Selection of corrosion inhibitors for the protection of oil production equipment

The corrosion behavior of steel in a hydrogen-sulfide medium is studied in model solutions simulating stratal water in some oil fields located in Perm’ oblast. A comparative analysis of the corrosion inhibitors used in the oil fields is presented. Some inhibitors are found to have a significant residual effect. Original Russian Text ? R.K. Vagapov, V.S. Bizyaeva, V.I. Kichigin, 2007, published in Korroziya: Materialy, Zashchita, 2006, No. 4, pp. 24–28.     

Atmospheric corrosion of metals in regions of cold and extremely cold climate (a review)

The results of atmospheric corrosion tests on a series of metals and alloys in marine and industrial atmospheres of the Earth’s regions with cold and very cold climate (Antarctic, sub-Arctic, Russian Far East) are considered. The class of most dangerous corrosive damage includes special types such as pitting, exfoliation corrosion, crevice corrosion and corrosion-induced cracking. Long-term prognosis is made concerning the influence of global warming on the atmospheric corrosion in cold climate regions. Original Russian Text ? A.A. Mikhailov, P.V. Strekalov, Yu.M. Panchenko, 2008, published in Korroziya: Materialy, Zashchita, 2007, No. 7, pp. 1–16.     

Comparative study of the corrosion behavior of platinum-based nanosized cathodic catalysts for fuel cells

The corrosion behavior of nanosized catalysts, in particular, of the commercial platinum catalyst and of PtCo synthesized on a XC72 carbon black carrier, are compared. Using electrochemical and structural research methods, it is shown that, under comparable conditions of the corrosion treatment, the PtCo/C system is less liable to degradation caused by the dissolution or aggregation of the catalyst particles. Original Russian Text ? M.R. Tarasevich, V.A. Bogdanovskaya, E.N. Loubnin, L.A. Reznikova, 2007, published in Korroziya: Materialy, Zashchita, 2006, No. 10, pp. 22–26.     

Contact corrosion of metals in aqueous media. Part I

The corrosion behavior of aluminum, steel, and cast iron in aqueous solutions is studied both for individual metal specimens and short-circuited systems (aluminum-steel, aluminum-cast iron, steel-cast iron, and aluminum-steel-cast iron). It is shown that aluminum behaves as a cathode with respect to steel and cast iron. The high corrosion rates of ferrous metals are caused by the specificity of iron surface state in aqueous solutions of electrolytes. Original Russian Text ? V.N. Esenin, L.I. Denisovich, 2007, published in Zashchita Metallov, 2007, Vol. 43, No. 4, pp. 390–395.     

Methods and setups for corrosion testing in moving media and under heat exchange conditions: 4. Crevice corrosion

The possibilities offered by various setups for the investigation of crevice corrosion are considered. It is pointed out that the setups with rotating electrodes, despite their ability to create controlled hydrodynamic and heat exchange conditions, are not suited for studying crevice corrosion because of the forced removal of a medium from the crevice under the action of centrifugal forces. The design of a setup free of this disadvantage is proposed, which employs a combination of rotating and immobile disks. Original Russian Text ? V.S. Pakhomov, 2007, published in Korroziya: Materialy, Zashchita, 2006, No. 9, pp. 37–48. For part 3, see [1].     

Accumulating ability of biofouling microbiocenose with respect to certain heavy metals in harbor and control water of marine corrosion stations

The ability of microbe colonies on focusing screen to accumulate certain heavy metals and aluminum and the effect of impact seawater on the corrosion resistance of high-alloy steel are studied. Original Russian Text ? A.P. Suponina, M.D. Koryakova, V.G. Kuryavyi, 2007, published in Zashchita Metallov, 2007, Vol. 43, No. 3, pp. 320–325.     

Effect of the milling conditions for nanocrystalline iron powders on their corrosion behavior in neutral electrolytes

The corrosion behavior of nanocrystalline iron powders obtained by milling in oxygen-containing organic media (isopropyl alcohol, acetic acid, oleic acid, and its solutions in heptane) was studied. The high corrosion resistances of iron powders obtained by mechanoactivation in oleic acid were associated with a protective surface layer formed by iron oxide and chemisorbed oleic acid or products of its partial degradation. Nanocrystalline iron-based systems that contain oxide phases without forming protective layers were less resistant to corrosion. Original Russian Text ? S.F. Lomayeva, A.V. Syugaev, S.M. Reshetnikov, A.S. Shuravin, O.M. Nemtsova, V.V. Aksenova, 2007, published in Zashchita Metallov, 2007, Vol. 43, No. 2, pp. 207–215.     

A Method for determining safe concentrations of chloride ions in pitting corrosion of steels in nitrate media

Features of how pitting corrosion develops on steels in nitrate-chloride media are analyzed, and the disadvantages of certain well-known electrochemical methods used to determine safe ratios of components under such conditions are found. A principally new approach to determining these parameters is proposed, based on the induction of intense pitting in definitely aggressive media with subsequent suppression of this process by continuously dilution of the solution or by gradual addition of an inhibitor. Equations are obtained for determining safe component concentrations depending on the volume of solution passing through the cell. Using the proposed method, safe ratios of components are determined for 12Kh18N10T chromium-nickel steel at chloride ion concentrations within 0.02–2.0 M. Original Russian Text ? V.P. Razygraev, M.V. Lebedeva, I.I. Korchak, 2008, published in Korroziya: Materialy, Zashchita, 2007, No. 8, pp. 42–47.     

Thermodynamics of chemical and electrochemical stability of corrosion active nonmetal inclusions

Diagrams potential-pH are plotted for different phase components of corrosive nonmetal inclusions in steels in sulfide-containing media at 25°C, 1 atm (air), and a _i = 10⁻³ mol/l. Thermodynamic peculiarities of their corrosion and electrochemical behavior are analyzed. Original Russian Text ? A.G. Tyurin, I.Yu. Pyshmintsev, I.V. Kostitsyna, I.M. Zubkova, 2007, published in Zashchita Metallov, 2007, Vol. 43, No. 1, pp. 39–49.     

A practical application of thermal desorption mass spectrometry for studying inhibitors and corrosion products

In the present review, examples of the practicality of applying thermal desorption mass spectrometry (TDMS) to study inhibitors and corrosion products are given. It is shown that the highly informative aspect of the method allows regularities of the processes occurring in volume, on surfaces, and in near-surface layers of steels and alloys to be established. The TDMS method makes it possible to identify adsorbed and chemisorbed inhibitors and corrosion products, as well as products of their destruction. Original Russian Text ? A.K. Buryak, T.M. Serdyuk, A.V. Ul’yanov, 2008, published in Korroziya: Materialy, Zashchita, 2008, No. 4, pp. 33–41.     

Peculiarities of the inhibiting effect of cadmium chloride on the corrosion of aluminum in hydrochloric solutions

The concentration effect of cadmium chloride on the corrosion rate of aluminum under conditions of the contact deposition of cadmium in hydrochloric acid solutions is studied. At changes in the contact deposition rate of the metal, in the surface area of the cadmium deposit, and the character of the deposits formed, the inhibiting effect of cadmium cations is shown to transform into the stimulating effect with an increase in the cadmium concentration in the solution. The reasons for the nonmonotonic character of the concentration dependence of the corrosion rate of aluminum are discussed. Original Russian Text ? V.V. Bartenev, O.I. Barteneva, 2007, published in Zashchita Metallov, 2007, Vol. 43, No. 6, pp. 647–651.     

New concept of the mechanism of intergranular corrosion of stainless steels

The electronic structure of chromium-nickel austenite stainless steels of type X20H20 and X10H20, in particular, added with 4 to 6% Si, is studied using nuclear γ-resonant (M?ssbauer) spectroscopy. The structure varies significantly depending on the chromium and silicon content. Low-chromium steels are used for the modeling of chromium-depleted boundary zones that neighbor chromium-rich excess phases. Eventually, a mechanism of the intergranular corrosion of stainless steels that takes into account the changes in the electronic structure of the chromium-depleted boundary zones is first suggested. These changes in the chemisorption interaction of the iron carcass ions with corrosive components of the medium, cannot but affect the zones’ stability. It is this interaction that synergistically intensifius the intergranular corrosion of austenite stainless steels containing combinations of silicon dopant and carbon impurity, or the phosphorus and carbon impurities. Original Russian Text ? O.V. Kasparova, Yu.V. Baldokhin, 2007, published in Zashchita Metallov, 2007, Vol. 43, No. 3, pp. 256–261.     

The effect of medium on the corrosion and electrochemical behavior of nickel

Electrochemical and corrosion properties of nickel in neutral, alkaline, and acidic solutions are studied. Chemical and phase composition of surface films and surface morphology are examined. The effect of electrolyte composition and concentration on the metal removal rate in the course of broaching is determined. Optical, electrochemical, and gravimetrical methods, x-ray diffraction analysis, and thermogravimetry were used in the work. Original Russian Text ? V.V. Parshutin, N.L. Bogdashkina, G.P. Chernova, 2007, published in Zashchita Metallov, 2007, Vol. 43, No. 1, pp. 64–70.     

Protection of systems with faulty sealing by volatile corrosion inhibitors

Processes that initiate corrosion in systems with faulty sealing are analyzed in terms of a mathematical model developed to describe metal protection with volatile inhibitors in such systems. It was demonstrated that the protection times are often determined by the kinetics of dilution of an inhibitor with water coming from the atmosphere. The ways of enhancing the vapor-phase protection are proposed. It is found that the effectiveness of a VCI in incompletely sealed systems can be estimated in accelerated tests by decreasing its dosage and increasing the mass exchange surface since these factors stimulate corrosion without violating the similarity principle. Original Russian Text ? N.N. Andreev, N.V. Lavrinova, N.A. Lebedeva, 2007, published in Zashchita Metallov, 2007, Vol. 43, No. 3, pp. 276–279.     

Polyfunctional effects of [1,3]thiazino[3,2- a ]benzoimidazol-4-ones on steel corrosion

[1,3]Thiazino[3,2-a]benzoimidazol-4-ones were found to be effective inhibitors of the acid corrosion of steel 20 in 1 M HCl and 1 M H₂SO₄(pH 0) and valuable polyfunctional additives that enhance the anticorrosion properties and stimulate the formation of an epoxy powder coating. Original Russian Text ? V.N. Chelyabieva, O.I. Sizaya, S.V. Gatsenko, A.N. Esipenko, V.N. Britsun, 2007, published in Zashchita Metallov, 2007, Vol. 43, No. 3, pp. 280–284.     

On the mechanism of the effect of plastic deformation on the corrosion resistance of high-strength cast iron

The mechanism of the effect of preliminary plastic deformation on the corrosion resistance of high-strength cast iron is analyzed. Based on the experimental results, a scheme of the mechanism considering the contribution of the variation in the number and shape of graphite inclusions to the anisotropy of corrosion rate of strained cast iron is proposed. Original Russian Text ? D.A. Baranov, 2007, published in Zashchita Metallov, 2007, Vol. 43, No. 1, pp. 55–58.     

The aftereffect of cyclic loading on the corrosion of aluminum-based alloys

Effects of bench loading and stresses on the corrosion resistance of д16AT alloy are studied. Complicated effect of the stress intensity and the cyclic loading on the surface morphology and pit concentration is demonstrated. Harmonic character of the loading dependence of the change of corrosion resistance is due to segregation effects. Original Russian Text ? V.Yu. Vasil’ev, V.S. Shapkin, N.V. Barulenkova, M.V. Antonova, and E.N. Antonova, 2006, published in Zashchita Metallov, 2006, Vol. 42, No. 3, pp. 227–232.     

Choice of effective corrosion inhibitors for acid treatment of wells

Protective effects of some commercial corrosion inhibitors (VNPP-2V, KI-1, and IKU) in fluids used for acid treatments of oil wells were studied by gravimetric and electrochemical measurements. The inhibitors were tested in the presence of Fe³⁺ ions and in “aged” inhibited fluids. Original Russian Text ? A.B. Shein, A.V. Denisova, 2006, published in Zashchita Metallov, 2006, Vol. 42, No. 1, pp. 39–42.     

Corrosion inhibitors of the SNPKh brand. 2. The P,N-Containing corrosion inhibitor for protection of oil-field equipment

Series of functionalized pyridinium alkyl[poly(oxyethylene)] phosphites, isoquinolinium alkyl[poly(oxyethylene)] phosphites, pyridinium aryl[poly(oxyethylene)] phosphites, and isoquinolinium aryl[poly(oxyethylene)] phosphites were obtained and their properties were studied systematically. Some of them were found to be effective corrosion inhibitors in aqueous CO₂-and H₂S-containing media. Isoquinolinium dodecyl-and dodecylphenyl[dodeca(oxyethylene)] phosphites proved to be the best inhibitors. The isoquinolinium aryl[poly(oxyethylene)] phosphites obtained were used to create a new corrosion inhibitor. Original Russian Text ? O.V. Ugryamov, O.A. Varnavskaya, V.N. Khlebnikov,V.A. Ivanov, S.I. Vasyukov, G.V. Romanov, Ya.V. Ivshin, R.A. Kaidrikov, Kh.E. Kharlampidi, F.Sh. Shakirov, 2007, published in Zashchita Metallov, 2007, Vol. 43, No. 1, pp. 94–102.     

Increasing the corrosion resistance of oil production equipment and pipelines

The protective properties of corrosion inhibitors have been studied in stratal waters of some oil fields located in the Perm region and the Timano-Pechorsk oil and gas bearing province, which are characterized by a high level of mineralization and contain corrosion-aggressive components. The ability of inhibitors to produce protective aftereffect is evaluated. The dependence of the anodic and cathodic processes on steel on the composition of medium, corrosive agents, temperature, and inhibitors has been studied by electrochemical techniques. Original Russian Text ? R.K. Vagapov, 2008, published in Korroziya: Materialy, Zashchita, 2007, No. 7, pp. 16–21