On Construction of the Structures of Adsorbed Films of Mefenamic and Phenylundecanoic Acids on Passive Iron

Yu. I. Kuznetsov, N. P. Andreeva, N. P. Sokolova,
R. A. Bulgakova, and A. M. Gorbunov

Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences,
Leninskii pr. 31, Moscow, 119991 Russia; e-mail: This e-mail address is being protected from spam bots, you need JavaScript enabled to view it

Received October 25, 2006

Abstract — Successive adsorption of the components of a mixed inhibitor at oxidized iron was further studied by ellipsometry and IR spectroscopy. The mixed inhibitor was composed of salts of aromatic amino acids, viz., sodium mefenamate (SMEF) NaOOCC₆H₄NHC₆H₃(CH₃)₂ and sodium phenylundecanoate (SPU) C₆H₅(CH₂)₁₀COONa. Ultrathin adsorbed films obtained on oxidized iron by different methods were tested in a moist atmosphere to compare their protective properties. Adsorbed PU forms an iron complex on oxidized iron. Adsorption of MEF anions over a PU layer changes the IR spectral pattern, thus indicating a change in the adsorption mechanism
of MEF anions in the presence of PU anions.

PACS numbers: 82.45.Bb

DOI: 10.1134/S0033173207040017

Passivating Film As a Structured Solid Solution of the Alloy Oxide Particles. The Structuring Effects (Ordering and Stratifying)

Yu. V. Alekseev^{a, b} and I. Yu. Alekseev^c

^a Karpov Institute of Physical Chemistry, ul. Vorontsovo Pole 10, Moscow, 103064 Russia; Institute of High Temperatures,
^bRussian Academy of Sciences, ul. Izhorskaya 13/19, Moscow, 127412 Russia

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^c Research Institute of Precision Instruments, ul. Dekabristov 51, Moscow, 127490 Russia

Received August 23, 2005

Abstract — The investigations deal with the passivating films that can be modeled as a solid solution of the alloy oxides. Models of unstructured (regular) solutions enable one to explain the dependence of the dissolution rate of a Fe–Cr alloy at a chromium concentration higher than 0.2 atomic parts. Irregular solution models, which take into account the alloy structuring due to the interactions between its components is applicable to the compositions below a chromium content of 0.2. The physical effects predicted by the model are studied, namely the higher dissolution rate of the alloy compared to the dissolution rate of the most active component, the different alloying mechanisms at the different kinds of interactions between the components, as well as the kinetic metastability and its role in the initiation of pitting by some admixtures.

PACS numbers: 81.65.Rv; 82.45.Bd

DOI: 10.1134/S0033173207040029

Character of the Dissolution and Partial Electrode Processes at the Alternating-Current Infralow-Frequency Polarization of Brasses in Chloride Media. II. Cu44Zn -Brass

I. K. Marshakov, O. Yu. Kuksina, and V. Yu. Kondrashin

Voronezh State University, Universitetskaya pl. 1, Voronezh, 394006 Russia

Received May 8, 2006

Abstract — The dissolution of -brasses in a chloride medium at a pulse anodic polarization proceeds at first (up to ~1 min) nearly uniformly, but when the charge of anodic pulse is carried out partly on the ionization of zinc and partly on the ionization of copper, it becomes selective. In this case the most part of the copper component does not oxidize, but rearranges to form the individual phase, which causes a substantial destruction of the brass electrode. When the cathodic alternating-current component is also switched on and hydrogen evolution begins, pH of the layer near electrode increases preventing the formation of soluble oxidation products in the subsequent anodic half-period. Thus, on a -brass electrode, the partial cathodic processes affect the anodic oxidation of copper and zinc.

PACS numbers: 82.45.Qr

DOI: 10.1134/S0033173207040030

Phenomenology of the Double-Layer Capacitor (Supercapacitor)

R. R. Salem

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Received October 16, 2006

PACS numbers: 82.47.Yv; 82.47.Wx

DOI: 10.1134/S0033173207040042

Corrosion-Electrochemical Behavior of 13% Chromium (Cr) Martensitic Stainless Steel in Hydrochloric Acid (HCl) Solutions¹

N. Chermat-Aourasse^a and R. Kesri^b

^a Research and Development Center of Sonatrach, Avenue du 1ér novembre 35 000 Boumerdés-Algeria

^b Laboratory of Electrochemical Corrosion, Structural Metallurgical and Mineral Chemistry; Chemical Institute-University
of Science and Technology Houari Boumedienne (USTHB)—Algiers

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Received February 3, 2006

Abstract — Corrosion-Electrochemical behavior of a commercial API5CT grade L80 type 13Cr tubing enriched with microalloying elements is studied in 6, 7.5, 9, 12 and 15% HCl solutions by electrochemical methods. The objective is to contribute to the comprehension of corrosion phenomena caused by HCl of similar concentrations, generally used in acidizing job. The corrosion morphology is examined by scanning electron microscopy (SEM) coupled with EDAX. The soluble corrosion products are analyzed by atomic absorption spectroscopy and colorimetric methods. General, as well as localized, corrosion is present. The severest general corrosion with a maximum rate of 26 mm/year is obtained at 15% HCl. The localized corrosion which morphologically differs as function of HCl concentrations is revealed by SEM investigation. In all the above HCl solutions, the commercial 13% Cr martensitic stainless steel tubing shows no passive state. Above 6% HCl, the microalloying elements promote forming a discontinuous film of the corrosion products. The corrosion rate slightly decreases in 15% HCl compared to the published data on a conventional 13% Cr martensitic stainless steel tubing. This is due to both the chemical composition (silicon, manganese and vanadium) and microstructural properties. Copper seems to additionally accelerate the corrosion of the alloy.

Key: words: 13% Cr, martensitic stainless steel, polarization, hydrochloric acid, corrosion resistance, pitting.

PACS numbers: 82.45.Bb

DOI: 10.1134/S0033173207040054

On the Electro-corrosion of the Elements of Radio-Electronic Network

A. A. Gerasimenko and A. N. Mikhailov

Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences,
Leninskii pr. 31, Moscow, 119991 Russia

Received October 10, 2005

Abstract — Certain peculiarities of the corrosion of elements of radio-electronic devices are studied. The mechanism of this phenomenon, kinetic factors, concomitant hazards, and conditions for its prevention are described.

PACS numbers: 81.65.Kn; 82.45.Bb; 82.45.Qr

DOI: 10.1134/S0033173207040066

Contact Corrosion of Metals in Aqueous Media. Part I

V. N. Esenin and L. I. Denisovich

Nesmeyanov Institute of Organometallic Compounds, Russian Academy of Sciences, ul. Vavilova 28, Moscow, 117813 Russia

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Received April 25, 2006

Abstract — 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.

PACS numbers: 82.45.Bb, 73.40.Jn

DOI: 10.1134/S0033173207040078

Protection of Low-Carbon Steel in Aqueous Solutions by Lignosulfonate Inhibitors

A. A. Chirkunov, Yu. I. Kuznetsov^a, and M. A. Gusakova^b

^a Frumkin Institute of Physical Chemistry and Electrochemistry, Russian Academy of Sciences,
Leninskii pr. 31, Moscow, 119991 Russia

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^b Arkhangel’sk State Technical University, Arkhangel’sk, Russia

Received December 4, 2006

Abstract — The corrosion and electrochemical behavior of low-carbon steel and iron in a neutral aqueous solution containing ZnHEDP, lignosulfonates LS1 and LS2, and their mixtures was studied. Corrosion tests showed that these lignosulfonates stimulate corrosion at room temperature but act as weak inhibitors at 80°C. However, adding LS1 and LS2 to ZnHEDP enhanced the steel protection by the latter; a synergism of their protective effects was observed at certain ratios of the complexonate and polymers. Although LS1 and LS2 are compounds of the same type, their effects on steel corrosion in a neutral aqueous solution containing ZnHEDP differ sub-stantially: LS1 favors the inhibition by ZnHEDP of the cathodic reaction only, while LS2 affect both electrode
reactions.

PACS numbers: 82.45.Bb

DOI: 10.1134/S003317320704008X

The Effect of the Microstructure of Unalloyed Steels, on Their Anodic Dissolution and Passivation in Oxalate Media

M. S. Putilina, I. V. Bespalova, and S. N. Saltykov

Lipetsk State Technical University, Lipetsk, Russia

Received February 3, 2006

Abstract — The sequence in which the elements are dissolved from ferrite–perlite alloys in oxalate media is found. A part of the cementite phase in the salt passivation accompanied by the appearance of several anodic current peaks in the passive range is demonstrated. The peaks are identified and shown to depend on the carbon-containing phase content.

PACS numbers: 82.45.Bb

DOI: 10.1134/S0033173207040091

Metal-Ceramic Coatings Formed under the Action of Electron Beam. 1. A Study of the Base Layer

N. A. Rudenskaya and V. A. Guletskii

Belarussian National Technical University “Metolit,” Minsk, Belarus

Received May 22, 2006

Abstract — Microstructure of metal-ceramic coatings formed under the action of electron beam is studied. Peculiarities of modified microvolumes in coatings, depending on the dispersivity of reinforcing component, are revealed. A new structure type is reported.

PACS numbers: 81.15.Jj; 82.45.Bb

DOI: 10.1134/S0033173207040108