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Corrosion Resistance of Bimetals with Cladding Stainless Steel Layers in Nearly Neutral Aqueous Media I. I. Reformatskayaa, A. N. Podobaeva, I. I. Ashcheulovaa, I. G. Rodionovab, A. A. Pavlovb, A. N. Rybkinb, and O. N. Baklanovab aFGUP GNTs RF Karpov Research Institute of Physical Chemistry, ul. Vorontsovo pole 10, Moscow, 103064 Russia bFGUP Bardin Central Research Institute of Ferrous Metallurgy, Vtoraya Baumanskaya ul. 9/23, Moscow, 107005 Russia Received May 5, 2005 Abstract — In neutral aqueous media containing 0.4 g/l [Cl], steel 04142, in the form of mono- or bimetal with a weld, retains its steady passive state unlike steel 0813.This is due to stabilizing the ferrite phase by silicon and the absent tendency to the grain growth and precipitation of chromium carbides when heated below 1025°C because of modifying with niobium. In aqueous media close to neutral which contain ~10 g/l [Cl–], the cladding layer of 1810 steel, in contrast to the massive metal of the same composition, is insusceptible to pitting because of the absence of manganese sulfide in its structure due to its low sulfur content insufficient for the manganese sulfide concentration in the metal to reach the solubility product. PACS numbers: 82.45.Bb, 81.65.Kn, 89.60.Ec DOI: 10.1134/S0033173206060014
11/09/2008 | 1306 Hits | Print
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Essential Shortcomings of Tafel Equations in Describing Electrochemical Dissolution Kinetics of a Solid Electrode Yu. V. Alekseeva, G. Yu. Alekseevb, V. A. Bityurinb, and A. V. Plaskeeva aKarpov Institute of Physical Chemistry, ul. Vorontsovo Pole 10, Moscow, 103064 Russia b Institute of High Temperatures, Russian Academy of Sciences, Moscow, Russia E-mail:
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Received April 6, 2005 Abstract — A simplified topokinetic dissolution model of a solid taking into account the correlation between the dissolution rate and the atomic surface topography enables one to interpret a linear (in semilogarithmic coordinates) segment of the steady-state curves of the active anodic dissolution of metals. Its slope corresponds to the product of a concentration of kinks and the elementary reaction rate, both of which exponentially depend on the potential, rather than a simple (Tafel) elementary rate of the atom dissolution at a semi-crystal kink. PACS numbers: 82.45.In, 82.45.Qr DOI: 10.1134/S0033173206060026
11/09/2008 | 1326 Hits | Print
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3.
On Prerequisites for Electronic Mechanism of Electrode Reactions R. R. Salem E-mail:
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Received August 27, 2005 Abstract — Equilibrium state of a two-phase system (metal–solution) is conventionally considered (see e.g. [1–3]) as a reversible process of the charge transfer by a metal cation through the interface boundary (this concept is applied to both first-kind electrodes and second-kind electrodes reversible in the anion of the metal salt, as well as redox electrodes, which may be reduced to the first-kind electrodes using the Luther rule). However, it is actually an electron that is the main charged component in all these exchanges. The exchange processes cannot be directly measured at the molecular level, while the electron current in the external circuit of the galvanic cell can be measured quite accurately. The current and potential (the potential difference between the studied and auxiliary electrodes) are the main characteristics of the electrode processes. Theoretical analysis of these phenomena by an example of electrolysis is the object of the present study. PACS numbers: 05.70.Np, 13.20.+g, 82.45.Hk DOI: 10.1134/S0033173206060038
11/09/2008 | 1369 Hits | Print
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4.
Theoretical Estimation of the Ionization Potential of Water in Condensed Phase. I. Amorphous Ice 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 March 5, 2006 Abstract — The possibilities of modern quantum chemical calculations in estimating the physicochemical characteristics of condensed phase specimens, when an increase in the number of particles does not lead to principal changes in the electronic structure, are demonstrated by an example of water, which is the most important sol-vent in actual corrosion–electrochemical processes. Stationary quantum chemical calculations of (H2O)n water clusters comprising up to 12 molecules and their cations showed that ionization induces the formation of OH and H3O+ fragments. Based on the analysis of the electron density distribution in the systems, a functional dependence of the calculated adiabatic ionization potentials of the clusters on the number of water molecules in them is derived. Extrapolation of this dependence to n provides a theoretical estimate of the photoionization threshold of ice. PACS numbers: 31.15.Az, 33.15.Ry, 36.40.Wq DOI: 10.1134/S003317320606004X
11/09/2008 | 1364 Hits | Print
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5.
Silicon as an Alloying Element in Ferrite Stainless Steels Containing 813% Cr I. I. Reformatskayaa, I. G. Rodionovab, A. N. Podobaeva, I. I. Ashcheulovaa, and E. V. Trofimovaa a FGUP GNTs RF Karpov Institute of Physical Chemistry, ul. Vorontsovo Pole 10, Moscow, Russia E-mail:
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b FGUP Bardin Central Research Institute of Ferrous Metals, Moscow, Russia Received May 5, 2005 Abstract — A jumpwise improving of the passivation ability and pitting-resistance of the Fe–(8–13)% Cr–(0.32–2.7)% Si alloys upon surpassing the limit of ~14–15 at % by the chromium and silicon summary concentration is found. It is suggested that the nature of the critical summary concentration CCr + CSi is identical to that in Fe–Cr binary alloys; it is caused by the silicon building-in to the alloy’s crystal lattice and its substitution for chromium in the statistical proportion to its atomic part in alloys. When the summary concentration CCr + CSi approaches ~14–15 at %, each elementary cell in the Fe bcc lattice must necessarily contain either a Cr atom or the proportional number of Si atoms. The improved passivation ability and pitting-resistance of the Fe–Cr–Si alloy, compared with the Fe–Cr alloys, is explained by the fayalite formation at the alloy surface. PACS numbers: 81.65.Kn, 82.45.Bb DOI: 10.1134/S0033173206060051
11/09/2008 | 1468 Hits | Print
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6.
The Effect of Oxidation of Amorphous Fe70Cr15B15 Alloy on Its Corrosion Behavior in the Acidic Sulfate Media V. G. Makletsov, O. M. Kanunnikova, and A. N. Lubnin Udmurt State University, Krasnoarmeiskaya ul. 71, Izhevsk, 426037 Russia Received August 23, 2005 Abstract—The effect of surface oxidation on the corrosion behavior of amorphous Fe70Cr15B15 alloys in the acidic sulfate media with constant ionic strength is studied. It is found that the main factor determining the electrochemical behavior of alloy is not only the elemental composition of the surface, but primarily, its chemical composition. Surface nanooxide films have the strongest effect. Films with spinel structure are most corrosion-resistant. Oxidation has an effect predominantly on the anodic process. PACS numbers: 61.43.Dq, 81.05.Kf DOI: 10.1134/S0033173206060063
11/09/2008 | 1352 Hits | Print
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7.
Electroplating of Chromium Coatings from Cr(III)-Based Electrolytes Containing Water Soluble Polymer F. I. Danilov, V. S. Protsenko, T. E. Butyrina, E. A. Vasil’eva, and A. S. Baskevich Ukrainian State Chemical and Technological University, pr. Gagarina 8, Dnepropetrovsk, 49005 Ukraine Received August 3, 2005 Abstract — The effect of certain water-soluble synthetic polymers on the current efficiency, the kinetics of partial cathodic reactions, and certain properties of coatings at the chrome plating from sulfate–formate baths based on Cr(III) salts is studied. A polymeric additive of the nonionogenic type N1 (3106 g/mol) is proposed, which favors the deposition of chromium coatings that have good adhesion to the surface, do not crack, and have a thickness of several tens micrometers. It is found that the polymers have an accelerating effect on the aggregation of the particles of the chromium-hydroxide sol formed in the near-electrode layer, which, apparently, improves the deposit quality and enhances the current efficiency. It is shown that the resulting amorphous–crystalline chromium deposits are sufficiently hard and exhibit good protectiven ability at the anodic dissolution in aggressive media. PACS numbers: 81.15.Fg, 82.45.Gj DOI: 10.1134/S0033173206060075
11/09/2008 | 1492 Hits | Print
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8.
Effect of the Structure of Benzohydrazides on Cadmium Electrodeposition from Perchlorate and Iodide Electrolytes 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 July 8, 2005 Abstract — A correlation between the polar properties of substituents R in an additive molecule (with benzohydrazide derivatives as examples) and the nature of adsorbed and reduced species was found and analyzed. It was demonstrated that an increase in the electron-donating and electron-withdrawing properties of R stimulates complexation between the metal and the additive in the surface layer, which makes the adsorbed layer more permeable and accelerates the electroreduction of metal ions. PACS numbers: 81.15.Fg, 82.45.Gj DOI: 10.1134/S0033173206060087
11/09/2008 | 1445 Hits | Print
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9.
Inhibitor of Hydrogen Sulfide Corrosion of Steel Based on Di- and Polypropylene Polyamines G. I. Akhmadeeva and R. N. Zagidullin Research Center ZAO “KAUSTIK,” ul. Tekhnicheskaya 32, Sterlitamak, 453110 Russia e-mail:
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Received July 10, 2003 Abstract — Several aminoimidazolines and their derivatives are produced from di- and polypropylene polyamines and higher isomeric acids. Varying of the composition and ratio between the components of preparative form enabled us to produce a water-soluble corrosion inhibitor that effectively protects steel against hydrogenation and corrosion in hydrogen sulfide media. PACS numbers: 81.65.Kn DOI: 10.1134/S0033173206060099
11/09/2008 | 1496 Hits | Print
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10.
Acid Corrosion of Iron in the Presence of Mixtures of Anionic Additives and Compounds of the Reaction Series of o-Hydroxyazomethine Derivatives with Nucleophilic Substituents V. P. Grigor’ev and V. V. Boginskaya Rostov State University, ul. Zorge 7, Rostov-on-Don, 344090 Russia E-mail:
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Phone: +7 (863) 253 8159 Received July 19, 2005 Abstract — The effects of halide- and sulfur-containing additives on iron corrosion in 1 M H2SO4 in the presence of nucleophilic -hydroxyazomethine derivatives are studied. Dependences of the inhibition factor (as well as its sensitivity to a change in the polarity of the substituents) and the effective activation energy on the nature and concentration of both the groups of additives are interpreted in terms of the Linear Gibbs Energy Relation (LGER) and the principle of Hard and Soft Acids and Bases (HSAB). PACS numbers: 81.65.Kn, 82.45.Bb DOI: 10.1134/S0033173206060105
11/09/2008 | 1578 Hits | Print
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