С О Д Е Р Ж А Н И Е

P. G. Ovcharenko, E. V. Kuzminykh, V. I. Ladyanov

ABSTRACT

     The thermodynamic calculations results of interaction of ironCcarbon melts with non-stick coating based on corundum at temperatures of steelmaking processes (1600–1700°C) are presented. The melts of construction steel (steel 10), tool steel (U8) and grey cast iron (SChC15) with oxygen and aluminum content [O] = 0.001%, [Al] = 0.02% respectively have been selected as objects of research. The processes of nonCstick coating dissolution in metal, his deoxidation by melt components (carbon, silicon) and interaction with dissolved oxygen were considered in assessing the interaction of corundum with ironCcarbon melts. As a results of calculations boundary aluminum concentration [Al] in melt is determined. The dissolution and deoxidation of corundum is possible above this aluminum concentration in melt. Oxygen transfer in the form of FeO from metal in nonCstick coating with formation of hercynite and liquid slags of the system FeO–Al₂O₃ is shown to be possible at high oxidation of the melt ([O] > 0.05% at 1600°C). In the process of manufacturing castings by lost form casting the models made of expanded polystyrene (casting molds) are destructed from melt heat energy with separation gas-vapor mixture (phase). The gasCvapor mixture (phase) is led in supporting material through the pores of non-stick coating. To estimate the effect of this component on non-stick coating the reactions of corundum interaction with the components of the gas-vapor medium are considered.

KEYWORDS non-stick coating; corundum; iron-carbon melts; thermodynamic calculations, lost-foam casting

DOI: 10.1134/S0235010619050074

E. V. Shlyakova.

ABSTRACT

The article deals with the problem of increasing resistance to corrosion of steel 38KhVFuYA used for the production of critical engine parts by laser heat treatment. The technique of carrying out corrosion tests by weight and electrochemical methods and their results are described, a significant reduction in the corrosion rate of the steel under study after laser heat treatment is established, optimal values of the power density of laser radiation are determined to achieve the most effective anticorrosive protection.

KEYWORDS corrosion, corrosion rate, electrochemical determination of corrosion rate, laser heat treatment

DOI: 10.1134/S0235010619050098

V. V. Smolenski, А. V. Novoselova, А. L. Bovet, P. N. Mushnikov

ABSTRACT

Separation of lanthanides from actinides can be successfully applied in the system “liquid metal–molten salt”. Separation factors of lanthanum, praseodymium and neodymium from uranium at different temperatures in the molten system Me(Ga–In)/3LiCl–2KCl were calculated. The influence of the lanthanide nature on the separation factors of Ln/U was established.

KEYWORDS uranium, lanthanum, praseodymium, neodymium, alloys, molten salts, separation factors

DOI: 10.1134/S0235010619050104

O. V. Grishenkova, Yu. P. Zaykov, V. A. Isaev

ABSTRACT 

The results of numerical simulation of multiple formation and diffusion-controlled growth of noninteracting new-phase clusters under conditions of cyclic potential sweep are presented. The factors influencing the shape of nucleation loops are analyzed. The possibility of using model to study nucleation/growth processes is discussed.

KEYWORDS electrocrystallization, cyclic voltammetry, nucleation loop, diffusion controlled growth

DOI: 10.1134/S0235010619050062

M. M. Gafurov, K. Sh. Rabadanov, Z. Yu. Kubatayev, A. M. Amirov, A. R. Aliev,

A. Sh. Asvarov,  M.G. Kakagasanov

ABSTRACT

The influence of nanosized aluminum oxide powder on the molecular relaxation properties of nitrate ion in the melt of a 0.42LiNO₃–0.58KNO₃ eutectic mixture was studied by vibrational spectroscopy. It is shown that the presence of nano-Al₂O₃ leads to a significant change in the microstructure of the melt and a change in the nature of the elementary dynamic interactions of the particles in them

KEYWORDS lithium and potassium nitrate, eutectic, dispersed system, Raman spectrum, infrared absorption, vibrational and orientational relaxation

DOI: 10.1134/S0235010619050050

O. V. Chernova, S. V. Zhykovin, D. A. Kondratyev

ABSTRACT

RareCearth metals and their alloys are used in various fields of technology. This is due to their many unique physical and chemical properties. To obtain coatings with rareCearth metals, information is needed on the kinetics of electrode processes with their participation in molten salt media. These problems for rareCearth metals have not been sufficiently studied. In this work we have determined the kinetic parameters (transport coefficients, heterogeneous constants of the charge transfer rate) of cathode reduction of holmium ion in the equimolar NaCl–KCl melt by chronopotentiometry and chronovoltamperometry in temperature range of 1073–1173 and containing 1–10 mas % HoCl₃. The dependences of the kinetic parameters on temperature and the rareCearth metal chloride concentration are presented. A mechanism is proposed for the reduction of the complex in the equimolar NaCl–
KCl melt: НoCl₆^3– = НoCl₄^– + 2Cl^–, НoCl₄^– + e = НoCl₄^2–

KEYWORDS chlorides of rareCearth metals, holmium trichloride, kinetic parameters, chronopotentiometry and chronovoltamperometry

DOI: 10.1134/S0235010619050049

O. V. Volkova, V. V. Zakharov, E. G. Vovkotrub, S. V. Plaksin, S. V. Pershina.

ABSTRACT

Discharge characteristics of the heat activated battery with NiCl2–MoO3 mixtures as a cathode material has been investigated. Composition and morphology of reduction products of the cathode materials have been determined. The addition of molybdenum(VI) oxide to nickel(II) chloride leads to stabilization of the discharge curves and increase of the cell voltage. The formation of MoO2 was accompanied by the reduction process of Ni²⁺ to Ni⁰. The electrode process was complicated by interaction of the cathode material with the reduction products and the formation of the melt of molybdenum oxide / lithium molybdates with lithium halogenides. A mechanism of the reduction of Ni²⁺ and Mo⁶⁺ to metallic nickel and molibdenum has been proposed, which includes an intermediate step of a melt formation of
NiCl₂ and lithium molybdates with lithium halogenides.

KEYWORDS thermally activated chemical current sources, cathode, nickel chloride, molybdenum oxide

DOI: 10.1134/S0235010619050116

CONTENTS

E. A. Karfidov, E.V. Nikitina, N.A. Kazakovtseva, L.M. Babushkina

ABSTRACT

KEYWORDS

DOI: