ISSN 2305-6894

2015, Vol. 4, Issue 2 (pp. 108–196)

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Why we reject papers with calculations of inhibitor adsorption based on data on protective effects

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A. N. Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, Leninskii pr. 31, Moscow, 119071 Russian Federation

Abstract: The reasons for which some submitted papers can be rejected are outlined.

Int. J. Corros. Scale Inhib., , 2, 108-109 PDF (284 K)

Effect of inhibitor mixture composition on the protective properties in carbon-dioxide corrosion of steel

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1 Southern Federal University, Zorge st., 7, Rostov-on-Don, 344090 Russian Federation
2 Don State Technical University, Gagarin sq., 1, Rostov-on-Don, 344010, Russian Federation

Abstract: The problem of corrosion control is one of the cardinal problems in the gas-and-oil producing industry. Because of it, defects occur during operation of oil-field equipment that lead to financial expenses and environmental pollution. The use of inhibitors is the simplest and cheapest method of corrosion protection [1, 2]. The presence of carbon dioxide in stratal water contributes to carbon dioxide corrosion of equipment. The specific features of this kind of corrosion require the selection of specific inhibitors in development and operation of wells. They must have high protective properties at minimal concentrations, have a positive impact on the processes of extraction, preparation, transportation and processing of oil and gas [3–8]. This paper presents the results on the effect of the composition and concentration of inhibitor mixtures on their protective properties in the corrosion of St3 steel in CO2 saturated solution of sodium chloride.

Int. J. Corros. Scale Inhib., , 2, 110-115 PDF (600 K)
doi: 10.17675/2305-6894-2015-4-2-110-115

Surface cleaning and corrosion protection using plasma technology

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University of Miskolc Institute of Metallurgy and Foundry Engineering, Chemical Metallurgy and Surface Techniques, Miskolc-Egyetemvaros, 3515 Miskolc, Hungary

Abstract: Nowadays plasma techniques are getting more and more involved in production technologies because the traditional chemical treatments are sometimes less feasible and/or environmentally harmful. Besides the plasma pre-treatments, the plasma technology can also be utilized to develop thin protective layers. Day by day new techniques come into sight, so the categorization and review of them is an important task, which was the primary aim in this paper by trying to make an account on the most up-to-date ones. In this way, some important characteristic features and major advantages are presented here for the plasma treatment of plastic surfaces under ambient atmosphere, ultrafine surface cleaning with low-pressure plasma sources, and an example for the RF-PACVD deposition of protective and highly corrosion resistant thin glassy layers by plasma polymerization of HMDSO precursors. Envisaged future utilization of a small-scale atmospheric pressure plasma (APP) jet system installed in the Laboratory of Surface Techniques at University of Miskolc is also discussed.

Int. J. Corros. Scale Inhib., , 2, 116-124 PDF (1 154 K)
doi: 10.17675/2305-6894-2015-4-2-116-124

The interplay between cationic polyethyleneimine and anionic polyelectrolytes for the control of silica scale formation in process waters

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Engineering, Growth and Design Laboratory, Department of Chemistry, University of Crete, Voutes Campus, Crete, GR-71003, Greece

Abstract: Stabilization of mono- and disilicic acids is accomplished by using a cationic polymeric chemical additive, polyethyleneimine (PEI), in supersaturated silica solutions (the starting solution contained 500 ppm/8.3 mM sodium orthosilicate, Na2SiO3·5H2O, expressed as SiO2) at pH = 7. The PEI polymeric system contains an excess of amine groups (~25% primary amines, ~50% secondary amines and ~25% tertiary amines) that become protonated at circumneutral pH, hence charging the molecules positively. PEI was found to be efficient as a silica scale inhibitor only at the low dosage of 10 ppm. Its inhibitory activity was found to drop as its concentration increased. It was hypothesized that PEI is entrapped into the colloidal silica matrix and deactivated. Thus, one way to maintain its activity was to create blends of PEI and anionic polymers. Anionic polyelectrolytes that were tested included polyacrylic acid (PAA), phosphonated polyacrylic acid (PAA(PO3H2)2), carboxymethylinulin (CMI), poly(acrylamide-co-acrylic acid) (PAM-co-AA), phosphonomethylated chitosan (PCH) are also studied for their silica scale inhibition efficiency. It is observed that the silica inhibitory activity of PEI was improved upon its combination with anionic polyelectrolytes.

Int. J. Corros. Scale Inhib., , 2, 125-138 PDF (845 K)
doi: 10.17675/2305-6894-2015-4-2-125-138

Effect of hydrodynamic conditions on copper pitting corrosion inhibition in hydrocarbonate–chloride solutions by benzotriazole

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1 MESC Air Force Military Air Academy named after N. E. Zhukovsky and Yu. A. Gagarin, ul. Staryh bolshevikov 54a, Voronezh, 394000 Russian Federation
2 Voronezh State University, Universitetskaya pl. 1, Voronezh, 394006 Russian Federation

Abstract: It has been found that in hydrocarbonate–chloride solutions (pH = 8.4) benzotriazole inhibits copper pitting corrosion. Comparative results obtained on stationary and rotating disc electrode have shown that rotation stabilizes the metal/electrolyte systems. Under drastic hydrodynamic conditions, the benzotriazole concentration required for full suppression of copper pitting corrosion was reduced 10-fold on a rotating disc.

Int. J. Corros. Scale Inhib., , 2, 139-145 PDF (581 K)
doi: 10.17675/2305-6894-2015-4-1-139-145

Protection of nickel-chromium steel in sulfuric acid solution by a substituted triazole

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1 K.E.Tsiolkovsky Kaluga state university, 248023 Kaluga, Russian Federation
2 A. N. Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, Leninskii pr. 31, Moscow, 119071 Russian Federation

Abstract: The corrosion of 12Kh18N10T nickel-chromium steel in 2.0 М H2SO4 (t = 20–100°C) was studied using mass loss, potentiometric, and polarization methods. It was shown that the corrosion resistance of this material in H2SO4 solutions is low, particularly at temperatures close to 100°C. Efficient steel protection in sulfuric acid solutions can be achieved using mixtures of IFKhAN-92 (a triazole derivative) with KI (molar ratio of the components 1:1), KBr (1:9), or KCNS (4:1) as corrosion inhibitors. Of the IFKhAN-92 formulations studied, the highest corrosion inhibition coefficients are provided by the equimolar mixture with KI, despite an antagonism in the action of its components. Decreasing the concentration of this formulation to 0.005–0.025 mM (depending on temperature) does not considerably decrease the protective effect. Mixed inhibitors based on the substituted triazole protect the metal in the acid solution for at least 8 h. The presence of the inhibitors being studied in the solution considerably increases the contribution of diffusion control to the corrosion process, as indicated by a significant decrease in the activation energy from 60±1 to 35±2 kJ/mol in the presence of these compounds. Steel corrosion occurs in the active dissolution region both in background and inhibited acid solutions. A correlation was noted between the free corrosion potential of steel (Ecor) in an acid solution containing an inhibitor and the protective effect of the latter (γ): the higher the γ value of the inhibitor, the more positive the potential of steel. The corrosion inhibition of stainless 12Kh18N10T steel in H2SO4 solutions by formulations based on IFKhAN-92 results from strong hindrance of electrode reactions on the metal by these compounds in a broad temperature range (up to 100°С). The strongest inhibition of electrode reactions on stainless steel is provided by the IFKhAN-92+KI mixture. As a result, it has the maximum efficiency in suppression of metal corrosion. A considerable effect on the characteristics of electrode reactions on stainless steel in background and inhibited acid solutions results from selective dissolution of metal surface components.

Int. J. Corros. Scale Inhib., , 2, 146-161 PDF (990 K)
doi: 10.17675/2305-6894-2015-4-1-146-161

Some surfactants based on the vegetable oils as CO2 corrosion inhibitors for mild steel in oilfield formation water

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1 Mamedaliev Institute of Petrochemical Processes, National Academy of Sciences of Azerbaijan, AZ1025 Baku, Azerbaijan
2 2Chemistry Department, Faculty of Science, Sohag University, Sohag, Egypt

Abstract: The new complex surfactants were synthesized based on sunflower oil and its inhibiting action on the corrosion of carbon steel in CO2-saturated oilfield formation water was investigated by means of weight loss and linear polarization resistance corrosion rate. The results revealed that the studied surfactants were excellent inhibitors. The percentage inhibition efficiency (IE %) increases by increasing the inhibitor concentration until the critical micelle concentration (CMC) is reached. The strong adsorption ability of the surfactant molecules leads to formation of a mono-layer, which isolates the surface from the environment and thereby reduces the corrosion attack on the surface. The adsorption process was found to obey the Langmuir adsorption isotherm.

Int. J. Corros. Scale Inhib., , 2, 162-175 PDF (1 586 K)
doi: 10.17675/2305-6894-2015-4-2-162-175

Application experience and new approaches for volatile corrosion inhibitors

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1 Northern Technologies International Corporation, 23205 Mercantile Rd., Beachwood, OH 44122, USA
2 ZAO MostNIC-Zerust, Architect Vlasov Street 51, office 101, Moscow, 117393 Russian Federation

Abstract: The efficiency and service life of a wide range of volatile corrosion inhibitors (VCIs) are summarized and discussed. Important data, related to experiences in application of these VCIs, during last 10 years, is presented. It is shown that in most cases ferrous, non-ferrous, and multimetal VCI films, diffusers, and plastic strips make it possible to achieve a high efficiency of corrosion protection of metal parts and equipment during storage, shipping, and application of a wide range of spare parts and equipment in various industries. The existing and new VCI systems presented in this paper allow us to select the most effective type of metal preservation, based on different application conditions with required service life. New methods allow for a range of VCI applications to be reliably extended into new areas of applications, which are described. These existing and new technologies increase efficiency and service life and decrease the total cost of corrosion protection in Oil & Gas, Military, Automotive, Electronic, Electrical, and other industrial sectors.

Int. J. Corros. Scale Inhib., , 2, 176-192 PDF (1 741 K)
doi: 10.17675/2305-6894-2015-4-2-176-191

Review for the monograph by Alec Groysman “Corrosion in Systems for Storage and Transportation of Petroleum Products and Biofuels”

A. N. Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences, Leninskii pr. 31, Moscow, 119071 Russian Federation


Int. J. Corros. Scale Inhib., , 2, 193-196 PDF (554 K)

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