Global industry tends to follow the path of increasing the working
life of products of metallurgical production. One of the most promising directions is production and use of laminated composite materials. In particular, the practice shows a multiple increase in the working life due to the use of bimetal and lined pipes instead of monometallic pipes. Lined pipes are bimetal pipes produced by the method of simultaneous expansion of a pipe made of dissimilar materials. In the literature devoted to the production of composite and bimetal pipe not enough attention is paid to the production of lined pipes. Forming of bimetal pipes in their manufacturing by the method of lining has distinctive features in comparison with other methods of producing bimetal and composite materials, which must be considered in the development of lining technology. Lack of information on the specifics of forming layered pipe at lining complicates the development of technology and modes of lined pipes processing. Therefore, the aim of this work was to study the deformation characteristics of layered pipe forming, non-uniform distribution of strain between the layers under lining and its impact on the ratio of the strength properties of the materials.

The heat- and wear-resistant layer was created by sputtering aluminum and chromium-nickel coatings to increase service life of continuous casting mold on its narrow sides from M1 copper before the last renovation. Previously, the authors have investigated the structure of the coatings, composition phases, hardness and microhardness of the surface layers. Chrome-nickel thermal spray coating with thickness of 0.5 – 0.6 mm was deposited on the surface of the pair of narrow walls of thick-walled mold. Machining by grinding is necessary to obtain the required cleanliness class of the walls surface, and it is required to increase the thickness of the chrome-nickel coating. When the chrome-nickel coating thickness is more, than 0.8 mm it can be detached. Therefore, to increase the adhesive strength of the chrome-nickel coating with a copper basis the use of aluminum underlayer is considered. As a result, the application of a chrome-nickel coating with aluminum layer can be used to increase the resistance of the narrow walls of a continuous casting mold if there is interaction of the porous layer with α-phase or the porosity reduction of the layer.

The analysis of quality of large diameter welded pipes depending
on the parameters and modes of the slab forming on press equipment is presented. Mathematical modeling of the processes was performed using the finite element method. The results of the stress-strained state of metal during round billet forming billets in forging equipment are shown. Established computer program allows calculating of process parameters settings of press equipment to determine the value of controlled geometric parameters of round billets, required in the regulations. The theoretical solutions were experimentally tested on assortment of large diameter pipes, produced at TESA 1420. It is recommended to use this method to calculate the LDP forming parameters and pressing equipment settings that allows reducing the number of defects caused by the geometry of the fl anging press and JCO- press.

The main scientifi c and practical results improve the efficiency of the cameras for recycling of metallurgical dust through the development and introduction of the units of new generation capable
to improve environmental protection and working conditions and to reduce the loss of useful product. The article describes analysis and evaluation of technologies and means of improving the efficiency of dust collection chambers. A theoretical study of the mechanism of dust deposition in the collecting chamber and the results of laboratory studies of its effi ciency with fi ber curtains and inertial deposition of the aerosol on the fi ber curtain are considered. The authors have proposed the new mechanism for dust deposition in the collection chamber and the infl uence of the electric charge on the particle and fi ber deposition effi ciency of dust in the camera. The expressions for the degree of inertia and diff usion deposition of dust particles in the thin cylindrical fi ber and regular system of vertical fi bers were determined.

The use of brackish water for indoor cooling of rollers of metallurgical machines leads to the formation of scale on the inner surface of the cooling channel. When forecasting the temperature conditions of service of rollers, the fact that in the initial period of operation of the roller cooling channel is clean and in working conditions dramatically different from those of the final period of operation, is usually not taken into account. Continuously increasing layer of scum on the surface of the cooling channel, which has high mechanical properties and low coefficient of thermal conductivity, causes a rise in temperature of the working surface to the tempering temperature of the material of metallurgical machinery rollers. The aim of this work was to study the temperature conditions of service of metallurgical machinery rollers at scale formation in the cooling channel surface. The authors have proposed a method of estimating the temperature conditions of service of metallurgical machinery rollers for this case. For example, the estimation for roller of continuous casting machine has shown that for selected operating conditions the maximum temperature of the roller outer surface reaches its critical value after six months of work of metallurgical machines. The technique allows a differentiated approach to the definition of average and maximum temperature of the surface of the rollers in view of the magnitude and nature of the heat load, cooling conditions, and scale formation on the heat transfer surface. It can serve as a basis for definition of rollers operation life and rational consumption of reagents for the preparation of cooling water.

The problem of assessment of the steel loss in the thickness of scale is considered for industrial furnaces. The possibilities of different ways to reduce steel oxidation are analyzed. Particular attention is paid to the attendant diffi culties of decrease of steel loss by reducing the oxidant consumption coeffi cient (n). The reality of achievement of substantially nonoxidative steel heating in industrial furnaces at present is shown. The author has highlighted their important technological characteristics: almost molecular mixing of the primary components of combustion (natural gas at n = 0.48 – 0.5), the synchronicity of the burners work and limit n deviation at regulation of primary combustion of fuel Δn ≤ 0,01, the eff ective jet-mechanical throttling of primary gas flow precluding the reverse circulation of the primary products of incomplete combustion from the post-combustion zone to the metal heating zone. Directions of design and work options of forging and rolling furnaces are proposed with the achievement of the relevant indicators for the reduction or complete suppression of steel loss. The problems of internal high-temperature oxidation of silicon of transformer steel are particularly analyzed as well as the nondecarburization heating of ball-bearing steel

Manufacturing of periodic profi le bars of nickel and titanium alloys is an independent task in the general problem of improving blade manufacturing technology (single-locked, double-locked). It was found that under certain schemes and vibrational deformation modes (in particular, when vibratory drawing) the eff ect of periodic changes of the bar or wire diameter along its axis is observed. It also was found that the eff ect of the periodic variation of the diameter of the rod or wire at vibratory drawing is associated with friction fl uctuations, loss of stability during deformation both during the yield stress in the bar material and the formation of a “neck”, and also as a result of the action of the inertia forces. The dependences for determining the conditions of the unstable strain and stabilizing the manufacturing process of a periodic profile by controlling the parameters of the vibratory drawing were obtained.

Thermodynamic analysis of oxygen solutions in liquid nickel containing aluminum and titanium was carried out. It is shown that the aluminum and titanium presence in the melt signifi cantly reduces the solubility of oxygen with their content increasing. However, after reaching contents of 0.205 % in the case of aluminum and 0.565 % in the case of titanium the oxygen concentration in the melt begins to increase with aluminum and titanium contents increasing. The minimum oxygen concentration during deoxidation of nickel melt by aluminum (1.44·10–4 % O) and titanium (2.98·10–4 % O) was determined. Obtained results allow to off er the best option of nickel alloys alloying by aluminum and titanium. Initially the deoxidation of melt is produced by aluminum in an amount providing the minimum oxygen concentration in the melt (~ 0,2 % Al). Then the formed oxide phase is removed to prevent the reoxidation of the melt. Only then alloying the melt is made by aluminum and titanium to desire their contents in the alloy.

The article reviews the regularities of formation of the excess phase in the cast high-manganese steel in a wide range of cooling rates. It was found that this phase can stand out both along grain boundaries and within them and it can be represented by phosphide eutectic and by secondary carbides. At low cooling rates of the casting the phosphide eutectic and a small amount of secondary carbides are mainly formed, moreover, the excess phase with mixed morphology is also formed. It consists of eutectic carbides and secondary carbides with coherent boundaries between them. With increasing of cooling speed the excess phase is allocated predominantly in the form of secondary carbides, wherein there is a decrease in its size. Influence of cooling speed of a casting on the chemical composition of the excess phase also was studied. It was determined that due to increasing the cooling rate the amount of manganese in the formed secondary carbides decreases. The ratio of iron to manganese in the standing out phosphide eutectic does not depend from the cooling rate and is virtually unchanged.

The task of counterfl ow heating of thermally massive bodies was defi ned and solved. The mathematical model considers heating bodies of classical geometry (panel, cylinder and sphere) by radiation and convection simultaneously, as well as linearly dependent thermal characteristics from temperature. Initial equations of heat exchange were mostly realized through technological processes of metal heating in continuous furnaces of rolling manufacture. The solution of double nonlinear problem was realized by the equivalent sources method (ESM) which is an effective mathematical apparatus to solve different tasks, including applied problems of metallurgical thermal engineering. Testing of approximate analytical solution in accordance with ESM algorithm was fulfi lled for the following cases: for Kavaderov-Kalugin method (case of plate pure radiant heating) and numerical solution in accordance with the algorithm of apparent finite-difference approximation of the initial system of diff erential equations. Comparison of computational results of all methods showed a satisfactory fi t and the availability of solution in an explicit form with an opportunity to simplify it proves the advisability of its application in heating engineering calculations of metallurgical furnaces.

Approaches to solving the central problem of the highest hierarchical
level of industrial complex management system are conside red. This is the problem of choosing the strategy of volume schedu ling (VC) of pipe production: production to the “warehouse” or production “order”. Each strategy can be characterized by the specific risks of expected revenues losses. The solution of the procedure of forming the optimal structure of the production program (portfolio of orders) is presented. Adequate implementation of this procedure signifi cantly aff ects the performance of the pipe business. This applies primarily to the shops with the multiproduct production of cold deformed pipes. Production logistics in such shops is based on the use of various combinations of technological routes (rolling, broaching, heat treatment, chemical treatment, etc.). The solution was implemented in the form of multicriterial selection process. Decrease in the dimension of optimization problems of VC was implemented using techniques of assortment aggregation of the pipe shop. The technique is based on the algorithm of the synthesis method of principal components factor analysis and automatic classifi cation. Coordination of the production process and the departure sequence of finished products to custo mers were made via an interactive multicriteria iterative procedure. The author has used the method of interval estimation of the substitution criteria, adequate to functionality of the actual users of the services that does not have special training in the theory of decision making.