At production of pellets one makes special demands on them, including the strength requirements. Pellets are subjected to the additional impact stresses in transfer units and ports; as a result there is not only their partial destruction but the decrease of strength properties in totality. The paper presents the research results on the destruction of pellets according to the classes, depending on the impact stress. When producing the pellets, it should be taken into consideration the probability of their softening in the results of loading and unloading ope rations during the transportation. Thereby, the safety factor increases with the increase of the number of loads and their height. For example, in the case from 5 to 10 loads the strength of the produced pellets should be not less than 285 kg/pellet; and when they are received by the consumers their strength should be not less than 200 kg/pellet. At the impact of stresses the compression strength of pellets decreases as the result of inner fractions formation. The primary strength of pellets should be more than the value, guaranteed by technical or contractual conditions.

The article contains the results of a study of the specific magnetic susceptibility of primary concentrates of Siberian iron ore deposits and its dependence on the magnetic fi eld of the separator. The experiments (laboratory separation, magnetic measurements) were performed on the class size of –0.07 mm. Study of ore subjected to seven deposits, four of which are magnetite and three – lightly oxidized, due to their content of martite, hematite and limonite from 3% to 6%. The middlings of magnetite ore have the largest values of magnetic susceptibility, the middlings of lightly oxidized ores have the less value. But the fields of maximum specific susceptibility of lightly oxidized ore samples are higher than the maximum specific susceptibility of magnetite middlings samples. The experiments have shown that the values of specific magnetic susceptibility of primary concentrates are proportional to the content of magnetite iron in them.

The article describes the possibilities of formation of iron ore pellets structure with regulated distribution of the porosity along the pellets cross section, obtained using heat-spraying of wet charge. With the help of the video and analysis of the macrostructure of sprayed charge layer, which is a matrix for germinal centers, the author gives the description of formation mechanism of the sprayed charge layer and the growth of its geometrical dimensions. The formation of the sprayed charge layer starts with the formation and growth of spraying focus. The formation mechanism of pellets porosity relies on shifting deformation of charge due to existence of friction forces between the air stream and the surface of the sprayed layer. It was found that the heat-spraying of wet charge on the charge skull forms a sprayed layer with an increased proportion of open pores along the cross-section.
The value of the open porosity of the sprayed layer depends on the distance to the sprayed surface and the point on surface of the charge scull pelletizer, in which the spaying is organized. The distribution of open and closed pores in the volume of pellets, depending on the mass fraction of the germinal centers, was obtained by the heat-spraying of wet charge.

t. Iron is one of the impurities limited in the Ni – Cu alloys. It may enter into the metal from charge materials and the lining. The content of Fe2O3 in the refractory may reach 2.5 % therefore the estimation of iron concentration growth in the alloys during the interaction of the metal and the lining is the important issue. The aim of this work was to estimate the influence of Fe2O3 content in the crucible material and capacity on the concentration of iron in finished metal. Using the thermodynamic calculations and the experimental data it was determined that nickel and copper may reduce iron from the refractory in the Ni – Cu alloys. Thus, iron turns from the crucible material to the melt almost completely if low-iron charge is used for smelting. The assessment of iron content growth in the Ni – Cu alloys was provided depending on the VIF capacity and Fe2O3 content in periclase crucibles upon condition of the complete transfer of iron into the metal from the lining.
The concentration of reduced iron decreases with the increasing of the furnace capacity, and when the mass of the metal is over 200 kg, the growth of the concentration of iron depends not on the capacity but on Fe2O3 content in the refractory. It was shown that the refractory with Fe2O3 concentration not exceeding 0.5 % is necessary to use for the Ni – Cu alloys production with less 0.01 % of iron. The crucibles with Fe2O3 content not exceeding 2.5 % are recommended for melting of the Ni – Cu alloys with less 0.05 % of iron.

The mathematical method is proposed for determining the forces and bending moments at preliminary cold flattening of the thick steel sheet on the seven-roller sheet-straightening machine. The calculations allow us to determine the support reaction of working rollers, residual stresses in the wall of steel sheet, the proportion of plastic deformation on the sheet thickness and the relative deformation of the longitudinal surface fibers of the sheet under straightening depending on the rollers’ radius. It is also possible to establish the pitch between the straightening machines’ working rollers, the magnitude of sheet reduction by the upper rollers, the sheet thickness, as well as elastic modulus, yield stress and hardening modulus of the sheet metal. The results of the research can be used at metallurgical plants.

The analysis of lever mechanisms performance, having internal degrees of freedom conditioned by the presence of clearance in joints, has shown that clearances in the joints were the reason of appearance of additional dynamic forces. In order to eliminate the influence of clearances in joints on the origin of additional dynamic forces it is necessary to find regularities of pulse loading appearance. The analysis of the joint performance of a crank–bearing support with a clearance of crank-androcker mechanism of a cheek crusher was made. Based on the obtained results it was defined at which positions of mechanism links the contact surfaces changeover of a joint crank – bearing support appears. This allows to use rationally the mechanisms for the choice of clearances with resilient elements, which choose the clearance in a junction crank – bearing support during the cycle of work of crank-and-rocker, thus, preventing the appearance of the additional dynamic loadings

The analysis of the use of pulverized coal injection (PCI) in the practice of blast furnaces of the Russian Federation was made. It is shown that the current level of injecting of PCI is much lower than in the world’s best practices. The factors hindering the development of this direction in Russia are presented. The authors have analyzed the activities suggested in order to reduce carbon dioxide emissions from the production of iron (ULCOS program). It is proposed to enter the poly-fuel gas generators of bubble type into the blast-furnace shops for the production of hot reducing gases (HRG) for subsequent injection into blast furnaces. The calculation was made for the performance of blast furnace with volume of 1033 m3  and HRG injection of up to 400 Nm3/t of cast iron. When such HRG injection the coke savings are 100–120 kg/t of cast iron. Expected savings of coke while HRG injection of 700 Nm3/t are up to 200 kg/t of cast iron. It is proposed to create a consortium of leading metallurgical enterprises for testing the proposed technology in pilot industrial conditions.

The research of the eff ect of installing the redesigned iron curtains in the turbine of the shot blasting machine (SBM) for notch of the work rolls surface was carried out for the temper mills “1700” and “2500” of sheet rolling shop – 5 of OJSC “MMK”. Curtains were installed in a plane perpendicular to the plane of rotation of shot blast wheel mounted in a turbine. The sizes of the curtains and place of the installation were determined, providing increased density of shot torch at notch of rolls with minimal shielding action of split shot bounces off the iron curtains. The researches have shown that a fraction speed after collision with a curtain changes not only the direction but also the magnitude. Change of direction and speed reduction of the shot after the collision with the curtain depends on the friction conditions between the shot surface and curtains, as well as the angle of attack.
Shot blasting machine modernization provided opportunity to increase the density of shot torch peaks on the surface of work rolls of temper mill, and thus to increase also the density of a trained metal peaks at 1.22 times compared with metal, trained before the improvement of shot blasting machine design.

The paper presents the localization of the plastic deformation features. The studies were performed for the test samples of low-carbon 08ps steel sheet after hot rolling as a result of electrolytic saturation by hydrogen in a thermostatic three-electrode cell at constant potential. Enhancement of the localization of plastic deformation was established. Analysis of the stages of the stress-strain curves revealed the yield line, linear work-hardening stage and (Taylor) parabolic work-hardening stage. Using the speckle-photography technique, the patterns of plastic deformation localization were exposed with subsequent determination of the displacement vector fi eld in the fl at sample and calculation of the components of the tensor plastic distortion (local elongation εxx , εxy shift and rotation ωz ). The main type and parameters of the localization of plastic fl ow for distinct work-hardening stages were determined

During magnesium desulfurization of molten iron, high – sulfur and heterogeneous slag with high content of prills is formed in the ladle. Generally these slags are sour with various oxidizing ability. The high content of sulfur in the slag increases the “danger” of the reversion of sulfur from the slag to the melt. In this paper the kinetics of sulfur transfer through the metal – slag interface surface was examined.
The results of hot metal treatment with magnesium in the factories in China were used as a basis for experimental data. The interfacial transfer of sulfur was modeled using diffusion boundary layer theory.
The coefficient values of sulfur mass transfer in the slag were determined using a simplified expression of the second Fick’s law. While using these kinetic characteristics during calculations, it was proved that after refining of hot metal with magnesium under present conditions, a fast return of the sulfur from the slag into the metal droplets takes place. At the same time the estimated sulfur content in the iron in the ladle remains practically invariable.

The paper is devoted to the realization of the diagnostic of origin and development of the steel damage of energy equipment at microand submicrolevels. It requires taking into account special parameters, reflecting individual properties of the material, as well as the introduction into the analysis of the processes, which one can observe in the elements of the equipment, and the parameters of substructure. Such parameters are the period of crystal lattice and inner structural states of the Ist and IInd kind. The authors also give the results of the essence of stress states at elastic plastic deformation of austenitic chromiummanganese steel. It has been shown that the processes of cyclic deformation are accompanied by the oscillation of inner states in the sphere of functioning states, limited by the curve of hardening-softening. The results have been analyzed from the point of view of the establishment of the characteristic features of preliminary fracture. The article gives the complex of distinguishing features and the material parameters, under which fractions in the area of deformation among the lines of hardening and softening are not active. The paper presents the results of metallographic research of the destroyed metal, matching with the conclusions of X-ray diagnostics.

The problem of data pre-processing in the identification of multidimensional discrete-continuous processes is considered. The main content of the paper is devoted to the method of generating working training sample from the initial one, represented by the data of the object normal operation. This step is very important in the non-parametric identification of discrete-continuous processes. Non-parametric identification algorithms belong to the class of local approximations of unknown stochastic dependencies. In nonparametric identification the step of selecting an object model to the accuracy up to the parameter vector is absent. This approach takes place in the variety of real problems, because the priori existing information is not enough to determine the reasonable parametric model structure. The procedure presented below is similar to butsrtap based on the initial training sample, which reflects the characteristics of the identified object.
Numerous computational experiments carried out by statistical modeling have showed high efficiency of generation techniques discussed below which is laid into the foundation of the adaptive system modeling. In addition, it can automatically solve the problem of restoration an unknown stochastic dependence on the definition boundary of the relevant input-output object variables. The following technics and algorithms of nonparametric recovery stochastic dependencies were used to study the oxygen-converter process. A sample of observations made from passports of 176 low carbon oxygen steel melted by the contract at JSC “EVRAZ ZSMK” oxygen-converter workshop No. 2.
New working sample which contains both the measurements and the generated data was formed according to the proposed methodology.
Using the working sample makes it possible to increase the accuracy of the training simulation in 2–3 times.