Production of ferrous metals, extraction and processing of raw  materials  are  environmentally  hazardous  industries.  In  addition to emissions of gases into the atmosphere and pollution of water bodies a lot of solid waste is formed. Chlorine plays a special role in blast furnace processes. The presence of chlorine compounds in the blast furnace gas leads to corrosion of pipelines, air heaters and tuyeres of  blast  furnaces.  Behavior  of  chlorine  in  blast furnace determines the properties of the agglomerate during the technological process of recovery. Monitoring the mineral chlorine in the sediments on the filters and dust collectors (in the form of chlorine associated with the metals) are important for estimating the toxicity of waste, as well as for evaluating the production process. In the practice of chlorine determination, a number of physical methods of analysis are used: AES,  ICP-MS, neutron activation analysis methods. But chemical methods:  titrimetric,  photometric,  electrochemical,  inframetrics  are  the  most widespread. The development of rapid and inexpensive methods for determining chlorine is relevant for the analysis of technological objects,  including  the  objects  of  metallurgical  production. The objects of research in this work were the samples of blast furnace slag enterprises for the production of cast iron of JSC «Tulachermet», as well as the dusty waste of the iron foundry of JSC «Kosogorsky metallurgical plant». A preliminary analysis of the composition of investigated samples was performed by X-ray fluorescent method. The interfering effect  of  the  accompanying  components  was  discussed. A  selective  method  for  ionometric  determination  of  chlorine  was  proposed  using  a  hard-crystalline  chloride-selective  electrode.  The  sample  was  decomposed by high-temperature sintering with a mixture of Na₂CO₃ and ZnO and subsequent leaching with water. The description of the  research method was given. The trueness of the analysis results was confirmed by the method of variation of the sample’s mass (n  =  10; t  =  2.26; P  =  0.95), and also by comparison with the results obtained  by the X-ray fluorescent method. The estimation of accuracy indicators of the method of ionometric chlorine determination in the objects  of blast furnace production was performed. The working interval of  the determined chlorine concentrations was 0.037 – 1.340  %  by mass.

 

 

The data on the feasibility of production and application of  complex ferroalloys from the standpoint of manufacturing technology, the used raw materials and the interaction with the steel are  provided. The production need of complex ferroalloys has been validated; the main principles of determination of ferroalloys chemical  composition are shown. The rational composition of complex fer-roalloys (ferro silicon manganese with boron, ferrosilicon with boron,  ferrosilicon manganese with boron and chrome) has been determined  based on the research of their physicochemical properties and their  specific interaction with basic melt. The comparison of characteristics of complex boron-bearing ferroalloys (melting temperatures,  density, melting time of ferroalloys in melt, etc.) was made against  the most used ferroboron and their advantages were shown. It was  noted that the complex boron-bearing ferroalloys must have active  element (Si, Al, Ti), because they promote binding oxygen and nitrogen from steel melt in firm compounds, and the compounds prevent  interaction of active element with boron. The boron concentration  in ferroalloy must be 0.7–2.0  %, because it increases the volume of  complex boron-bearing ferroalloy as consequence increase of reliability and stability of boron absorption. The study of oxidation of  boron-bearing ferroalloy has shown that ferrosilicon with boron are  far less oxidative (4–7 times) at higher temperatures (1430–1570  °С)  than ferroboron. The results have been given for manufacturing and  application of boron ferrosilicon in steel production. The recovery  rate of boron has been studied. The usage of ferrosilicon with boron  provided high recovery rate of boron in range of 77.8–96.3  % (average 86.6  %), without changes in present techno logy of steel deoxidation with ferrosilicon. The concentration of boron in metal at ladle  treatment is 0.0021–0.0027  % and the concentration of boron is not  less than 0.0020  % at casting. It was found that the entering of boron  with the help of ferrosilicon manganese with boron provides increase  of recovery rate of boron in 1,6 times (in average from 48 to 77  %)  relative to ferroboron usage.

The  effect  of  the  guiding  slope  of  the  industrial  railway  track on the temperature in the contact area of the wheel of the career locomotive with the rail has been analyzed. As a result of theoretical and experimental studies it was found that the magnitude of the guiding slope of industrial railways affects a temperature change in the system wheel – rail of locomotives and is characterized by a temperature  coeffi cient of the slope ky . To determine the values of k_y on the mine locomotive  of  SCHÖMA  model  –  350  (Germany)  the  experimental stu dies were conducted at the enterprise of JSC “MOSMETROSTROY” in the context of the mines under construction in the Moscow metro. The temperature and sliding velocity in the contact zone of the  wheel – rail system was measured at different speeds and inclines of  the track. It was found that with increasing of track slope the temperature in contact zone of the wheel – rail system increases. Therefore the permissible speed of slipping of traction wheel pairs of the locomotive with the profiled sections in the quarry conditions will be higher. It was also shown that the new profiles of the working surfaces of wheel and rail, based on the criterion of temperature increase in the contact zone of 300 °С for conditions characteristic for open mining  parameters,  do  not provide rational operating conditions. Value of the temperature coefficient of the slope k_y in the interval of career track slope from 0 to 10 ‰ is equal to k_y = 0. The necessity to determine the temperature in the contact zone of the wheel –rail system for conditions of open mining works according to the formulas recommended for railways of general use is shown. The results of calculations performed by the developed technique showed satisfactory convergence with the experimental results. The approximation error of the coefficient of the mining conditions impact Kmc in the range of 25 ‰ to 45 ‰ is less than 5 %. The results of studies carried out according to the developed methodology, depending on the area of interest, are accepted for use by the enterprises of OJSC Uralasbest  and ZUMK-Engineering LLC (Zapadno-Uralsky Concern Group of  Companies, Russia).

 

 

The authors have investigated the influence of structure damageability of low-alloy and carbon steels, formed during the cyclic  deformation by curve at the coercive force and electrical resistivity.  Samples of low-alloy and carbon steel (09G2S, 10G2S1 and 3sp steel)  were deformed cyclically according to the scheme of pure bending at  a symmetrical cycle. The steel damageability was assessed by the ratio  of the number of bending cycles to the number of bends at destruction. Increase of damage up to 0.2 – 0.3 was accompanied by intense  hardening, and then the stabilization occurs. The coercive force with  increasing degree of deformation under tension is growing on a decaying curve. The electrical resistance changes similarly. During cyclic  deformation, the coercive force varies in a complicated way. This is  due to the nature of the changes of dislocation structure and the occurrence of compressive stresses near the sample surface and the stretching tension in the center. During cyclic deformation, the resistivity  initially increases slightly, then stabilizes and then abruptly increases.  Such an abrupt change of the electrical resistance of steels at cyclic  deformation is apparently caused by the occurrence of vacancies when  the direction of deformation is changed. On the basis of the conducted  research the authors have made the conclusion about the possibility of  control of structure damageability according to the changes of physical  and mechanical properties of steels.

Methods for calculating the geometrical parameters of edge of the billet and the profile of the deforming tool are proposed for the process of forming welded large-diameter longitudinal pipes on the TESA 1420 line. A comparative analysis of geometry of the edge at the hem on the edge press was performed using the working surfaces of the tool, made by involute and single-radial schemes. Single-radial scheme allows to get the edge geometry that meets the technical requirements. For the section of an edge press the calculation procedure is presented, which allows to calculate the geometrical parameters of the edge during loading and unloading. Height of the bent edge, the residual radii of curvature, coordinates of the points of loading and unloading of outer and inner contours of the pipe billet edge have been defined. The involute profile of the tool is universal when changing one pipe size to another from a unifying pipe group. Further, in the calculations, a transition was made from profile of edge contour obtained by involute to the profile obtained by the multi-radial scheme, after which the fixed coordinates of the billet’s points were determined after unspringing. From the obtained coordinates, the output geometric parameters of the edge were estimated. For the unification group of 1220 – 1420  mm the longitudinal deformations of the edge for the size 1220×10  mm have been calculated and it was shown that the unification principles are much easier to implement with a single-radial profile of the tool. A technique for calculating the parameters of the edge of a pipe billet was developed and tested in the field of edge-bending presses using an instrument with a contact profile of a tool made by an involute. A  one-dimensional calibration of the profile of an edge-bending tool is proposed, which provides fixed coordinates of the edge, similar to the coordinates for the involute profile of the punch. The calculated value of the weighted average radius of billet’s curvature ensures maximum approximation of the profile coordinates of the billet at fixed points for both calibrations (maximum divergence of coordinates according to the proposed schemes does not exceed 6 – 7 %). edge;

The structure and mechanical properties ofsteel 35Kh12G3MVFDR were investigated. It is shown that after normalization or quenching there is austenite to 35  vol.  % in the steel and according to this it refers to martensitic-austenitic class. During the thermal treatment (tempering, long-term temperature keeping or isothermal quenching) austenite transforms into martensite in time not exceeding 2  hours. Martensite in 35Kh12G3MVFDR steel has great thermal stability: the first signs of its transformation into sorbitic structure are observed after 25  hours at 640  °C isothermal hardening, and its complete decomposition occurs after 50  hours. The martensite decomposition is accompanied by a reduction in the characteristics of heat resistance and hardness. Aging of quenched and tempered 35Kh12G3MVFDR steel at temperatures of 670  –  720  °C leads to decrease in hardness from 61  –  65  HRA to 55  –  60  HRA in time of 1600  –  3200  hours, the yield stress at 20  °C decreases from 1350 to 750  –  850  MPa and at 720  °C  – from 310 to 160  –  230  MPa for the first 600  hours, after which the reduction of mechanical characteristics are terminated. The extent of decomposition of martensitic structure in 35Kh12G3MVFDR steel determines its creep resistance at 700  °C: the preservation of martensitic structure at short times isothermal hardening (24 hours at 640  °C) did not reduce creep strength in comparison with the state after a simple quenching and tempering (86,21  ±  9,4 and 89,26  ±  8,8  MPa, respectively), but decomposition of martensitic structure (after long-term aging at 670  °C during 1600  hours) reduces this characteristic to 63,87  ±  7,1  MPa. In contrast to martensite austenite in 35Kh12G3MVFDR steel is thermally unstable and undergoes transformation into martensite after 1-2 hours depending on heating temperature.

 

The model of ideal associated solutions was used for the analysis of thermodynamic properties of liquid metal systems with negative deviations from Raoult’s law. However, absolute mass properties, rather than relative mass properties, were used for the chemical equilibrium determination according to the law of mass action. This allowed direct determination of the constants of equilibrium between solution associates and monomers and, thus, finding the value of free energy consumed for the formation of associates from monomers. With the assumption that such energy is identical to the energy of formation of the respective intermetallide from elementary substances, any adjustable parameters can be totally excluded from the model and reference thermodynamic information can be used from available data bases. The rule of associated solution phases was previously defined, which established that the number of associate types in each point of binary solution could not be greater than two. However, the number of known intermetallides for some alloys can exceed the indicated “limit” in several times. Consequently, it is necessary to find the criteria for identification of associates that stably present in solution. To study systems with a large number of associates in solution, reference information was used about intermetallides of ten A– B-type systems, in which one of the components was aluminum or copper. The assessment of possibility of spontaneous chemical reactions with the participation of associates has indicated that only А_рВ- and АВ-type associates can preserve in the solution area with predominant concentration of component A, and that only АВ- and АВ_q -type associates can preserve in the solution area with the predominant concentration of component B (р  and q are stoichiometric coefficients most often equal to two or three). Two stable “peripheral” associates А_рВ and АВq also interact with one another forming a small equilibrium area in the contact zone containing all three aforementioned associates. Stable associates can also be determined without analysis of running reactions if the associates with the least formation energy are considered to be stable. Therefore, А_рВ_q -type intermetallides with complex composition can be entirely omitted in the consideration of potential associates. The systems that have only one stable “peripheral” associate are characterized, as a rule, by sign-variable deviations from Raoult’s law in one of the solution components.

 

 

Thermodynamic data about the TiN and VN formation in iron melts were obtained at the National University of Science and Technology “MISIS” using advanced Sieverts apparatus based on the compensation method of gas volume and pressure measuring using high-sensitive zero reader (pressure sensor). Using of such method for gas – metal interaction investigations was early offered and realized at Chelyabinsk Institute of Metallurgy by Professor A.G.  Ponomarenko. Obtained experimental data were used for the calculations of Ti and V initial activity coefficients in the iron-based solutions. Thus the refined Gibbs energy values of VN formation from elements were used. Obtained values for the Ti and V initial activity coefficients in the ironbased solutions: = 0.055 and   =  0.24 are compatible with the literature data.

 

The article represents a thermodynamic analysis of phase interaction during cast iron melting in cupola and electric furnaces at foundry. The author has studied the influence of the components’ activities on the cast iron melting in various compositions of the interacting phases corresponding to the melting conditions in cupola, induction and arc furnaces. The influence of each factor on the phase interaction has been studied in the presence of temperature fluctuations. The effect of the components’ activities on the Gibbs free energy in both the equilibrium conditions and the presence of temperature fluctuations have been determined. This is particularly essential when contacting with the molten metal, slag and carbon. The influence of temperature fluctuation on the interaction of the metal with the gas phase, slag and carbonic solid materials has been revealed. The conditions of cast iron melting can be characterized by the presence of temperature fluctuations disturbing the equilibrium of the process. Temperature macrofluctuations with a significant relaxation time can be observed in arc furnaces. Such macrofluctuations can be considered as the spatial temporal heterogeneity of the temperature field. There are also temperature fluctuations in gas flame. Temperature fluctuations occur upon contact of metal drops with hot surface of coke lumps. Based on the research, a fundamentally new design of gas cupola furnace with heterogeneous fire-resistant bed charge has been developed, patented and introduced. 

 

The modeling tasks of thermal effect of power impulse action on a surface of the plate of VК10 (КS) alloy were considered and solved. As modeling tasks for homogeneous equations of parabolic and hyperbolic heat conductions, a wave equation in a cylindrical solid of final sizes with boundary conditions of III kind were chosen. The action of power impulse from an exterior radiant was modeled by sudden appearance of initial high temperature, which spreads on a plate body under the laws expressed by various heat conduction equations, on one of the surface ends of a cylinder. Approaches of temperature fields were received in the form of a series segment of functions from eigenvalues of tasks, gradients of fields were defined. Simultaneous presence in the equation of heat conductivity of private derivatives on time of the first and second usages (the hyperbolic equation), statement of the task for it with boundary conditions of III kind and the entry condition at a cylinder end surface provides two ways (modes) of the problem’s decision, both of diffusion type. For the value of the relaxation time of the heat flux of 10–11  s, the complete cooling of the cylindrical sample (tungsten carbide) in the first mode is minutes, in the second  –  10–10  s. It can be concluded that the modes for solving the problem for the hyperbolic heat equation do not correspond to the actual pattern of heat propagation. However, the linear combination of these modes as a solution of the problem preserves the possibility of obtaining a diffusion dynamics adequate to the actual process. Gradients of the temperature field in the solutions of the problems for the parabolic heat conduction equation and the wave equation are in the same order of values. The temperature field of the moving thermal wave for several of its first reflections in experimental samples should be taken into account when evaluating phase transformations and temperature stresses. The results of the theoretical analysis are compared with changes in the microstructure of the near-surface layer of a plate of alloy VK10 (KS), subjected to electric explosive loading by plasma of a titanium foil.

 

The article considers the issues related to production reindustrialization using an example of creating a working model of engineering design of the current heat treatment of stamping tool from special steel. In the process of reindustrialization it requires restoring or modernizing the production facilities, lost or outdated during deindustrialization in the postindustrial period. The development is relevant because heat treatment is integral part of the most manufacturing and conditioning processes of different instruments. With the help of national modern equipment there are opportunities for high-quality heat treatment of wide range of special steels in order to ensure the required mechanical properties of products. All major groups of die steels are considered in terms of working properties: steels with increased wear resistance, rehardened steels with high-resistance to crumbling, high impact steels, steels with medium heat resistance and higher viscosity, steels with increased heat resistance and higher viscosity, high heat resistance steels. The requirements to their properties and possible ways of obtaining these properties by different kinds of heat treatment were analyzed. Based on this analysis, by comparing of knowledge about precise use of die steels, required operation properties and possible ways of their obtaining with help of heat treatment, the modern equipment was selected to achieve the required results. There is a possibility for highquality heat treatment of wide range of die steels with Russian modern equipment in order to ensure the required mechanical characteristics of products. Currently, it is important to create modern productions that combine the colossal accumulated scientific and production experience and modern advanced technologies and equipment. It`s quite a difficult task both from a technical and economic perspective.

 

Thermodynamic analysis of oxygen solutions in aluminum-containing Ni – Co – Cr melts has been carried out. As the base alloys Ni  –  10  %  Co  –  15  %  Cr, Ni  –  15  %  Co  –  10  %  Cr, Ni  –  20  %  Co  –  15  %  Cr and Ni  –  40  %  Co  –  10  %  Cr were considered. The dependences of the oxygen solubility on the content of aluminum in Ni – Co – Cr melts were calculated at 1873  K. Aluminum at very low levels practically does not effect on the oxygen concentration in the melt, a further increase of the aluminum content leads to a very significant decrease of the oxygen concentration in the melt. Aluminum contents under which the mechanism of the deoxidation reaction changes were determined in investigated melts.