Highly reliable energy-efficient glass coatings for pipes transporting energy carriers, liquids, and gases

Comparative characteristics of known materials which are used to increase the longevity of steel pipes are presented. It is shown that glass enamel coatings provide effective protection from corrosion. The physical and technological characteristics of fused frits (water resistance, impact strength, microhardness) fall within the GOST 24405-80 limits. __________ Translated from Steklo i Keramika, No. 3, pp. 23–25, March, 2007.     

Effect of prolonged high-temperature loading on the structure of the KhN65VMTYu alloy

A complex analysis of changes in the structure and in the phase composition arising as a result of both a prolonged operation of articles made of the alloy KhN65VMTYu (EI893) and after conducting imitation tests of model samples. The tests for long-term strength using samples cut out from the body of a large-dimension turbine blade which was exploited for 63 622 h showed that the blade preserved a significant residual reserve of service life (at 750°C and 250 MPa, the time to failure is 4243.5 h).     

Computer simulation of the growth of intermediate phases in a complex metallic system

The technique and results of computational experiment on the contact melting in a two-component system with an intermetallic compound have been considered. The possibility of existence of metastable states in the liquid interlayer has been assumed. The conditions under which the parabolic law of growth of the liquid-interlayer extension is obeyed and the liquid-interlayer concentration field fits the equilibrium phase diagram have been clarified. Results of the simulation and real experiment have been compared.     

Simulation Studies of Electronic Properties and Atomic Ordering in the b-Si3N4 – Mg – O SYSTEM

Simulation studies of the electronic structure, interatomic bonds, chemical composition, and atomic ordering in solid solutions Si_6–x Mg_xO_2x N_8–2x of the β-Si₃N₄ – Mg – O system and solid solutions Si_6–x Mg_xO_xN_8–2x X_x (X = S, Se) and Si_6–x Mg _x/2M _x/2O_xN_8–x (M = C, Si, Ti, Ge, Zr, Sn, and Pb) are carried out using the strong-coupling energy-band method. Stabilization of solid solutions Si_6–x Mg_xO_2x N_8–2x is accomplished in the presence of S, Se or Zr. In these solutions, Mg and O atoms are capable of forming quasi-unidimensional structures (dopant, or impurity, channels) similar to those predicted for β-sialons.     

Effect of phase transformation in higher iron silicide on the electrical conductivity of the multiphase system iron silicide-glass. I. Conductivity mechanisms in a composite,prepared on the basis of iron silicides and barium-borosilicate glass

Conductivity mechanisms for a composite based on cermet containing iron and barium borosilicate glasses are studied. It is established that in the region of elevated (above room) temperatures the resistance of a composite is mainly governed by the conducting properties of metal inclusions consisting of iron silicides and monoboride. In the low-temperature region (T<260 K) With T180 K transfer of charges is caused by the passage of electrons beconductivity is noticeably affected by a glass-crystalline component. With T180 K transfer of charges is caused by the passage of electrons between donors and traps, whereas at higher temperatures the most probable transfer mechanism is thermal activation of electron from donors directly into the conductivity zone.Translated from Poroshkovaya Metallurgiya, No. 8(356), pp. 64–68, August, 1992.     

Layer-by-layer magnetization reversal of nanophase crystals of a cobalt-platinum alloy after annealing under tensile loading

Behavior of magnetic domain structure in the course of magnetization reversal of CoPt crystals with optimum hysteresis properties after annealing under tensile stresses has been studied. Magnetic heterogeneities, which were periodically distributed in {100} and {110} planes have been revealed. An electron-microscopic investigation of the structure of the above CoPt crystals has been performed to show that the crystals are in a nanophase stressed-strained state. A connection between the magnetization-reversal mechanism and characteristic properties of the nanophase state of the crystals is discussed. An important role of magnetoelastic energy in the complicated quasi-periodic distribution of magnetization of the CoPt crystals investigated is emphasized.     

Examination of Pellets Made from Concentrate of Oxidized Ferruginous Quartzites of Mikhailovsky GOK

Metallurgist - The production of pellets from a concentrate of oxidized ferruginous quartzites that are tailings at the Mikhailovsky GOK pelletizing plant is studied. The conditions for the...     

Method for Controlling the Parameters and Characteristics of an Electric Arc to Evaluate the Efficiency of Using Briquetted Metallized Scale for Steel Smelting

Metallurgist - A method for controlling dynamic current-voltage characteristics in an electric arc furnace is described. The influence of the electrode’s current direct component on the...     

Effect of crystallization conditions of pulse die forging on structure formation in TiAl-and Ti3Al-base alloys

The structure and properties of alloys based on TiAl and Ti₃Al titanium aluminides obtained by the method of pulse die forging are studied. It is shown that the content of aluminum and the changes in the structural factors (the grain size and the width of Ti₃Al lamellas) that control the strength characteristics of TiAl-base alloys with lamellar structure are correlated.     

Luminescence of a Transparent Alumina Ceramic Doped with Chromium and Titanium

Specimens of transparent alumina ceramic (TAC) are prepared by slip casting. An alumina spinel, formed during sintering under vacuum or under reducing conditions, as well as individual phases, produced by thermochemical doping with chromium and titanium, are identified. The spectra of steady-state x-ray luminescence (SXL) and pulsed cathodoluminescence (PCL) and the PCL decay kinetics are studied. The highest STL and PCL intensity were observed in specimens that were prepared by thermal diffusion using a carbon + TiO₂ pack. Ti-doped TAC, characterized by a rapid decay of luminescence in the UV region, can be recommended as a promising material for the detector of a scintillation dosimeter. The luminescent chromium ions (isomorphic substituents of aluminum ions in the crystal lattice) are unsuitable for that purpose because of their long luminescence de-excitation time.