Vol 2017, No 6 (2017)

A physical model is used to study the effect of submerged nozzles during their replacement on the trajectory of motion of the metal streams in the mold of a slag continuous caster in the course of casting. Recommendations are made to decrease the time of action of this factor on the ingot formation conditions.

The dependences of the electric and electrotechnological parameters of electric arc furnaces on the arc length in different heat periods are considered.

The thermodynamic conditions of formation of a joint between metals using the solid-phase methods of powder metallurgy, welding, and deposition of functional coatings upon electric-current heating of the surfaces to be joined are studied. Relations are obtained to quantitatively estimate the critical sizes of the circular and linear active centers that result in the formation of stable bonding zones.

The angle of wetting of aluminum oxide with a high-carbon iron melt is studied as a function of temperature and time. It is found that the angle is nearly 94° in the temperature range 1200–1400°C. A preliminary study of the interface is performed using confocal and scanning electron microscopy.

The effect of the method of welding on the mechanical properties of the welded joints of the 1565chM alloy is studied at room, high, and low temperatures.

The regularities and mechanism of the electrochemical borating of cathodic carbographite materials under the conditions of electrolysis of cryolite–alumina melts are studied. The effect of carbon surface wetting is proved to take place upon the formation of a melted aluminum layer at a cathode. These facts are confirmed by X-ray diffraction analysis of the surface layer of the cathode. Compounds TiC and TiB2 are observed. The mechanisms of electrochemical and physical processes of the formation of Ti–B–C complexes in the surface layers of the cathode are studied.

The deposition of a VT20 alloy onto the airfoil shroud platform of a compressor in an argon atmosphere and the composition, the structure, and the properties of a restored wear-resistant VK-25M coating are studied. The coating deposited onto the built-up material is found to contain (%) 3–4 C, 72–74 W, and 23–24 Co. This coating does not undergo cracking when a diamond pyramid is indented at a load of 50 kg or a diamond cone is indented at a load of 100 kg at a layer thickness of 0.15, 0.25, and 0.38 mm.

The possibilities of computerized procedures for comparing the heterogeneous structures and the fractures of hard alloys are estimated in order to evaluate the factors determining the wear resistance of hard iron-based alloys and premature fracture.

The increase in the erosion of plasma generator electrodes with controlled rectifiers that is caused by the appearance of a pulsed current component when the power supply voltage and power decrease is experimentally studied. The recommendation of using plasma generators under nominal operating conditions of power supplies with short periods of low-current operation is substantiated.

On the basis of comparison of the influence of the stock exchange factors on the pricing of nonferrous metals for medium term with similar results for short term, it has been established that the main attention should be paid to the changes in the pricing environment on the metal market as a function of the prices of exchange traded metals. The situation on the market of energy carriers (hydrocarbons) and the European, American, and Asian stock exchanges can be based on parity and even significantly influence the variation of the metal prices. In the medium term, constructive development of metal trade should be reasonably promoted by changing the elasticity of supply with regard to prices for exchange traded metals and by applying the stock exchange factors that positively influence the pricing on commodity and stock markets.