Metallurgist (v.57, #3-4)

The casting of a large steel globe-cock plug is examined to illustrate the use of computer modeling to find zones where macro- and micro-porosity are concentrated. The article discusses the key aspects of the problem’s formulation in ProCAST software, presents modeling results, and compares the defects that are found by modeling with experimental data obtained in a foundry.
Keywords: steel casting; computer modeling of casting processes; ProCAST; shrinkage defects; microporosity

A method is described for making a tee designed with a complex set of internal stiffening elements. The article describes the main stages of the modern process of pneumothermal forming in the superplastic regime with the use of diffusion welding. The production of a tee by superplastic pneumothermal forming after diffusion welding is modeled and the calculated results are presented.
Keywords: pneumothermal forming of sheet parts; superplastic effect; tube parts made from sheets

Development of sinter production at the Chelyabinsk Metallurgical Combine by N. N. Gorshkov; E. A. Kazantsev; N. P. Myagchenkova; O. V. Tregubov; E. Yu. Skorik (176-180).
The sinter production facility at the Chelyabinsk Metallurgical Combine has gone through several stages of development, from a waste-recycling plant to a modern complex that makes high-quality sinter. A program for making the sintering operation more efficient has been developed and is currently being implemented. The use of high-quality gas-cleaning equipment has reduced harmful atmospheric emissions per ton of product by a factor of 8–10.
Keywords: sintering; sinter; sintering machine; homogenization; balling; the sintering process; homogenization complex; upgrading of equipment

Technology for restoring the original profile of blast furnaces at the Chelyabinsk Metallurgical Combine by D. V. Zotov; V. A. Andreev; N. N. Gorshkov; N. S. Polyakov; A. V. Denisov (181-182).
The smelting of charges with a high content of iron-bearing wastes in a blast furnace runs the risk of forming slag crusts in the furnace due to the wastes’ high zinc content. A technology for restoring the original profile of the furnace has been developed and is being successfully used.
Keywords: blast furnace; pig iron; slag crust; furnace profile; shaft

Statistical analysis is used to examine the effect of the main raw-material and process factors on coke rate and productivity for the blast furnaces at the Chelyabinsk Metallurgical Combine during the period from 2007 to July 2012. A method is developed for calculating and predicting coke rate and daily pig-iron output in the blast-furnace shop, and a combination of parameters is found to reduce coke rate and increase the productivity of the shop. The factors table which is used throughout the industry is refined for the conditions that exist in the blast-furnace shop at the ChMK.
Keywords: sinter; blast-furnace coke; iron; abradability M10 ; oxygen; correlation; design procedure; consumption; basicity; productivity; strength; natural gas

Experimental testing of the validity of mathematical models of hydrodynamics and heat transfer for the melt-processing conditions in a ladle-furnace unit by V. P. Piptyuk; S. E. Samokhvalov; I. A. Pavlyuchenkov; V. V. Motsnyi; A. G. Rod’; S. N. Pavlov; G. A. Andrievskii; A. A. Anosova (194-198).
Results are presented from experimental testing of the validity of mathematical models of the hydrodynamics and heat transfer of the melt in a ladle-furnace unit during the finishing of steel with respect to chemical composition. The degree of agreement and validity of the experimental and theoretical results are determined.
Keywords: numerical modeling; experimental testing; validity; ladle-furnace unit; homogenizing; ferromanganese

Effect of chilling of the top part of a steel ingot on the conditions of its crystallization and the quality of forgings obtained from it by A. N. Galkin; N. A. Zyuban; D. V. Rutskii; S. B. Gamanyuk; A. Ya. Puzikov; V. V. Firsenko (199-206).
The crystallization of a steel ingot is physically modeled to determine features of its solidification and the growth of shrinkage defects. The modeling is done using ingots with a standard hot top and ingots with a chilled top. The results obtained in the modeling were substantiated by a study of the cast structure of actual ingots. The character of the development of carbon, sulfur, and phosphorus segregation over the cross section of ingots is determined along with the location and size of shrinkage defects in ingots cast with tops having different thermal properties. Results are presented from a study of the quality of the metal of tubular forgings obtained from experimental and control ingots.
Keywords: ingot; crystallization; shrinkage defects; segregation; ingot top; physical modeling; forging

Study of the quality of ultrathick high-strength shipbuilding steel plate by V. G. Milyuts; V. V. Tsukanov; N. F. Vladimirov (207-214).
The effect of top and bottom pouring of large forging ingots on the quality of high-strength shipbuilding steel plate 150 mm thick is studied. It is shown that technology developed for forging billet top pouring in argon at atmospheric pressure and bottom pouring under a slag-forming mix with protection of the metal stream by argon provides a high level of quality for ultrathick shipbuilding steel plate.
Keywords: shipbuilding steel; top and bottom pouring; argon; forging ingot; ultrathick plate; metal quality; non-metallic inclusions; mechanical properties

Experience of using accelerated cooling in production of steel X70 plate for the Central Asia – China gas pipeline by A. V. Pogozhev; E. O. Tskitishvili; Yu. I. Matrosov; M. B. Klyukvin; M. Yu. Matrosov; G. N. Konovalov (215-220).
At the Azovstal Metallurgical Combine together with the Bardin Central Research Institute of Ferrous Metallurgy production of thick plate (3266 × 19.1 mm) is being developed for a large diameter gas pipeline of strength category X70. Plates are manufactured using controlled rolling technology with accelerated cooling (CR + AC) instead of previous controlled rolling technology with air cooling. Introduction of CR + AC promotes an increase in average values of energy for failure KV with impact tests on finished metal plate, and also a marked improvement in 3600 rolling mill productivity.
Keywords: pipe steel X70; controlled rolling; accelerated cooling; pipe processing; mechanical properties

The possibility of activated sintering by combined use of two activating additions is studied by experiment and demonstrated. The combined effect of two types of additives is studied: additives participating catalytically during gas phase generation, i.e., a carbon donor (Na2CO3 or BaCO3), and micro-additions of surface-active element (B). It is established that both combined additives (Na2CO3 + B or BaCO3 + B) accelerate PM alloy Fe–5%Si–1%C sintering considerably. The effect of combined additives is stronger than the effect of the additive components.
Keywords: powder metallurgy; activated sintering; combined additive

Powder particle formation mechanism with dispersion of different molten metals by P. A. Lykov; E. V. Safonov; A. O. Shul’ts (232-236).
The effect of atomized material nature on particle shape and properties of material obtained is demonstrated, and the significance of chemical reactions proceeding during atomization is evaluated.
Keywords: metal atomization; particle shape; cooling time; formation time; powder bulk density; powder fluidity

Formation features of highly resistant carbide and boride coatings prepared by a two-stage method by G. V. Levchenko; A. B. Sychkov; A. M. Nesterenko; V. L. Plyuta (237-243).
Features of high resistance coatings in the surface area of a tool steel and hard-alloy inserts for a cutting tool with a two-stage preparation method are studied. Pure tantalum and niobium coatings on tool steel specimens and inserts are prepared by electrolysis of tantalum and niobium fluorides in a salt bath. After this, carburizing or boriding of a coating (tantalum or niobium) is performed in order to form carbide (TaC, NbC) or boride (TaB, NbB) claddings. It is established that formation within a surface area of test specimens of cladding layers of carbide (boride) phases with high abrasive and corrosion resistance is determined by external “outsourcing” of carbon (boron) atoms. Test evaluation for cutting tool life with hard-alloy inserts with a TaC-coating, prepared by the method developed, demonstrates their operating efficiency during machining with component cleaning (finishing) treatment. The promising nature of using the method developed for improving mining and metallurgical equipment component, cutting tool, and engine component life in mechanical engineering is demonstrated.
Keywords: highly-resistant carbide and boride surface coatings; fluorides; tantalum; niobium; boriding; microstructure; abrasion and corrosion resistance; cutting tool

Status of the organized recycling of cadmium-bearing secondary raw materials by A. R. Barashev; S. V. Karelov; S. V. Mamyachenkov; O. S. Anisimova (244-246).
The main methods being used in metallurgy to systematically recycle cadmium-bearing secondary raw materials are examined. Hydrometallurgical methods which use sequestering reagents that can be regenerated are the most promising technologies from the standpoint of suitability for industrial use, environmental safety, and the selectivity with which cadmium is extracted.
Keywords: cadmium-bearing secondary raw materials; regenerable sequestering reagents

Technology for the hydrometallurgical processing of a complex multicomponent sulfide-based raw material by D. A. Rogozhnikov; S. V. Karelov; S. V. Mamyachenkov; O. S. Anisimova (247-250).
An analysis of the methods currently used for the metallurgical processing of polymetallic middlings from the beneficiation of sulfide ores shows that the oxidant which is the most promising for use as an agent to leach the middlings is nitric acid. A technology is developed to process hard-to-decompose middlings with the use of nitric acid.
Keywords: multicomponent sulfide middlings; nitric-acid leaching; processing technology

Analysis of the feasibility of reducing fuel consumption and carbon-dioxide emissions and obtaining carbon credits with the use of sverdlovskaya-oblast factories as an example by V. P. Anufriev; V. G. Lisienko; A. P. Kuligin; A. V. Lapteva; Yu. N. Chesnokov; Yu. K. Malikov; T. P. Ryzhova (253-260).
This article discusses aspects of improving the efficiency of heating and heat-treatment furnaces from the standpoint of the fuel savings that can be realized by the use of different methods to modernize such furnaces.
Keywords: greenhouse gas; carbon dioxide; regenerative burner; thermal efficiency; monetary savings; automation

Prospects for involvement of low-grade molybdenum and tungsten concentrates in metallurgical processing by A. S. Medvedev; P. V. Aleksandrov; B. Z. Razykov; A. O. Rodionov; O. V. Sannikova (261-267).
The expediency of involving low-grade concentrates and middlings in metallurgical processing is substantiated. The possibility of efficient processing of low-grade molybdenite (15–20% Mo) and scheelite (7–10% WO3) concentrates by hydrometallurgical and combined methods (with a preliminary roasting of scheelite concentrate) is shown. Technologies aimed at preparing synthetic scheelite and powellite suitable for smelting ferrotungsten and ferromolybdenum are developed. Extraction of metals from ores into end products is greater by 15–20% than traditional treatment methods: flotation with preparation of conditioned concentrates and subsequent processing. This provides more rational use of natural resources.
Keywords: low-grade; molybdenum; tungsten; leaching; sintering; processing

A laboratory unit is assembled, criteria are substantiated, and tests are performed for the cold modeling of Ausmelt-furnace–settler systems. The article shows the potential of this approach for evaluating the overall productivity of the process, the condition of the bath, and the completeness of phase separation in the settler.
Keywords: modeling; Ausmelt; autogenic processes; submersible lance; settling; phase separation

Problems are considered for choice of properties for evaluating sinter quality, and also choice of structure and creation of a simulation model for calculating mechanical cold (tumble) strength index using a selection of models describing the effect of individual features of the process.
Keywords: metallurgical sinter quality; mechanical cold strength (tumble index); basicity; simulation model

A method is developed for quantitatively determining the emissivity of the tuyere zone and the temperature of the pig iron during its tapping from a blast furnace when the furnace is injected with up to 230 kg of pulverized-coal fuel for each ton of pig iron that is produced. An evaluation is made of the changes in the thermal regime of the hearth in this case, with particular attention being given to the intensified heating of the smelting products.
Keywords: pulverized-coal fuel; pig-iron temperature; theoretical combustion temperature; emissivity

Mastering a Technology for Making Stainless Steel on a VOD Unit at the Chelyabinsk Metallurgical Combine by V. N. Artyushov; S. P. Bochkarev; S. V. Igolkin; A. N. Makarevich; S. M. Fomchenko (292-294).
This article describes the main stages of introduction of a new technology in electric-steelmaking shop No. 6 at the ChMK for making stainless steels in a vacuum-oxygen decarbonization (VOD) unit. It discusses the solutions that were found to different problems, the results that were obtained, and the dynamics of the production of stainless steel by the VOD method.
Keywords: stainless steel; argon-oxygen refining unit; vacuum-oxygen decarbonization and refining unit

The Use of Thermal-Imaging Inspection at the Chelyabinsk Metallurgical Combine by M. I. Zuev; I. V. Konovalov; A. V. Kuznetsov; R. R. Gareev; S. P. Bochkarev (295-297).
Thermal-imaging inspection of electrical equipment and metallurgical production equipment at the Chelyabinsk Metallurgical Combine is examined.
Keywords: thermal-imaging system; thermal-imaging inspection; thermogram; equipment

Study of Steel 08Kh18N10T Centrifugally-Cast Pipe Billet Properties by B. V. Barichko; Ya. I. Kosmatskii; S. V. Rushchits; A. M. Akhmed’yanov; M. I. Gaslenko; V. B. Voskhodov; A. M. Zubkov (298-302).
Steel 08Kh18N10T deformation resistance under hot upsetting conditions is studied in the Gleeble-3800 research unit. The test material is two batches of cylindrical specimens 8 mm in diameter and 12 mm high, cut from a centrifugally-cast pipe billet in longitudinal and transverse directions. It is shown that with a high strain rate (10 sec–1) in the region of high strains transverse specimens have a higher strengthening factor compared with longitudinal specimens.
Keywords: centrifugally-cast billet; deformation resistance; Gleeble

An experimental study is made to determine how the mechanical properties of grade-T wheel steel are affected when hollow shells of this steel obtained by piercing solid semifinished products are deformed by rotary rolling. It is shown that piercing the semifinished products on the mill significantly improves the steel’s impact toughness and resistance to fatigue fracture.
Keywords: piercing of solid semifinished products; rotary rolling mill; mechanical properties of steel; wheel steel

Features of Multi-Electrode Submerged-Arc Welding in the Production of High-Strength Thick-Walled Pipes by A. N. Bortsov; I. P. Shabalov; A. A. Velichko; K. Yu. Mentyukov; I. Yu. Utkin (310-319).
An increase in the thickness of the wall of large-diameter pipes is accompanied by an increase in heat input during the welding of the longitudinal weld. The increased heat input results in slower cooling of the heat-affected zone (HAZ) and diminishes the reliability of the welded joint. It was shown on production equipment at the Izhorsky Pipe Plant that the heat input during welding of the lengthwise joint is directly proportional to the thickness of the pipe wall. This finding contradicts the thesis adopted in existing welding technology that heat input can be reduced. Experiments involving the direct recording of thermal cycles on factory equipment established the parameters for cooling of the HAZ and showed that the rate of cooling of this zone decreases when the welding operation is performed on hot metal.
Keywords: large-diameter pipe; heat input; multiple-arc submerged welding with multiple arcs; HAZ

Development of a Competitive Technology to Make Wire for Metal Cord by V. A. Kharitonov; A. Yu. Stolyarov (320-325).
A method is proposed for developing an efficient technology to make high-quality wire for the production of metal cord. Experimental data and results obtained from modeling in DEFORM software are used to determine the limiting value of the Cockcroft–Latham fracture criterion. That value is then used to calculate the limiting drawing ratio for wire rod when the drawing operation is performed without an intermediate heat treatment. The new technology developed for making the wire has made the metal cord a more competitive product.
Keywords: competitiveness; metal cord; wire rod; wire; technology design; Cockcroft–Latham fracture criterion; limiting drawing ratio; intermediate patenting; tensile testing; notched specimens

Method of Measuring the Mass Fraction of Selenium in Heat-Resistant Nickel Alloys by V. A. Maslov; V. A. Tikhonova; D. G. Rafikova; E. N. Udilova (326-328).
The central analytical laboratory at the ChMK has developed a method of measuring mass fractions of selenium based on atomic-emission and mass-spectrometric analyses. The method is very accurate in measuring low contents of selenium in heat-resistant nickel alloys. The procedure developed for mass-spectrometric analysis of mass fractions of selenium has halved the length of time needed to obtain the analytical results and made the measurement process less labor-intensive.
Keywords: selenium; nickel alloys; measurement method; atomic-emission analysis; mass-spectrometric analysis

Preparation of Rapidly Cooled Fibers by Melt Extraction by V. N. Antsiferov; A. S. Nechaev (329-332).
Preparation of rapidly cooled fibers by extraction of a suspended melt droplet is considered. A model of fiber crystallization on a crystallizer disk is proposed. Fiber cross section calculated and experimental data are compared.
Keywords: molten droplet; extraction; crystallization; rapidly-cooled fiber; fiber cross section

High-Energy Forming of Monolithic and Powder Materials by Pressure by M. N. Samodurova; L. A. Barkov; V. A. Ivanov; B. A. Yarov (333-341).
Well-established and new processes for the high-energy shaping of materials are analyzed along with the equipment they use. Most of the attention is given to the latest methods of high-energy compaction of metallic and nonmetallic powders on equipment made by the Swedish company Hydropulsor. Results are presented from studies performed on metal powders by scientists at the Swedish companies Höganäs and Sinterheat and Dalarna University, on powder ceramics (Al2O3) by French scientists, on copper and iron powders by Chinese scientists, and on carbon powders by the authors of the article.
Keywords: treatment by pressure; compaction; powders; velocity; carbon

Features of Powder Steel Formation with Electric-Contact Compaction by T. A. Litvinova; S. N. Egorov (342-345).
Conditions are analyzed for powder steel formation with electric-contact compaction (ECC). Areas of production regimes with different ratios of moving and retarding surface consolidation between interparticle surface growth (IPSG) migration forces and areas of ECC production regimes, providing homogenization of an iron-graphite charge and high quality consolidation between particles, are indicated. The dependence of steel true ultimate strength on electric-contact compaction regime is considered.
Keywords: electric-contact compaction; material homogenization; consolidation between particles; true ultimate strength; IPSG migration moving force; IPSG migration retardation force

Determination of Aluminum Oxide Concentration in Molten Cryolite-Alumina by V. A. Ershov; I. A. Sysoev; V. V. Kondrat’ev (346-351).
A method is developed for determining alumina concentration in molten cryolite-alumina. The divergence between alumina concentration values, determined by the proposed method and by leaching AlCl3, is on average 1.5 wt.% Al2O3. It is established that the electrolyte melting temperature depends to a considerable extent on the current melt alumina concentration. Values are determined of specific influence coefficients for the content of AlF3, CaF2, MgF2, LiF, and Al2O3 in electrolyte on melt liquidus temperature. The method makes it possible to exclude errors connected with the residual insoluble alumina content within an electrolyte sample, due to the use of a device providing operational and precise determination of data required for calculating alumina concentration.
Keywords: aluminum oxide concentration; molten cryolite-alumina; electrolyte liquidus temperature; determination of alumina content; melting temperature; electrolyte chemical composition

Preparation of Copper Electrical Engineering Alloy Strip with High Service Properties by P. A. Vasilevskii; L. M. Zheleznyak; M. Yu. Borodin; K. Yu. Mal’tseva (352-358).
Output is organized for industrial batches of electrical engineering strip with improved service properties, i.e., copper bus bars of rectangular section (σu determination is simplified and surface quality evaluation after bend testing is improved), commutator copper-cadmium strip of trapezoidal section (hardness increased, strip camber reduced, bulges and scratches absent from basic profile), and commutator copper-silver strip (electrical conductivity increased and stable mechanical properties achieved).
Keywords: electrical engineering strip; copper rectangular bus bars; commutator copper-cadmium and copper-silver trapezoidal sections; quality improvement and copper bus bar production labor content reduced; copper-silver alloy chemical composition optimization

Russian Shelf 2013 by L. A. Kondratov (359-363).