Metallurgist (v.56, #11-12)

Analysis of efficient operating cycles for blast-furnace stoves by Li Zhi; Wen Zhi; Su Fu-yong (799-806).
The stove of a blast furnace is one of its most important elements, helping to make the furnace more efficient by preheating the blast. Blast-furnace stoves operate as a unit in order to provide a continuous supply of hot blast to the furnace, this being done by alternating the stoves between cycles in which they heat the blast and cycles in which their checkerwork is heated. Fixed cycles are often used due to the difficulty of operating stoves in cycles of different durations. However, this practice inevitably leads to fuel losses and destabilizes the temperature of the blast. This article presents a model of heat transfer that the authors have developed for a blast-furnace stove. An alternating cycle for heating the blast with a group of stoves is analyzed and methods are proposed for solving problems concerning operating cycles with the use of a three-stove or four-stove group.
Keywords: operating cycles; stove group; variable cycles

Technology for obtaining metallized sinter by D. K. Isin; A. M. Gazaliev; S. E. Oryngozhina; B. D. Isin (807-809).
Sinter which is 50–68% metallized has been obtained by combining the sintering operation with metallization of the sinter by products obtained from the conversion of natural gas at high gas pressures. The duration of the metallization stage was 20–30 min when the hot sinter cake was metallized at temperatures within the optimum range of 1030–1100°C. The content of the –5 mm fraction in samples of the metallized sinter obtained after testing in a Linder drum was 4–5 times lower than in normal sinter.
Keywords: sinter; degree of metallization; oxidation; natural gas; blast-furnace gas; concentrate; coke; metallurgical properties

Optimum content of carbon in the charge of an EAF by A. G. Belkovskii; S. F. Filippov; Ya. L. Kats (810-818).
Results are presented from a study performed to determine how the quantity of carbon-bearing materials charged into an electric-arc steelmaking furnace to carbonize the metal affects the main indices of the heat – electric-power consumption, the duration of the heat, the time of furnace operation under current, and hourly productivity. The use of a mathematical model developed previously showed that there is a quantity of carbon-bearing materials that is optimum from the standpoint of minimizing electric-power consumption and maximizing the hourly productivity of the furnace. The existence of this optimum quantity has been substantiated theoretically, but it has not yet been confirmed by statistical studies due to the large number of other factors that have a significant effect on the above-named indices.
Keywords: EAF; carbon-bearing materials; mathematical modeling; heat indices

Comprehensive approach to choice of CBCM mold coating by A. Luese; S. R. Sivrikova (819-825).
Data are provided for deposition of coatings VHN and H-VHN, developed by SMS Millcraft and assimilated by SP SMS-CHELTEK. These coatings have greater strength compared with nickel coatings used extensively. A comprehensive approach is recommended for coating choice taking account of mold construction and operating regime, coating concept, and specific continuous casting production process.
Keywords: VHN and H-VHN coatings; construction; mold operating regime; cooling water

Current trends in the production and use of two-layer steels by A. I. Zaitsev; I. G. Rodionova; A. V. Amezhnov; A. A. Pavlov (826-831).
This article examines trends in the production and use of two-layer steels in the chemicals industry, petroleum engineering, oil-field equipment, agriculture, road-building, and maritime construction.
Keywords: corrosion resistance; heavily loaded parts and components of agricultural equipment; hardness; bimetal; electroslag hard-facing; cladding layer; bond strength; heat treatment

Questions are considered of simulating a production process for manufacture of rolled sheet with thermomechanical treatment based on integration of special structure formation models with hot plastic deformation and accelerated cooling into a single integral model. Working models are presented for static recrystallization, taking account of the effect of carbonitride and alloying element separation in solid solution, bainitic and ferritic transformation, making it possible to predict the average structural element size and considering the effect of previous plastic deformation on austenite content. Ways are demonstrated for further improvement of special models: dynamic recrystallization, fragmentation, texture formation, and carbide transformation during tempering.
Keywords: physical modelling; thermomechanical treatment; static recrystallization; dynamic recrystallization; bainitic transformation; ferritic transformation; production process integral model

Use of the software deform 2D to model the process of rolling with vibration of the top work roll by M. M. Skripalenko; D. A. Ashikhmin; M. N. Skripalenko; A. A. Sidorov; Yang Xu (844-847).
Results are presented from computer modeling of the rolling of aluminum strip with vibration of the top work roll. Data which are obtained show how vibration of the deforming tool affects variations in the thickness of the product that is being rolled.
Keywords: work-roll vibration; computer modeling; Deform 2D; rolling mill; longitudinal variation of thickness; rolled product; finite-element analysis

Shears for cutting rolled shapes and thick-walled tubes by V. I. Truskovskii; V. G. Sherkunov (848-853).
Results are presented from the development and testing of a new design of shears for cutting rolled shapes of circular cross section and thick-walled tubes. The shears employ a mechanical cutting scheme based on translational motion of the cut portions of the workpiece in two directions as they also rotate. All of the innovations incorporated into the shears have been awarded Russian patents.
Keywords: shears; hydraulic actuator; toothed rack; pinion; flat wedge-shaped blades; cutting edge; clamping plates; angle of inclination; rolled shape; semifinished product

Prediction of ferroalloy production results by V. I. Gusev; V. Ya. Khrolenko; D. V. Kravchenko (854-862).
An existing method is considered for calculating a charge for carbothermal manganese ferroalloys with preliminary distribution of elements within melting products. Significant divergence is demonstrated in calculated and production results. A new method is proposed for charge calculation. An alternative includes replacement of the existing method for element distribution by a production process material balance. The possibility of objective economic evaluation of charge variations and production technology is demonstrated.
Keywords: manganese alloys; charge; calculation method; element distribution; technology material balance; conformity; production results

Surface Defects in Foil Direct Chill Strip from Highly-Alloyed Aluminum Alloys by V. Yu. Bazhin; V. M. Sizyakov; A. A. Vlasov; R. Yu. Feshchenko (863-866).
The metallurgical industry is faced with the task of improving specific output of final product with high added value. Production of aluminum foil and thin rolled product is not more than 5% of the total output of aluminum within Russia. Within the scope of OK RUSAL there are three foil rolling plants who produce aluminum foil for overseas technology. In processing highly alloyed materials of the 8006 and 3003 series, a problem remains of billet surface quality, reducing output of finished product.
Keywords: aluminum foil; casting and rolling unit; surface defect; oxide film; aluminum strip

The copper industry in Russia has undergone a significant transformation in recent years. Trends and prospects in the domestic market for copper and copper-based semifinished products were the subject of discussion by participants in the All-Russia Conference “Copper, Brass, Bronze: Trends in Production and Consumption – 2012.” The conference was held in Ekaterinburg in the middle of September.

Exhibition Aluminum 2012 in Dusseldorf by L. Khazanov (874-876).
The exhibition Aluminum is held every two years in Germany, this show having already become a traditional review of the latest achievements in the international aluminum industry. The participants include representatives of every company that is associated with the production, distribution, or use of this metal and its alloys. Despite the complicated situation in the global market, the attendees were guardedly optimistic about the future.

Market Forecast for Stainless Steel* by S. Ilmark (883-887).

Graph Model for Carbon Dioxide Emissions from Metallurgical Plants by Yu. N. Chesnokov; V. G. Lisienko; A. V. Lapteva (888-893).
Mathematical models are presented for estimating carbon dioxide emissions from metallurgical processes. The article also presents a new mathematical model in graph form to calculate transit and net emissions of carbon dioxide based on the estimates obtained for the individual processes. The graph model is used to compare the blast-furnace–converter process with the blast-furnace–EAF process.
Keywords: integral emission of a process; transit emission; net emission of carbon dioxide; graph; carbon footprint

Forming of Tee Parts by a Process That Combines Diffusion Welding and Pneumothermal Forming in the Superplastic Regime by A. A. Cheslavskaya; V. V. Mironenko; S. A. Bersenev; V. V. Kotov (899-903).
An alternative method is described for making tees. The article discusses the main stages in the advanced method, which combines diffusion welding and pneumothermal forming in the superplastic regime. The process of superplastic pneumothermal forming is modeled and calculated results are reported. In the method, pneumothermal forming is preceded by diffusion welding.
Keywords: pneumothermal forming of sheet metal parts; superplastic effect; tubular parts made from sheets

The exacting requirements on the durability of electrolysis cells used to make produce aluminum – the service life of which is determined mainly by the durability of the bottom – are driving improvements in the quality of carbon-bearing lining materials which are used. A readily compactible cold-rammed bottom refractory in bulk form is needed to solve the problems encountered in forming the vulnerable joints between the lining blocks and at the periphery of the bottom. The introduction of a plasticizing additive to coal-tar pitch effectively lowers its softening point and viscosity, which improves the plastic properties of the bulk carbon refractory.
Keywords: aluminum electrolysis cells; bulk bottom refractory; coal-tar pitch; carbon-based materials; cold-rammed bulk refractory

Effect of Waste and Alternative Fuels on Blast-Furnace Operation by P. Pustejovska; S. Jursova; S. Brozova; J. Sousek (908-911).
Ninety-eight percent of the pig iron produced in the world is made in blast furnaces. Pig-iron smelting is presently being impacted by a serious shortage of coking coals. Moreover, the production of coke used in the smelting operation has an adverse effect on the environment. One method of partially replacing coke in the smelting operation is to inject hydrocarbons into the blast furnace. The injection of hydrocarbon through the tuyeres alters the mass- and heat-transfer conditions inside the furnace and increases the volume and hydrogen content of the hearth gases and top gases. The hydrogen content of the gases depends on the value of the C/H2 ratio in the fuel that is injected. All these changes decrease the amount of direct reduction that iron undergoes in the furnace. This article presents results from model calculations that took into account the complex effect of injected hydrocarbons on reduction and heat exchange in a blast furnace. The models were used to quantitatively estimate the amount of reduction that takes place and to determine the value of a coefficient which characterizes the replacement of coke by injected fuel. The calculations that were performed make it possible to predict changes in coke consumption in a blast furnace when it is injected with liquid hydrocarbons.
Keywords: injected fuel; fuel oil; tars; conventional oils; coke consumption; coke replacement coefficient; degree of direction reduction

It is established that the main criteria for implementing mechanochemical synthesis in systems Ti + C and WO3 + Mg + C are the structure of carbon modifications and their degree of aromaticity. The possibility is demonstrated of using carbon modifications, obtained as a result of plant raw material pyrolysis, for synthesizing carbides with a minimum sulfur content.
Keywords: renewable plant raw material; mechanical activation; mechanochemical synthesis; titanium carbide; tungsten carbide; degree of aromaticity; carbon structure; graphite ash content

Results are reported from a study of phase transformations in manganese ores and in charges used to make pellets. The study was performed by the method of differential-thermal analysis (DTA) with continuous heating. The article also presents data obtained by using DTA curves to determine kinetic parameters.
Keywords: manganese pellets; ferroalloy; kinetic parameters; nonisothermal method

Extruded Briquettes (bricks) for Ferroalloy Production by A. M. Bizhanov; R. B. Steele; G. S. Podgorodetskyi; I. F. Kurunov; V. Ya. Dashevskyi; V. V. Korovushkin (925-932).
Results are provided for laboratory studies, full-scale industrial tests, and industrial utilization of extruded briquettes (bricks) based on technogenic and natural materials, and fuel, for ferroalloy production. The possibility is demonstrated of achieving marked saving in electrical energy, a reduction in coke consumption, and improvement in the degree of extraction of the main component during operation on a briquetted charge.
Keywords: extruded briquette (bricks); stiff vacuum extrusion; Steele extruder; ferroalloys; ferronickel; laterite nickel ore; ferromanganese; aspiration dust; ore-smelting furnace

Improvement in Efficiency, Resource and Ecological Indices for Extra-Furnace Steel Treatment with Flux-Cored Wire Containing Calcium Reagents by V. V. Belousov; A. Ya. Babanin; M. V. Beskrovnaya; O. A. Babanina; E. S. Korotenko (933-937).
Features are established for formation of flux-cored wire spatial movement trajectories in relation to its parameters and rate of introduction, and possible areas of filler release are identified. A procedure is developed and a nomogram is constructed for evaluating existing technologies of steel treatment with flux-cored wire containing calcium reagents, and reasons for a reduction in calcium release are sought, making it possible to optimize flux-cored wire introduction rate in order to increase the efficiency, resource and ecological indices of the process.
Keywords: extra-furnace treatment; flux-cored wire; resource and ecological indices

Reduction of the Length of Strip Rolled on Roll-Forming Machines by V. I. Punin; L. S. Kokhan; Yu. A. Morozov (938-940).
This article examines the deformation of sections during their bending on a roll-forming machine. Thin-walled semifinished products can became unstable in the longitudinal direction between the stands of the machine, which results in the formation of a product that is shorter than the length specified for it. Euler’s method is used to explain this phenomenon and calculations are performed to determine the change in the product’s length. Practical recommendations are given for rolling sections on a roll-forming machine.
Keywords: bending; longitudinal deformation; Euler’s method

Results are reported from a study of the dependence of the reduction in the thickness of strip on the main process parameters as the strip is bent in the rolls of a roll-forming machine. The study was performed with the use of the theory of experiment planning.
Keywords: thickness reduction; coding; planning matrix

Study of heat-resistant steel strain hardening by indentation by P. O. Maruschak; I. B. Okipnyi; L. Ya. Poberezhnyi; E. V. Maruschak (946-951).
Physicomechanical interpretation is proposed for the use of indentation on different scales of structural levels for evaluating the condition of heat-resistant steel 15Kh2MFA(II) after high-temperature static deformation. Analysis of the results is carried out using a phenomenological hypothesis formulated taking account of known features of correlation of hardness and microhardness measurement data with material structural parameters. It is demonstrated by experiment that the sensitivity of indentation methods depends on participation of different material structural levels in deformation.
Keywords: deformation; hardening; indentation; hardness; steel heat resistance; microhardness

Extraction of carbon nanoparticles from fluorinated alumina during aluminum production by V. A. Ershov; V. V. Kondratiev; I. A. Sysoev; A. O. Mekhnin (952-956).
Alumina used as a sorbent in exhaust gas dry cleaning during electrolytic aluminum production is studied. The distribution of dust and gas emission ingredients with respect to absorbent fractions, specified by different sizes, is considered. The predominant role of fine alumina fractions in retaining carbon within the composition of solid emission formation is demonstrated. It is established that within fluorinated alumina the carbon fraction contains highly organized carbon nanostructures.
Keywords: electrolytic aluminum production; exhaust gas dry cleaning system; fluorinated alumina; carbon concentration; dust and gas emission ingredients with respect to absorbent fractions; impurity removal from fluorinated alumina; nanostructured carbon particles.

Oxy-oil heater for Vanyukov furnaces by A. V. Balasanov; V. G. Verein; A. A. Tupikov; A. B. Usachev (957-958).
This article describes technical innovations developed to provide additional heat for the Vanyukov furnaces at the Balkhash Copper Smelter in order to maintain the necessary temperature when there is not enough sulfur in the copper concentrate. The problem was solved by installing two oxy-oil heaters on each furnace. The heaters were installed in the side wall of the furnaces above the slag bath. Oil consumption per furnace is 500–1200 kg/h. The article reports the results obtained from the introduction of these heaters at the Balkhash Copper Smelter.
Keywords: Vanyukov furnace; oxy-oil burner