Metallurgical Materials Research Articles

Intelligent system for automatic control of powerful rotating furnaces, designed for sintering of free-flowing metallurgical materials using associative knowledge bases

Intelligent system for automatic control of powerful rotating furnaces, designed for sintering of free-flowing metallurgical materials using associative knowledge bases

Minimizing the Risks in the Storage of Metallurgical Material

The paper focuses on minimizing the risks in the storage of metallurgical material in a specific company which needs to cope with a limited space for material storage in general. At present, the metallurgical material, together with other purchased items, is stored in a designated space in the production hall, from which it is directly distributed to the production. The aim of the solution is to propose a more efficient use of the designated storage space while increasing the safety of work and minimizing occupational injuries.

Characterization of Cu–Ti powder metallurgical materials

Powder metallurgical Cu–Ti alloys with different titanium additions produced by hot pressing were characterized by optical microscopy, scanning electron microscopy, X-ray diffraction analysis, and hardness, wear and bending tests. The addition of titanium to copper caused the formation of different intermetallic layers around titanium particles. The titanium content of the intermetallics decreased from the center of the particle to the copper matrix. The hardness, wear resistance, and bending strength of the materials increased with increasing Ti content, whereas strain in the bending test decreased. Worn surface analyses showed that different wear mechanisms were active during the wear test of specimens with different chemical compositions. Changes in the properties of the materials with titanium addition were explained by the high hardness of different Cu–Ti intermetallic phases.

Computational study of Jeffrey’s non-Newtonian fluid past a semi-infinite vertical plate with thermal radiation and heat generation/absorption

Abstract The nonlinear, steady state boundary layer flow, heat and mass transfer of an incompressible non-Newtonian Jeffrey’s fluid past a semi-infinite vertical plate is examined in this article. The transformed conservation equations are solved numerically subject to physically appropriate boundary conditions using a versatile, implicit finite-difference Keller box technique. The influence of a number of emerging non-dimensional parameters, namely Deborah number (De), ratio of relaxation to retardation times (λ), Buoyancy ratio parameter (N), suction/injection parameter (fw), Radiation parameter (F), Prandtl number (Pr), Schmidt number (Sc), heat generation/absorption parameter (Δ) and dimensionless tangential coordinate (ξ) on velocity, temperature and concentration evolution in the boundary layer regime is examined in detail. Also, the effects of these parameters on surface heat transfer rate, mass transfer rate and local skin friction are investigated. This model finds applications in metallurgical materials processing, chemical engineering flow control, etc.

The Reduction Processes of the Titanium Containing Iron Ores Treatment

The questions of metallurgical processing of titanium-containing ores are considered. The ores and concentrates of the Kachkanarsky deposit of low-titanous and high-titanous are studied. The reducibility, durability, temperatures of a softening and melting of metallurgical iron ore raw materials are studied in vitro. Via X-ray the structural analysis are carried out. The calculations by means of mathematical models of pyrometallurgical processes are executed. Possibility of the processing of these ores according to schemes is shown: «blast furnace melting − converter melting» and «metallization – electric melting».

Natural convection on heat transfer flow of non-newtonian second grade fluid over horizontal circular cylinder with thermal radiation

This article numerically studies for multi-physical transport of an optically-dense, free convective incompressible non-Newtonian second grade fluid past an isothermal, impermeable horizontal circular cylinder. The governing boundary layer equations for momentum and energy transport, which are parabolic in nature, have been reduced to non-similarity non-linear conservation equations using appropriate transformations and then solved numerically by employing with most validated, efficient implicit finite difference method with Keller box scheme. The numerical code is validated with previously existing results and found to be very good agreement. The results are reported graphically and in tabular form for various physical parameters; Deborah number, Prandtl number and thermal radiation on flow velocity and temperature profiles. Furthermore, the effects of these parameters on non dimensional wall shear stress (skin friction) and surface heat transfer rate (Nusselt number) are also investigated. Increasing the Deborah number reduces velocity profile, skin friction and Nusselt number where as it enhances the temperature profile. Increasing Prandtl number decelerates the flow velocity, temperature and skin friction but Nusselt number enhances considerably. Increase in radiation parameter retards the flow velocity, temperature profiles and skin friction. But Nusselt number enhances markedly with increase in radiation parameter. Applications of the model arise in polymer processing in chemical engineering, metallurgical material processing.

The development of new metallurgical materials and technologies. Part 2. Powder nanomaterials

Methods of producing nanopowders and consolidated powder nanomaterials are reviewed. Various methods of nanopowder production are analyzed, and the properties of nanopowders are presented. Consolidation of nanopowders by pressing, sintering, and pressure sintering is discussed. The properties of consolidated powder nanomaterials are presented. The prospects for their application as constructional, functional, and high-energy materials are assessed.

The development of new metallurgical materials and technologies. Part 1

Work by researchers at the Russian Academy of Sciences on new materials (metals and ceramics) and new technologies is reviewed. The topics include new high-strength corrosion-resistant nitrogen steels; high-temperature light alloys and composites based on intermetallics; modifiers for wheel steels; complex ferroalloys containing V, Cr, and Ni; anticorrosive protective coatings based on ultrafine Zn powders; catalytic converters for vehicle exhaust gases; magnetically hard materials with high temperature–time stability and excellent mechanical characteristics; nanostructured stents for endovascular operations; and corrosionand wear-resistant coatings and corresponding methods of plasma application. Methods have been developed for longitudinal rolling with shear deformation to improve the properties of the rolled product; recycling of oily scale; monitoring of the wear of the refractory lining at any point of the blast-furnace hearth; and monitoring of the content of inclusions in rail steel. Technologies have been developed for special electroproduction of steel for the power industry; synthesis of massive monocrystalline samples of transition-metal nitrides and nanopowders of W, Pt, and Ti and their carbides and nitrides; the processing of leucoxene concentrates from the Yareg Basin; the production of titanium implants with porous coatings; ferrous and nonferrous metal shot and powder; ultrafine Zn powder; recycling of metallurgical wastes with the extraction of Zn, Sb, Sn, and Fe; the production of sintered nanocrystalline Ta powder for capacitors; the processing of molybdenum-bearing sulfide material to obtain rare-earth metals, MoO3, and CaMoO4; and the utilization of sulfur dioxide. Injection units and technologies for their use have been developed, as well as high-speed systems for the plasma application of metals on surfaces including paint coatings, plastics, and cardboard. Data have been obtained regarding the thermodynamic functions of the solution of oxygen in Fe-based melts and the reactions of elements dissolved in such melts (Cr, Mn, Nb, V, Si, B, C, Ti, Zr, Al) with oxygen.

On the Applicability of the Concept of Process Signatures to Hard Turning

Process Signatures correlate the thermo-mechanical load within the workmaterial during the manufacturing process with resulting modifications of the material properties. In the case of hard turning, new mechanical and metallurgical material properties in the workpiece surface may severely influence the structural stability and fatigue resistance.This work investigated whether the concept of Process Signatures is applicable to hard turning of steel AISI 52100. Experimentally obtained surface properties are correlated with numerically simulated material loads, which the surface was subjected to during turning. The process was analyzed under consideration of different tool wear states in order to assess the material modifications for different thermo-mechanical loads.

On Expediency of the Preliminary Heat Treatment for Liquid-Phase Reduction of Waste Steelmaking Slag

The problem of using waste steelmaking slags as a technogenic source of metallurgical raw materials still has no sustainable solution and requires innovative ideas and approaches. The purpose of this paper is a theoretical and experimental study of the possibility and expediency of the preliminary heat treatment of steelmaking slags in a reducing medium for greater metal recovery. The subject of research is a slag sample taken from the slag heaps at Zlatoust Metallurgic Plant (the Russian Federation). To perform thermodynamic simulation of the processes running during heat treatment of a slag substance, the FactSage software package (version 6.4) was applied. For the ease of analysis the key calculation results are presented as a logarithmic dependence of component weights and composition of the considered phases on temperature. The experimental studies include heat treatment tests on slag samples at temperatures of 1100 and 1200°C in air and in the carbon monoxide medium with further separation of the derived product. The composition of test samples is determined by electron microprobe analysis and X-ray diffraction analysis. It has been reported that heat treatment in carbon monoxide medium makes possible to significantly increase the iron content in the derived magnetic fraction. The results of thermodynamic simulation, composition analysis of samples and weight data for the obtained magnetic fractions (resistant or non-resistant to the magnetic field) suggest that the preliminary heat treatment of slag in carbon monoxide medium is expedient.

Investigation of thermal plasma generator of technological function

Experimental results on energy characteristics of electric-arc plasma generator for heating technical nitrogen with the power of up to 500 kW are presented. The features of arc discharge glow, thermal efficiency, and service life of the electrodes were determined under the regime of melting the metallurgical raw material in the test plasma electric furnace.

THE POSSIBILITIES OF THE STRUCTURE AND VARIABILITY EVALUATION OF INVENTORY CONSUMPTION

Inventory can be evaluated from the point of view of a number of aspects. Production and trade organizations nowadays are under great pressure from their competitors and face high expectations from their customers. That is why the cost cutting in all areas can provide a significant competitive advantage. Inventory and its management and administration can therefore represent a source of substantial potential savings. Large inventory volume can significantly increase the costs, but its shortage influences the course of the manufacturing process and, ultimately, the customer satisfaction. It is therefore necessary to continuously optimize the inventory management system in the enterprise. The conducted research also involved an analysis of the structure and variability of the inventory consumption in a business organization dealing with the sale and storage of metallurgical materials. The objective of this article is to evaluate the possibility of the application of the tools used to analyze the structure and variability of inventories in the industrial and commercial practice.

Polymeric and Bentonite Binders for Agglomerating Metallurgical Raw Materials and Foundry Mixtures

Polymeric and Bentonite Binders for Agglomerating Metallurgical Raw Materials and Foundry Mixtures

Ab initio study of compositional trends in solid solution strengthening in metals with low Peierls stresses

We identify and analyze general trends governing solid solution strengthening in binary alloys containing solutes across the Periodic table using quantum-mechanical calculations. Here we present calculations for the model system of Al binary solid solutions. The identified trends originate from an approximately parabolic dependence of two strengthening parameters to quantitatively predict the solid solution strengthening effect, i.e. the volume and slip misfit parameters. The volume misfit parameter shows a minimum (concave-up behavior) as a function of the solute element group number in the periodic table, whereas the slip misfit parameter shows a maximum (concave-down behavior). By analyzing reported data, a similar trend is also found in Ni and Mg (basal slip) binary systems. Hence, these two strengthening parameters are strongly anti-correlated, which can be understood in terms of the Fermi level shift in the framework of free electron model. The chemical trends identified in this study enable a rapid and efficient identification of the solutes that provide optimum solid–solution strengthening. The approach described here may thus serve as basis for ab initio guided metallurgical materials design.

Modeling of Microstructure Evolution with Dynamic Recrystallization in Finite Element Simulations of Martensitic Steel

A metallurgical material description of the flow behavior for finite element (FE) simulations was developed. During hot compression tests, the dynamic microstructure evolution is modeled on the example of high‐strength martensitic steel MS‐W 1200. Compression tests at 900–1000 °C with a strain rate of 0.1 s−1 on fine‐grain and coarse‐grain samples were performed. An analysis of the flow behavior identified a strong correlation between the dynamic recrystallization kinetics and the initial microstructure. The regression analysis has been used to determine correction factors of the new model to describe the dynamic recrystallization. A good agreement between FE simulation and measurement shows the validity of the new model.

PHYSICAL-MECHANICAL PROPERTIES OF NEW GREEN BUILDING MATERIALS BASED ON GLASS WASTE

Recently several innovative suggestions on how industrial wastes can be utilised in new products have been presented in literature, e.g. as filler or additives in concrete, incorporated in ceramic materials to produce glass-ceramics and pavement construction. In this work, metallurgical materials from secondary aluminium scrap processing and glass waste derived from treatments of packaging and fluorescent lamps were considered for fabrication of new ceramic materials using powder technology and sintering process. The effect of composition and heat treatment temperature, on the sintering process and then final properties, were evaluated. The results showed that, with the proper firing temperature, lightweight ceramic materials containing high amount of glass waste and an innovative product resulting from the processing of secondary aluminum (ArgAlum.) can be produced. The low water absorption (. 1%), low density (. 2 g/cm3) and the good flexural strength (16-20 MPa) associated to relatively low sintering temperatures obtained with the addition of ArgAlum. can be considered as promising initial results to obtain new green building materials.

Compound materials by PM-HIP

There are many applications where compound materials can be of interest, for example when different properties are needed in different parts of a component. Compound materials can be produced by hot isostatic pressing (HIP) of powder metallurgical materials. One aspect that should be considered in the design is the quality of the interface between the two different material compositions. Diffusion during HIP can cause formation of brittle phases in the interface or deteriorate properties by diffusion of alloying elements. The present work shows results from a study where different steel types were joined (quench and temper steel/air hardening steel/bearing steel with a tool steel/corrosion resistant martensitic steel). The evaluation was performed by computational predictions and by small scale HIP experiments that were evaluated by microstructure analysis and chemical analysis.

System for scenario planning and forecasting world prices for steel and metallurgical raw materials

The article describes the methodology for construction and the main results obtained by implementing a scenario and modeling system intended for generating scenarios and forecasting the long-term performance of the world prices for steel and metallurgical raw materials.

Prospects for Using Combined Metallurgical Production Technogenic Raw Material in the Refractory Industry

Features are provided for the chemical and mineral composition of standard electrocorundum sludge and transformation of its components during oxidation firing, and also analysis of chamotte based on combined technogenic raw material and kaolin. Properties are indicated for the mullite and glass phase formed, and mullite refractoriness based on different components. An indispensable condition for obtaining high quality chamotte and mullite in poured layers is oxidation of the lower titanium compounds contained in sludge. The temperature for liquid phase appearance is 830 – 1130°C. Mineralizer admixtures reduce aluminosilicate melt viscosity.

Numerical Simulation of Machining Nickel-Based Alloys

The phenomenological models for material flow stress and fracture, typically used in the Finite Element simulations of machining Nickel-based alloys, are often deemed to represent only certain metallurgical material states. In contrast, these models are not suitable to describe the constitutive behavior of the workpiece for different metallurgical states (i.e., annealed, aged, etc.) and, consequently, different hardness values.Since the description of the material behavior requires correct formulation of the constitutive law, new flow stress models which include also the hardness effect should be developed and used, for computer simulation of machining Nickel-based alloys.This paper describes the development of a hardness-based flow stress and fracture models for machining Inconel 718 alloy which can be applied for a wide range of work material hardness. These models have been implemented in a non-isothermal viscoplastic numerical model to simulate the influence of work material hardness on the chip formation process. The predicted results are being validated with experimental results properly carried out for this research. They are found to satisfactory predict the cutting forces, the temperature and the chip morphology from continuous to segmented chip as the hardness values change.