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1.
Dynamics of Stress-Strained State and Corrosion of a Reservoir Casing. Theoretical Calculation R. K. Galimov N.P. Mel’nikov Central Scientific, Research, and Planning Institute of Building Metal Structures,
ul. Arkhitektora Vlasova 49, Moscow, 117393 Russia E-mail:
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Received April 17, 2006 Abstract — The results of mathematical modeling of the evolution of the stress-strained state of a reservoir casing are presented and discussed. PACS numbers: 81.40.Ef; 81.40.Lm; 81.40.Np DOI: 10.1134/S0033173207010018
12/09/2008 | 1116 Hits | Print
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2.
Thermodynamic Causes of the High Diffusion Rate of Atoms in the Superficial Layer of a Metallic Electrode Yu. Ya. Andreev Moscow State Institute of Steel and Alloys, Leninskii pr. 2, Moscow, Russia E-mail:
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Received January 31, 2006 Abstract — Concentration of vacancies NV(S) in a superficial layer (SL) of fcc lattices of Ag, Cu, and Au metals is thermodynamically estimated and analyzed. The calculations are based on a thermodynamic vacancy model of the metal SLs, by which the NV(S) value is related to the surface Gibbs energy  Gs =  RT ln NV(S). A strongGs dependence on the electrode potential and the zero point value of the metal results in the increase in NV(S) value, which reaches nearly 10 2 at standard potentials of the above metals. The high surface self-diffusivity of atoms (D  10 15 cm2/s) calculated from the in situ STM measurements of the electrode surfaces is due to the high concentration of vacancies in the metal SLs. PACS numbers: 05.70.Np; 68.35.Md DOI: 10.1134/S003317320701002X
12/09/2008 | 1270 Hits | Print
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3.
Theoretical Estimation of the Ionization Potential of Water in Condensed Phase. II. Superficial Water Layers Yu. V. Novakovskaya Laboratory of Quantum Mechanics and Molecular Structure, Chair of Physical Chemistry, Department of Chemistry,
Moscow State University, Leninskie Gory, Moscow, 119992 Russia E-mail:
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Received May 7, 2006 Abstract — Quantum chemical calculations of neutral and charged (H2O)n water clusters modeling fragments of a real hydrogen-bond network of water and dynamic simulations of the clusters either upon the electron removal from a stable neutral cluster or upon the excitation of various cluster vibrations enabled us to distinguish separate stages of the structure reorganization. Thermal motion of molecules in a liquid modeled by the low-frequency rotational vibrations and swinging of molecules prevents the formation of cations with the opti-mum mutual arrangement of the OH radical and H3O+ ion. Judging from the typical periods of reactive vibra-tions and those motions, which impede the desired structure reorganization, the most probable should be the formation of OH H2O H3O+ fragments in liquid water. The energy necessary for the ionization of superficial water layers (at the irradiation) can be estimated from the intermediate ionization potentials of water clusters. Extrapolating the dependence of these potentials on the number of water molecules constituting the cluster provided the first ever theoretical estimate of the threshold ionization energy of water: 9.5 eV. PACS numbers: 31.15.Ar; 31.15.Qg; 33.15.Ry; 34.50.Ez; 36.40.Wa DOI: 10.1134/S0033173207010031
12/09/2008 | 1250 Hits | Print
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4.
Thermodynamics of Chemical and Electrochemical Stability of Corrosion Active Nonmetal Inclusions A. G. Tyurina, I. Yu. Pyshmintsevb, I. V. Kostitsynab, and I. M. Zubkovab aChelyabinsk State University, ul. Br. Kashirinykh 129, Chelyabinsk, 454021 Russia bOAO RosNITI, ul. Novorossiiskaya 30, Chelyabinsk, 454139 Russia Received April 19, 2006 Abstract — 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 ai = 10 3 mol/l. Thermodynamic peculiarities of their corrosion and electrochemical behavior are analyzed. PACS numbers: 81.65.Kn DOI: 10.1134/S0033173207010043
12/09/2008 | 1283 Hits | Print
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5.
Physicochemical Properties of Electrodeposits Based on Tungsten Carbide and Zirconium Diboride on Steels V. V. Malyshev and A. I. Gab National Technical University of Ukraine “Kiev Polytechnical Institute,” pl. Pobedy 37,
korp. 4, komn. 039, Kiev-56, 03056 Ukraine Open International University of Human Development “Ukraine,” ul. Khorevaya 1g, Kiev-71, 04071 Ukraine Received October 20, 2005 Abstract — The electrodeposition of coatings based on tungsten carbide and zirconium diboride on steel materials and their physicochemical and mechanical properties are studied. The coatings enhance the wear resistance of steel samples by a factor of 6–11 and the abrasive stability by a factor of 7–10. PACS numbers: 81.15 Pq; 81.65.Kn DOI: 10.1134/S0033173207010055
12/09/2008 | 1353 Hits | Print
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6.
On the Mechanism of the Effect of Plastic Deformation on the Corrosion Resistance of High-Strength Cast Iron D. A. Baranov Donetsk National Engneering University, ul. Artema 58, Donetsk, 83000 Ukraine Received September 14, 2005 Abstract — The mechanism of the effect of preliminary plastic deformation on the corrosion resistance of highstrength 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. PACS numbers: 81.40.-z; 68.55.Gk DOI: 10.1134/S0033173207010067
12/09/2008 | 1290 Hits | Print
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7.
Anodic Dissolution of Iron Silicides in Alkaline Electrolyte A. B. Sheina, I. L. Rakityanskayaa, and S. F. Lomaevab a Perm’ State University, ul. Bukireva 15, Perm, 614600 Russia E-mail:
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b Physicotechnical Research Institute, Russian Academy of Sciences, Ural Branch, Izhevsk, Russia Received November 11, 2005 Abstract — Anodic dissolution of iron and its silicides (FeSi, FeSi2, as well as the eutectic alloy FeSi2–Si) and pure Si, in 0.1 to 5.0 N NaOH solutions is studied by cyclic voltammetry and x-ray photoelectron spectroscopy. Principal characteristic features of the silicide anodic dissolution are revealed and the composition of surface films investigated. It is shown that, despite an increase in Si solubility at higher pHs, the iron silicides are highly resistant to anodic dissolution due to especial protective properties of the complex oxide surface film. PACS numbers: 81.65.Rv; 82.45.Bb DOI: 10.1134/S0033173207010079
12/09/2008 | 1274 Hits | Print
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8.
The Effect of Medium on the Corrosion and Electrochemical Behavior of Nickel V. V. Parshutina, N. L. Bogdashkinab, and G. P. Chernovab aInstitute of Applied Physics, Academy of Sciences of Moldova, ul. Akademicheskaya 5, Chisinau, MD-2028 Moldova b Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences,
Leninskii pr. 31, Moscow, 119991 Russia e-mail:
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Received January 13, 2006 Abstract — 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. PACS numbers: 82.42.Bb; 82.45.Kr DOI: 10.1134/S0033173207010080
12/09/2008 | 1213 Hits | Print
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9.
Steady-State Anodic Dissolution of Iron in Neutral and Close-to-Neutral Media A. Yu. Aleksanyan, A. N. Podobaev, and I. I. Reformatskaya *FGUP GNTs RF Karpov Research Institute of Physical Chemistry, ul. Vorontsovo pole 10, Moscow, 103064 Russia Received May 6, 2006 Abstract—In neutral and close-to-neutral solutions, which contain no surface-active substances, iron dissolves via a two-step scheme. The transfer of the first electron across the interface involves water molecules that dissociate during the adsorption; the transfer of the second electron limits the process under steady-state condi-tions. In parallel, a passivator, namely, adsorbed oxygen is formed via a similar scheme. The passivator is removed from the surface due to its chemical reaction with hydroxonium ions, water molecules, or hydroxide ions. The process is adequately described by a mathematical model based on an assumption that the metal dissolves from an energy-uniform surface free from passivating species. PACS numbers: 82.85.Bb DOI: 10.1134/S0033173207010092
12/09/2008 | 1124 Hits | Print
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10.
Cadmium Electrodeposition from Water Acetone Perchlorate Baths V. V. Kuznetsov, L. M. Skibina, and R. R. Khalikov Rostov State University, ul. Zorge 7, Rostov-on-Don, 344090 Russia E-mail:
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Received October 20, 2005 Abstract — It is the composition of the bath that determines a) the nature of species adsorbed and reduced at the cathode (such as molecules of a nonaqueous solvent, perchlorate anions, metal ions, or their complexes with organic ligands) and b) the electrode reaction rate. The process is best inhibited in a range of water structure stabilization under conditions of the predominant adsorption of acetone molecules, when the discharge of electroactive species is preceded by their “constrained” dissociation during the penetration through the layer adsorbed at the cathode. The highest reduction rate was observed in the acetone structuration range, when the adsorption of perchlorate anions reaches a maximum because of the desalting effect of the mixed solvent and the selective solvation ( '-effect). PACS numbers: 81.15.Pk; 82.45 Cj DOI: 10.1134/S0033173207010109
12/09/2008 | 1136 Hits | Print
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