bluuebunny/crossref_metadata_2025 huggingface dataset:
Using fuzzy logic to select coloured-fibre cotton genotypes based on adaptability and yield stability
Authors: Cardoso Daniel Bonifácio Oliveira , Oliveira Lírian França , Souza Gabriela Santana de , Garcia Myllena Fernandes , Medeiros Luiza Amaral , Faria Priscila Neves , Cruz Cosme Damião , Sousa Larissa Barbosa de
Published: April 2021

Cotton (Gossypium hirsutum L.) is the world’s leading natural textile fibre and is grown in over 60 countries, including Brazil, where it is an important agricultural commodity. The cultivation area currently covers approximately one million hectares in Brazil and has expanded into every region of the country, especially the Cerrado biome. Because of this expansion, it is necessary to analyse the influence of the environment on the genotype behaviour to optimize yields. Thus, the objective of this study was to compare fuzzy logic to traditional methods for selecting coloured-fibre cotton genotypes with high adaptability and yield stability. The experiment was conducted on the 2013/2014, 2014/2015, 2015/2016, and 2016/2017 crops of the Capim Branco farm at the Federal University of Uberlândia, Uberlândia, Minas Gerais, Brazil. The following methods were used to select genotypes for adaptability and stability: the Lin and Binns model, additive main effects and multiplicative interaction (AMMI) analysis and the Sugeno fuzzy logic controller. An interaction of the genotype with the environment that affected yield was detected. Environment 4 (the 2016/2017 crop) showed to the lowest genotype to environment interaction. The fuzzy logic approach showed agreement with AMMI and the nonparametric Lin and Binns method. The linguistic fuzzy logic used in the Sugeno fuzzy logic controller demonstrated the potential for selecting cotton genotypes in plant breeding programmes. The UFUJP-16 and UFUPJ-17 genotypes were adaptable, stable and showed promising yields within the tested environments. The fuzzy logic method was effective for estimating adaptability and stability.
Protocol for detecting Curtobacterium flaccumfaciens pv. flaccumfaciens in the leaves of infected bean plants (Phaseolus vulgaris L.)
Authors: Puia Jacqueline Dalbelo , Murari Rafaela Rodrigues , Borsato Leandro Camargo , Sugahara Vanessa Hitomi , Machineski Gabriela da Silva , Canteri Marcelo Giovanetti , Vigo Sandra Cristina
Published: April 2021

Curtobacterium flaccumfaciens pv. flaccumfaciens (Cff), which is a gram-positive bacterium that causes wilting in several cultivated plants, is one of the main disease-causing bacteria in beans (Phaseolus vulgaris L.). Different techniques are employed to detect pathogens in bean plants; however, only a few slow and inefficient methodologies can be used to detect Cff. Hence, there is a need for rapid and efficient techniques to detect Cff for disease management. The objective of our study was to develop a technique to effectively detect Cff in the leaves of infected bean plants by optimizing a previously developed method. We modified the extraction method by reducing the amount of water used, replacing seeds with leaf tissues (obtained from the veins and petioles) and using CffFOR2 and CffREV4 primers specific for Cff. Our optimized method exploits a concentration gradient generated in the plant tissue through osmosis to disrupt the plant cell wall and efficiently isolate bacterial cells. DNA extracted from the isolated bacterial cells was amplified by polymerase chain reaction. This method allowed efficient detection of Cff in leaf tissues.
Strategies for vegetative propagation and viral cleaning of a miniature ornamental pineapple hybrid
Authors: Silva Bruna de Fátima Batista da , Souza Everton Hilo de , Oliveira Rafaelle Souza de , Ledo Carlos Alberto da Silva , Souza Fernanda Vidigal Duarte
Published: April 2021

This study assessed and compared different methods for vegetative propagation of a miniature ornamental pineapple hybrid (ORN-MUT), seeking to determine the best method for production of plantlets, as well as for removal of the PMWaV viral complex from plants cultured in vitro, for production of healthy parent plants. Pineapple wilt is a disease that can cause large economic and is caused by a viral complex called Pineapple mealybug wilt-associated virus (PMWaV). For this, four propagation methods were evaluated (conventional, stem sectioning, micropropagation and etiolation of nodal segments). The time necessary for each method and the number of plants formed were assessed. Stem tips (0.5 mm) were cultured and indexed for three PMWaV types. Conventional propagation produced 17 plantlets per plant in 566 days, stem sectioning produced 2.3 plantlets per stem in 591 days, while the conventional micropropagation technique produced 1,284 plants after four subcultures in 778 days. Stems etiolated for 60 days showed peak production in the second subculture, with 1,224 plants. This method required 883 days to obtain plants with ideal size for transplantation to the field. In turn, stems etiolated for 120 days produced 935 plants at the end of four subcultures, with peak output in the third subculture, in which the plants could be cultivated in the field after 943 days. Conventional micropropagation and etiolation for 60 days were the best methods for production of plantlets of the ORN-MUT hybrid. The results of this work showed that the cultivation of shoot tips is an efficient strategy to remove the PMWaV complex and obtain healthy mother plants and can be a useful tool for other varieties of pineapple.
The Possibility of Using the Ultra-Thin Liquid Thermal Insulation to Insulate the Ceiling above the Basement in Residential Buildings
Authors: Burlachenko Oleg V. , Chesnokova Oksana G. , Cherednichenko Tatiana F.
Published: April 2021

The issues of energy saving, as well as comfortable operation of buildings in modern construction practice are relevant. The experience of operation of the premises, located above the basement, shows that the most common problem is the cooling of the floor slab and, as a consequence, the presence of a cold floor. The article presents the results of calculations on the change of thermal properties of the ceiling above the basement in residential buildings. A variant of insulation of the ceiling with ultra-thin liquid insulation is proposed. The graphical analysis of the problem is carried. As a result of graphical analysis, it was revealed that the proposed method of insulation makes it possible to increase the floor temperature in the rooms of the ground floor in the residential buildings.
Geo-Composite Drainage Material for Hydro-Technical and Civil Engineering
Authors: Kosichenko Yuri M. , Baev Oleg A. , Vasilyev Sergey Mikhailovich
Published: April 2021

The article deals with the «GP» geo-composite drainage material, which is used in hydro-technical, civil, as well as environmental, industrial and landscape construction. This material is intended for complex application, as a separating, filtering and reinforcing layer in the structures of protective dams on rivers, reservoirs, channels, an earth work of linear transport constructions (automobile and railway facilities) and other hydraulic engineering constructions. It is a combined geo-synthetic material, including a rigid geo-grid of the lattice structure and a filtering geotextile element. As a result of the carried out researches, its basic physical and mechanical characteristics have been established: tensile strength, surface density of geotextile and the material, relative elongation at maximum load, filtration coefficient normal to the material level.
Synthesis of YFeO3-δ and LaFeO3-δ Perovskites with High Catalytic Activity in Carbon Oxidation Reactions
Authors: Kirichenko Evgeny Alexandrovich , Chigrin Pavel G. , Gnidenko Anton A.
Published: April 2021

YFeO3-δ (δ = 0.26) and LaFeO3-δ (δ = 0.5) perovskites with a high specific surface and oxygen non-stoichiometry was firstly synthesized by pyrolysis of polymer-salt compositions. It was shown that the catalytic oxidation of carbon in the presence of these complex oxide systems proceeds in the range of 400 - 700 °С, with a maximum temperature at 556 °С for YFeO3-δ; and 380 - 620 °С ,with a maximum temperature at 501 °С for LaFeO3-δ, in one-stage mode for both. By means of thermal analysis and diffractometry, it was shown that there is no contribution to the soot oxidation mechanism by cyclic perovskite surface transformations, due to the reduction of metal oxides by the soot and their subsequent reoxidation. It has been established that the basis of the catalytic reaction mechanism for both perovskites is the presence of oxygen vacancies on the surface of complex oxides.
Studying the Performance of Composites Based on Thermally Modified and UV-Treated Wood
Authors: Khasanshin Ruslan R. , Safin Ruslan R. , Mukhametzyanov Shamil R.
Published: April 2021

To enhance the quality of wood and extend its industrial applications, various methods of wood modification are being developed. It is well known that the thermal treatment of wood may considerably enhance its moisture resistance, reduce its hygroscopicity, and increase its rot proofing. However, reducing the absorptive capacity of wood adversely affects the process of obtaining wood-based composites. Pressure and pressing time increase, which finally increases the cost of the end product. Thus, this study represents the research in how ultraviolet exposure affects the physical properties of wood that has been pre-treated thermally, followed by obtaining a composite. An experimental wood-modifying facility has been developed. We have considered the process of the moisture absorption of the material that has been exposed to thermal modification and UV-radiation. From the experiments conducted, we have found that the UV exposure of wood samples causes an increase in the surface wettability of the thermally modified material. It is found that the most active process of surficial inactivation runs within 60-90 minutes of the UV-exposure of wood. Post-treatment does not result in any considerable changes in the surface wettability. This treatment promotes the increasing adhesion of water-borne binders to the material surface in developing high-strength composites based on modified wood.
Synthesis of Highly Dispersed Spherical Metal Granules by Laser Ablation Method
Authors: Chkalov Ruslan V. , Kochuev Dmitry A. , Chkalova Darya G.
Published: April 2021

The work is devoted to the problem of synthesis of highly dispersed spherical powder granules by laser ablation. The formation of microspheres is carried out by the action of femtosecond laser radiation on the surface of a titanium target in a two-component reaction medium. The process of titanium treatment in n-hexane by ultrashort laser pulses is investigated. It is shown that the use of n-hexane as a working medium component allows the synthesis of micro-and nanopowders containing titanium carbide, which are resistant to atmospheric environment during prolonged exposure. The presented method provides the possibility of synthesis of high-purity powder materials with typical sizes from 1 to 3 microns.
Processing of Alumina Reinforced Copper Metal Matrix Composite by Selective Laser Melting Technology
Authors: Baitimerov R.M. , Bykov V.A.
Published: April 2021

For the development of the additive technologies it is necessary to expand the range of the used materials. One of the most promising directions is the creation of products from composite materials. In this work copper-alumina composite powder was prepared by ball milling, and used in selective laser melting, to produce a composite material. The raw powder materials consisted of the gas atomized Cu powder (with the regular spherical shape and mean particle diameter of 32 μm) and alumina powder, produced by condensation of vapor on electrostatic filter (average particle size is about 220 nm). The alumina weight ratio was 5%. Four 30x10x6 mm copper-alumina specimens were manufactured. The scanning electron microscopy was used for the analysis of composite microstructure. Obtained copper-alumina composite material has higher hardness, in comparison with cast copper (HRB is 60 and 45, respectively).
Diagnostic of Structural Changes in Ferromagnetic Powders during Milling in Beater Mill
Authors: Egorov Ivan N. , Egorova Svetlana I. , Lemeshko G.F.
Published: April 2021

Problem of obtaining fine powders of strontium hexa-ferrite is actual because of its wide applications. The paper provides the results of studies of particle size distribution and structural characteristic changes of strontium hexa-ferrite powder (SrFe12O19) during milling in impact mill and after its consequent annealing. Mechanical processing of coarse particulate system was carried out in the mill for 120 minutes without electromagnetic effect and with creation of magneto fluidized bed, formed by perpendicular constant and alternating magnetic field with induction gradient of 210 mT/m, providing reciprocating motion of particles and aggregates with sizes of 3 – 4 mm. It was shown that milling of coarse strontium hexa-ferrite with average particle size 1558.5 μm and the most possible size 1500 μm in magneto fluidized bed allowed to intensify milling process and to provide a significant increase of powder particle sizes uniformity. It was found out, that milling in magneto fluidized bed leads to a great decrease of coherent scattering regions sizes and an increase of lattice micro-deformations and relative dislocation density. Consequent annealing of the powder for 2 hours at 850°C refined structural characteristics significantly. The carried out research allows to choose the optimal milling duration for solution of practical problems of powder metallurgy.
Studying the Effect of Tempering Temperature during Heat Treatment on the Corrosion Resistance of 13Mn6 Steel Samples
Authors: Nasibullina O.A.
Published: April 2021

In the conditions of development of rates of the modern production the role of a heat treatment as a main way of receiving steels with the given structure and mechanical characteristics increases. The details applied on production have to have a long endurance not only at an ambient temperature, but also have high strength characteristics at low and high temperatures. In this regard, special attention is paid to the steel applied to manufacturing of such details. 13Mn6 steel concerns one of them. The definition of an influence of a heat treatment of steel - training at various temperatures, steel 13Mn6 on its rust resistance was the purpose of this work. For achievement of a goal such problems as a research of an influence of the various temperature of annealing of steel 13Mn6 on a value of hardness on Rockwell's method were solved; gravimetric researches after a heat treatment for identification of a temperature schedule of the annealing having the maximum indicators of corrosion were held. It is shown that, after spending vacation hardness of exemplars decreases with an increase in temperature. For assessment of corrosion aggression of the environment on the studied exemplars mass and deep indicators of corrosion were paid off. The maximum corrosion rate is observed when training, and the subsequent annealing at a temperature of 300°C, minimum at a temperature of annealing of 500°C.
Development of Accelerated Weather Testing Procedure for Materials of Polypropylene Tanks
Authors: Suleymanov Alfred M. , Tuisina Ekaterina B. , Shafigullin Lenar N.
Published: April 2021

Ageing and failure of materials, products, and structures when exposed to operational factors, including climatic ones, cause significant losses for the economies of different countries. Ageing of a material under operation conditions in different climate regions or storage conditions is a result of a wide range of chemical and physical conversions that occur in complex multiple component systems. This paper addresses to the development of accelerated weather testing procedure for polypropylene expansion tanks, which are a part of an engine cooling system in KAMAZ vehicle. The operating conditions of expansion tanks were analyzed, and the primary factors and their energy values, responsible for their ageing and failure, were determined. The chart of operating conditions was made for expansion tanks. The accelerated weather testing procedure was developed for materials of expansion tanks for the climate regions of India and Venezuela. The requirements were specified for equipment and samples for accelerated weather testing of polypropylene expansion tank materials.
The Technology of Distortion-Free Quenching in a Magnetic Field of Thin-Walled Details of the Ring Form
Authors: Pustovoit Viktor N. , Dolgachev Yuri V. , Dombrovskii Yu.M.
Published: April 2021

During heat treatment of machine parts and tools, besides the usual task of ensuring a high complex of mechanical and operational properties, there is a problem of distortion of products in the process of heat treatment and the need for editing operations (which are carried out manually and require significant labor costs). The known methods do not solve the problem of removing distortion for thin-walled parts of the ring shape completely. This paper shows the technical possibility of using the energy of a constant magnetic field for the "internal" straightening of products during heat treatment in the temperature range of super-plasticity of transformation. The use of special equipment makes it possible to eliminate virtually the distortion of thin-walled parts of the ring shape and to improve their mechanical properties.
Microstructure of the Heat Treated Advanced Low Carbon Steel
Authors: Maisuradze Mikhail V. , Ryzhkov Maxim A. , Lebedev Dmitriy I.
Published: April 2021

The microstructure of the advanced low carbon steel with a superior hardenability was studied. The steel contained the following main alloying elements, wt. %: C – 0.20; Cr – 2.0; Mn – 2.0; Si – 1.04 Ni – 1.0; Mo – 0.3. The dilatometer investigation of the steel under consideration revealed the only phase transformation occurring during continuous cooling (0.1...30 °C/s), which started at the martensite start temperature Ms. It was shown that the isothermal treatment of the studied steel led to the bainite formation above and below Ms. The temperature of the bainite morphology shift was determined.
Testing the Cross-Sectional Microhardness in Sheets with A 0.08% Carbon Concentration
Authors: Tipalin Sergey A. , Belousov Vladislav B. , Lyubetskaya Svetlana I.
Published: April 2021

The research team studied the hardness of cold-rolled sheets of varying thicknesses containing 0.08% carbon. Greater thickness correlated with lower mean hardness. The hardness was found to drop in the middle of a plate and to increase gradually towards the edges. This pattern was observed regardless of the thickness of thin cold-rolled sheet steel. The change in hardness may indicate uneven accumulated strain in the sheets rolled to a desired value. Pre-hardened sheets were analyzed to find whether the hardness was homogeneous through the thickness. The material was hardened by axial tensioning. Analysis showed that at greater accumulated strain, the through-thickness hardness was affected as well. However, the difference was less pronounced at the edge as well as in the middle of sheets. The paper shows graphs of the hardness distribution through thickness.
High Performance Process Development for Iron Ore Concentration
Authors: Yur'ev Boris P. , Gol'tsev Vladimir A. , Dudko Vyacheslav A.
Published: April 2021

References on microwave energy use were reviewed and it demonstrated wide use of this kind of energy in various sectors of national economy. However in ferrous metallurgy this type of energy practically is not used despite the fact that it holds much promise and offers a number of advantages over other kinds of energy. In this work an attempt was made to use microwave energy in ferrous metallurgy and it was implemented in terms of concentration process development for limonite ores of the Lisakskoye deposit with hydro-goethite being a base iron-bearing mineral. Qualitative and quantitative characteristics of the subsequent magnetic separation process were determined. The developed concentration process of the Lisakovskoye deposit ores with the microwave energy used for baking and magnetizing of intermediate concentration products was compared with the current deep concentration process of the Lisakovskiy Mining and Processing Works and its advantages were demonstrated. Technical and economic calculation showed that the concentration process with microwave energy used is more efficient than deep concentration process without the product baking; it allows a significant increase of iron recovery into the concentrate and provides additional profit to the Company.
Study of Causes of Plastic Pipe Failures
Authors: Shafigullin Lenar N. , Romanova Natalya V. , Suleymanov Alfred M.
Published: April 2021

It has been observed that critical failures and loss of function occur in a shorter period than specified service life during operation of polypropylene pipes in hot water systems. The paper analyzes the failure causes of polypropylene pipes in closed loop hot water systems, and provides recommendations for increasing their service life. It has been established that the primary factors responsible for ageing and failure of polypropylene pipes during operation are medium temperature, stress due to internal pressure, water composition. It has been observed that a combined influence of the above mentioned factors provides a synergistic effect. We developed the recommendations for increasing a pipe service life, including close monitoring and recording of energy carrier temperature and pressure; changes in specifications for propylene pipes, including the recommendation for using random propylene pipe grades with high thermal oxidation stability in hot water systems.
Determination of Key Parameters Required to Optimize Calcination Process in Ferrous Metallurgy Heating Plants
Authors: Yur'ev Boris P. , Dudko Vyacheslav A.
Published: April 2021

Lime is the product of calcination. Its formation is always related to removal of carbon dioxide generated in the course of carbonate decomposition. Ferrous metallurgy, construction material, chemical and food industry companies account for about 90 % of lime produced in the country. Ferrous metallurgy is the major consumer of commercial lime using up to 40 % of all produced lime. Currently, despite occurrence of new binding and artificially produced chemical compounds, lime remains the major chemical compound produced by the industry in terms of output. Various units (shaft, rotary tubular kilns and fluidized bed kilns) are used for calcination. Shaft kilns are used the most widely. Considering continuously growing demand for lime, the need occurs for intensification of the burning process and optimization of the shaft kiln operating conditions. This requires knowledge of calcination physicochemical and heat transfer process mechanisms. Thus, the work deals with the issues related to determination of the optimal specific fuel consumption for burning of limestone from a particular deposit. It may be done only basing on thermal calculations for an operating shaft kiln, what, in its turn, causes the need for determination of the whole set of limestone and lime heat transfer properties. The obtained work results may be used to optimize the operating conditions of not only shaft but also rotary kilns intended for limestone heat treatment.
Forecasting the Microstructure of a Microalloyed Steel Plate Strip
Authors: Platov Sergey I. , Maslennikov Konstantin B. , Urtsev Nicolay
Published: April 2021

A description of the experience in the development and implementation of a model for forecasting the microstructure of rolled tubular products steel during thermomechanical processing of a semi-finished product and the relative IT-solution for the plate mill 5000 of PJSC MMK is presented. This solution is based on modeling the kinetics of structure formation in the mill technological line. The article describes briefly the result of analysis of a number of existing kinetics models of phase and structural transformations from the point of view of their application under the conditions of interest to us. An empirical study of the thermal effects of phase transformations and the influence of the heat removal mode on the kinetics of structure formation is described. The process of development of an empirical kinetics model and implementation of IT-solution, that implements this model, is also described.
Influence of Nano-Modification on Structural, Mechanical and Physico-Chemical Characteristics of Bentonite
Authors: Buntin Artem E.
Published: April 2021

The paper studies the influence of nanodispersed aluminum and silicon oxides on the structural, physico-chemical and mechanical characteristics of calcium-magnesium bentonite deposits of the Republic of Tatarstan, in order to determine the optimal concentrations of the nanomodifier, and to improve the performance of respective materials. It was found that nanomodification of bentonite increases the strength of samples after firing by more than 1,5 times, the adsorption index by 20–25 %. The optimal concentration of nanoparticles was determined by changing the properties. The methods of Brunauer-Emmett-Teller (BET), x-ray phase analysis and infrared spectroscopy show an increase in the specific surface area, a change in the phase composition of the annealed samples, the intensity and position of the characteristic absorption bands, as well as the chemical bond silicon-oxygen in bentonite, modified by nanoparticles of aluminum and silicon oxides of similar nature.
The Density of Deformations Distribution on the Side Edges during Strip Rolling
Authors: Rekov A.M.
Published: April 2021

Experimental densities of intensity distribution for main deformations, as well as the stress strain state of a metal on the side edges of an aluminum strip during its flat rolling, have been determined. Strain, spread and extrusion ratio have been evaluated. The dimensions of the strip cross-section have been chosen in a way that minimizes spreading. Therefore, the deformed state under rolling is close to a flat one. The correlation between the deformation intensity and the stress-strain state of macro-volumes occurred on strip edges has been estimated. The parameters of two-dimensional probability-density function for the joint distribution of deformation intensity and the Nadai-Lode stress-strain parameter have been determined. Distribution densities for longitudinal, transverse deformations and the intensity of main deformations in the zone of strip rolling are bimodal, which corresponds to both forward and backward slip zones under rolling. The results of the work can be used to predict the depletion of plasticity resources during strip rolling.
On the Use of Photometric Separation for the Processing of Techno-Genic Raw Materials
Authors: Burdonov Alexander E.
Published: April 2021

This work presents studies on the material composition and physico-mechanical characteristics of an alumina-containing estimate formed during the production of aluminum on electrolyzers with self-baking anodes during technological operations. The material is a mixture of fine powder 2.5 mm in size (62.78% on average mass) with the presence of pieces of material ranging in size from 0.5 to 6 cm (average 20.26% by weight). The samples contain pieces of hardened aluminum with sizes from 5 to 20 mm (16.96%). The largest content in the sample has the fineness classes-0.315 + 0.16 mm in the volume of 29.85% and the largest class +2.5 mm-37.22%. B It was established that aluminum is concentrated in the fractions-0.315 + 0.16 mm (45.7%) and 0.16 + 0 mm (48.8%), silicon in the fraction-0.63 + 0.315 mm (1.91%), iron at-1.25 + 0.63 mm (0.601%) and-0.63 + 0.315 mm (0.62%). The material consists of cryolite (Na3AlF6), chiolite (Al3F14Na5), quartz, feldspar, carbonaceous matter and the technogenic phase of the composition (NaF) 1.5CaF2 AlF3. The material is characterized as non-abrasive (working index Ai - 0.0184) and very soft in relation to impact crushing (working index CWi - 3.64), the working index of ball grinding Bond (BWi - 6.47) characterizes a very low resistance to ball grinding. The implementation of the crushing operation of an alumina-containing estimate will allow the use of dry cascade-gravity and centrifugal classification to separate impurities in the form of SiO2, and Fe2O3 for the use of alumina-containing material in primary aluminum technology. On the basis of laboratory tests, it is established that alumina-containing raw materials can be separated and photometric and gravitational separation methods can be used. A mathematical model of the motion of particles of primary and prepared alumina-containing raw materials in a cascade-gravity classifier was developed. The criteria and factors characterizing the alumina-containing material, as well as influencing and determining the maximum material enrichment, are established.
Friction Stir Welding of the Carbon-Doped Dual-Phase High Entropy Alloy
Authors: Shaysultanov Dmitry , Raimov Kazimzhon , Stepanov Nikita
Published: April 2021

Fe49Mn30Cr10Co10C1 high entropy alloy (HEA) is produced by induction melting. The as-cast alloy is cold rolled and annealed at 900°C, to produce fine recrystallized structure before friction stir welding (FSW). The structure of the annealed alloy consists of a recrystallized face-centered cubic (fcc, γ) and hexagonal close-packed (hcp, ε) phases with volume fractions of 91% and 5%, respectively, as well as M23C6 carbides with the volume fraction of 4%. Sound weld without visible defects, such as porosity or cracks, are obtained. Friction stir welding results in a decrease in the average grain size from 7.0 to 1.9 μm in the stir zone. The volume fraction of the M23C6 carbides decreases to 1% after FSW. The alloy shows high yield strength and ultimate tensile strength of 475 MPa and 865 MPa, respectively, together with elongation of 70%.
Experience of Using Complex Modifiers to Increase Corrosion Resistance of Pipe Steels
Authors: Shapovalov Aleksey N. , Dema Roman R. , Nefed'ev Sergey P.
Published: April 2021

The article presents the test results of complex microcrystalline modifiers containing calcium, barium, strontium, rare earth metals. Complex modifiers were used in the processing of steel for 17G1S-U pipes in order to reduce its contamination with non-metallic inclusions, including corrosive ones. The use of modifiers allowed to reduce metal contamination by non-metallic inclusions of all kinds. The most experimental non-metallic inclusions were obtained during metal processing with INSTEEL®5.1 and INSTEEL®9.4 modifiers. In addition, the use of experienced modifiers ensured the production of complex oxysulfides of calcium, cerium and lanthanum with low oxygen content and thermal expansion coefficients, which increases the corrosion resistance of steel.
Investigation of Temperature-Time Modes of Rolling of Thick-Sheet Steel and Mechanical Properties of Finished Products
Authors: Platov Sergey I. , Nekit V.A. , Urtsev Nicolay
Published: April 2021

The article is devoted to the study of technological modes of hot rolling of tube steel on a thick-sheet mill and mechanical properties of the finished products. Five slabs were rolled under the experimental regime in accordance with the study plan. The temperature conditions of rolling at the final stage of deformation and the modes of accelerated cooling of rolled products were changed. Dependencies between technological parameters and mechanical properties allowed developing recommendations on improvement of technology of rolling and of the subsequent accelerated cooling of metal.
Pyro-Metallurgical Processing of Ilmenite Concentrate with Production of Iron and Titanium Oxides
Authors: Smirnov K.I. , Gamov P.A.
Published: April 2021

The main problem of processing of ores with a high content of titanium oxides is refractory slag based on TiO2, which makes it difficult to melt. The methods of processing of titanomagnetite and ilmenite ores were analyzed. It is shown that the existing scheme of processing does not meet the requirements of complex use of materials. The paper presents the results of laboratory studies on reduction of ilmenite concentrate and subsequent pyrometallurgical separation of reduction products without addition of flux or slag-forming materials. Solid-phase reduction of iron enabled to extract iron selectively from the ilmenite crystal lattice, not diluting the oxide phase with the reducing agent ash. Using the advantages of solid-phase reduction, the possibility of obtaining pure iron and slag with a high content of titanium oxides was shown.
Seamless Pipes Manufacturing Process Improvement Using Mandreling
Authors: Goncharuk Aleksander V. , Fadeev Viktor A. , Kadach Maksim V.
Published: April 2021

The paper discusses the specific aspects of hot rolled seamless pipes manufacture using pipe rolling plants including screw-rolling mills. The method of accuracy enhancement of pipe dimensions, as well as external and internal surface quality improvement, is proposed. The article specifies the results of computer and physical modeling of the pipes mandreling process. The application of the mandreling process within the cage using different diameter mandrels is shown. We managed to decrease the typical mark caused by the metal deformation, due to the screw-rolling mill and to manufacture pipes with more accurate dimensions, as a result of the mandreling process modeling. The results of the physical experiment on mandreling the shell pierced at the screw-rolling mill showed a positive effect from the process of hollow billet cold treatment using the mandrel.
The Effect of Boron, Manganese and Sulfur on the Microstructure and Mechanical Properties of Pipe Steel 17G1SU
Authors: Babenko Anatolij A. , Smirnov Leonid A. , Upolovnikova Alena G.
Published: April 2021

The paper presents the results of the effect of boron, manganese and sulfur on the microstructure and mechanical properties of pipe steel 17G1SU. It was shown that the microstructure of boron-free steel sample containing 1.4% Mn and 0.01% S consists mainly of ferrite and a small amount of perlite. Samples microalloyed by boron are represented by a dispersed ferritic-bainitic structure. A decrease in ferrite grain size from 8.7 μm, in a comparative sample without boron containing 1.4% Mn and 0.010% S to 5.8 μm in a sample of steel containing 0.006% B, 1.6% Mn and 0.011% S, shows increasing the dispersity of the ferritic-bainitic structure. A decrease in the manganese content to 1.4, sulfur to 0.004% and an increase in boron concentration to 0.0011%, despite an increase in grain size to 6.8 μm, retain a fine-grained structure. The effect of boron, manganese, and sulfur content on the microhardness of the structural phases of the studied pipe steel samples is noted. The smallest microhardness of ferrite and perlite is observed in the base sample without boron, reaching 180 and 214 HV10, respectively. The microalloying of pipe steel containing 1.6% Mn, 0.011% S with boron is accompanied by an increase in the microhardness of the bainitic phase to 314 HV10, which increases to 400 HV10 with an increase in boron concentration to 0.011%, and a decrease in the content of manganese and sulfur to 1.4 and 0.003%. In this case, the microhardness of the ferrite phase, reaching an increase to 260 HV10, is practically independent of the content of boron, manganese, and sulfur. The mechanical properties of the experimental metal rolling with a thickness of 10 mm provide the production of rolled steel of strength class X80, without heat treatment, regardless of the content of boron, manganese, and sulfur, as a result of the formation of a finely dispersed ferrite-bainitic structure.
The Evaluation Model Efficiency of Ladle Graphitizing Inoculation of Cast Iron
Authors: Boldyrev D.A. , Latypov O.R. , Amirov R.N.
Published: April 2021

The model for evaluation of quality of ladle graphitizing inoculation of cast iron, according to the most common technological schemes, using the triple integral, is proposed and implemented. The necessary boundary conditions and parameters of the integral model are presented, described and justified. A concrete example confirms the practical conclusion that graphitizing inoculation of cast iron, melt into a stream in the process of filling a mold, is preferable.
To the Question of the Manufacturing Ability a Contact Wire by Continuous Casting Rod
Authors: Mysik Raisa K. , Sulitsin Andrey V. , Morgunov Vadim V.
Published: April 2021

The article presents the results of pilot-industrial experiments in the field of manufacturing technology of contact wire made of Cu-Sn alloys. Cast rods with a diameter of 20 mm, made of CuSn0.04, CuSn0.1, CuSn0.2, CuSn0.3, CuSn0.4 alloys, were obtained in a continuous casting plant on an Upcast system. Cast rods were deformed using a Conform technology, and extruded billets with a diameter of 18 and 20 mm were produced, which were subsequently drawn on a shaped contact wire with a cross section of 100 mm2. Cast rods macrostructure and microstructure were studied. The macrostructure quantitative assessment of samples was studied in a cross and longitudinal section. A plot of the effect of the tin content in the alloy on the average grain area in cross section is obtained. An increase in the tin content in the alloy leads to a decrease in the average grain area. An analysis of the rod microstructure in a cross section showed that the structure is a grain of an α-solid solution of tin in copper, and the grain boundaries are thin and clean. After deformation by Conform technology a uniform fine-grained structure is ensured. The effect of the tin content in the alloy on the Brinell hardness of cast billets, made by Conform technology, is determined. An increase in the tin content in the alloy leads to an increase in the hardness of both cast and deformed billets. The microstructure analysis of the contact wire in the cross section is carried out. The mechanical and electrical properties of the contact wire with a cross section of 100 mm2 are determined. An analysis of the results showed when the tin content in the alloy is up to 0.4 wt. %, the required level of mechanical and electrical properties of the contact wire is not provided. It may be necessary to change the size of the initial billet before drawing or to increase the tin content in the alloy more than 0.4 wt. %.
Investigation of the Effect of Tungsten Carbide (WC) Nanopowder on Iron-Based Powder Structural Materials
Authors: Gavrish V.M. , Chayka Tatyana , Baranov G.A.
Published: April 2021

Studies of a powder used as a modifier obtained from solid-alloy waste, such as tungsten carbide (drill balls), are presented. Dispersion, particle morphology and phase analysis of the powder were studied. The powder obtained from solid-alloy waste is a phase – it is tungsten carbide WC, it consists of nanoobjects of various shapes (nanoparticles, nanoplastics) up to 100 nm in size, with a slight presence of agglomerates up to 250 nm in size. The influence of tungsten carbide nanopowder as a modifier on the mechanical properties (strength and hardness) of PK70D3 iron-based powder structural steel has been studied. For the study, two different modes of preparation of powder alloy have been used with the use of one-stage and two-stage sintering. The influence of additive nanopowder of tungsten carbide on the mechanical properties of structural alloy powder based on iron PK70D3 has been defined: strength increases by more than 23% (in single-stage sintering), by more than 28% (in double-sintering), hardness decreases by more than 6% in single-stage sintering and increases by more than 26% with two stages of sintering, compared to the initial alloy. It has been shown that samples, obtained using double sintering with a tungsten nanopowder modifier (2.5%), have higher values of strength (more than 80%) and hardness (more than 13%), compared to modified samples, obtained by single-stage sintering technology. Thus, the modification of a 2.5 % nanoprobe of tungsten carbide, a widely used structural powder alloy based on iron PC70D3 allows for a significant change in mechanical properties. The use of powder alloys in double sintering technology provides the material hardness and the strength increase.
Heat-Resistant Composite Materials on the Base of Mica and Glass
Authors: Shishelova Tamara I. , Fedchishin Vadim V. , Khramovskih Mikhail A.
Published: April 2021

Present-day materials science requires development of compositions and technologies for production of composites with enhanced physical and technical properties. One of requirements towards such materials is an elevated heat strength. Materials, earlier used in electrothermy (ceramics, porcelain, asbestos and items made of them), have operating temperature of 400-500°С, high cost, low mechanical strength and a number of other drawbacks. Therefore, development of heat-resistant, mechanically strong and inexpensive insulation materials is an immediate problem. Mica’s characteristics to the maximum extent meet the requirements to a filler for the composite materials. Its use would enhance electric and physical properties of composites, contribute to development of waste-free technology, thus favoring the environment. Objectives of the paper: development of technology for production of heat-resistant materials on the base of heat-proof mica and special glass with elevated softening point; study of the interaction between composite components and high-temperature medium; giving recommendations on technology for fabricating heat-resistant composites with enhanced physical and technical properties. Objects of study: specimens of heat-proof mica (phlogopite), wastes of abrasive production, modifiers, glasses with high softening point. Methods of investigation: methods of thermodynamic and quantum-chemical studies were used with involvement of a complex of state-of-art physical and chemical methods. Results of study: development of theoretical grounds for forming the heat-resistant composite materials on the base of experimental studies and scientific generalizations. The technology for production of new heat-resistant materials on the base of rational use of mineral raw material and production wastes is proposed.
Evaluating Plasticity of Alloy AD31 on Ingot Height
Authors: Smyrnov Yevgen , Skliar Vitalii , Parpiev Doston
Published: April 2021

The authors present the results of evaluating the distribution of plastic properties on the height of a log ingot with the diameter of 145 mm, obtained by means of semi-continuous casting, from the aluminum alloy AD31. The authors study semi-continuous alloys of three manufacturers. One part of ingots was obtained with the use of only primary aluminum, secondary raw materials and secondary raw materials with the addition of primary aluminum. With the purpose of stabilizing the process of presswork the authors define the values of yield stress in the ingot lower and upper parts and study its microstructure. The research was conducted for the ingots without thermal treatment after accelerated homogenization. It is shown that the ingots, produced with the use of primary aluminum only, have less scattered plastic properties in terms of the height. That is why, for the case of press-working the items with thin components, it is reasonable to use the ingots from primary aluminum.
Influence of External Action on the Internal Structure of Continuously Cast Slab Produced from Tube Steel
Authors: Stolyarov A.M. , Buneyeva Ye.A. , Potapova Marina V.
Published: April 2021

The paper compares the internal structure of two continuously cast slabs with a section of 300 × 2600 mm from a tube steel of the strength class K60, one of which is molded with a soft reduction, and the other is without external influence. A comparative analysis of the structure of two templates showed that the location of areas with an increased metal pickle ness in the axial part of the templates varies. On the template from a slab cast without reduction, this section is below the geometric center of the work-piece in thickness, at a distance of 49.2% from the underside, that is, the "lower" asymmetry of the slab structure is observed. On the template from the slab cast off with soft reduction, the area with an increased pickle-ness is located above the middle of the work-piece: at a distance of 51.7% of the side of the large radius, an "upper" asymmetry of the slab structure is formed. Consequently, as a result of the external action on the cast work-piece, the location of the axial sponginess, relative to the geometric centre of the slab, is changed by moving from the lower to the upper half of the work-piece. The metal of the axial part of the reduced slab has a denser structure, the degree of development of axial looseness in the metallographic evaluation is reduced by an average of 0.5 points. The work shows the change in the content of chemical elements along the thickness of slabs. In the reduced metal, the maximum value of the degree of zonal inhomogeneity of the most impurities is higher than in the metal without external influence. This is explained by the fact that, as a result of reduction, the zone of location of the axial chemical heterogeneity in the slab becomes smaller in width.
Criteria of Material Failure in Relation to Hydrogen Saturation
Authors: Mironov Vladimir I. , Emel'yanov Igor G. , Lukashuk Olga A.
Published: April 2021

A steadily rising interest which specialists in various fields show towards the problem of hydrogen affecting metallic materials and causing their failure is connected to all-increasing requirements set on the durability of machines and equipment in operation. Metallic structures are most often surrounded by such environment which contains hydrogenous components or hydrogen itself (in chemical industry, power engineering, etc). And it leads to various types of degradation in metals (hydrogen embrittlement, hydrogen corrosion, and so on), which, in its turn, could cause catastrophic results. Ultimate strength is considered to be a representative parameter of the process of hydrogen degradation in steels. The authors cite the results of testing conducted on hydrogen-saturated specimens made of A516-55 steel which register a significant decrease in the ultimate strength. It is proposed to use a diagram which describes a fall in metal strength and transition of structural materials into their brittle states following an increase in hydrogen concentration. Discussion is made on criteria for hydrogen-saturated materials of metallic structures failing when a momentary overload occurs under default working conditions.
Influence of Temperature and Holding Time on Number and Size of Metal Particles during Solid-Phase Reduction of Iron by Carbon
Authors: Bil'genov A. , Tabylbaeva A.R. , Gamov P.A.
Published: April 2021

There is a lack of complete understanding of the mechanism and kinetics of reduction of metals from oxides. This paper presents results and methods of a series of experiments on direct reduction of metals by solid carbon in the form of graphite from a complex oxide with a low iron content in a laboratory muffle furnace at temperatures of 1300, 1400, 1500, 1600 °C and holding time of 1, 3, 5, 7 hours. The statistical analysis of amount and average size of reduced iron particles inside the oxide was studied. Dependence of amount and average size of the reduced iron particles on temperature and time of reduction is presented. The phenomena of iron crystals’ growth, occurring as a result of changes in the crystal lattice of oxide, was studied under experimental conditions. The influence of temperature and holding time on iron particles’ nucleation and their growth in the crystal lattice of a complex oxide were compared. Investigation of mechanism of metals’ reduction from complex oxides and influence of experimental conditions on the nucleation and growth enables to identify new patterns in the process of reduction of metals from their oxides, in general.