Porphines obeys the Langmuir adsorption isotherm. • Scanning electrochemical microscopy is used to discuss the insulated and conductive surface. • Examination of surface morphology by AFM. - Abstract: Corrosion inhibition of J55 steel in 3.5 wt.% NaCl solution saturated with CO{sub 2} by the three Porphines 5,10,15,20-Tetra(4-pyridyl)-21H,23H-porphine (P1), 5,10,15,20-Tetraphenyl-21H,23H-porphine (P2), 5,10,15,20-Tetrakis(4-hydroxyphenyl)-21H,23H-porphine (P3), electrochemical impedance spectroscopy (EIS), Contact angle measurement, scanning electrochemical microscopy (SECM), and atomic force microscopy (AFM). Adsorption of such Porphines on the J55 steel surface obeyed to the Langmuir adsorption isotherm. Atomic force microscopy (AFM), SECM, and Contact angle results confirm the formation of inhibitor film on J55 steel surface thereby mitigating corrosion.

Electrochemical and surface studies of some Porphines as corrosion inhibitor for J55 steel in sweet corrosion environment

International Nuclear Information System (INIS)

Singh, Ambrish; Lin, Yuanhua; Ansari, K.R.; Quraishi, M.A.; Ebenso, Eno. E.; Chen, Songsong; Liu, Wanying

2015-01-01

Graphical abstract: Corrosion inhibition of J55 steel in 3.5 wt.% NaCl solution saturated with CO2 by the three Porphines 5,10,15,20-Tetra(4-pyridyl)-21H,23H-porphine (P1), 5,10,15,20-Tetraphenyl-21H,23H-porphine (P2), 5,10,15,20-Tetrakis(4-hydroxyphenyl)-21H,23H-porphine (P3), electrochemical impedance spectroscopy (EIS), contact angle measurement, scanning electrochemical microscopy (SECM), and atomic force microscopy (AFM). - Highlights: • J55 steel protection in 3.5% NaCl solution saturated with CO2 by Porphines. • Weight loss and impedance results are in good agreement. • The adsorption of Porphines obeys the Langmuir adsorption isotherm. • Scanning electrochemical microscopy is used to discuss the insulated and conductive surface. • Examination of surface morphology by AFM. - Abstract: Corrosion inhibition of J55 steel in 3.5 wt.% NaCl solution saturated with CO_2 by the three Porphines 5,10,15,20-Tetra(4-pyridyl)-21H,23H-porphine (P1), 5,10,15,20-Tetraphenyl-21H,23H-porphine (P2), 5,10,15,20-Tetrakis(4-hydroxyphenyl)-21H,23H-porphine (P3), electrochemical impedance spectroscopy (EIS), Contact angle measurement, scanning electrochemical microscopy (SECM), and atomic force microscopy (AFM). Adsorption of such Porphines on the J55 steel surface obeyed to the Langmuir adsorption isotherm. Atomic force microscopy (AFM), SECM, and Contact angle results confirm the formation of inhibitor film on J55 steel surface thereby mitigating corrosion.

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.

Non toxic biodegradable cationic gemini surfactants as novel corrosion inhibitor for mild steel in hydrochloric acid medium and synergistic effect of sodium salicylate: Experimental and theoretical approach

Energy Technology Data Exchange (ETDEWEB)

Mobin, Mohammad, E-mail: drmmobin@hotmail.com; Aslam, Ruby; Aslam, Jeenat

2017-04-15

Two biodegradable, non toxic cationic gemini surfactants having ester linkage in the spacer namely, C{sub m}H{sub 2m+1}(CH{sub 3}){sub 2}N{sup +}(CH{sub 2}COOCH{sub 2}){sub 2}N{sup +}(CH{sub 3}){sub 2}C{sub m}H{sub 2m+1}.2Cl{sup -} (m-E2-m, m = 12, 14), were synthesized and characterized using elemental analysis, FT-IR and {sup 1}H-NMR. The corrosion inhibition performance of synthesized compounds separately and in combination with sodium salicylate (SS), along with the nature and stability of inhibitive film, for mild steel (MS) in 1 M HCl solution at 30–60 °C was evaluated using weight loss, potentiodynamic polarization, EIS, UV–visible spectroscopy, FTIR, SEM/EDAX, TGA and quantum chemical calculations. Results of the studies confirm m-E2-m as effective corrosion inhibitor for MS in HCl; the inhibition effect being synergistically strengthened in presence of SS. The synthesized compounds act as mixed type inhibitor and adsorb on MS surface in accordance with Langmuir adsorption isotherm. Experimentally measured inhibition efficiencies are correlated with the molecular parameters obtained using PM6 semi-empirical method. Empirical results are in good agreement with the theoretical predictions. - Graphical abstract: (a) Optimized geometry of studied inhibitors by PM6 method with (b) HOMO and (c) LUMO orbital occupation. - Highlights: • Environment friendly gemini surfactants were studied as corrosion inhibitor for MS. • Studied compounds act as good inhibitor for MS corrosion in 1 M HCl at 30–60 °C. • η of inhibitors is synergistically increased in presence of sodium salicylate. • The synthesized cationic gemini surfactants act as mixed-type inhibitor. • Experimentally obtained results are in good agreement with theoretical results.

Corrosion of metallic materials. Dry corrosion, aqueous corrosion and corrosion by liquid metal, methods of protection

International Nuclear Information System (INIS)

Helie, Max

2015-01-01

This book is based on a course on materials given in an engineering school. The author first gives an overview of metallurgy issues: metallic materials (pure metals, metallic alloys), defects of crystal lattices (point defects, linear defects or dislocations), equilibrium diagrams, steels and cast, thermal processing of steels, stainless steels, aluminium and its alloys, copper and its alloys. The second part addresses the properties and characterization of surfaces and interfaces: singularity of a metal surface, surface energy of a metal, energy of grain boundaries, adsorption at a material surface, metal-electrolyte interface, surface oxide-electrolyte interface, techniques of surface analysis. The third chapter addresses the electrochemical aspects of corrosion: description of the corrosion phenomenon, free enthalpy of a compound and free enthalpy of a reaction, case of dry corrosion (thermodynamic aspect, Ellingham diagram, oxidation mechanisms, experimental study, macroscopic modelling), case of aqueous corrosion (electrochemical thermodynamics and kinetics, experimental determination of corrosion rate). The fourth part addresses the different forms of aqueous corrosion: generalized corrosion (atmospheric corrosion, mechanisms and tests), localized corrosion (galvanic, pitting, cracking, intergranular, erosion and cavitation), particular cases of stress cracking (stress corrosion, fatigue-corrosion, embrittlement by hydrogen), and bi-corrosion (of non alloyed steels, of stainless steels, and of aluminium and copper alloys). The sixth chapter addresses the struggle and the protection against aqueous corrosion: methods of prevention, scope of use of main alloys, geometry-based protection of pieces, use of corrosion inhibitors, use of organic or metallic coatings, electrochemical protection. The last chapter proposes an overview of corrosion types in industrial practices: in the automotive industry, in the oil industry, in the aircraft industry, and in the

Preparation of Some Eco-friendly Corrosion Inhibitors Having Antibacterial Activity from Sea Food Waste.

Science.gov (United States)

Hussein, Mohamed H M; El-Hady, Mohamed F; Shehata, Hassan A H; Hegazy, Mohammad A; Hefni, Hassan H H

2013-03-01

Chitosan is one of the important biopolymers and it is extracted from exoskeletons of crustaceans in sea food waste. It is a suitable eco-friendly carbon steel corrosion inhibitor in acid media; the deacetylation degree of prepared chitosan is more than 85.16 %, and the molecular weight average is 109 kDa. Chitosan was modified to 2-N,N-diethylbenzene ammonium chloride N-oxoethyl chitosan (compound I), and 12-ammonium chloride N-oxododecan chitosan (compound II) as soluble water derivatives. The corrosion inhibition efficiency for carbon steel of compound (I) in 1 M HCl at varying temperature is higher than for chitosan and compound (II). However, the antibacterial activity of chitosan for Enterococcus faecalis, Escherichia coli, Staphylococcus aureus, and Candida albicans is higher than for its derivatives, and the minimum inhibition concentration and minimum bacterial concentration of chitosan and its derivatives were carried out with the same strain.

硫代氨基咪唑啉盐缓蚀剂的合成及性能研究%Research on the synthesis and performances of thiocarbamates imidazoline salts corrosion inhibitor

Institute of Scientific and Technical Information of China (English)

杨根全; 李志元

2017-01-01

To solve the problem of comparatively poor compatibility of cationic imidazoline corrosion inhibitor and anionic scale inhibitor appeared in the gas-oil field,imidazoline has been synthesized,by using organic acid and triethylenetetramine as reaction raw materials.The water soluble anionic corrosion inhibitor can be obtained under the following conditions:n (imidazoline) ∶ n (CS2) ∶ n (NaOH) =1 ∶ 1 ∶ 1,ethanol as solvent,temperature 60 ℃,and reaction time 2 hours.The corrosion capacity of the corrosion inhibitor and its compatibility with scale inhibitor are investigated.The research results show that when the mass concentration of the dosed corrosion inhibitor is 50 mg/L,salt content 25％,pressure 0.5 MPa in corrosion media,and within 24 hours,the corrosion inhibiting rate of A3 carbon steel is higher than 92％.It has good compatibility with the anionic scale inhibitor.%针对油气田阳离子型咪唑啉类缓蚀剂与阴离子型阻垢剂配伍性较差的问题,以有机酸和三乙烯四胺为反应原料合成了咪唑啉,在n(咪唑啉)∶n(CS2)∶n(NaOH)为1∶1∶1、乙醇为溶剂、温度为60℃条件下反应2h,得到水溶性的阴离子缓蚀剂,并考察了该缓蚀剂的缓蚀性能及其与阻垢剂的配伍性.研究结果表明,在含盐25％、温度60℃、压力为0.5 MPa的腐蚀介质中,该缓蚀剂加药质量浓度为50 mg/L时,24 h内对A3碳钢的缓蚀率＞92％,与阴离子阻垢剂的配伍性良好.

Experimental and computational studies of naphthyridine derivatives as corrosion inhibitor for N80 steel in 15% hydrochloric acid

Science.gov (United States)

Ansari, K. R.; Quraishi, M. A.

2015-05-01

The inhibition effect of three naphthyridine derivatives namely 2-amino-4-(4-methoxyphenyl)-1,8-naphthyridine-3-carbonitrile (ANC-1), 2-amino-4-(4-methylphenyl)-1,8-naphthyridine-3-carbonitrile (ANC-2) and 2-amino-4-(3-nitrophenyl)-1,8-naphthyridine-3-carbonitrile (ANC-3) as corrosion inhibitors for N80 steel in 15% HCl by using gravimetric, electrochemical techniques (EIS and potentiodynamic polarization), SEM, EDX and quantum chemical calculation. The order of inhibition efficiency is ANC-1>ANC-2>ANC-3. Potentiodynamic polarization reveals that these inhibitors are mixed type with predominant cathodic control. Studied inhibitors obey the Langmuir adsorption isotherm. The quantum calculation is in good agreement with experimental results.

Corrosion of beryllium oxide

International Nuclear Information System (INIS)

Elston, J.; Caillat, R.

1958-01-01

Data are reported on the volatilization rate of beryllium oxide in moist air depending on temperature and water vapour concentration. They are concerned with powder samples or sintered shapes of various densities. For sintered samples, the volatilization rate is very low under the following conditions: - temperature: 1300 deg. C, - water vapour concentration in moist air: 25 g/m 3 , - flow rate: 12 I/hour corresponding to a speed of 40 m/hour on the surface of the sample. For calcinated powders (1300 deg. C), grain growth has been observed under a stream of moist air at 1100 deg. C. For instance, grain size changes from 0,5 to at least 2 microns after 500 hours of exposure at this temperature. Furthermore, results data are reported on corrosion of sintered beryllium oxide in pressurized water. At 250 deg. C, under a pressure of 40 kg/cm 2 water is very slightly corrosive; however, internal strains are revealed. Finally, some features on the corrosion in liquid sodium are exposed. (author) [fr

A combinatorial matrix of rare earth chloride mixtures as corrosion inhibitors of AA2024-T3: Optimisation using potentiodynamic polarisation and EIS

International Nuclear Information System (INIS)

Muster, T.H.; Sullivan, H.; Lau, D.; Alexander, D.L.J.; Sherman, N.; Garcia, S.J.; Harvey, T.G.; Markley, T.A.; Hughes, A.E.; Corrigan, P.A.; Glenn, A.M.; White, P.A.; Hardin, S.G.; Mardel, J.; Mol, J.M.C.

2012-01-01

A combinatorial matrix of four rare earth chlorides has been evaluated for the corrosion inhibition of aluminium alloy AA2024-T3 in aqueous solution. Two electrochemical techniques, potentiodynamic polarisation (PP) and electrochemical impedance spectroscopy (EIS), were used to evaluate AA2024-T3 corrosion in 0.1 M NaCl with the addition of 10 −3 M of rare earth chloride mixtures at time periods up to 18 h. PP experiments showed rare earth inhibition of up to 98% within the first hour and thereafter corrosion rates were steadily decreased. The open-circuit potential (OCP) of AA2024-T3 decreased as a function of time for all solutions indicating predominantly cathodic inhibition. However, differing trends in the OCP were observed during PP and EIS experiments and are discussed in terms of likely time-dependent mechanisms. A comparative study of optimisation models indicated the best mixture at 10 −3 M total inhibitor concentration was predicted to be 72% cerium (Ce) and 28% (praseodymium (Pr)/lanthanum (La)) ions. As the amount of Ce is decreased from this level the corrosion inhibition is predicted to decrease also, regardless of what other rare earths (La, Pr and Nd) are added alone or in combination. Individually, La, Pr and Nd show varying levels of corrosion inhibition activity, all of which are inferior to that of Ce. If Ce is absent entirely, then a mixture of approximately 50% Pr and 50% Nd is predicted to be preferred. This is one of the first applications of combinatorial design for the optimisation of corrosion inhibitor mixtures.

Effects of Organic Corrosion Inhibitor and Chloride Ion Concentration on Steel Depassivation and Repassivation in Solution

Institute of Scientific and Technical Information of China (English)

WANG Zixiao; YU Lei; LIU Zhiyong; SONG Ning

2015-01-01

Effect of an organic corrosion inhibitor (OCI) named PCI-2014 added in chloride solution on the critical chlo-ride concentration of mild steel depassivation and the critical OCI concentrations for repairing the steel in different chlo-ride solution were investigated. The results show that the critical chloride concentration increases exponentially with raises of PCI-2014 concentration in the solution. Within a certain chloride ion concentration range, the critical PCI-2014 concentration for repairing the corroded steel is also increases exponentially with enhancement of chloride content in the solution. Atomic force microscopy images display the molecular particles of inhibitor are adsorbed on the steel surface and formed a protective layer. Analysis of X-ray photoelectron spectroscopy shows the chloride ions at the surface of steel are displaced by atoms or molecules of the inhibitor in chloride condition.

Environmentally Friendly Coating Technology for Autonomous Corrosion Control

Science.gov (United States)

Calle, Luz M.; Li, Wenyan; Buhrow, Jerry W.; Johnsey, Marissa N.; Jolley, Scott T.; Pearman, Benjamin P.; Zhang, Xuejun; Fitzpatrick, Lilliana; Gillis, Mathew; Blanton, Michael;

Cassava starch graft copolymers an eco-friendly corrosion inhibitor for steel in H{sub 2}SO{sub 4} solution

Energy Technology Data Exchange (ETDEWEB)

Li, Xianghong; Deng, Shuduan [Southwest Forestry University, Kunming (China)

2015-11-15

Cassava starch graft copolymer (CSGC) was prepared by grafting acryl amide (AA) onto cassava starch (CS). The inhibition effect of CSGC on the corrosion of cold rolled steel (CRS) in 1.0M H{sub 2}SO{sub 4} solution was first studied by weight loss, potentiodynamic polarization curves, electrochemical impedance spectroscopy (EIS) and scanning electron microscope (SEM) methods. The results show that CSGC is a good inhibitor, and inhibition efficiency of CSGC is higher than that of CS or AA. The adsorption of CSGC on steel surface obeys Langmuir adsorption isotherm. CSGC is a mixed-type inhibitor at 20 .deg. C, while mainly a cathodic inhibitor at 50 .deg. C.

The oxidation and corrosion of ODS alloys

Science.gov (United States)

Lowell, Carl E.; Barrett, Charles A.

1990-01-01

The oxidation and hot corrosion of high temperature oxide dispersion strengthened (ODS) alloys are reviewed. The environmental resistance of such alloys are classified by oxide growth rate, oxide volatility, oxide spalling, and hot corrosion limitations. Also discussed are environmentally resistant coatings for ODS materials. It is concluded that ODS NiCrAl and FeCrAl alloys are highly oxidation and corrosion resistant and can probably be used uncoated.

Oxidation And Hot Corrosion Of ODS Alloy

Science.gov (United States)

Lowell, Carl E.; Barrett, Charles A.

1993-01-01

Report reviews oxidation and hot corrosion of oxide-dispersion-strengthened (ODS) alloys, intended for use at high temperatures. Classifies environmental resistances of such alloys by rates of growth of oxides, volatilities of oxides, spalling of oxides, and limitations imposed by hot corrosion. Also discusses environmentally resistant coatings for ODS materials. Concludes ODS NICrAl and FeCrAl alloys highly resistant to oxidation and corrosion and can be used uncoated.

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

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

Recent Developments on Autonomous Corrosion Protection Through Encapsulation

Science.gov (United States)

Li, W.; Buhrow, J. W.; Calle, L. M.; Gillis, M.; Blanton, M.; Hanna, J.; Rawlins, J.

2015-01-01

This paper concerns recent progress in the development of a multifunctional smart coating, based on microencapsulation, for the autonomous detection and control of corrosion. Microencapsulation has been validated and optimized to incorporate desired corrosion control functionalities, such as early corrosion detection and inhibition, through corrosion-initiated release of corrosion indicators and inhibitors, as well as self-healing agent release triggered by mechanical damage. While proof-of-concept results have been previously reported, more recent research and development efforts have concentrated on improving coating compatibility and synthesis procedure scalability, with a targeted goal of obtaining easily dispersible pigment-grade type microencapsulated materials. The recent progress has resulted in the development of pH-sensitive microparticles as a corrosion-triggered delivery system for corrosion indicators and inhibitors. The synthesis and early corrosion indication results obtained with coating formulations that incorporate these microparticles are reported. The early corrosion indicating results were obtained with color changing and with fluorescent indicators.

Effect of menthol coated craft paper on corrosion of copper in HCl ...

Indian Academy of Sciences (India)

Administrator

The effect of menthol on copper corrosion was studied by gravimetric and ... lable for temporary protection of metals and alloys from corrosion, the use of volatile .... The corrosion kinetic parameters were obtained from the anodic and cathodic.

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 and quantum chemical studies of some indole derivatives as corrosion inhibitors for C38 steel in molar hydrochloric acid

International Nuclear Information System (INIS)

Lebrini, M.; Robert, F.; Vezin, H.; Roos, C.

2010-01-01

A comparative study of 9H-pyrido[3,4-b]indole (norharmane) and 1-methyl-9H-pyrido[3,4-b]indole (harmane) as inhibitors for C38 steel corrosion in 1 M HCl solution at 25 o C was carried out. Potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques were applied to study the metal corrosion behavior in the absence and presence of different concentrations of these inhibitors. The OCP as a function of time were also established. Cathodic and anodic polarization curves show that norharmane and harmane are a mixed-type inhibitors. Adsorption of indole derivatives on the C38 steel surface, in 1 M HCl solution, follows the Langmuir adsorption isotherm model. The ΔG ads o values were calculated and discussed. The potential of zero charge (PZC) of the C38 steel in inhibited solution was studied by the EIS method, and a mechanism for the adsorption process was proposed. Raman spectroscopy confirmed that indole molecules strongly adsorbed onto the steel surface. The electronic properties of indole derivates, obtained using the AM1 semi-empirical quantum chemical approach, were correlated with their experimental efficiencies using the linear resistance model (LR).

The validation of corrosion inhibitors for ancillary cooling systems at Sizewell B PWR

International Nuclear Information System (INIS)

Allan, S.J.; Garnsey, R.; Lawson, W.F.

1994-01-01

Sizewell B has several low temperature ancillary cooling circuits for removing low grade heat. One of the principal circuits is the Component Cooling Water System (CCWS) primarily constructed from carbon steel pipework but also containing stainless steel, titanium, copper and cupronickel components. Linked to the CCWS is another carbon steel system namely the Reserve Ultimate Heat Sink (RUHS) a system unique to Sizewell B providing an independent heat removal capability for the CCWS as a safety back-up. Both systems utilize demineralized water with the addition of an inhibitor to prevent corrosion. The vendor recommended inhibitor namely potassium chromate is highly toxic to marine life and initial discussions with the regulatory authorities indicated that it would be extremely difficult to obtain a discharge consent to cover leakage or potential system purges and dumps associated with maintenance operations. Thus an alternative was sought. Sodium nitrite (anhydrous NaN0 2 )/borax (Na 2 B 4 0 7 1OH 2 0) inhibitor solutions have been used for many years in the power industry for preservation of carbon steel plant and several proprietary formulations are based on this mixture. There has been extensive test work in the UK on this inhibitor for secondary side boiler storage on gas reactors and therefore it was considered a prime candidate for use at Sizewell B. Starting in 1985 a programme of work sponsored by Nuclear Electric plc has been completed by NNC Ltd to compare nitrite/borax with other suitable inhibitors and validate its use for Sizewell B. (authors). 5 figs., 1 tab

New Coumarin Derivative as an Eco-Friendly Inhibitor of Corrosion of Mild Steel in Acid Medium

Directory of Open Access Journals (Sweden)

Ahmed A. Al-Amiery

2014-12-01

Full Text Available The anticorrosion ability of a synthesized coumarin, namely 2-(coumarin-4-yloxyacetohydrazide (EFCI, for mild steel (MS in 1 M hydrochloric acid solution has been studied using a weight loss method. The effect of temperature on the corrosion rate was investigated, and some thermodynamic parameters were calculated. The results indicated that inhibition efficiencies were enhanced with an increase in concentration of inhibitor and decreased with a rise in temperature. The IE value reaches 94.7% at the highest used concentration of the new eco-friendly inhibitor. The adsorption of inhibitor on MS surface was found to obey a Langmuir adsorption isotherm. Scanning electron microscopy (SEM was performed on inhibited and uninhibited mild steel samples to characterize the surface. The Density Function theory (DFT was employed for quantum-chemical calculations such as EHOMO (highest occupied molecular orbital energy, ELUMO (lowest unoccupied molecular orbital energy and μ (dipole moment, and the obtained results were found to be consistent with the experimental findings. The synthesized inhibitor was characterized by Fourier transform infrared (FTIR and nuclear magnetic resonance (NMR spectroscopic studies.

Influence of biofilm formation on corrosion and scaling in geothermal plants

Science.gov (United States)

Kleyböcker, Anne; Lerm, Stephanie; Monika, Kasina; Tobias, Lienen; Florian, Eichinger; Andrea, Seibt; Markus, Wolfgramm; Hilke, Würdemann

2017-04-01

Process failures may occur due to corrosion and scaling processes in open loop geothermal systems. Especially after heat extraction, sulfate reducing bacteria (SRB) contribute to corrosion processes due to a more favorable temperature for their growth. In biofilms containing FeS scales, corrosion processes are enhanced. Furthermore, scales can lead to reduced pipe profiles, to a diminished heat transfer and a decrease in the wellbore injectivity. Inhibitors are frequently applied to minimize scaling in technical systems. A prerequisite for the application of inhibitors in geothermal plants located in the Molasse basin is their degradability under reservoir conditions, e. g. in a reduced environment. In order to determine the effects of scale-inhibitors on the subsurface and microbial processes, laboratory experiments were performed focusing on the microbial inhibitor degradation. First results indicate that the inhibitor degradation under anaerobic conditions is possible. Besides the inhibitor application also other techniques are investigated to economically reduce corrosion and scaling in geothermal plants. In a mobile bypass system, the influence of biofilm formation on corrosion and scaling was investigated. The bypass system was tested at a geothermal heat store in the North German Basin. The plant is operated with highly saline fluid (salinity 130 g/L) and known to be affected by SRB. The SRB contributed to corrosion damages especially at the pump in the well on the cold side. Heat shocks were successfully used in the bypass system to reduce biofilm formation as well as corrosion and scaling processes.

New 1H-pyrrole-2,5-dione derivatives as efficient organic inhibitors of carbon steel corrosion in hydrochloric acid medium: Electrochemical, XPS and DFT studies

International Nuclear Information System (INIS)

Zarrouk, A.; Hammouti, B.; Lakhlifi, T.; Traisnel, M.; Vezin, H.; Bentiss, F.

2015-01-01

Highlights: • 1H-pyrrole derivatives act as good corrosion inhibitors for carbon steel in 1 M HCl. • Adsorption of the inhibitors on carbon steel surface obeys Langmuir’s isotherm. • XPS showed that the inhibitors are chemisorbed on the metal surface. • Quantum chemical parameters were correlated with experimental results. - Abstract: New 1H-pyrrole-2,5-dione derivatives, namely 1-phenyl-1H-pyrrole-2,5-dione (PPD) and 1-(4-methylphenyl)-1H-pyrrole-2,5-dione (MPPD) were synthesised and their inhibitive action against the corrosion of carbon steel in 1 M HCl solution were investigated at 308 K by weight loss, potentiodynamic polarization curves, and electrochemical impedance spectroscopy (EIS) methods. The results showed that the investigated 1H-pyrrole-2,5-dione derivatives are good corrosion inhibitors for carbon steel in 1 M HCl medium, their inhibition efficiency increased with inhibitor concentration, and MPPD is slightly more effective than PPD. Potentiostatic polarization study showed that PPD and MPPD are mixed-type inhibitors in 1 M HCl. Impedance experimental data revealed a frequency distribution of the capacitance, simulated as constant phase element. The results obtained from electrochemical and weight loss studies were in reasonable agreement. The adsorption of MPPD and PPD on steel surface obeyed Langmuir’s adsorption isotherm. Thermodynamic data and XPS analysis clearly indicated that the adsorption mechanism of 1H-pyrrole-2,5-dione derivatives on carbon steel surface in 1 M HCl solution is mainly controlled by a chemisorption process. Quantum chemical calculations using the Density Functional Theory (DFT) were performed on 1H-pyrrole-2,5-dione derivatives to determine the relationship between molecular structures and their inhibition efficiencies

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)

Stress corrosion and corrosion fatigue crack growth monitoring in metals

International Nuclear Information System (INIS)

Senadheera, T.; Shipilov, S.A.

2003-01-01

Environmentally assisted cracking (including stress corrosion cracking and corrosion fatigue) is one of the major causes for materials failure in a wide variety of industries. It is extremely important to understand the mechanism(s) of environmentally assisted crack propagation in structural materials so as to choose correctly from among the various possibilities-alloying elements, heat treatment of steels, parameters of cathodic protection, and inhibitors-to prevent in-service failures due to stress corrosion cracking and corrosion fatigue. An important step towards understanding the mechanism of environmentally assisted crack propagation is designing a testing machine for crack growth monitoring and that simultaneously provides measurement of electrochemical parameters. In the present paper, a direct current (DC) potential drop method for monitoring crack propagation in metals and a testing machine that uses this method and allows for measuring electrochemical parameters during stress corrosion and corrosion fatigue crack growth are described. (author)

Aluminum surface corrosion and the mechanism of inhibitors using pH and metal ion selective imaging fiber bundles.

Science.gov (United States)

Szunerits, Sabine; Walt, David R

2002-02-15

The localized corrosion behavior of a galvanic aluminum copper couple was investigated by in situ fluorescence imaging with a fiber-optic imaging sensor. Three different, but complementary methods were used for visualizing remote corrosion sites, mapping the topography of the metal surface, and measuring local chemical concentrations of H+, OH-, and Al3+. The first method is based on a pH-sensitive imaging fiber, where the fluorescent dye SNAFL was covalently attached to the fiber's distal end. Fluorescence images were acquired as a function of time at different areas of the galvanic couple. In a second method, the fluorescent dye morin was immobilized on the fiber-optic imaging sensor, which allowed the in situ localization of corrosion processes on pure aluminum to be visualized over time by monitoring the release of Al3+. The development of fluorescence on the aluminum surface defined the areas associated with the anodic dissolution of aluminum. We also investigated the inhibition of corrosion of pure aluminum by CeCl3 and 8-hydroxyquinoline. The decrease in current, the decrease in the number of active sites on the aluminum surface, and the faster surface passivation are all consistent indications that cerium chloride and 8-hydroxyquinoline inhibit corrosion effectively. From the number and extent of corrosion sites and the release of aluminum ions monitored with the fiber, it was shown that 8-hydroxyquinoline is a more effective inhibitor than cerium chloride.

INHIBITION OF CORROSION OF ZINC IN (HNO3 + HCl) ACID ...

African Journals Online (AJOL)

2015-05-01

May 1, 2015 ... corrosion inhibitor for zinc in phosphoric acid. Vashi et al.[8-9] studied the corrosion inhibition of zinc in (HNO3 + H2SO4) and (HNO3 + H3PO4) binary acid mixture by aniline. In the present work, the role of aniline as inhibitor for corrosion of zinc in (HNO3 + HCl) binary acid mixture has been reported. 2.

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

Directory of Open Access Journals (Sweden)

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.

The jet impingement cell: A valuable device for investigating CO{sub 2} corrosion

Energy Technology Data Exchange (ETDEWEB)

Kinsella, Brian; John, Douglas; Bailey, Stuart; De Marco, Roland [Western Australian Corrosion Research Group, School of Applied Chemistry, Curtin University of Technology, GPO Box U1987, Perth WA, 6845 (Australia)

2004-07-01

The jet impingement cell (JIC) is a valuable technique for the investigation of carbon dioxide corrosion of steel and its inhibition under high flow conditions or high wall shear stress. Despite the use of the JIC in corrosion testing laboratories not a great deal has been published on the design and calibration of these cells. In the evaluation of corrosion inhibitors, the type of corrosion and relative performance of the inhibitors depends on the metallurgy of the steel used to manufacture electrodes and measure the corrosion rate. This paper covers aspects of cell design and the determination of mass transfer and wall shear stress at electrodes used in the cell. The performance of different generic type corrosion inhibitors and their affect on the type of corrosion (i.e, uniform, pitting and crevice corrosion) is shown and discussed. (authors)

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.

Development of Bio-Based Paint by using Methyl Esters from Palm Oil for Corrosion Inhibitor

International Nuclear Information System (INIS)

Mohibah Musa; Miradatul Najwa Muhd Rodhi; Najmiddin Yaakob; Ku Halim Ku Hamid; Juferi Idris

2013-01-01

Paint is used as a means of protection to prevent surfaces from being corroded over time. This research is focused on the development of a Bio-based paint made from palm oil methyl ester (POME) which originated from crude palm oil (CPO). New formulation paint has been developed to protect the pipeline from corrosion thus reducing the cost of the operation. Bio-based paint is made up of four components which are solvent, binder, additives, and pigment. The solvent in the bio-based paint is POME. The additives used are wetting and dispersing agent. The pigment used in the bio-based paint is TiO 2 . The formulation was developed by using a constant amount of additives and binder but varying the amount of POME at 10 ml, 15 ml, 20 ml, 25 ml and 30 ml with addition of water. The Standard Testing Methods for measuring the corrosion rate (ASTM G5-94(2011)) was carried out for each sample. In conclusion, it is proven that in the making of bio-based paint formulation for better corrosion inhibitor; the best amount of binder, additives and de-foam that should be used is 20 ml, 10 ml and 10 ml, respectively. (author)

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.

Exopolysaccharides from lactic acid bacteria as corrosion inhibitors

Science.gov (United States)

Ignatova-Ivanova, Tsveteslava; Ivanov, Radoslav

2016-03-01

Bacterial EPSs (exopolysaccharides) are believed to play an important role in the environment by promoting survival strategies such as bacterial attachment to surfaces and nutrient trapping, which facilitate processes of biofilm formation and development. These microbial biofilms have been implicated in corrosion of metals, bacterial attachment to prosthetic devices, fouling of heat exchange surfaces, toxicant immobilization, and fouling of ship hulls. In this paper, data on EPS production and the effect of EPS on corrosion of steel produced by Lactobacillus sp. are presented and discussed. Lactobacillus delbrueckii K27, Lactobacillus delbrueckii B8, Lactobacillus delbrueckii KO43, Lactobacillus delbrueckii K3, Lactobacillus delbrueckii K15 and Lactobacillus delbrueckii K17 was obtained from Collection of Department of General and Applied Microbiology, Sofia University. It was tested for its ability to produce exopolysaccharides when cultivated in a media containing 10% sucrose, 10% lacose and 10% maltose. The study of the corrosive stability of steel samples was conducted on the gravimetrique method. The rate of corrosion, the degree of protection, and coefficient of protection have been calculated. The structure of layer over steel plates was analysed by SEM (scanning electron microscopy) JSM 5510. It could be underlined that 10% sucrose, 10% lactose and 10% maltose in the media stimulated the process of protection of corrosion.

Evaluation of the potential of additives as corrosion inhibitors of CA-50 carbon steel used as reinforcement in concretes; Avaliacao da potencialidade de aditivos como inibidores de corrosao do aco carbono CA-50 usado como armadura de estruturas de concreto

Energy Technology Data Exchange (ETDEWEB)

Mennucci, Marina Martins

2006-07-01

In this work, various compounds were tested to evaluate their potential capability for their use as corrosion inhibitors of carbon steel reinforcement in concretes. The additives tested were sodium benzoate, polyethylene glycol, hexamethylenetetramine, benzotriazole and yttrium carbonate. Initially, exploratory tests were carried out to select the ones to be used as corrosion inhibitors, based on the inhibit ion efficiency determined from electrochemical tests, specifically polarization tests and electrochemical impedance spectroscopy. These tests were carried out in a solution composed of 0.01 N sodium hydroxide (NaOH) and 0.05 N potassium hydroxide (KOH) to simulate the composition of the solution inside the pores in concretes. The additive that presented the most promising potential to be used as corrosion inhibitor was benzotriazole (BTA). After the elimination of some compounds and selection of the additive with higher corrosion inhibit ion efficiency in the test medium, the effect of its concentration on the corrosion inhibition efficiency was evaluated. Sodium nitrite solutions with the same concentrations as those solutions with BTA were tested for comparison reasons. Sodium nitrite is a well established corrosion inhibitor for carbon steel reinforcement in concretes but it has been related to toxic effects. The BTA was associated to higher corrosion inhibition efficiencies than that of sodium nitrite in similar concentrations. A blackish adherent film was formed on the steel surface exposed to BTA solutions during long periods of immersion in the alkaline medium. The results suggest that BTA is a potential candidate for substitution of nitrites as corrosion inhibitor of reinforcements in concrete. (author)

Development of Novel Corrosion Techniques for a Green Environment

Directory of Open Access Journals (Sweden)

Zaki Ahmad

2012-01-01

Full Text Available The synergistic effect of air pollution, brown clouds and greenhouse gasses is deleterious to human health and industrial products. The use of toxic inhibitors, chemicals in water treatment plants, and anti-fouling agents in desalination plants has contributed to the greenhouse effect. Conventional anti-corrosion techniques such as paints, coatings, inhibitor treatments, and cathodic protection paid no regard to greenhouse effect. Work on eco-friendly anti-corrosion techniques is scanty and largely proprietary. The use of nano-TiO2 particles introduced in alkyds and polyurethane-based coatings showed a higher corrosion resistance compared to conventional TiO2 coatings with significant photocatalytic activity to kill bacteria. The use of UV radiations for photo-inhibition of stainless steel in chloride solution can replace toxic inhibitors. Corrosion inhibition has also been achieved by using natural materials such as polymers instead of toxic chemical inhibitors, without adverse environmental impact. TiO2 films exposed to UV radiation have shown the capability to protect the steel without sacrificing the film. Self-healing materials with encapsulated nanoparticles in paints and coatings have shown to heal the defects caused by corrosion. These innovative techniques provide a direction to the corrosion scientists, engineers, and environmentalists who are concerned about the increasing contamination of the planet and maintaining a green environment.

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

Emerging surface characterization techniques for carbon steel corrosion: a critical brief review

OpenAIRE

Dwivedi, D.; Lepkova, K.; Becker, T.

2017-01-01

Carbon steel is a preferred construction material in many industrial and domestic applications, including oil and gas pipelines, where corrosion mitigation using film-forming corrosion inhibitor formulations is a widely accepted method. This review identifies surface analytical techniques that are considered suitable for analysis of thin films at metallic substrates, but are yet to be applied to analysis of carbon steel surfaces in corrosive media or treated with corrosion inhibitors. The rev...

Exopolysaccharides from lactic acid bacteria as corrosion inhibitors

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Ignatova-Ivanova Tsveteslava

2016-03-01

Full Text Available Bacterial EPSs (exopolysaccharides are believed to play an important role in the environment by promoting survival strategies such as bacterial attachment to surfaces and nutrient trapping, which facilitate processes of biofilm formation and development. These microbial biofilms have been implicated in corrosion of metals, bacterial attachment to prosthetic devices, fouling of heat exchange surfaces, toxicant immobilization, and fouling of ship hulls. In this paper, data on EPS production and the effect of EPS on corrosion of steel produced by Lactobacillus sp. are presented and discussed. Lactobacillus delbrueckii K27, Lactobacillus delbrueckii B8, Lactobacillus delbrueckii KO43, Lactobacillus delbrueckii K3, Lactobacillus delbrueckii K15 and Lactobacillus delbrueckii K17 was obtained from Collection of Department of General and Applied Microbiology, Sofia University. It was tested for its ability to produce exopolysaccharides when cultivated in a media containing 10% sucrose, 10% lacose and 10% maltose. The study of the corrosive stability of steel samples was conducted on the gravimetrique method. The rate of corrosion, the degree of protection, and coefficient of protection have been calculated. The structure of layer over steel plates was analysed by SEM (scanning electron microscopy JSM 5510. It could be underlined that 10% sucrose, 10% lactose and 10% maltose in the media stimulated the process of protection of corrosion.

Corrosion and anticorrosion. Industrial practice

International Nuclear Information System (INIS)

Beranger, G.; Mazille, H.

2002-01-01

This book comprises 14 chapters written with the collaboration of about 50 French experts of corrosion. It is complementary to another volume entitled 'corrosion of metals and alloys' and published by the same editor. This volume comprises two parts: part 1 presents the basic notions of corrosion phenomena, the properties of surfaces, the electrochemical properties of corrosion etc.. Part 2 describes the most frequent forms of corrosion encountered in industrial environments and corresponding to specific problems of protection: marine environment, atmospheric corrosion, galvanic corrosion, tribo-corrosion, stress corrosion etc.. The first 8 chapters (part 1) treat of the corrosion problems encountered in different industries and processes: oil and gas production, chemical industry, phosphoric acid industry, PWR-type power plants, corrosion of automobile vehicles, civil engineering and buildings, corrosion of biomaterials, non-destructive testing for the monitoring of corrosion. The other chapters (part 2) deal with anticorrosion and protective coatings and means: choice of materials, coatings and surface treatments, thick organic coatings and enamels, paints, corrosion inhibitors and cathodic protection. (J.S.)

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.)

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.

The repair and protection of reinforced concrete with migrating corrosion inhibitors

International Nuclear Information System (INIS)

Stefanescu, D.

2016-01-01

The concrete is a very durable construction material and his use is based on the principle that concrete is an ideal environment for steel if properly proportioned and placed. In general, reinforced concrete has proved to be successful in terms of both structural performance and durability. However, there are instances of premature failure of reinforced concrete components due to corrosion of the reinforcement. Experience has shown that there are certain portions of exposed concrete structures more vulnerable than others. Methodology for concrete repair it addresses to suggestions of the types of repair methods and materials and a detailed description of the uses, limitations, materials, and procedures for Repair of Concrete. At same the time the methodology presents recommendation on materials, methods of mixing, application, curing and precautions to be exercised during placement. This work presents guidelines for managing reinforced concrete components and specifies the repair strategy with inhibitors incorporating. (authors)

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.

Low Toxicity Corrosion Inhibitors for Smart Coatings, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — The Kennedy Space Center (KSC) is located near one of the most corrosive natural environments in the world. Corrosion of KSC ground assets is exacerbated by the...

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

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

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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.

Smart Coatings for Corrosion Protection

Science.gov (United States)

Calle, Luz Marina; Li, Wendy; Buhrow, Jerry W.; Johnsey, Marissa N.

2016-01-01

Nearly all metals and their alloys are subject to corrosion that causes them to lose their structural integrity or other critical functionality. It is essential to detect corrosion when it occurs, and preferably at its early stage, so that action can be taken to avoid structural damage or loss of function. Protective coatings are the most commonly used method of corrosion control. However, progressively stricter environmental regulations have resulted in the ban of many commercially available corrosion protective coatings due to the harmful effects of their solvents or corrosion inhibitors. This work concerns the development of a multifunctional, smart coating for the autonomous control of corrosion. This coating is being developed to have the inherent ability to detect the chemical changes associated with the onset of corrosion and respond autonomously to indicate it and control it.

Corrosion/94 conference papers

International Nuclear Information System (INIS)

Anon.

1994-01-01

The approximately 500 papers from this conference are divided into the following sections: Rail transit systems--stray current corrosion problems and control; Total quality in the coatings industry; Deterioration mechanisms of alloys at high temperatures--prevention and remediation; Research needs and new developments in oxygen scavengers; Computers in corrosion control--knowledge based system; Corrosion and corrosivity sensors; Corrosion and corrosion control of steel reinforced concrete structures; Microbiologically influenced corrosion; Practical applications in mitigating CO 2 corrosion; Mineral scale deposit control in oilfield-related operations; Corrosion of materials in nuclear systems; Testing nonmetallics for life prediction; Refinery industry corrosion; Underground corrosion control; Mechanisms and applications of deposit and scale control additives; Corrosion in power transmission and distribution systems; Corrosion inhibitor testing and field application in oil and gas systems; Decontamination technology; Ozone in cooling water applications, testing, and mechanisms; Corrosion of water and sewage treatment, collection, and distribution systems; Environmental cracking of materials; Metallurgy of oil and gas field equipment; Corrosion measurement technology; Duplex stainless steels in the chemical process industries; Corrosion in the pulp and paper industry; Advances in cooling water treatment; Marine corrosion; Performance of materials in environments applicable to fossil energy systems; Environmental degradation of and methods of protection for military and aerospace materials; Rail equipment corrosion; Cathodic protection in natural waters; Characterization of air pollution control system environments; and Deposit-related problems in industrial boilers. Papers have been processed separately for inclusion on the data base

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 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

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.

SERS and DFT study of copper surfaces coated with corrosion inhibitor

Directory of Open Access Journals (Sweden)

Maurizio Muniz-Miranda

2014-12-01

Full Text Available Azole derivatives are common inhibitors of copper corrosion due to the chemical adsorption occurring on the metal surface that gives rise to a protective film. In particular, 1,2,4-triazole performs comparable to benzotriazole, which is much more widely used, but is by no means an environmentally friendly agent. In this study, we have analyzed the adsorption of 1,2,4-triazole on copper by taking advantage of the surface-enhanced Raman scattering (SERS effect, which highlights the vibrational features of organic ligand monolayers adhering to rough surfaces of some metals such as gold, silver and copper. To ensure the necessary SERS activation, a roughening procedure was implemented on the copper substrates, resulting in nanoscale surface structures, as evidenced by microscopic investigation. To obtain sufficient information on the molecule–metal interaction and the formation of an anticorrosive thin film, the SERS spectra were interpreted with the aid of theoretical calculations based on the density functional theory (DFT approach.

Influence of increasing phosphate/silikate contents on the pitting and general corrosion of galvanized steel tubing and the corrosion of copper in warm water mixed installation systems

International Nuclear Information System (INIS)

Ehreke, J.; Stichel, W.

1989-01-01

In hot tap water (65 0 C) the influence of a mixture of phosphate/silicate inhibitor on the general, the pitting and the galvanic corrosion of galvanized steel tubes and the general corrosion of copper in mixed installations of both metals was investigated. Increasing concentration of inhibitors descreases the general corrosion rate of galvanized steel and copper. A worth mentioning reduction of pitting and galvanic corrosion of steel could be reached only with high concentrations of 5 mg/l P 2 O 5 and 30 mg/l SiO 2 . Galvannealed tubes are much more sensitive to pitting corrosion than galvanized ones. Referring to this they could not be inhibited. (orig.) [de

Corrosion inhibitors 26. Pt. 1

International Nuclear Information System (INIS)

Horner, L.; Pliefke, E.

1981-01-01

The analysis of the protective coating produced during the corrosion of copper in the presence of 2-aminopyrimidine (2-AP) is consistent with the composition [Cu 1 + -2-AP-Cl]sub(n). The individual units form a three-dimensional macro-structure via chloride bridging and hydrogen bonding. The assignment of the structure was supported by NMR, IR, UV and magnetic susceptibility measurements and an X-ray investigation using the Debye-Scherrer powder method. The thermal behaviour of the coating was studied by mass-spectral and DTA (differential thermal analysis) methods. Radiochemical experiments were carried out using active copper samples (i.e. containing 64 Cu), or using added 64 CuCl and 64 CuCl 2 in the corrosion of non-active copper both in the presence and absence of added 2-AP. The results elucidate the exchange reactions at the copper surface between dissolved and metallic components. The equilibrium between Cu 2 + and metallic copper on the one hand and 2 Cu 1 + ions on the other is central to the problem, as is also the dissociation of the [Cu 1 + -2-AP-Cl]sub(n) complex. The concepts here developed were confirmed by studies of the autoxidation of CuCl and CuO in the presence and absence of 2-AP. (orig.)

Wire-Arc-Sprayed Aluminum Protects Steel Against Corrosion

Science.gov (United States)

Zimmerman, Frank R.; Poorman, Richard; Sanders, Heather L.; Mckechnie, Timothy N.; Bonds, James W., Jr.; Daniel, Ronald L., Jr.

1995-01-01

Aluminum coatings wire-arc sprayed onto steel substrates found effective in protecting substrates against corrosion. Coatings also satisfy stringent requirements for adhesion and flexibility, both at room temperature and at temperatures as low as liquid hydrogen. Developed as alternatives to corrosion-inhibiting primers and paints required by law to be phased out because they contain and emit such toxic substances as chromium and volatile organic compounds.

2-Mercaptopyrimidine as an effective inhibitor for the corrosion of cold rolled steel in HNO_3 solution

International Nuclear Information System (INIS)

Li, Xianghong; Deng, Shuduan; Lin, Tong; Xie, Xiaoguang; Du, Guanben

2017-01-01

Highlights: • MP acts an effective inhibitor in HNO_3, but other pyrimidine derivatives are poor. • MP is a mixed inhibitor, while mainly retards anodic reaction. • EIS exhibit depressed capacitive loops whose diameters are increased with MP. • The most active adsorption site is S atom for any MP molecular form. • The adsorptive order is thiol-MP < thione-MP < p-thiol-MP < p-thione-MP. - Abstract: The inhibition effect of five pyrimidine derivatives (2-chloropyrimidine, 2-hydroxypyrimidine, 2-bromopyrimidine, 2-aminopyrimidine, 2-mercaptopyrimidine) on the corrosion of cold rolled steel (CRS) in 0.1 M HNO_3 solution was comparatively examined. 2-Mercaptopyrimidine (MP) was found to be an effective inhibitor with the inhibition efficiency as high as 99.1% at a low concentration 0.50 mM. But other four pyrimidine derivatives exhibited poor inhibitive ability. The addition of MP caused both anodic and cathodic curves to low current densities, and was found to significantly strengthen the impedance. Quantum chemical calculation and molecular dynamic simulation were performed to theoretically investigate the adsorption mechanism.

Corrosion mitigation of J55 steel in 3.5% NaCl solution by a macrocyclic inhibitor

Energy Technology Data Exchange (ETDEWEB)

Singh, Ambrish [State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation (Southwest Petroleum University), Chengdu, Sichuan 610500 (China); Department of Chemistry, LFTS, Lovely Professional University, Phagwara, Punjab 144402 (India); Lin, Yuanhua, E-mail: yhlin28@163.com [State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation (Southwest Petroleum University), Chengdu, Sichuan 610500 (China); Obot, I.B. [Centre of Research Excellence in Corrosion, Research Institute, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Ebenso, Eno E. [Department of Chemistry, School of Mathematical & Physical Sciences, North-West University (Mafikeng Campus), Private Bag X2046, Mmabatho 2735 (South Africa); Material Science Innovation & Modelling (MaSIM) Focus Area, Faculty of Agriculture, Science and Technology, North-West University (Mafikeng Campus), Private Bag X2046, Mmabatho 2735 (South Africa); Ansari, K.R.; Quraishi, M.A. [Department of Applied Chemistry, Indian Institute of Technology, Banaras Hindu University, Varanasi 221005, Uttar Pradesh (India)

2015-11-30

Graphical abstract: SECM studies revealed decrease of steady current in the presence of inhibitor while it increased for 3.5% NaCl solution that acted as the conductor. - Highlights: • J55 steel protection in 3.5% NaCl solution saturated with CO{sub 2} by HPT. • Potentiodynamic polarization curves reveal that the actions of HPT are mixed type. • The adsorption of HPT obeys the Langmuir adsorption isotherm. • Scanning electrochemical microscopy is used to discuss the insulated and conductive surface. - Abstract: 1,2,4,7,9,10-Hexaazacyclo-pentadeca-10,15-dien-3,5,6,8-tetraone (HPT) a macrocyclic compound has been studied using electrochemical methods and scanning electrochemical microscopy (SECM) techniques. The R{sub ct} values increased and C{sub dl} values decreased with the increase in concentration of the inhibitor. The corrosion inhibition of J55 steel in 3.5 wt.% NaCl solution saturated with CO{sub 2} by polarization studies revealed that HPT acted as a mixed type inhibitor. The adsorption of HPT on the J55 steel surface obeyed the Langmuir adsorption isotherm. The thermodynamic parameters (K{sub ads}, ΔG°{sub ads}) were also computed and discussed.

Corrosion mitigation of J55 steel in 3.5% NaCl solution by a macrocyclic inhibitor

International Nuclear Information System (INIS)

Singh, Ambrish; Lin, Yuanhua; Obot, I.B.; Ebenso, Eno E.; Ansari, K.R.; Quraishi, M.A.

2015-01-01

Graphical abstract: SECM studies revealed decrease of steady current in the presence of inhibitor while it increased for 3.5% NaCl solution that acted as the conductor. - Highlights: • J55 steel protection in 3.5% NaCl solution saturated with CO 2 by HPT. • Potentiodynamic polarization curves reveal that the actions of HPT are mixed type. • The adsorption of HPT obeys the Langmuir adsorption isotherm. • Scanning electrochemical microscopy is used to discuss the insulated and conductive surface. - Abstract: 1,2,4,7,9,10-Hexaazacyclo-pentadeca-10,15-dien-3,5,6,8-tetraone (HPT) a macrocyclic compound has been studied using electrochemical methods and scanning electrochemical microscopy (SECM) techniques. The R ct values increased and C dl values decreased with the increase in concentration of the inhibitor. The corrosion inhibition of J55 steel in 3.5 wt.% NaCl solution saturated with CO 2 by polarization studies revealed that HPT acted as a mixed type inhibitor. The adsorption of HPT on the J55 steel surface obeyed the Langmuir adsorption isotherm. The thermodynamic parameters (K ads , ΔG° ads ) were also computed and discussed.

Investigation of SiO{sub 2}:Na{sub 2}O ratio as a corrosion inhibitor for metal alloys

Energy Technology Data Exchange (ETDEWEB)

Mohamad, N.; Othman, N. K. [School of Applied Physics, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor Darul Ehsan (Malaysia); Jalar, A. [Institute of Micro Engineering and Nanoelectronics (IMEN), Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor Darul Ehsan (Malaysia)

2013-11-27

The silicate is one of the potential compounds used as a corrosion inhibitor for metal alloys. The mixture between silica and sodium hydroxide (NaOH) succeeded to produce the silicate product. The formulation of a silicate product normally variable depended by the different ratio of SiO{sub 2}:Na{sub 2}O. This research utilized the agriculture waste product of paddy using its rice husk. In this study, the amorphous silica content in rice husk ash was used after rice husk burnt in a muffle furnace at a certain temperature. The X-ray diffraction (XRD) analysis was done to determine the existence of amorphous phase of silica in the rice husk ash. There are several studies that recognized rice husk as an alternative source that obtained high silica content. The X-ray fluorescence (XRF) analysis was carried out to clarify the percentage amount of Si and O elements, which referred the silica compound in rice husk ash. The preparation of sodium silicate formulation were differ based on the SiO{sub 2}:Na{sub 2}O ratio (SiO{sub 2}:Na{sub 2}O ratio = 1.00, 2.00 and 3.00). These silicate based corrosion inhibitors were tested on several testing samples, which were copper (99.9%), aluminum alloy (AA 6061) and carbon steel (SAE 1045). The purpose of this study is to determine the appropriate SiO{sub 2}:Na{sub 2}O ratio and understand how this SiO{sub 2}:Na{sub 2}O ratio can affect the corrosion rate of each metal alloys immersed in acidic medium. In order to investigate this study, weight loss test was conducted in 0.5 M hydrochloric acid (HCl) for 24 hours at room temperature.

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 ...

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)

Fluvoxamine-based corrosion inhibitors for J55 steel in aggressive oil and gas well treatment fluids

Directory of Open Access Journals (Sweden)

E.B. Ituen

2017-09-01

Full Text Available Fluvoxamine (FLU, a non-toxic compound was investigated as an alternative anti-corrosive additive for inhibition of J55 steel corrosion in acidic oil well treatment fluids. The aggressive fluid was simulated using 15% and 1 M HCl. Corrosion of the steel was monitored by Electrochemical Impedance Spectroscopy (EIS, Potentiodynamic Polarization (PDP, Linear Polarization Resistance (LPR, Electrochemical Frequency Modulation (EFM and Weight Loss (WL techniques. UV–Vis spectroscopy provided evidence of formation of a complex surface film due to adsorption of FLU on the J55 steel surface. The adsorption process was both physical and chemical in mechanism as best approximated by the Langmuir adsorption isotherm. The adsorption was also spontaneous and exothermic in the direction of increase in entropy of the bulk phase. Maximum inhibition efficiency was obtained with 1.0 μM FLU and decreased from 91.5% to 78.0% when concentration of HCl was increased from 1 M to 15% at 30 °C. Effectiveness of FLU declined with an increase in temperature and improved with an increase in concentration of FLU. Blending of FLU with some intensifiers improved the efficiency from 68% and 40% to 88% and 72% in 1 M and 15% HCl respectively at 90 °C. EIS measurement reveals that the corrosion process was controlled by charge transfer process. PDP measurements showed that FLU acts as a mixed type inhibitor. Inhibition efficiency values obtained from the different techniques were comparable. SEM micrographs of J55 steel surface indicate good surface protection of FLU. Theoretical calculations were performed using Material Studio Acceryls 7.0 to relate electronic properties of FLU with its structure.

Development of Novel Corrosion Techniques for a Green Environment

OpenAIRE

Ahmad, Zaki; Patel, Faheemuddin

2012-01-01

The synergistic effect of air pollution, brown clouds and greenhouse gasses is deleterious to human health and industrial products. The use of toxic inhibitors, chemicals in water treatment plants, and anti-fouling agents in desalination plants has contributed to the greenhouse effect. Conventional anti-corrosion techniques such as paints, coatings, inhibitor treatments, and cathodic protection paid no regard to greenhouse effect. Work on eco-friendly anti-corrosion techniques is scanty and l...

EXTRACT OF COMBRETUM MICRANTHUM AS CORROSION ...

African Journals Online (AJOL)

user

2016-10-04

Oct 4, 2016 ... methanol extract CM is a good adsorption inhibitor for the corrosion of Al-Si-Mg in 3.5wt% NaCl solution. Tafel polarization analysis indicates that the studied plant extract is a mixed ..... (2008). [2] Shreir, L. L., Jarman, R. A. and Burstein, G. T.. Corrosion ... [6] Maqsood Ahmad Malik, Mohammad Ali Hashim,.

Recent Developments on Microencapsulation for Autonomous Corrosion Protection

Science.gov (United States)

Calle, Luz M.; Li, Wenyan; Buhrow, Jerry W.; Fitzpatrick, Lilliana; Jolley, Scott T.; Surma, Jan M.; Pearman, Benjamin P.; Zhang, Xuejun

2014-01-01

This work concerns recent progress in the development of a multifunctional smart coating based on microencapsulation for the autonomous control of corrosion. Microencapsulation allows the incorporation of desired corrosion control functionalities, such as early corrosion detection and inhibition through corrosion controlled release of corrosion indicators and inhibitors, as well as self-healing agent release when mechanical damage occurs.While proof-of-concept results have been reported previously, more recent efforts have been concentrated in technical developments to improve coating compatibility, synthesis procedure scalability, as well as fine tuning the release property of encapsulated active agents.

Treatment screening for internal corrosion control of PETROBRAS oil pipelines; Selecao de tratamento para controle da corrosao interna de oleodutos da PETROBRAS

Energy Technology Data Exchange (ETDEWEB)

Andrade, Cynthia de Azevedo; Muller, Eduardo Gullo [PETROBRAS, Rio de Janeiro, RJ (Brazil). Centro de Pesquisas; Antunes, Warlley Ligorio; Shioya, Nilce Hiromi; Salvador, Angelica Dias [PETROBRAS, RJ (Brazil). Unidade de Negocios da Bacia de Campos

2005-07-01

The use of corrosion inhibitors is spread out in oil and gas industry and is the most common methodology to control pipeline internal corrosion. However, their effectiveness depends on the pipeline material, inhibitor composition, flow type and scale characteristics. When a pipeline has heavy scale deposits, thick bacterial biofilm, or oxygen contamination, the corrosion control via filmic inhibitors is not effective. So, the only way to control internal corrosion of an oil pipeline is to primary identifies the corrosive agent and the main corrosion mechanism. The monitoring of the inhibitor efficiency and the determination of minimal residual concentration to prevent corrosion, are also fundamental. In this paper, is presented the criteria used to identify the main corrosion mechanism of oil pipelines, the treatment proposed in each case and the techniques employed in real time corrosion monitoring. (author)

Corrosion Control in the Aerospace Industry

Science.gov (United States)

Calle, Luz Marina; Li, Wenyan; Buhrow, Jerry W.; Johnsey, Marissa N.

2016-01-01

Nearly all metals and their alloys are subject to corrosion that causes them to lose their structural integrity or other critical functionality. It is essential to detect corrosion when it occurs, and preferably at its early stage, so that action can be taken to avoid structural damage or loss of function. Protective coatings are the most commonly used method of corrosion control. However, progressively stricter environmental regulations have resulted in the ban of many commercially available corrosion protective coatings due to the harmful effects of their solvents or corrosion inhibitors. This work concerns the development of a multifunctional, smart coating for the autonomous control of corrosion. This coating is being developed to have the inherent ability to detect the chemical changes associated with the onset of corrosion and respond autonomously to indicate it and control it..

New Mechanism on Synergistic Effect of Nitrite and Triethanolamine Addition on the Corrosion of Ductile Cast Iron

Directory of Open Access Journals (Sweden)

K. T. Kim

2016-01-01

Full Text Available In general, we compared the different inhibition mechanisms of organic inhibitor with that of anodic inhibitor. When triethanolamine or nitrite was added separately to tap water for inhibiting the corrosion of ductile cast iron, large amounts of inhibitor were needed. This is because the corrosion inhibitors had to overcome the galvanic corrosion that occurs between graphite and matrix. In this work, we investigated the corrosion of ductile cast iron in tap water with/without inhibitors. The corrosion rate was measured using chemical immersion test and electrochemical methods, including anodic polarization test. The inhibited surface was analyzed using EPMA and XPS. Test solutions were analyzed by performing FT-IR measurement. When triethanolamine and nitrite coexisted in tap water, synergistic effect built up, and the inhibition effect was ca. 30 times more effective than witnessed with single addition. This work focused on the synergistic effect brought about by nitrite and triethanolamine and its novel mechanism was also proposed.

Monitoring corrosion and corrosion control of iron in HCl by non-ionic surfactants of the TRITON-X series - Part II. Temperature effect, activation energies and thermodynamics of adsorption

International Nuclear Information System (INIS)

Amin, Mohammed A.; Ahmed, M.A.; Arida, H.A.; Arslan, Taner; Saracoglu, Murat; Kandemirli, Fatma

2011-01-01

Research highlights: → TX-305 exhibits inhibiting properties for iron corrosion more than TX-165 and TX 100. → Inhibition efficiency increases with temperature, suggesting chemical adsorption. → The three tested surfactants act as mixed-type inhibitors with cathodic predominance. → Validation of corrosion rates measured by Tafel extrapolation method is confirmed. - Abstract: The inhibition characteristics of non-ionic surfactants of the TRITON-X series, namely TRITON-X-100 (TX-100), TRITON-X-165 (TX-165) and TRITON-X-305 (TX-305), on the corrosion of iron was studied in 1.0 M HCl solutions as a function of inhibitor concentration (0.005-0.075 g L -1 ) and solution temperature (278-338 K). Measurements were conducted based on Tafel extrapolation method. Electrochemical frequency modulation (EFM), a non-destructive corrosion measurement technique that can directly give values of corrosion current without prior knowledge of Tafel constants, is also presented. Experimental corrosion rates determined by the Tafel extrapolation method were compared with corrosion rates obtained by the EFM technique and an independent method of chemical analysis. The chemical method of confirmation of the corrosion rates involved determination of the dissolved cation, using ICP-AES (inductively coupled plasma atomic emission spectrometry). The aim was to confirm validation of corrosion rates measured by the Tafel extrapolation method. Results obtained showed that, in all cases, the inhibition efficiency increased with increase in temperature, suggesting that chemical adsorption occurs. The adsorptive behaviour of the three surfactants followed Temkin-type isotherm. The standard free energies of adsorption decreased with temperature, reflecting better inhibition performance. These findings confirm chemisorption of the tested inhibitors. Thermodynamic activation functions of the dissolution process were also calculated as a function of each inhibitor concentration. All the results

Corrosion and Protection of Metal in the Seawater Desalination

Science.gov (United States)

Hou, Xiangyu; Gao, Lili; Cui, Zhendong; Yin, Jianhua

2018-01-01

Seawater desalination develops rapid for it can solve water scarcity efficiently. However, corrosion problem in the seawater desalination system is more serious than that in normal water. So, it is important to pay attention to the corrosion and protection of metal in seawater desalination. The corrosion characteristics and corrosion types of metal in the seawater desalination system are introduced in this paper; In addition, corrosion protect methods and main influencing factors are stated, the latest new technologies about anti-corrosion with quantum energy assisted and magnetic inhibitor are presented.

Corrosion Inhibition of Aluminium in Acid Media By Citrullus Colocynthis Extract

Directory of Open Access Journals (Sweden)

Rajkiran Chauhan

2011-01-01

Full Text Available Inhibition of corrosion of aluminium in acid solution by methanol extract of Citrullus colocynthis plant has been studied using mass loss and thermometric measurements. It has been found that the plant extract act as a good corrosion inhibitor for aluminium in all concentrations of sulphuric and hydrochloric acid solution. The inhibition action depends on the concentration of acid and inhibitor. Results for mass loss and thermometric measurement indicate that inhibition efficiency increase with increasing inhibitor concentration. The inhibition action of the plant extract is discussed in view of Langmuir adsorption isotherm. It has been observed that the adsorption of the extract on aluminium surface is a spontaneous process. The plant extract provides a good protection to aluminium against corrosion.

Microencapsulation Technologies for Corrosion Protective Coating Applications

Science.gov (United States)

Li, Wenyan; Buhrow, Jerry; Jolley, Scott; Calle, Luz; Pearman, Benjamin; Zhang, Xuejun

2015-01-01

Microencapsulation technologies for functional smart Coatings for autonomous corrosion control have been a research area of strong emphasis during the last decade. This work concerns the development of pH sensitive micro-containers (microparticles and microcapsules) for autonomous corrosion control. This paper presents an overview of the state-of-the-art in the field of microencapsulation for corrosion control applications, as well as the technical details of the pH sensitive microcontainer approach, such as selection criteria for corrosion indicators and corrosion inhibitors; the development and optimization of encapsulation methods; function evaluation before and after incorporation of the microcontainers into coatings; and further optimization to improve coating compatibility and performance.

Investigation with slow traction conditions of the stress corrosion of carbon steels in alkaline media. Role of passivating inhibitors

International Nuclear Information System (INIS)

Miroud, Lakhdar

1991-01-01

The stress corrosion cracking (S.C.C.) sensitivity of carbon steels in basic media, such as carbonates, is well known. A constant strain-rate test have allowed to observe two steels (A42 [E26] and XC38) behaviour in such conditions at pH 9. The S.C.C. potentials susceptibility range has been found. Inter and Trans-granular cracking have been revealed and measured with micrographic methods. A crack growth rate has been studied as a function of strain rate: an experimental rate has been compared to calculated values from methods which have proposed previously, and methods which have been elaborated in this work. These last permit a best approach of cracking in our case. The chromates use, as inhibitor ions, has permit to decrease the corrosive attack and to cancel the crack growth rate. (author) [fr

Molecular dynamics and quantum chemical calculation studies on 4,4-dimethyl-3-thiosemicarbazide as corrosion inhibitor in 2.5 M H{sub 2}SO{sub 4}

Energy Technology Data Exchange (ETDEWEB)

Musa, Ahmed Y., E-mail: ahmed.musa@ymail.com [Department of Chemical and Process Engineering, Universiti Kebangsaan Malaysia, Bangi 43600, Selangor (Malaysia); Kadhum, Abdul Amir H.; Mohamad, Abu Bakar; Takriff, Mohd Sobri [Department of Chemical and Process Engineering, Universiti Kebangsaan Malaysia, Bangi 43600, Selangor (Malaysia)

2011-09-15

Highlights: {yields} This work deals with a study of chemical additives for corrosion inhibition of mild steel in acidic conditions. {yields} The effects of the additive 4,4-dimethyl-3-thiosemicarbazide (DTS) on mild steel were studied by means of electrochemical techniques. {yields} Quantum chemical calculations and molecular dynamic model were performed to characterize the inhibition mechanism. {yields} The calculations provided information that helps in the analysis/interpretation of the experimental work. - Abstract: The inhibition of mild steel corrosion in a 2.5 M H{sub 2}SO{sub 4} solution by 4,4-dimethyl-3-thiosemicarbazide (DTS) was studied at 30 deg. C using potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). Quantum chemical parameters were calculated for DTS using PM3-SCF method. The molecular dynamic method was performed to simulate the adsorption of the DTS molecules on Fe surface. Results showed that DTS performed excellent as inhibitor for mild steel corrosion in a 2.5 M H{sub 2}SO{sub 4} solution and indicated that the inhibition efficiencies increase with the concentration of inhibitor. Theoretical results indicated that DTS could adsorb on the mild steel surface firmly through heteroatoms.

Corrosion inhibition of brass by aliphatic amines

International Nuclear Information System (INIS)

Taha, K. K.; Sheshadri, B. S; Ahmed, M. F.

2005-01-01

Aliphatic amines hexylamine (HCA), octylamine (OCA) and decylamine (DCA) have been used as corrosion inhibitors for (70/30) brass in 0.I M HCIO 4 . The inhibitor efficiency (%P) calculated using weight loss, Tafel extrapolation, linear polarization and impedance methods was found to be in the order DCA> OCA> HCA. These adsorb on brass surface following bockris-swinkels' isotherm. DCA, OCA and HCA displaced 4, 3 and 2 molecules of water from interface respectively. Displacement of water molecules brought a great reorganization of double layer at the interface. These amines during corrosion form complexes with dissolved zinc and copper ions.(Author)

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.

Inhibiting Effect of Nicotinic Acid Hydrazide on Corrosion of Aluminum and Mild Steel in Acidic Medium

Energy Technology Data Exchange (ETDEWEB)

Bhat, J. Ishwara [Mangalore Univ., Karnataka (India); Alva, Vijaya D. P. [Shree Devi Institute of Technology, Karnataka (India)

2014-02-15

The corrosion behavior of aluminum and mild steel in hydrochloric acid medium was studied using a nicotinic acid hydrazide as inhibitor by potentiodynamic polarization, electrochemical impedance spectroscopy technique and gravimetric methods. The effects of inhibitor concentration and temperature were investigated. The experimental results suggested, nicotinic acid hydrazide is a good corrosion inhibitor for both aluminum and mild steel in hydrochloric acid medium and the inhibition efficiency increased with increase in the inhibitor concentration. The polarization studies revealed that nicotinic acid hydrazide exhibits mixed type of inhibition. The inhibition was assumed to occur via adsorption of the inhibitor molecules on the aluminum and mild steel surface and inhibits corrosion by blocking the reaction sites on the surface of aluminum.

Inhibiting Effect of Nicotinic Acid Hydrazide on Corrosion of Aluminum and Mild Steel in Acidic Medium

International Nuclear Information System (INIS)

Bhat, J. Ishwara; Alva, Vijaya D. P.

2014-01-01

The corrosion behavior of aluminum and mild steel in hydrochloric acid medium was studied using a nicotinic acid hydrazide as inhibitor by potentiodynamic polarization, electrochemical impedance spectroscopy technique and gravimetric methods. The effects of inhibitor concentration and temperature were investigated. The experimental results suggested, nicotinic acid hydrazide is a good corrosion inhibitor for both aluminum and mild steel in hydrochloric acid medium and the inhibition efficiency increased with increase in the inhibitor concentration. The polarization studies revealed that nicotinic acid hydrazide exhibits mixed type of inhibition. The inhibition was assumed to occur via adsorption of the inhibitor molecules on the aluminum and mild steel surface and inhibits corrosion by blocking the reaction sites on the surface of aluminum

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.

The effect of borate and phosphate inhibitors on corrosion rate material SS321 and incoloy 800 in chloride containing solution by using potentiodynamic method

International Nuclear Information System (INIS)

Febriyanto; Sriyono; Satmoko, Ari

1998-01-01

Determination of corrosion rate of steam generator materials (SS 321 and incoloy 800) in chloride containing solution using potentiodynamic method from CMS 100. NaCl 1%, 3% and 5% solution using is used as tested solution. A tested material is grounded by grinding paper on grade 400 600, 800 and 1000, then polished by METADI 1/4 microns paste to get homogeneity. Furthermore, the tested materials is mounted by epoxide resin, so only the surface which contacts to tested solution is open. From the result obtained that borate and phosphate inhibitor can reduce corrosion rate and aggressiveness of chloride ion

DEVELOPMENT OF AN ENVIRONMENTALLY BENIGN MICROBIAL INHIBITOR TO CONTROL INTERNAL PIPELINE CORROSION

Energy Technology Data Exchange (ETDEWEB)

Bill W. Bogan; Brigid M. Lamb; John J. Kilbane II

2004-10-30

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. Previous testing indicated that the growth, and the metal corrosion caused by pure cultures of sulfate reducing bacteria were inhibited by hexane extracts of some pepper plants. This quarter tests were performed to determine if chemical compounds other than pepper extracts could inhibit the growth of corrosion-associated microbes and to determine if pepper extracts and other compounds can inhibit corrosion when mature biofilms are present. Several chemical compounds were shown to be capable of inhibiting the growth of corrosion-associated microorganisms, and all of these compounds limited the amount of corrosion caused by mature biofilms to a similar extent. It is difficult to control corrosion caused by mature biofilms, but 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.

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.

Corrosion control. 2. ed.

International Nuclear Information System (INIS)

Bradford, S.A.

2001-01-01

The purpose of this text is to train engineers and technologists not just to understand corrosion but to control it. Materials selection, coatings, chemical inhibitors, cathodic and anodic protection, and equipment design are covered in separate chapters. High-temperature oxidation is discussed in the final two chapters ne on oxidation theory and one on controlling oxidation by alloying and with coatings. This book treats corrosion and high-temperature oxidation separately. Corrosion is divided into three groups: (1) chemical dissolution including uniform attack, (2) electrochemical corrosion from either metallurgical or environmental cells, and (3) stress-assisted corrosion. Corrosion is logically grouped according to mechanisms rather than arbitrarily separated into different types of corrosion as if they were unrelated. For those university students and industry personnel who approach corrosion theory very hesitantly, this text will present the electrochemical reactions responsible for corrosion summed up in only five simple half-cell reactions. When these are combined on a polarization diagram, which is also explained in detail, the electrochemical processes become obvious. For those who want a text stripped bare of electrochemical theory, several noted sections can be omitted without loss of continuity. However, the author has presented the material in such a manner that these sections are not beyond the abilities of any high school graduate who is interested in technology

Research on A3 steel corrosion behavior of basic magnesium sulfate cement

Science.gov (United States)

Xing, Sainan; Wu, Chengyou; Yu, Hongfa; Jiang, Ningshan; Zhang, Wuyu

2017-11-01

In this paper, Tafel polarization technique is used to study the corrosion behavior of A3 steel basic magnesium sulfate, and then analyzing the ratio of raw materials cement, nitrites rust inhibitor and wet-dry cycle of basic magnesium sulfate corrosion of reinforced influence, and the steel corrosion behavior of basic magnesium sulfate compared with magnesium oxychloride cement and Portland cement. The results show that: the higher MgO/MgSO4 mole ratio will reduce the corrosion rate of steel; Too high and too low H2O/MgSO4 mole ratio may speed up the reinforcement corrosion effect; Adding a small amount of nitrite rust and corrosion inhibitor, not only can obviously reduce the alkali type magnesium sulfate in the early hydration of cement steel bar corrosion rate, but also can significantly reduce dry-wet circulation under the action of alkali type magnesium sulfate cement corrosion of reinforcement effect. Basic magnesium sulfate cement has excellent ability to protect reinforced, its long-term corrosion of reinforcement effect and was equal to that of Portland cement. Basic magnesium sulfate corrosion of reinforced is far below the level in the MOC in the case.

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

Cerium-loaded algae exoskeletons for active corrosion protection of coated AA2024-T3

International Nuclear Information System (INIS)

Denissen, Paul J.; Garcia, Santiago J.

2017-01-01

Highlights: •Nanoporous diatom algae exoskeletons allow for local inhibitor loading. •Cerium loaded exoskeletons show diffusion controlled release from coatings. •In-situ opto-electrochemical analysis allows for accurate corrosion evaluation. •Raman spectroscopy allows for precise identification of Ce at IMs in a scribe. •High levels of protection were obtained with the Ce-diatom coatings. -- Abstract: The use of micron sized nanoporous diatom algae exoskeletons for inhibitor storage and sustained corrosion protection of coated aluminium structures upon damage is presented. In this concept the algae exoskeleton allows local inhibitor loading, limits the interaction between the cerium and the epoxy/amine coating and allows for diffusion-controlled release of the inhibitor when needed. The inhibitor release and corrosion protection by loaded exoskeletons was evaluated by UV/Vis spectrometry, a home-built optical-electrochemical setup, and Raman spectroscopy. Although this concept has been proven for a cerium-epoxy-aluminium alloy system the main underlying principle can be extrapolated to other inhibitor-coating-metal systems.

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).

Ampicillin potentials as Corrosion Inhibitor: fukui function ...

African Journals Online (AJOL)

The experimental study was carried out using gravimetric and Fourier transform infrared spectroscopy methods of monitoring corrosion while the computational study was carried out using quantum chemical approach via Hyperchem program suit. The results obtained showed that various concentrations of ampicillin ...

Synthetic sea water - An improved stress corrosion test medium for aluminum alloys

Science.gov (United States)

Humphries, T. S.; Nelson, E. E.

1973-01-01

A major problem in evaluating the stress corrosion cracking resistance of aluminum alloys by alternate immersion in 3.5 percent salt (NaCl) water is excessive pitting corrosion. Several methods were examined to eliminate this problem and to find an improved accelerated test medium. These included the addition of chromate inhibitors, surface treatment of specimens, and immersion in synthetic sea water. The results indicate that alternate immersion in synthetic sea water is a very promising stress corrosion test medium. Neither chromate inhibitors nor surface treatment (anodize and alodine) of the aluminum specimens improved the performance of alternate immersion in 3.5 percent salt water sufficiently to be classified as an effective stress corrosion test method.

Inhibition of Weld Corrosion in Flowing Brines Containing Carbon Dioxide

OpenAIRE

Alawadhi, Khaled

2009-01-01

The aim of this research was to study the effectiveness of a typical oilfield corrosion inhibitor, which is considered to be a green inhibitor (non toxic to the environment) in controlling internal corrosion of welded X65 pipeline steel in brines saturated with carbon dioxide at one bar pressure, under dynamic flowing conditions, over a range of temperatures. Several experimental configurations were used ranging from a simple flat plate design to a novel rotating cylinder electrode, to all...

Protecting solar collector systems from corrosion

Energy Technology Data Exchange (ETDEWEB)

1978-01-01

The main cause of the reduced life of a solar heating system is corrosion of the exterior parts and the internal components. This report outlines ways of reducing the cost of solar heating by reducing the corrosion in solar heating systems, and hence increasing the system's service life. Mechanisms for corrosion are discussed: these include galvanic corrosion and crevice corrosion. Means of minimizing corrosion at the design stage are then described. Such methods, when designing the solar collector, involve ensuring proper drainage of exterior water; eliminating situations where moisture, dirt and pollutants may collect; preventing condensation inside the collector; using proper gaskets and sealants at appropriate places; and selecting optimum materials and coatings. Interior corrosion can be minimized at the design stage by choosing a good heat transfer fluid and corrosion inhibitor, in the case of systems where liquids are used; ensuring a low enough flow rate to avoid erosion; designing the system to avoid crevices; and avoiding situations where galvanic corrosion could occur. Other procedures are given for minimizing corrosion in the construction and operation of solar heating systems. 7 figs., 7 tabs.

Some aspects of the role of inhibitors in the corrosion of copper in tap water as observed by cyclic voltammetry

International Nuclear Information System (INIS)

Bi, H.; Burstein, G.T.; Rodriguez, B.B.; Kawaley, G.

2016-01-01

Highlights: • The presence of Fernox ® inhibits both the anodic and cathodic reactions of copper in tap water, with the anodic reaction more heavily supressed. • Fernox ® is more inhibitive than the individual components, BTA or TEA, and also more inhibitive than a mixture of the two. • BTA is the dominant inhibitive component of Fernox ® . TEA also inhibits the reaction, but less effectively. • The inhibitors show the same degree of inhibition and the same mechanism of inhibition in hard and soft tap water. • A mechanism of inhibition is proposed whereby the inhibitor forms a film on the surface, which is reactive: surface polymerization of the reactive inhibitor is proposed. - Abstract: Cyclic voltammetric examination of the corrosion and inhibition of copper in hard and soft tap-waters in the presence of a commercial inhibitor containing benzotriazole (BTA) and triethanolamine (TEA), or its separate components, is presented. The anodic and cathodic reactions are both strongly inhibited, although the anodic reaction more so. BTA is by far the dominant inhibiting component. The inhibitor forms a polymerized reactive adsorbed surface film. Inhibition of the cathodic reaction (oxygen reduction) is not due to electron resistivity of the inhibitor, but rather, by heavily reduced surface coverage of adsorbed oxygen over a wide range of oxygen reduction overpotential.

Corrosion of beryllium oxide; Corrosion de l'oxyde de beryllium

Energy Technology Data Exchange (ETDEWEB)

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

1958-07-01

Data are reported on the volatilization rate of beryllium oxide in moist air depending on temperature and water vapour concentration. They are concerned with powder samples or sintered shapes of various densities. For sintered samples, the volatilization rate is very low under the following conditions: - temperature: 1300 deg. C, - water vapour concentration in moist air: 25 g/m{sup 3}, - flow rate: 12 I/hour corresponding to a speed of 40 m/hour on the surface of the sample. For calcinated powders (1300 deg. C), grain growth has been observed under a stream of moist air at 1100 deg. C. For instance, grain size changes from 0,5 to at least 2 microns after 500 hours of exposure at this temperature. Furthermore, results data are reported on corrosion of sintered beryllium oxide in pressurized water. At 250 deg. C, under a pressure of 40 kg/cm{sup 2} water is very slightly corrosive; however, internal strains are revealed. Finally, some features on the corrosion in liquid sodium are exposed. (author)Fren. [French] La volatilisation de l'oxyde de beryllium dans l'air humide est etudiee en fonction de la temperature pour differentes teneurs de vapeur d'eau. Les essais decrits portent sur de l'oxyde de beryllium en poudre ou sur des echantillons d'oxyde de beryllium fritte de differentes densites. Avec un debit d'air de 12 I/h contenant 25 g de vapeur par m{sup 3} correspondant a une vitesse de 40 m/h sur la surface de l'echantillon, la volatilisation des frittes a 1300 deg. C reste tres faible. Sur de la poudre d'oxyde de beryllium calcinee initialement a 1300 deg. C, on observe un grossissement de la taille des grains sous l'influence de l'air humide a 1100 deg. C. Par exemple, elle passe de 0,5 a au moins 2 microns apres 500 heures d'exposition a cette temperature. On donne d'autre part les resultats d'une etude de la corrosion de frittes d'oxyde de beryllium par l'eau, en autoclave. A 250 deg. C, sous une pression de 40 kg/cm{sup 2}, l'action de l'eau reste tres

In situ analysis of corrosion inhibitors using a portable mass spectrometer with paper spray ionization.

Science.gov (United States)

Jjunju, Fred P M; Li, Anyin; Badu-Tawiah, Abraham; Wei, Pu; Li, Linfan; Ouyang, Zheng; Roqan, Iman S; Cooks, R Graham

2013-07-07

Paper spray (PS) ambient ionization is implemented using a portable mass spectrometer and applied to the detection of alkyl quaternary ammonium salts in a complex oil matrix. These salts are commonly used as active components in the formulation of corrosion inhibitors. They were identified in oil and confirmed by their fragmentation patterns recorded using tandem mass spectrometry (MS/MS). The cations of alkyl and benzyl-substituted quaternary ammonium salts showed characteristic neutral losses of CnH2n (n carbon number of the longest chain) and C7H8, respectively. Individual quaternary ammonium compounds were detected at low concentrations (oil samples without prior sample preparation or pre-concentration was also demonstrated using a home-built miniature mass spectrometer at levels below 1 ng μL(-1).

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.

Corrosion Inhibition of Aluminium in Acid Media By Citrullus Colocynthis Extract

OpenAIRE

Chauhan, Rajkiran; Garg, Urvija; Tak, R. K.

2011-01-01

Inhibition of corrosion of aluminium in acid solution by methanol extract of Citrullus colocynthis plant has been studied using mass loss and thermometric measurements. It has been found that the plant extract act as a good corrosion inhibitor for aluminium in all concentrations of sulphuric and hydrochloric acid solution. The inhibition action depends on the concentration of acid and inhibitor. Results for mass loss and thermometric measurement indicate that inhibition efficiency increase wi...

Corrosion control in electric power plants

International Nuclear Information System (INIS)

Syrett, B.C.

1992-01-01

This paper reports that corrosion of components in power plants costs the US electric power utility industry billions of dollars each year. Through the Electric Power Research Institute's (EPRI) research and development, several approaches have been developed to reduce these huge costs. They include improved materials selection procedures, coatings, cathodic protection, inhibitors, removal of aggressive species from the environment, and on-line corrosion monitoring. In addition, as part of an on-going technology transfer effort, EPRI is developing databases and expert systems that will help utilities obtain corrosion information and guide them in materials selection and failure analysis

Study of New Thiazole Based Pyridine Derivatives as Potential Corrosion Inhibitors for Mild Steel: Theoretical and Experimental Approach

Directory of Open Access Journals (Sweden)

T. K. Chaitra

2016-01-01

Full Text Available Three new thiazole based pyridine derivatives 5-(4-methoxy-phenyl-thiazole-2-carboxylic acid pyridin-2-ylmethylene-hydrazide (2-MTPH, 5-(4-methoxy-phenyl-thiazole-2-carboxylic acid pyridin-3-ylmethylene-hydrazide (3-MTPH, and 5-(4-methoxy-phenyl-thiazole-2-carboxylic acid pyridin-4-ylmethylene-hydrazide (4-MTPH were synthesized and characterized. Corrosion inhibition performance of the prepared compounds on mild steel in 0.5 M HCl was studied using gravimetric, potentiodynamic polarisation, and electrochemical impedance techniques. Inhibition efficiency has direct relation with concentration and inverse relation with temperature. Thermodynamic parameters for dissolution and adsorption process were evaluated. Polarisation study reveals that compounds act as both anodic and cathodic inhibitors with emphasis on the former. Impedance study shows that decrease in charge transfer resistance is responsible for effective protection of steel surface by inhibitors. The film formed on the mild steel was investigated using FTIR, SEM, and EDX spectroscopy. Quantum chemical parameters like EHOMO, ELUMO, ΔE, hardness, softness, and ionisation potential were calculated. Higher value of EHOMO and lower value of ΔE indicate the better inhibition efficiency of the compounds. Lower ionisation potential of inhibitors indicates higher reactivity and lower chemical stability.

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.

Undoped Polyaniline/Surfactant Complex for the Corrosion Prevention

Science.gov (United States)

Liu, Lo-Min; Levon, Kalle

1998-01-01

Due to the strict regulations on the usage of heavy metals as the additives in the coating industries, the search for effective organic corrosion inhibitors in replace of those metal additives has become essential. Electrically conducting polymers have been shown to be effective for corrosion prevention but the poor solubility of these intractable polymers has been a problem. We have explored a polyaniline/4-dodecylphenol complex (PANi/DDPh) to improve the dissolution and it has been shown to be an effective organic corrosion inhibitor. With the surfactant, DDPh, PANi could be diluted into the coatings and the properties of the coatings were affected. Emeraldine base (EB) form of PANi was also found to be oxidized by the hardener. The oxidized form of polyaniline provides improved corrosion protection of metals than that of emeraldine base since the value of the standard electrode potential for the oxidized form of PANi is higher than that of EB. Additionally, the surfactant improves the wet adhesion property between the coating and the metal surface.

Substituted benzotriazoles as inhibitors of copper corrosion in borate buffer solutions

Science.gov (United States)

Agafonkina, M. O.; Andreeva, N. P.; Kuznetsov, Yu. I.; Timashev, S. F.

2017-08-01

The adsorption of substituted 1,2,3-benzotriazoles (R-BTAs) onto copper is measured via ellipsometry in a pure borate buffer (pH 7.4) and satisfactorily described by Temkin's isotherm. The adsorption free energy (-Δ G a 0 ) values of these azoles are determined. The (-Δ G a 0 ) values are found to rise as their hydrophobicity, characterized by the logarithm of the partition coefficient of a substituted BTA in a model octanol-water system (log P), grows. The minimum concentration sufficient for the spontaneous passivation of copper ( C min) and a shift in the potential of local copper depassivation with chlorides ( E pt) after an azole is added to the solution (i.e., Δ E = E pt in - E pt backgr characterizing the ability of its adsorption to stabilize passivation) are determined in the same solution containing a corrosion additive (0.01M NaCl) for each azole under study. Both criteria of the passivating properties of azoles (log C min and Δ E) are shown to correlate linearly with log P, testifying to the role played by surface activity of this family of organic inhibitors in protecting copper in an aqueous solution.

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

Risk Based Corrosion Studies at SRS

International Nuclear Information System (INIS)

Hoffman, E.

2010-01-01

TYPE I and II (ASTM 285-B) - Experienced stress corrosion cracking (SCC), 2 have been closed; 22 scheduled for closure by 2017, and No active leak sites today. TYPE III (ASTM A516-70 and A537 Class I) - Post-fabrication relief of weld residual stresses, Improved resistance to SCC and brittle fracture, No leakage history, and Receives new waste. The objectives are to utilize statistical methods to reduce conservatism in current chemistry control program; and express nitrite inhibitor limits in terms of pitting risk on waste tank steel. Conclusions are: (1) A statistically designed experimental study has been undertaken to improve the effectiveness of the minimum nitrite concentrations to inhibit pitting corrosion; (2) Mixture/amount model supports that pitting depends on the ratio of aggressive to inhibitive anions, as well as the concentration of each species; (3) Secondary aggressive species, Cl - and SO 4 2- , significantly effect the corrosion response; and (4) Results support the reduction of the chemistry control nitrite inhibitor concentrations in the regime of 0.8-1.0 M nitrate.

Indeno-1-one [2,3-b]quinoxaline as an effective inhibitor for the corrosion of mild steel in 0.5 M H2SO4 solution

International Nuclear Information System (INIS)

Obot, I.B.; Obi-Egbedi, N.O.

2010-01-01

Indeno-1-one [2,3-b] quinoxaline (INQUI), synthesized in our laboratory, was tested as inhibitor for the corrosion of mild steel in 0.5 M H 2 SO 4 using gravimetric method at 30 o C. The inhibitor (INQUI) showed about 81% inhibition efficiency (E (%)) at an optimum concentration of 10 x 10 -6 M. The inhibition efficiency increases with increase in inhibitor concentration but decreases with increase in immersion time. The adsorption of the inhibitor on the mild steel in the acid solution was found to accord with Temkin's adsorption isotherm. The calculated value of the free energy for the adsorption process, ΔG ads , reveals a strong chemisorbed bond between the inhibitor and mild steel surface and a spontaneous adsorption of the inhibitor on the mild steel surface. Density functional theory (DFT) proves that INQUI molecule is adsorbed on the mild steel surface by the most negatively charged nitrogen and oxygen atoms.

Material compatibility and corrosion control of the KWU chemical cleaning process

International Nuclear Information System (INIS)

Odar, S.

1994-01-01

The concentrations of salt impurities within the deposits on the tube sheet and in the tube to tube-support-plate crevices can induce a variety of corrosion mechanisms on steam generator tubes. One of the most effective ways of counteracting corrosion mechanisms and thus of improving steam generator performance is to clean the steam generators and keep them in a clean condition. As shown by field results chemical cleaning is a way of removing hazardous deposits from steam generators. All available chemical cleaning processes use inhibitors to control the corrosion except the KWU chemical cleaning process. In this article the corrosion control technique of KWU Chemical Cleaning Process without using conventional inhibitors will be explained and the state of the field experience with respect to material compatibility will be presented. (author). 4 figs., 1 tab., 8 refs

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

Downhole corrosion mechanisms and mitigation strategies

Energy Technology Data Exchange (ETDEWEB)

McDougall, D. [Baker Hughes Canada, Calgary, AB (Canada)

2010-07-01

Pipeline corrosion refers to its deterioration because of a reaction with its environment. Although the physical condition of the metal at the anode initiates the corrosion process, it is the chemistry and composition of the electrolyte that controls the rate of the corrosion reaction and the severity of the corrosion. This presentation described the role of corrosion rate accelerators, with particular reference to dissolved gases such as oxygen, hydrogen sulfides and carbon dioxide, as well as pH levels, salinity, flow rate, temperature and presence of solids such as iron sulfides and sulfur. The effects of these accelerators were shown to be additive. Mitigation strategies include using materials such as resistant metal alloys or fiberglass, and applying coatings and chemical inhibitors. The importance of corrosion monitoring was also emphasized, with particular reference to the value of examining the number of corrosion related failures that have occurred over a fixed period of time. It was concluded that the ability to analyze samples of failed materials results in a better understanding of the cause of the failure, and is an integral part of designing any successful corrosion control program. tabs., figs.

Effect of Calcium Nitrate and Sodium Nitrite on the Rebar Corrosion of Medium Carbon Steel in Seawater and Cassava Fluid

OpenAIRE

Adamu, M; Umoru, LE; Ige, OO

2014-01-01

Inhibitors are regularly used as one of the principal prevention and control techniques in reinforcement corrosion. Hence this study investigates the effect of calcium nitrate and sodium nitrite inhibitors on the rebar corrosion of medium carbon steel in seawater and cassava fluid with a view to determining inhibitive potentials of the different inhibitors in the two media. Gravimetric and voltametric techniques were employed in this study and a total of forty-five corrosion coupons of differ...

Problems raised by corrosion in the nuclear fuel cycle

International Nuclear Information System (INIS)

Tricot, R.; Boutonnet, G.; Perrot, M.; Blum, J.-M.

1977-01-01

In the uranium ore processing industry, materials which resist both mechanical abrasion and corrosion in an acid medium are required. Different typical cases are examined. For the reprocessing of irradiated fuels, two processes are possible: the conventional wet process, of the Purex type, and the fluoride volatilization process. In the latter case, the problems raised by fluoride corrosion in the presence of fission products is examined. The other parts of the fuel cycle are examined in the same manner [fr

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...

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.

Corrosion and passivation behavior of various stainless steels in libr solution used in absorption-type refrigeration system

International Nuclear Information System (INIS)

Shahid, M.

2007-01-01

Various structural materials have been suggested for the refrigeration units to combat high corrosiveness of the absorbent. The corrosion behavior of three grades of austenitic stainless steels, have been investigated in lithium bromide (LiBr) solutions, using electrochemical techniques. Potentiodynamic E- log-i curves, potential-time scans and polarization resistance diagrams obtained by using three-electrode system connected to a computerized Gamry at the rate framework, have been used to analyze their corrosion and passivation behavior in various concentrations of LiBr i.e. commercial LiBr (850 g/J solution containing chromate inhibitor), 400 g/l LiBr and 700 g/J LiBr solutions, at room temperature. Relatively higher corrosion current was observed in SS304 exposed to inhibitor-free electrolyte compared to inhibited commercial solution. Inhibitor proved to be more efficient in case of AISI 304 as it showed significantly higher corrosion rate in un-inhibited solutions. (author)

Investigation of corrosion experienced in a spray calciner/ceramic melter vitrification system

International Nuclear Information System (INIS)

Dierks, R.D.; Mellinger, G.B.; Miller, F.A.; Nelson, T.A.; Bjorklund, W.J.

1980-08-01

After periodic testing of a large-scale spray calciner/ceramic melter vitrification system over a 2-yr period, sufficient corrosion was noted on various parts of the vitrification system to warrant its disassembly and inspection. A majority of the 316 SS sintered metal filters on the spray calciner were damaged by chemical corrosion and/or high temperature oxidation. Inconel-601 portions of the melter lid were attacked by chlorides and sulfates which volatilized from the molten glass. The refractory blocks, making up the walls of the melter, were attacked by the waste glass. This attack was occurring when operating temperatures were >1200 0 C. The melter floor was protected by a sludge layer and showed no corrosion. Corrosion to the Inconel-690 electrodes was minimal, and no corrosion was noted in the offgas treatment system downstream of the sintered metal filters. It is believed that most of the melter corrosion occurred during one specific operating period when the melter was operated at high temperatures in an attempt to overcome glass foaming behavior. These high temperatures resulted in a significant release of volatile elements from the molten glass, and also created a situation where the glass was very fluid and convective, which increased the corrosion rate of the refractories. Specific corrosion to the calciner components cannot be proven to have occurred during a specific time period, but the mechanisms of attack were all accelerated under the high-temperature conditions that were experienced with the melter. A review of the materials of construction has been made, and it is concluded that with controlled operating conditions and better protection of some materials of construction corrosion of these systems will not cause problems. Other melter systems operating under similar strenuous conditions have shown a service life of 3 yr

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.

Electrochemical Behaviour of Environmentally Friendly Inhibitor of ...

African Journals Online (AJOL)

Electrochemical Behaviour of Environmentally Friendly Inhibitor of Aloe Secundiflora Extract in Corrosion Control of Carbon Steel in Soft Water Media. ... The investigation was performed at different inhibitor concentrations under static and dynamic conditions using a Rotating Disk Electrode (RDE). The impedance and ...

Inhibitor efficiency in long-time protection of steel tanks for the chemical surface preparation against local corrosion by process solutions containing hydrochloric acid; Inhibitorwirksamkeit beim Langzeitschutz von Stahlbehaeltern fuer die chemische Oberflaechenvorbereitung gegen oertliche Korrosion durch salzsaeurehaltige Prozessloesungen

Energy Technology Data Exchange (ETDEWEB)

Stieglitz, U.; Schulz, W.D. [Institut fuer Korrosionsschutz Dresden GmbH, Gostritzer Str. 61-63, D-01217 Dresden (Germany)

2004-02-01

The efficiency of prevailing acid inhibitors is examined by age hardening heavy tank-steel plates in technically usual hot-galvanizing solutions for 1000 hours. With acid inhibitors local corrosion emerged as shallow pit formation first and foremost in hydrochlorid acid pickles (20 g/l HCl) at ambient temperature as well as in cleaners containing hydrochloric acid (10-30 g/l HCl) at 40 C when other conditions also applied. Above all, local corrosion was produced if the inhibitor concentration became too low (0.2 g/l) in connection with a minimum hydrochloric acid concentration (10-30 g/l). However, oxidizing agents like iron(III)-ions (5-10 g/l), atmospheric oxygen and free chlorine (100-1000 mg/l) lead to local corrosion, too. Local corrosion did not emerge in rinse baths (2-10 g/l HCl) and fluxing material solutions of zinc chloride and ammonium chloride (pH value: 2.0-5.5). Here uniform corrosion developed. Acid inhibitors turned out to be very effective against uniform corrosion in the examined long-time period (inhibiting values up to 99%). (Abstract Copyright [2004], Wiley Periodicals, Inc.) [German] Die Wirksamkeit handelsueblicher Saeureinhibitoren wird durch eine Auslagerung von Grobblechen aus Behaelterstahl ueber 1000 Stunden in technisch gebraeuchlichen Loesungen der Feuerverzinkung untersucht. Oertliche Korrosion ist als Muldenkorrosion in Gegenwart von Saeureinhibitoren vor allem in Salzsaeurebeizen (20 g/l HCl) bei Raumtemperatur und in salzsaeurehaltigen Reinigern (10-30 g/l HCl) bei 40 C aufgetreten, wenn Zusatzbedingungen erfuellt sind. Oertliche Korrosion wird vorwiegend durch eine Unterschreitung der Inhibitorkonzentration (0,2 g/l) in Verbindung mit einer minimalen Salzsaeurekonzentration (10-30 g/l) ausgeloest. Aber auch Oxidationsmittel wie Eisen(III)-Ionen (5-10 g/l), Luftsauerstoff und freies Chlor (100-1000 mg/l) fuehren zu oertlicher Korrosion. In Spuelbaedern (2-10 g/l HCl) und Flussmittelloesungen aus Zinkchlorid und Ammoniumchlorid (p

Corrosion Inhibition of High Speed Steel by Biopolymer HPMC Derivatives

Directory of Open Access Journals (Sweden)

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.

Application of electrochemical methods in corrosion and battery research

Science.gov (United States)

Sun, Zhaoli

Various electrochemical methods have been applied in the development of corrosion protection methods for ammonia/water absorption heat pumps and the evaluation of the stability of metallic materials in Li-ion battery electrolyte. Rare earth metal salts (REMSs) and organic inhibitors have been evaluated for corrosion protection of mild steel in the baseline solution of 5 wt% NH 3 + 0.2 wt% NaOH to replace the conventionally used toxic chromate salt inhibitors. Cerium nitrate provided at least comparable corrosion inhibition efficiency as dichromate in the baseline solution at 100°C. The cerium (IV) oxide formed on mild steel through the cerating process exhibited increasing corrosion protection for mild steel with prolonged exposure time in the hot baseline solution. The optimum cerating process was found to be first cerating in a solution of 2.3 g/L CeCl3 + 4.4 wt% H2O2 + appropriate additives for 20 minutes at pH 2.2 at room temperature with 30 minutes solution aging prior to use, then sealing in 10% sodium (meta) silicate or sodium molybdate at 50°C for 30 minutes. Yttrium salts provided less corrosion protection for mild steel in the baseline solution than cerium salts. Glycerophosphate was found to be a promising chromate-free organic inhibitor for mild steel; however, its thermostability in hot ammonia/water solutions has not been confirmed yet. The stability of six metallic materials used in Li-ion batteries has been evaluated in 1M lithium hexafluorophosphate (LiPF6) dissolved in a 1:1 volume mixture of ethylene carbonate and diethyl carbonate at 37°C in a dry-box. Aluminum is the most stable material, while Copper is active under anodic potentials and susceptible to localized corrosion and galvanic corrosion. The higher the concentration of the alloying elements Al and/or V in a titanium alloy, the higher was the stability of the titanium alloy in the battery electrolyte. 90Pt-10Ir can cause decomposition of the electrolyte resulting in a low stable

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

Directory of Open Access Journals (Sweden)

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.

Some Phthalocyanine and Naphthalocyanine Derivatives as Corrosion Inhibitors for Aluminium in Acidic Medium: Experimental, Quantum Chemical Calculations, QSAR Studies and Synergistic Effect of Iodide Ions

Directory of Open Access Journals (Sweden)

Masego Dibetsoe

2015-08-01

Full Text Available The effects of seven macrocyclic compounds comprising four phthalocyanines (Pcs namely 1,4,8,11,15,18,22,25-octabutoxy-29H,31H-phthalocyanine (Pc1, 2,3,9,10,16,17,23,24-octakis(octyloxy-29H,31H-phthalocyanine (Pc2, 2,9,16,23-tetra-tert-butyl-29H,31H-phthalocyanine (Pc3 and 29H,31H-phthalocyanine (Pc4, and three naphthalocyanines namely 5,9,14,18,23,27,32,36-octabutoxy-2,3-naphthalocyanine (nPc1, 2,11,20,29-tetra-tert-butyl-2,3-naphthalocyanine (nPc2 and 2,3-naphthalocyanine (nP3 were investigated on the corrosion of aluminium (Al in 1 M HCl using a gravimetric method, potentiodynamic polarization technique, quantum chemical calculations and quantitative structure activity relationship (QSAR. Synergistic effects of KI on the corrosion inhibition properties of the compounds were also investigated. All the studied compounds showed appreciable inhibition efficiencies, which decrease with increasing temperature from 30 °C to 70 °C. At each concentration of the inhibitor, addition of 0.1% KI increased the inhibition efficiency compared to the absence of KI indicating the occurrence of synergistic interactions between the studied molecules and I− ions. From the potentiodynamic polarization studies, the studied Pcs and nPcs are mixed type corrosion inhibitors both without and with addition of KI. The adsorption of the studied molecules on Al surface obeys the Langmuir adsorption isotherm, while the thermodynamic and kinetic parameters revealed that the adsorption of the studied compounds on Al surface is spontaneous and involves competitive physisorption and chemisorption mechanisms. The experimental results revealed the aggregated interactions between the inhibitor molecules and the results further indicated that the peripheral groups on the compounds affect these interactions. The calculated quantum chemical parameters and the QSAR results revealed the possibility of strong interactions between the studied inhibitors and metal surface. QSAR

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.

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

OpenAIRE

I. B. Obot; N. O. Obi-Egbedi

2010-01-01

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 ad...

Corrosion inhibition of Armco iron by 2-mercaptobenzimidazole in sodium chloride 3% media

International Nuclear Information System (INIS)

Amar, H.; Tounsi, A.; Makayssi, A.; Derja, A.; Benzakour, J.; Outzourhit, A.

2007-01-01

The effect of 2-mercaptobenzimidazole (2MBI) on the corrosion of Armco iron in NaCl media has been investigated in relation to the concentration of the inhibitor by various corrosion monitoring techniques. Surface morphology was studied by scanning electron microscopy (SEM). Results obtained revealed that 2MBI is a good anodic inhibitor. The addition of increasing concentrations of 2MBI moves the corrosion potential towards positive values and reduces the corrosion rate. EIS results show that the changes in the impedance parameters (R t and C dl ) with concentrations of 2MBI is indicative of the adsorption of these molecules leading to the formation of a protective layer on iron surface. The adsorption of this compound is also found to obey Langmuir's adsorption isotherm in NaCl

Cephradine as corrosion inhibitor for copper in 0.9% NaCl solution

Science.gov (United States)

Tasić, Žaklina Z.; Petrović Mihajlović, Marija B.; Radovanović, Milan B.; Simonović, Ana T.; Antonijević, Milan M.

2018-05-01

The effect of (6R,7R)-7-[[(2R)-2-amino-2-cyclohexa-1,4-dien-1-ylacetyl]amino]-3-methyl-8-oxo-5-thia-1-azobicyclo[4.2.0]oct-2-ene-2-carboxylic acid (cephradine) on corrosion behavior of copper in 0.9% NaCl solution was investigated. The electrochemical methods including the open circuit potential measurements, potentiodynamic polarization and electrochemical impedance spectroscopy measurements, scanning electron microscopy with energy dispersive X-ray spectroscopy and quantum chemical calculations were used for this investigation. According to the results obtained by potentiodynamic polarization, cephradine acts as mixed type inhibitor. Also, the results obtained by electrochemical impedance spectroscopy indicate that cephradine provides good copper protection in 0.9% NaCl solution. The inhibition efficiency of cephradine increases with increasing its concentration. The scanning electron microscopy with energy dispersive X-ray spectroscopy confirms that a protective layer is formed on the copper surface due to the adsorption of cephradine on the active sites on the copper surface. Adsorption of cephradine in 0.9% NaCl solution follows the Langmuir adsorption isotherm. Quantum chemical calculations are in agreement with results obtained by electrochemical measurements.

Study of Henna (Lawsonia inermis) as Natural Corrosion Inhibitor for Aluminum Alloy in Seawater

International Nuclear Information System (INIS)

Nik, W B Wan; Zulkifli, F; Sulaiman, O; Samo, K B; Rosliza, R

2012-01-01

Commercial henna (Lawsonia inermis) was investigated to inhibit the corrosion of aluminum alloy through immersion in seawater. The aluminum alloy (5083) was prepared in size of 25mm × 25mm × 3mm. The immersion test was conducted in seawater with different concentration of henna, 100ppm, 300ppm, 500ppm for duration of 60 days. Four characterizations were performed in this study which was weight loss study, Fourier Transform Infrared (FTIR), Electrochemical Impedance Spectroscopy (EIS) and adsorption isotherm. The results indicated that henna has major constituents of lawsone which contributed to the chemisorptions or adsorption process by forming an isolation layers on the aluminum alloy surface which follows the Langmuir adsorption isotherm. It was found that the protection layer attached on metal was not permanent and precipitation occurred as the time increases. The highest inhibition efficiency was found at 88% (500ppm). This research found that henna is an excellent natural inhibitor for aluminum alloy in seawater.

Corrosion Inhibition and Adsorption Properties of Ethanolic Extract of Calotropis for Corrosion of Aluminium in Acidic Media

OpenAIRE

Sudesh Kumar; Suraj Prakash Mathur

2013-01-01

The corrosion inhibition of aluminium in sulfuric acid solution in the presence of different plant parts, namely, leaves, latex, and fruit was studied using weight loss method and thermometric method. The ethanolic extracts of Calotropis procera and Calotropis gigantea act as an inhibitor in the acid environment. The inhibition efficiency increases with increase in inhibitor concentration. The plant parts inhibit aluminium, and inhibition is attributed, due to the adsorption of the plant part...

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

Internal corrosion control of northern pipelines

Energy Technology Data Exchange (ETDEWEB)

Papavinasam, S.

2005-02-01

The general causes of internal corrosion in pipelines were discussed along with the methods to control them. Efficient methods are needed to determine chemical efficiency for mitigating internal corrosion in transmission pipelines, particularly those used in environmentally sensitive regions in the Arctic where harsh environmental conditions prevail. According to the Office of Pipeline Safety, 15 per cent of pipeline failures in the United States from 1994 to 2000 were caused by internal corrosion. Since pipelines in the United States are slightly older than Canadian pipelines, internal corrosion is a significant issue from a Canadian perspective. There are 306,618 km of energy-related pipelines in western Canada. Between April 2001 and March 2002 there were 808 failures, of which 425 failures resulted from internal corrosion. The approach to control internal corrosion comprises of dehydrating the gases at production facilities; controlling the quality of corrosive gases such as carbon dioxide and hydrogen sulphide; and, using internal coatings. The approaches to control internal corrosion are appropriate, when supplemented by adequate integrity management program to ensure that corrosive liquids do not collect, over the operational lifetime of the pipelines, at localized areas. It was suggested that modeling of pipeline operations may need improvement. This paper described the causes, prediction and control of internal pitting corrosion. It was concluded that carbon steel equipment can continue to be used reliably and safely as pipeline materials for northern pipelines if the causes that lead to internal corrosion are scientifically and accurately predicted, and if corrosion inhibitors are properly evaluated and applied. 5 figs.

Environmentally safe corrosion inhibition of Mg-Al-Zn alloy in chloride free neutral solutions by amino acids

Energy Technology Data Exchange (ETDEWEB)

Helal, N.H. [Chemistry Department, Faculty of Science, Fayoum University, Fayoum (Egypt); Badawy, W.A., E-mail: wbadawy@cu.edu.eg [Chemistry Department, Faculty of Science, Cairo University, 12 613 Giza (Egypt)

2011-07-30

Highlights: > Phenyl alanine at a concentration of 2 x 10{sup -3} mol dm{sup -3} gives 93% corrosion inhibition efficiency for the corrosion of the Mg-Al-Zn alloy. > The corrosion inhibition process is based on the adsorption of the amino acid molecules on the active sites of the alloy surface by physical adsorption mechanism. > The adsorption free energy was 15.72 kJ mol{sup -1}. - Abstract: The corrosion inhibition of Mg-Al-Zn alloy was investigated in stagnant naturally aerated chloride free neutral solutions using amino acids as environmentally safe corrosion inhibitors. The corrosion rate was calculated in the absence and presence of the corrosion inhibitor using the polarization technique and electrochemical impedance spectroscopy. The experimental impedance data were fitted to theoretical data according to a proposed electronic circuit model to explain the behavior of the alloy/electrolyte interface under different conditions. The corrosion inhibition process was found to depend on the adsorption of the amino acid molecules on the metal surface. Phenyl alanine has shown remarkably high corrosion inhibition efficiency up to 93% at a concentration of 2 x 10{sup -3} mol dm{sup -3}. The corrosion inhibition efficiency was found to depend on the concentration of the amino acid and its structure. The mechanism of the corrosion inhibition process was discussed and different adsorption isotherms were investigated. The free energy of the adsorption process was calculated for the adsorption of different amino acids on the Mg-Al-Zn alloy and the obtained values reveal a physical adsorption of the inhibitor molecules on the alloy surface.

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

An Auger and XPS survey of cerium active corrosion protection for AA2024-T3 aluminum alloy

Energy Technology Data Exchange (ETDEWEB)

Uhart, A. [IPREM-ECP-UMR CNRS 5254, Université de Pau et des Pays de l' Adour, Technopole Hélioparc, 2 Avenue Président Pierre Angot, 64053 Pau Cedex 09 (France); Ledeuil, J.B. [IPREM-ECP-UMR CNRS 5254, Université de Pau et des Pays de l' Adour, Technopole Hélioparc, 2 Avenue Président Pierre Angot, 64053 Pau Cedex 09 (France); Université de Toulouse, UPS-INP-CNRS, Institut Carnot CIRIMAT, 118 Route de Narbonne, 31062 Toulouse Cedex 09 (France); Gonbeau, D. [IPREM-ECP-UMR CNRS 5254, Université de Pau et des Pays de l' Adour, Technopole Hélioparc, 2 Avenue Président Pierre Angot, 64053 Pau Cedex 09 (France); Dupin, J.C., E-mail: dupin@univ-pau.fr [IPREM-ECP-UMR CNRS 5254, Université de Pau et des Pays de l' Adour, Technopole Hélioparc, 2 Avenue Président Pierre Angot, 64053 Pau Cedex 09 (France); Bonino, J.P.; Ansart, F. [Université de Toulouse, UPS-INP-CNRS, Institut Carnot CIRIMAT, 118 Route de Narbonne, 31062 Toulouse Cedex 09 (France); Esteban, J. [Messier-Bugatti-Dowty, Etablissement de Molsheim, 3, rue Antoine de St Exupéry, 67129 Molsheim (France)

2016-12-30

Graphical abstract: Coupled SAM/SEM survey of cerium inhibitor migration towards corrosion pits in a conversion coating over AA2024-T3 substrate. - Highlights: • XPS evidenced the proximity of the inhibitor with the surface AA2024 alloy. • Cerium conversion coatings with [Ce] = 0.1 M offer the best corrosion resistance. • SAM shown the migration of Ce + III entities towards the corrosion pits or crevices. • High resolution analyses (Auger) connecting the nano-scale order with the chemical distribution.

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.

USAF Corrosion Prevention and Control Enterprise - Sustainability Links

Science.gov (United States)

2014-11-18

projects and $84M  Example of potential synergy: From FY05-14, the DoD Corrosion Program funded 21 projects on hexavalent chromium reduction  OSD...coatings, effects on structural integrity, environmental effects, etc  Some topics of interest  Inhibitor mechanisms for mg-rich primer (non- chrome ...approach  Financial and engineering resources are limited  Potential costs of corrosion are significant  Supporting replacements for hexavalent

Pitting corrosion of copper in aqueous solutions containing phosphonic acid as an inhibitor. Hosuhon san wo inhibita toshite fukumu suiyoekichu ni okeru do no koshiku ni tsuite

Energy Technology Data Exchange (ETDEWEB)

Yamada, Y. (Muroran Univ., Hokkaido (Japan). Graduate School); Seri, O.; Tagashira, K. (Muroran Univ., Hokkaido (Japan)); Nagata, K. (Sumitomo Light Metal Co. Ltd., Tokyo (Japan). Technical Research Lab.)

1993-09-15

Phosphonic acid-based inhibitors that are poured into cooling water for copper-tube circulation systems for open heat-accumulators were studied on their influence on pitting corrosion of copper. Amino trimethylene phosphonic acid (ATMP) dissolved into distilled water to 50 ppm was used for the immersion corrosion test. The corrosion-proof effect of additives such as ZnSO4, benzotriazole (BTA) was tested too. 0.5 mm thick phosphate-treated copper plates with a hole of 5 mm in diameter were used as test specimens. Pitting corrosion on the copper plate occurred when ATMP, BTA and ZnSO4 coexisted. It was proved that SO4 [sup 2-] is essential since Na2SO4 in stead of ZnSO4 induced also corrosion. The pitting took place when 0.6 ppm or more of SO4 [sup 2-] was present in a BTA-added ATMP solution. It was observed that the pitting is prone to occur with increase of SO4 [sup 2-] and the number of pitting increases. The following relationship is established when pitting corrosion occurs; E[sub b] [le] E[sub corr], where the former is a potential value at which current density shows a steep increase and the latter is an average value of spontaneous electrode potential showing a plateau. 8 refs., 11 figs., 1 tab.

Melamine derivatives as effective corrosion inhibitors for mild steel in acidic solution: Chemical, electrochemical, surface and DFT studies

Science.gov (United States)

Verma, Chandrabhan; Haque, J.; Ebenso, Eno E.; Quraishi, M. A.

2018-06-01

In present study two condensation products of melamine (triazine) and glyoxal namely, 2,2-bis(4,6-diamino-1,3,5-triazin-2-ylamino)acetaldehyde (ME-1) and (N2,N2‧E,N2,N2‧E)-N2,N2‧-(ethane-1,2-diylidene)-bis-(1,3,5-triazine-2,4,6-triamine) (ME-2) are tested as mild steel corrosion inhibitors in acidic solution (1M HCl). The inhibition efficiency of ME-1 and ME-2 increases with increase in their concentrations and maximum values of 91.47% and 94.88% were derived, respectively at 100 mgL-1 (34.20 × 10-5 M) concentration. Adsorption of ME-1 and ME-2 on the surface of metal obeyed the Langmuir adsorption isotherm. Polarization investigation revealed that ME-1 and ME-2 act as mixed type inhibitors with minor cathodic prevalence. The chemical and electrochemical analyses also supported by surface characterization methods where significant smoothness in the surface morphologies was observed in the images of SEM and AFM spectra. Several DFT indices such as EHOMO and ELUMO, ΔE, η, σ, χ, μ and ΔN were derived for both ME-1 and ME-2 molecules and correlated with experimental results. The DFT studies have also been carried out for protonated or cationic form of the inhibitor molecules by considering that in acidic medium the heteroatoms of organic inhibitors easily undergo protonation. The experimental and density functional theory (DFT) studies (neutral and protonated) were in good agreement.

Synthesis and evaluation of new long alkyl side chain acetamide, isoxazolidine and isoxazoline derivatives as corrosion inhibitors

International Nuclear Information System (INIS)

Yildirim, A.; Cetin, M.

2008-01-01

2-(Alkylsulfanyl)-N-(pyridin-2-yl) acetamide derivatives were synthesized via amidation reaction of acyl chlorides bearing S atom in the long chain with 2-aminopyridine. Derivatives of isoxazolidine and isoxazoline were synthesized through 1,3-dipolar cycloaddition reactions with three different long chain alkenes containing O or S as hetero atoms and C,N-diphenyl nitrone or benzonitrile-N-oxide, respectively. Synthesized compounds were characterized with their FT-IR, 1 H NMR spectra and then their physical properties and corrosion prevention efficiencies were investigated. All compounds were tested with steel coupons in acidic medium by gravimetric method, and also some of them were tested with steel stripe in paraffin based mineral oil medium via standard method. Acidic test was done with a medium concentration of 2 M HCl for 20 h at room temperature. Mineral oil was used and the test in this medium was done at 60 deg. C constant temperature but varying time from 42 to 63 h. The best inhibition was generally obtained at 50 ppm inhibitor concentration in the acidic medium. All tested inhibitors except two of them in oil medium also showed promising inhibition efficiencies

Avaliação do uso de inibidores de etileno sobre a produção de compostos voláteis e de mangiferina em manga Evaluation of the use of ethylene inhibitors on production of volatile compounds and mangiferin in mango fruit

Directory of Open Access Journals (Sweden)

Kirley Marques Canuto

2010-01-01

Full Text Available Effects of two ethylene inhibitors, 1-methylcylopropene (1-MCP and aminoethoxyvinylglycine (AVG, on production of volatile compounds and mangiferin (a bioactive xanthone in 'Tommy Atkins' mango fruit were investigated. Volatile composition and mangiferin content, in treated and untreated fruits at three maturity, stages were determined by SPME-GC-MS and HPLC, respectively. These chromatographical analysis revealed that the volatile profiles and mangiferin concentrations were not significantly different, suggesting that the use of ethylene inhibitors does not affect the mango aroma and functional properties relative to this xanthone. Moreover, a simple, precise and accurate HPLC method was developed for quantifying mangiferin in mango pulp.

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.

Case histories of microbial induced corrosion

Energy Technology Data Exchange (ETDEWEB)

Birketveit, Oe.; Liengen, T.

2006-03-15

Recent years bacterial activity has caused process problems and corrosion on several of Hydro s installations in the North Sea. The process problems are related to iron sulphide formed in process equipment and increased oil in discharge water. The corrosion problem is seen in downstream pipelines made of carbon steel, where deposits and formation of biofilm cause the corrosion inhibitor to be ineffective. In most cases the bacteria reproduce in the topside system and especially in the reclaimed oil sump tank. The problems observed, related to bacterial activity, are often a result of how the content from the reclaimed oil sump tank is re-circulated to the process system. Process modifications, changes in biocide treatment strategy, sulphide measurements, cleaning strategy and bio monitoring are presented. (author) (tk)

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 ...

Assessment of cytotoxic and cytogenetic effects of a 1,2,5-thiadiazole derivative on CHO-K1 cells. Its application as corrosion inhibitor

International Nuclear Information System (INIS)

Grillo, C.A.; Mirifico, M.V.; Morales, M.L.; Reigosa, M.A.; Mele, M. Fernandez Lorenzo de

2009-01-01

This work focuses on the possible use of phenanthro[9,10-c]-1,2,5-thiadiazole 1,1-dioxide (TDZ) as a harmless corrosion inhibitor. TDZ range-dose providing minimum adverse effects to the environment and human health, with satisfactory corrosion-inhibiting properties was evaluated. Cytotoxicity and genotoxicity of TDZ at 0.57-12.50 μM concentration range were tested by neutral red, chromosomal aberrations, mitotic index, and colony formation assays. Results showed a significant increase of chromatid-type aberrations for the highest concentration of TDZ assayed (12.50 μM). Additionally, a reduction in the proliferative rate for lower concentrations was detected by the MI assay. We concluded that TDZ should be used at concentrations lower than 1.16 μM. Corrosion assays performed showed good inhibition effect (ca. 50%) at low (0.65 μM) TDZ concentration. Consequently, our results indicated that TDZ induced a time- and dose-dependent genotoxic and cytotoxic response on CHO-K1 cells. Short assays should be complemented with long exposure tests to simulate chronic contact with TDZ since lower threshold levels may be found for shorter exposures and a wrong safety range could be determined.

EVELOPMENT OF AN ENVIRONMENTALLY BENIGN MICROBIAL INHIBITOR TO CONTROL INTERNAL PIPELINE CORROSION

Energy Technology Data Exchange (ETDEWEB)

Bill W. Bogan; Wendy R. Sullivan; Kristine M. H. Cruz; Kristine L. Lowe; John J. Kilbane II

2004-04-30

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. Previous testing of pepper extracts resulted in preliminary data indicating that some pepper extracts inhibit the growth of some corrosion-associated microorganisms. This quarter additional tests were performed to more specifically investigate the ability of three pepper extracts to inhibit the growth, and to influence the metal corrosion caused by two microbial species: Desulfovibrio vulgaris, and Comomonas denitrificans. All three pepper extracts rapidly killed Desulfovibrio vulgaris, but did not appear to inhibit Comomonas denitrificans. While corrosion rates were at control levels in experiments with Desulfovibrio vulgaris that received pepper extract, corrosion rates were increased in the presence of Comomonas denitrificans plus pepper extract. Further testing with a wider range of pure bacterial cultures, and more importantly, with mixed bacterial cultures should be performed to determine the potential effectiveness of pepper extracts to inhibit MIC.

Mechanistic studies of carbon steel corrosion inhibition by cashew ...

African Journals Online (AJOL)

The phenoxide, R-Ar-O- ions from the CNSL inhibitor were found to be responsible for the reduction of the corrosion rate of the carbon steel. Also, it was observed that the surface charge of the carbon steel electrodes was positive with respect to the solutions containing CNSL inhibitor. It is likely that the mechanism of the ...

A theoretical study of carbohydrates as corrosion inhibitors of iron

Energy Technology Data Exchange (ETDEWEB)

Khalil, Salim M.; Ali, Nozha M. [Libyan Academy for Graduate Studies, Tripoli (Libyan Arab Jamahiriya). Chemistry Dept.; Ali-Shattle, Elbashir E. [Tripoli Univ. (Libyan Arab Jamahiriya). Chemistry Dept.

2013-08-15

The inhibitive effect of fructose, glucose, lactose, maltose, and sucrose against the iron corrosion is investigated using density functional theory at the B3LYP/6-31 G level (d) to search the relation between the molecular structure and corrosion inhibition. The electronic properties such as the energy of the highest occupied molecular orbital (HOMO), the energy of lowest unoccupied orbital (LUMO), the energy gap (LUMO-HOMO), quantum chemical parameters such as hardness, softness, the fraction of the electron transferred, and the electrophilicity index are reported. The inhibition efficiency of the investigated carbohydrates follows the trend: maltose < sucrose < lactose < fructose < glucose. (orig.)

Study on the hot corrosion behavior of a cast Ni-base superalloy

Energy Technology Data Exchange (ETDEWEB)

Wang, W.; Guo, J.T.; Zhang, J.; Yuan, C.; Zhou, L.Z.; Hu, Z.Q. [Chinese Academy of Sciences, Shenyang (China). Inst. of Metal Research

2010-07-01

Hot corrosion behavior of Nickel-base cast superalloy K447 in 90% Na{sub 2}SO{sub 4} + 10% NaCl melting salt at 850 C and 900 C was studied. The hot corrosion kinetic of the alloy follows parabolic rate law under the experimental conditions. The external layer is mainly Cr{sub 2}O{sub 3} scale which is protective to the alloy, the intermediate layer is the Ti-rich phase, and the internal layer is mainly the international oxides and sulfides. With increased corrosion time and temperature, the oxide scales are gradually dissolved in the molten salt and then precipitate as a thick and non-protective scale. Chlorides cause the formation of volatile species, which makes the oxide scale disintegrate and break off. The corrosion kinetics and morphology examinations tend to support the basic dissolution model for hot corrosion mechanisms. (orig.)

New Developments in Mitigation of Microbiologically Influenced Corrosion

National Research Council Canada - National Science Library

Little, B; Lee, J; Ray, R

2007-01-01

.... These strategies include the following: 1) use of biofilms to inhibitor prevent corrosion and 2) manipulation (removal or addition) of an electron acceptor, including oxygen, sulfate and nitrate, to influence the microbial population.

Corrosion inhibition of mild steel by Capsicum annuum fruit paste

Directory of Open Access Journals (Sweden)

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.

Corrosion chemistry closing comments: opportunities in corrosion science facilitated by operando experimental characterization combined with multi-scale computational modelling.

Science.gov (United States)

Scully, John R

2015-01-01

Recent advances in characterization tools, computational capabilities, and theories have created opportunities for advancement in understanding of solid-fluid interfaces at the nanoscale in corroding metallic systems. The Faraday Discussion on Corrosion Chemistry in 2015 highlighted some of the current needs, gaps and opportunities in corrosion science. Themes were organized into several hierarchical categories that provide an organizational framework for corrosion. Opportunities to develop fundamental physical and chemical data which will enable further progress in thermodynamic and kinetic modelling of corrosion were discussed. These will enable new and better understanding of unit processes that govern corrosion at the nanoscale. Additional topics discussed included scales, films and oxides, fluid-surface and molecular-surface interactions, selected topics in corrosion science and engineering as well as corrosion control. Corrosion science and engineering topics included complex alloy dissolution, local corrosion, and modelling of specific corrosion processes that are made up of collections of temporally and spatially varying unit processes such as oxidation, ion transport, and competitive adsorption. Corrosion control and mitigation topics covered some new insights on coatings and inhibitors. Further advances in operando or in situ experimental characterization strategies at the nanoscale combined with computational modelling will enhance progress in the field, especially if coupling across length and time scales can be achieved incorporating the various phenomena encountered in corrosion. Readers are encouraged to not only to use this ad hoc organizational scheme to guide their immersion into the current opportunities in corrosion chemistry, but also to find value in the information presented in their own ways.

Effect of Nitrite Inhibitor on the Macrocell Corrosion Behavior of Reinforcing Steel

Directory of Open Access Journals (Sweden)

Zhonglu Cao

2015-01-01

Full Text Available The effect of nitrite ions on the macrocell corrosion behavior of reinforcing steel embedded in cement mortar was investigated by comparing and analyzing the macrocell corrosion current, macrocell polarization ratios, and slopes of anodic and cathodic steels. Based on the experimental results, the relationship between macrocell potential difference and macrocell current density was analyzed, and the mechanism of macrocell corrosion affected by nitrite ions was proposed. The results indicated that nitrite ions had significant impact on the macrocell polarization ratios of cathode and anode. The presence of nitrite could reduce the macrocell current by decreasing the macrocell potential difference and increasing the macrocell polarization resistance of the anode.

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 ...

Carbon steel corrosion prevention during chemical cleaning of steam generator secondary side components

International Nuclear Information System (INIS)

Fulger, M.; Lucan, D.; Velciu, L.

2009-01-01

During operation of a nuclear power plant, many contaminants, such as solid particles or dissolved species are formed in the secondary circuit, go into steam generator and deposit as scales on heat transfer tubing, support plate or as sludge on tube sheet. By accumulation of these impurities, heat transfer is reduced and the integrity of the steam generator tubing is influenced. Chemical cleaning is a qualified, efficient measure to improve steam generator corrosion performance. The corrosion mechanism can be counteracted by the chemical cleaning of the deposits on the tube sheet and the scales on the heat transfer tubing. The major component of the scales is magnetite, which can be dissolved using an organic chelating agent (ethylenediaminetetraacetic acid, EDTA) in combination with a complexing agent such as citric acid in an alkaline reducing environment. As the secondary side of SG is a conglomerate of alloys it is necessary to choose an optimal chemical cleaning solution for an efficient cleaning properties and at the same time with capability of corrosion prevention of carbon steel components during the process. The paper presents laboratory tests initiated to confirm the ability of this process to clean the SG components. The experiments followed two paths: - first, carbon steel samples have been autoclavized in specific secondary circuit solutions of steam generator to simulate the deposits constituted during operation of this equipment; - secondly, autoclavized samples have been cleaned with a solvent composed of EDTA citric acid, hydrazine of pH = 5 and temperature of 85 deg. C. Before chemical cleaning, the oxide films were characterized by surface analysis techniques including optical microscopy, scanning electron microscopy (SEM) and electrochemical impedance spectroscopy (EIS). Applied to dissolve corrosion products formed in a steam generator, the solvents based on chelating agents are aggressive toward carbon steels and corrosion inhibitors are

USING A DOE AND EIS TO EVALUATE THE SYNERGISTIC EFFECTS OF LOW TOXICITY INHIBITORS FOR MILD STEEL

Directory of Open Access Journals (Sweden)

G. V. Bueno

2015-03-01

Full Text Available Abstract Inhibitors are widely used to prevent corrosion in cooling-water systems, and their protective performance can be enhanced by combination. The aim of this paper is to identify possible synergistic effects between four low toxicity substances used as corrosion inhibitors for mild steel in industrial cooling-water systems. Electrochemical measurements were obtained following a design of experiments (DOE where the independent variables were the inhibitors concentrations and the response variable the charge transfer resistance estimated from impedance diagrams. Potentiodynamic polarization curves show that all of them act as anodic corrosion inhibitors. Among the tested formulations, only the interaction between sodium molybdate and sodium tungstate showed statistically significant effects, indicating that they can perform better when used together. The results of this work show the importance of using a statistical tool when designing inhibitor mixtures.

In situ analysis of corrosion inhibitors using a portable mass spectrometer with paper spray ionization

KAUST Repository

Jjunju, Fred Paul Mark; Li, Anyin; Badu-Tawiah, Abraham K.; Wei, Pu; Li, Linfan; Ouyang, Zheng; Roqan, Iman S.; Cooks, Robert Graham

2013-01-01

Paper spray (PS) ambient ionization is implemented using a portable mass spectrometer and applied to the detection of alkyl quaternary ammonium salts in a complex oil matrix. These salts are commonly used as active components in the formulation of corrosion inhibitors. They were identified in oil and confirmed by their fragmentation patterns recorded using tandem mass spectrometry (MS/MS). The cations of alkyl and benzyl-substituted quaternary ammonium salts showed characteristic neutral losses of CnH2n (n carbon number of the longest chain) and C7H8, respectively. Individual quaternary ammonium compounds were detected at low concentrations (<1 ng μL-1) and over a dynamic range of ∼5 pg μL-1 to 500 pg μL-1 (ppb). Direct detection of these compounds in complex oil samples without prior sample preparation or pre-concentration was also demonstrated using a home-built miniature mass spectrometer at levels below 1 ng μL-1.© 2013 The Royal Society of Chemistry.

Electrochemical noise measurements of steel corrosion in the molten NaCl-K2SO4 system

DEFF Research Database (Denmark)

Cappeln, Frederik Vilhelm; Bjerrum, Niels; Petrushina, Irina

2005-01-01

-called active corrosion (i.e., the corrosion proceeds with no passivation due to the influence of chlorine), characterized by the formation of volatile metal chlorides as a primary corrosion product. It was found possible to obtain an empirical separation of general and intergranular corrosion using kurtosis (a......Electrochemical noise measurements have been carried out on AISI347, 10CrMo910, 15Mo3, and X20CrMoV121 steels in molten NaCl-K2SO4 at 630 degrees C. Different types of current noise have been identified for pitting, intergranular and peeling corrosion. The corrosion mechanism was the so...... statistical parameter calculated from the electrochemical noise data). It was found that average kurtosis values above 6 indicated intergranular corrosion and average values below 6 indicated general corrosion. The response time for localized corrosion detection in in-plant monitoring was approximately 90 min...

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.

Emerging surface characterization techniques for carbon steel corrosion: a critical brief review

Science.gov (United States)

Dwivedi, D.; Lepkova, K.; Becker, T.

2017-03-01

Carbon steel is a preferred construction material in many industrial and domestic applications, including oil and gas pipelines, where corrosion mitigation using film-forming corrosion inhibitor formulations is a widely accepted method. This review identifies surface analytical techniques that are considered suitable for analysis of thin films at metallic substrates, but are yet to be applied to analysis of carbon steel surfaces in corrosive media or treated with corrosion inhibitors. The reviewed methods include time of flight-secondary ion mass spectrometry, X-ray absorption spectroscopy methods, particle-induced X-ray emission, Rutherford backscatter spectroscopy, Auger electron spectroscopy, electron probe microanalysis, near-edge X-ray absorption fine structure spectroscopy, X-ray photoemission electron microscopy, low-energy electron diffraction, small-angle neutron scattering and neutron reflectometry, and conversion electron Moessbauer spectrometry. Advantages and limitations of the analytical methods in thin-film surface investigations are discussed. Technical parameters of nominated analytical methods are provided to assist in the selection of suitable methods for analysis of metallic substrates deposited with surface films. The challenges associated with the applications of the emerging analytical methods in corrosion science are also addressed.

Model boiler studies on deposition and corrosion

International Nuclear Information System (INIS)

Balakrishnan, P.V.; McVey, E.G.

1977-09-01

Deposit formation was studied in a model boiler, with sea-water injections to simulate the in-leakage which could occur from sea-water cooled condensers. When All Volatile Treatment (AVT) was used for chemistry control the deposits consisted of the sea-water salts and corrosion products. With sodium phosphate added to the boiler water, the deposits also contained the phosphates derived from the sea-water salts. The deposits were formed in layers of differing compositions. There was no significant corrosion of the Fe-Ni-Cr alloy boiler tube under deposits, either on the open area of the tube or in crevices. However, carbon steel that formed a crevice around the tube was corroded severely when the boiler water did not contain phosphate. The observed corrosion of carbon steel was caused by the presence of acidic, highly concentrated chloride solution produced from the sea-water within the crevice. Results of theoretical calculations of the composition of the concentrated solution are presented. (author)

Effects of polymer corrosion inhibitor on widening etch tunnels of aluminum foil for capacitor

International Nuclear Information System (INIS)

Ban, Chaolei; He, Yedong; Shao, Xin; Wang, Zhishen

2014-01-01

Highlights: •With PSSA, the exterior surface dissolution of etched Al foil is suppressed. •With PSSA, the interior surface dissolution of etched Al foil is facilitated. •With PSSA, the tunnels are widened along the entire length. •With PSSA, the area and capacitance of etched Al foil are significantly improved. -- Abstract: We investigated the effects of polymeric corrosion inhibitor polystyrene sulfonic acid (PSSA) additive to 3% HNO 3 solution on widening tunnels of pre-etched aluminum foil by electrochemical DC etching for aluminum electrolytic capacitors, using scanning electron microscopy and polarization curves. With trace PSSA, the dissolution of exterior surface of etch tunnels of Al foil is suppressed and the dissolution of interior surface of etch tunnels of Al foil is facilitated, respectively. The tunnels transform from circular cone to circular column in shape and pits-merging on the surface is weakened, leading to significant increase in the surface area and specific capacitance of the Al foil. The amounts of reduced thickness and weight of Al foil during the widening process of etch tunnels can be decreased if PSSA is employed

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

Directory of Open Access Journals (Sweden)

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.

TRU drum corrosion task team report

Energy Technology Data Exchange (ETDEWEB)

Kooda, K.E.; Lavery, C.A.; Zeek, D.P.

1996-05-01

During routine inspections in March 1996, transuranic (TRU) waste drums stored at the Radioactive Waste Management Complex (RWMC) were found with pinholes and leaking fluid. These drums were overpacked, and further inspection discovered over 200 drums with similar corrosion. A task team was assigned to investigate the problem with four specific objectives: to identify any other drums in RWMC TRU storage with pinhole corrosion; to evaluate the adequacy of the RWMC inspection process; to determine the precise mechanism(s) generating the pinhole drum corrosion; and to assess the implications of this event for WIPP certifiability of waste drums. The task team investigations analyzed the source of the pinholes to be Hcl-induced localized pitting corrosion. Hcl formation is directly related to the polychlorinated hydrocarbon volatile organic compounds (VOCs) in the waste. Most of the drums showing pinhole corrosion are from Content Code-003 (CC-003) because they contain the highest amounts of polychlorinated VOCs as determined by headspace gas analysis. CC-001 drums represent the only other content code with a significant number of pinhole corrosion drums because their headspace gas VOC content, although significantly less than CC-003, is far greater than that of the other content codes. The exact mechanisms of Hcl formation could not be determined, but radiolytic and reductive dechlorination and direct reduction of halocarbons were analyzed as the likely operable reactions. The team considered the entire range of feasible options, ranked and prioritized the alternatives, and recommended the optimal solution that maximizes protection of worker and public safety while minimizing impacts on RWMC and TRU program operations.

TRU drum corrosion task team report

International Nuclear Information System (INIS)

Kooda, K.E.; Lavery, C.A.; Zeek, D.P.

1996-05-01

During routine inspections in March 1996, transuranic (TRU) waste drums stored at the Radioactive Waste Management Complex (RWMC) were found with pinholes and leaking fluid. These drums were overpacked, and further inspection discovered over 200 drums with similar corrosion. A task team was assigned to investigate the problem with four specific objectives: to identify any other drums in RWMC TRU storage with pinhole corrosion; to evaluate the adequacy of the RWMC inspection process; to determine the precise mechanism(s) generating the pinhole drum corrosion; and to assess the implications of this event for WIPP certifiability of waste drums. The task team investigations analyzed the source of the pinholes to be Hcl-induced localized pitting corrosion. Hcl formation is directly related to the polychlorinated hydrocarbon volatile organic compounds (VOCs) in the waste. Most of the drums showing pinhole corrosion are from Content Code-003 (CC-003) because they contain the highest amounts of polychlorinated VOCs as determined by headspace gas analysis. CC-001 drums represent the only other content code with a significant number of pinhole corrosion drums because their headspace gas VOC content, although significantly less than CC-003, is far greater than that of the other content codes. The exact mechanisms of Hcl formation could not be determined, but radiolytic and reductive dechlorination and direct reduction of halocarbons were analyzed as the likely operable reactions. The team considered the entire range of feasible options, ranked and prioritized the alternatives, and recommended the optimal solution that maximizes protection of worker and public safety while minimizing impacts on RWMC and TRU program operations

High temperature corrosion of silicon carbide and silicon nitride in the presence of chloride compound

International Nuclear Information System (INIS)

McNallan, M.

1993-01-01

Silicon carbide and silicon nitride are resistant to oxidation because a protective silicon dioxide films on their surfaces in most oxidizing environments. Chloride compounds can attack the surface in two ways: 1) chlorine can attack the silicon directly to form a volatile silicon chloride compound or 2) alkali compounds combined with the chlorine can be transported to the surface where they flux the silica layer by forming stable alkali silicates. Alkali halides have enough vapor pressure that a sufficient quantity of alkali species to cause accelerated corrosion can be transported to the ceramic surface without the formation of a chloride deposit. When silicon carbide is attacked simultaneously by chlorine and oxygen, the corrosion products include both volatile and condensed spices. Silicon nitride is much more resistance to this type of attack than silicon carbide. Silicon based ceramics are exposed to oxidizing gases in the presence of alkali chloride vapors, the rate of corrosion is controlled primarily by the driving force for the formation of alkali silicate, which can be quantified as the activity of the alkali oxide in equilibrium with the corrosive gas mixture. In a gas mixture containing a fixed partial pressure of KCl, the rate of corrosion is accelerated by increasing the concentration of water vapor and inhibited by increasing the concentration of HCl. Similar results have been obtained for mixtures containing other alkalis and halogens. (Orig./A.B.)

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)

Corrosion Inhibition of AISI/SAE Steel in a Marine Environment

Directory of Open Access Journals (Sweden)

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%.

Synergistic Effect of Molybdate and Monoethanolamine on Corrosion Inhibition of Ductile Cast Iron in Tap Water

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)

2017-02-15

A synergistic effect was observed in the combination of nitrite and ethanolamines. Ethanolamine is one of the representative organic corrosion inhibitors and can be categorized as adsorption type. However, nitrosamines can form when amines mix with sodium nitrite. Since nitrosamine is a carcinogen, the co-addition of nitrite and ethanolamine will be not practical, and thus, a non-toxic combination of inhibitors shall be needed. In order to maximize the effect of monoethanolamine, we focused on the addition of molybdate. Molybdate has been used to alternate the addition of chromate, but it showed insufficient oxidizing power relative to corrosion inhibitors. This work evaluated the synergistic effect of the co-addition of molybdate and monoethanolamine, and its corrosion mechanism was elucidated. A high concentration of molybdate or monoethanolamine was needed to inhibit the corrosion of ductile cast iron in tap water, but in the case of the co-addition of molybdate and monoethanolamine, a synergistic effect was observed. This synergistic effect could be attributed to the molybdate that partly oxidizes the metallic surface and the monoethanolamine that is simultaneously adsorbed on the graphite surface. This adsorbed layer then acts as the barrier layer that mitigates galvanic corrosion between the graphite and the matrix.

Inhibition of intergranular stress corrosion cracking of sensitized type 304 stainless steel. Annual report

International Nuclear Information System (INIS)

Brown, B.F.

1977-01-01

The effectiveness of various inhibitors in mitigating stress corrosion cracking of stainless steel in hot aqueous environment was evaluated. The inhibitors studied were of three types: poly-oxy-anions, organic competitive absorbers, and simple cations; the corrosive medium was 4M NaCl acidified with H 2 SO 4 to ph of about 2.3. The following conclusions were reached: pH does not affect cracking kinetics in a sensitive way; cracking time is highly dependent on chloride concentrations; poly-oxy-anions do not perform well; organics offer some possibilities as inhibitors; cationic additives can have effects varying from trivial to total suppression of cracking--behavior is both cation and concentration dependent. 2 figures, 5 tables

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

Understanding the corrosion inhibition of carbon steel and copper in sulphuric acid medium by amino acids using electrochemical techniques allied to molecular modelling methods

International Nuclear Information System (INIS)

Mendonça, Glaydson L.F.; Costa, Stefane N.; Freire, Valder N.; Casciano, Paulo N.S.; Correia, Adriana N.; Lima-Neto, Pedro de

2017-01-01

Highlights: • Corrosion inhibition of carbon steel and of copper by the amino acids was studied. • Inhibition efficiencies were experimentally achieved by electrochemical impedance. • DFT and Monte Carlo methods allowed correlating molecular properties with inhibition efficiency. • The corrosion inhibition followed the electron donation the electron-back donations process. - Abstract: Six amino acids were evaluated as corrosion inhibitors for carbon steel and copper in 0.5 mol L"−"1 H_2SO_4 solution by potentiodynamic polarization and electrochemical impedance techniques allied to Density Functional Theory (DFT) and Monte Carlo computations The corrosion inhibitor rankings were: Arg > Gln > Asn > Met > Cys > Ser, for copper, and Met > Cys > Ser > Arg > Gln > Asn, for carbon steel. The DFT approach failed to explain the corrosion inhibition rating based on the HOMO and LUMO energies of the isolated amino acid molecules, while the simpler classical Monte Carlo approach, performed considering the interaction energies between the corrosion inhibitor and the metallic substrate, was successful.

Novel Galvanic Corrosion Inhibitors: Synthesis, Characterization, Fabrication and Testing

Science.gov (United States)

2007-09-30

Polyimide Insulated Electrical Wire", SAMPE pp.16, Jan/Feb 1984. 11. Brown, S. R.; Deluccia, J.J., " Galvanic Corrosion Fatigue Testing of 7075-T6...Modified Microporous Aluminosilicate" Development of Adsorbents for Air and Water Treatment Conference, 226th American Chemical Society (ACS) National

Microbiological Corrosion in Low Carbon Steels

Directory of Open Access Journals (Sweden)

O. Medina–Custodio

2009-01-01

Full Text Available The Microbiologically Induced Corrosion affects several industries, such as oil industry where it is estimated that 20% to 30% pipes failures are related with microorganism . The chemical reactions generate ions transfer, this validate the use of electrochemical techniques for its analysis. Coupons submerged in a nutritional medium with presence and absence of three different microorganisms during two periods, 48 hours and 28 days we restudied. Polarization resistance (Rp and Electrochemical Impedance Spectroscopy (EIS techniques we re applied to determine the corrosivity of the systems. The results show a greater corrosive effect of abiotic system, this indicates a microorganisms protection effect to the metal, opposite to the first hypothesis. This result was ratified observing surfaces coupons by using Scanning Electron Microscopy (SEM technique. A possible mechanism based on Evans – Tafel graph is proposed to explain inhibitor microorganism effect.

Potential for erosion corrosion of SRS high level waste tanks

International Nuclear Information System (INIS)

Zapp, P.E.

1994-01-01

SRS high-level radioactive waste tanks will not experience erosion corrosion to any significant degree during slurry pump operations. Erosion corrosion in carbon steel structures at reported pump discharge velocities is dominated by electrochemical (corrosion) processes. Interruption of those processes, as by the addition of corrosion inhibitors, sharply reduces the rate of metal loss from erosion corrosion. The well-inhibited SRS waste tanks have a near-zero general corrosion rate, and therefore will be essentially immune to erosion corrosion. The experimental data on carbon steel erosion corrosion most relevant to SRS operations was obtained at the Hanford Site on simulated Purex waste. A metal loss rate of 2.4 mils per year was measured at a temperature of 102 C and a slurry velocity comparable to calculated SRS slurry velocities on ground specimens of the same carbon steel used in SRS waste tanks. Based on these data and the much lower expected temperatures, the metal loss rate of SRS tanks under waste removal and processing conditions should be insignificant, i.e. less than 1 mil per year

Corrosion behavior of AISI 4130 steel alloy in ethylene glycol–water mixture in presence of molybdate

International Nuclear Information System (INIS)

Danaee, I.; Niknejad Khomami, M.; Attar, A.A.

2012-01-01

The electrochemical behavior of steel alloy in ethylene glycol–water mixture with different concentrations was investigated by polarization curves, AC impedance measurements, current transient and atomic force microscopy. The results obtained showed that corrosion rate was decreased with increasing ethylene glycol concentration. The effect of molybdate as inhibitor was studied and high inhibition efficiency was obtained. It was found that surface passivation was occurred in presence of inhibitor. The inhibiting effect of the molybdate was explained on the basis of the competitive adsorption between the inorganic anions and the aggressive Cl − ions and the adsorption isotherm basically obeys the Langmuir adsorption isotherm. Thermodynamic parameters for steel corrosion and inhibitor adsorption were determined and reveal that the adsorption process is spontaneous. Also phenomenon of both physical and chemical adsorption is proposed. -- Highlights: ► Corrosion rate was decreased with increasing ethylene glycol concentration. ► High inhibition efficiency was obtained for molybdate. ► Surface passivation was occurred in presence of inhibitor. ► The adsorption isotherm basically obeys the Langmuir adsorption isotherm.