Mechanisms of Luders deformation in tensile tests of specimens of steel 08G2B with ultrafine ferrite-bainite structure are studied by the method of digital image correlation. The fields of displacements of εyy and εxy and their distribution over the length of a specimen are determined. Two kinds of Luders deformation differing in the behavior of the Chernov–Luders bands are detected. The results of

The temperatures of phase transformations and the oxidation-reduction reactions occurring under heat treatment of composite Al – Si + flux brazing metal used for brazing of Al alloys and produced by the TRILLIUM™ Technology are determined. It is shown that the melting mechanism is stepped and is accompanied by a chemical reaction between the flux and the oxide film and by diffusion transfer of silicon

The structures and phase compositions of a series of refractory alloys of the Co – Al – Mo – Nb system (the cobalt angle) are studied by differential scanning calorimetry (DSC) and scanning microscopy. The effect of the contents of niobium and molybdenum on the phase composition and the temperature boundaries of the range of existence of the Co3(Al, Mo, Nb) intermetallic phase are determined.

The domain structure and its change as a result of heat treatment of alloys of type Sm(Co, Cu, Fe, Zr)7.5 is simulated with the use of the FMRM software based on the phenomenological approach to analysis of processes of reversal magnetization. Adequacy of the results of the simulation of the domain structure is checked by comparison with published data on experimental studies of similar alloys and

Prospects of oxygen alloying of alloys in the process of deposition of rods on parts from titanium alloys aimed at raising their hardness are considered. Experiments on fabrication of samples of titanium alloys with remelting of filler rods with oxide coating formed by plasma electrolytic oxidation are performed. The main mechanical characteristics of the overlay rod material modified by introduction

Periods of the stage of concentrated strain of specimens of low-carbon steel 08G2B with ultrafine structure are studied by joint analysis of stress–strain curves and fields of digital image correlation (DIC). The DIC data and detection of a through crack on the surface of a tensile specimen are used to justify the use of the parameters of the second period of the stage of concentrated strain as criteria

The possibility of fabrication of powders from alloy 25Kh15KA for synthesizing permanent magnets by the method of selective laser melting is considered. The method is used to make specimens of permanent magnets 10 × 10 × 9 mm size with a density meeting the State Standard for 25Kh15KA magnets produced by the standard metallurgical process to obtain a coercivity of 45.4 kAm, a residual induction of

The integral method is used to simulate the kinetics of growth of γ′-phase layers during nitriding of Armco iron in a microwave discharge chamber. Solution of the system of differential algebraic equations is used to assess the diffusivity of nitrogen in the γ′-phase layers in the temperature range of 773 – 843 K at a surface concentration of nitrogen equal to 5.9 wt.%. The computed activation energy

The main factors responsible for the kinetics of isothermal bainitic transformation in alloy steels are determined using computer simulation of the solid-state phase transformation. The effect of the initial configuration of nuclei of the new phase in the volume of the metal on the parameters of the process of bainitic transformation is determined. Comparative analysis of the computed kinetics of phase

The EBSD technique is used to study the structural and textural states in an austenitic corrosion-resistant steel of type Kh18N9 after long-term service in a tube at high temperatures. It is shown that the grains of the α-phase nucleate on coherent twin boundaries (Σ3 of the CSL model) between austenite grains, which determines their unique crystallographic orientation.

Special features of high-temperature transformation of carbides in the eutectic and δ-eutectoid of a cast high-speed steel of type R6M5 are studied. The conditions of formation of a vanadium-enriched carbide during annealing at 1200°C with different holds are considered.

The method of orientation microscopy (EBSD) is used to study the structural and textural states of a nickel-base Ni – Cr – Mo alloy after cold rolling and subsequent annealing. It is shown that the deformation yields a multicomponent rolling texture. The Σ3 special boundary formed at the start of the deformation process is preserved after the deformation as a stable-energy object. Recrystallization

Titanium alloy VTI-4 based on orthorhombic titanium aluminide Ti2AlNb is studied in the initial condition and after charging with hydrogen to different concentrations. The kinetics and the rate of hydrogen release from the hydrogen-charged alloys during a 30-min hold at 900°C in a flow of a high-purity inert gas (argon) is analyzed. The curves obtained by differential scanning calorimetry and thermal

The methods of orientation microscopy, x-ray diffraction phase analysis and microindentation are used to study the effect of annealing at 680°C on the structure, texture, and physical and mechanical properties of a hot-pressed tube from titanium α-alloy PT-1M. It is shown that annealing of the hot-pressed tube from alloy PT-1M in the α-range causes secondary crystallization and grain growth, which

The methods of optical microscopy, x-ray phase analysis and microindentation are used to study the effect of vacuum annealing at 750, 800 and 850°C on the structure, phase composition and microhardness characteristics over cross section of welded joints of unlike alloys OT4 – VT6, VT20 – VT6 and VT23 – VT6. Recommendations are developed on the temperature of vacuum annealing of the welded compositions

Dilatometric, metallographic and durometric studies of transformations of supercooled austenite in modern commercial and experimental alloy steels under continuous cooling from the austenitization temperature at constant rates of 0.1 – 30 K/sec are performed. Thermokinetic diagrams of transformation of supercooled austenite are plotted and analyzed. The effect of alloying on the temperature and time

The possibility of fabrication of granulate based on an alloy of the Fe – Cr – Co system with reduced (7 – 10%) cobalt content for synthesizing permanent magnets by the MIM process is considered. A multicomponent granulate composition (polyformaldehyde, high-pressure polyethylene, stearic acid, beeswax) of spherical powders of the Fe – Cr – Co alloy with reduced cobalt content is produced by gas sputtering

The texture, structure and mechanical properties of thick strips from brass L63 produced by different methods and then annealed in a continuous cycle in a transverse magnetic field or statically (in coils) in an in-and-out furnace are studied. The effect of the mode of preliminary treatment on the relation between the texture and the properties of the annealed strips is considered. Reliable enough

Basic physical metallurgy principles of alloying of aluminum alloys with scandium are considered and the fundamentals of the production of deformed semiproducts from these alloys are discussed. The discussion is based on the expected widening of the range of application of deformed semiproducts from scandium-alloyed aluminum alloys.

Activation energy of boron diffusion during pack boriding of armco iron with a constant incubation time for boride formation is estimated using a mean diffusion coefficient model. Experimental verification is accomplished for the model by boriding armco iron at 1253 K for 5 h. Good correspondence is obtained between experimental and calculated Fe2B layer thicknesses.

A comprehensive research was conducted to study long-length (> 10 m), wide (> 2 m), 7 mm thick sheets of high-strength aluminum alloy V95pch after quenching and “softening” aging according to T2 temper conditions. It is shown that a homogeneous (length- and widthwise) structure, typical for such type of semi-finished products made of alloy V95pch, temper T2, can be sustained in wide, long-length sheets

The effect of heat treatment on the microstructure, hardness, and abrasive wear of the hammer mills knives made of steels EN 1.2080, 1.7225, 1.7131, and 1.1191 used in the grain crop processing into groats has been studied. The wear tests were performed using an “impeller-in-cup” type machine, and metallographic studies were performed using optical and scanning electron microscopy. A comparative analysis

Transformations of structure associated with relaxation processes in the inclusion-matrix interphase boundaries of 08Yu, 08Kh18N10T, É3 steels and armco-iron under various external impacts are studied. The possibilities of stress relaxation within the inclusion – matrix boundaries as a result of the emission of dislocations or the splitting of these boundaries are shown. The mechanisms of static, dynamic

The effect of laser treatment parameters for copper cladding applied by explosive welding and subsequent rolling on a titanium surface on coating structure and phase composition is studied. It is shown that the relative (compared with VT1-0 titanium alloy) wear resistance of a coating with an increase in titanium content from 30 to 50% increases at 20°C from 2.9 to 4.4, and at 400°C from 1.7 up to

The wear resistance characteristics of AISI 51B60H and 30MnB5 steels with different carbon and boron contents were investigated. The analysis of the microstructure and hardness of steels was carried out. The specific wear rates in the conditions of dry and wet friction were calculated, and the friction coefficients were determined. The worn surfaces of rail samples were studied by electron microscopy

The effects of primary ferrite on bainitic transformation, microstructure, and properties of low carbon bainitic steel Fe – 0.22C – 2.01Si – 2.20Mn – 0.22Mo are investigated by metallographic and dilatometric methods. It is found that the effect of primary ferrite on subsequent bainite formation appears as a change in the ratio of two competing processes: advance of the austenite–ferrite interface

The treatment conditions yielding steel with a natural ferrite-martensite composite structure are proposed. Structural steels having a banded ferrite-pearlite structure after hot rolling are analyzed. It is shown that the strength achievable by the composite is proportional to the volumetric fraction of the strengthening phase. Based on the experimental data obtained as a result of tension and dynamic

The quality, structure, chemical composition and mechanical properties of bimetallic materials prepared by argon- arc surfacing of copper alloys MNZhKT 5-1-0.2-0.2, Sv-MN18, Sv-MNZhMtsTK 40-1-1-0.3-0.1, MMts40, BrAZhNMts 8.5-4-5-1.5 and Monel NMZhMts 28-2.5-1.5 on high-strength low-alloy steel AB3 are investigated. It is shown that during surfacing copper alloys on steel, high-quality bimetal is provided

We consider specific features of formation of the structure and properties of 03Kh22N5AM3 corrosion-resistant duplex steel in the process of deformation and thermal treatment of rolled milled bars. We analyze the influence of the chemical composition and the conditions of smelting, casting, hot deformation, and heat treatment on the formation of intermetallic phases, which reduce the ductility of the

The kinetics of formation of precipitates in a Cu – 2% Be alloy is studied in terms of the Avrami and Orowan equations.We determine the structure and hardness of the alloy after aging at 260 – 440°C for 0.25 – 10 h and compute the activation energy of precipitates.

The influence of various heat treatment modes (annealing, quenching, tempering) of steel 20 on the carbon dioxide corrosion rate in a 3% NaCl solution in combination with carbon dioxide (CO2) barbotaging was studied. It is established that the quenching followed by high tempering is the most effective heat treatment of steel 20 to achieve a combination of increased mechanical properties and corrosion

The authors have studied grade R260 rail steel after austenization in the temperature range from 800 to 930°C and isothermal soaking at 500, 550, and 600°C followed by quenching in water. The steel structure and abrasive wear resistance were characterized. Recommendations concerning an increase in steel wear resistance were provided.

Steel AISI O2 (type 9G2) for a cold-working tool after different quenching, tempering, and cryogenic treatment regimes is studied. It is established that after cryogenic treatment the amount of residual austenite decreases by a factor of 4.3 compared with a quenched condition. The highest hardness 69 HRC is achieved after quenching and cryogenic treatment, and in this case wear resistance is higher

An experiment is performed for explosive convergence (collapse) of a cylindrical shell of low carbon steel with a ferrite-perlite structure. It is revealed that during ultra-rapid heating caused by high-speed deformation austenite formation occurs in an unusual sequence: first, free ferrite is converted, then pearlite. The decrease in free ferrite transformation temperature is explained by action of

Technology for low-temperature carbonitriding combined with high temperature tempering of cold-worked die steel 6Kh4M2FS (DI55) is proposed. The high efficiency of a paste-like coating based on amorphous carbon and nitrogen-containing components (carbamide and potassium ferricyanide) during die steel cyaniding in the temperature range from 500 to 580°C is demonstrated. The effect of thermochemical

We study the processes and mechanisms of electron-beam melting (EBM) used in the production of high-purity metals. We formulate the requirements that should be imposed on the EBM parameters for the production of high-quality materials and proposed some optimal modes.

Heat resistance and microstructure properties of a prospective multilayer protective coating on carbon-carbon composite materials are studied. Thermomechanical compatibility of a coating with base material, its thermal stability, thermal shock and cracking resistance are evaluated.

The possibility of evaluating the structural entropy of sheet samples of D16 alloy after aging at 50, 100, 150, and 200°C for 15, 30, 60, 120, and 240 min is considered. A quantitative relationship between the treatment conditions and crystallinity level is established. The effect of the stages of structural changes during aging on the variation of structural entropy is determined.

The effect of the regime of electrospark alloying (ESA) on the thickness, hardness, and phase composition of the alloyed hardened layer on the surface of specimens of titanium alloy VT1-0 is studied. The thickness of the layer depends considerably on the parameters of the ESA process, and the hardness level is determined by the phase composition.

Correlation between the ultimate tensile strength and the hardness of aluminum alloy 2219 and its joints welded with a variable-polarity tungsten electrode in inert gases (VPTIG) and by friction stir welding (FSW) is studied. The yield strength (σy) and the ultimate strength (σr) of the base metal, the microhardness and the strain hardening coefficient of the welded joints are determined. Linear correlation

We present the results of metallographic investigations of the structure and microhardness and the results of the bench tests of the threads of tubings made of steels of the strength class D after finishing electromechanical surface quenching in pairs with commercial couplings.

Medium-alloy chromium-nickel cast iron with different contents of silicon and vanadium is studied. The composition of the carbide phase, the distribution of elements in the carbide phase and in the metallic matrix, and the proportion of the structural components and of the carbides are determined. The effect of the form of globular graphite on the mechanical properties of the cast iron is described

The structure of retained austenite in wear-resistant steels 150KhNML and Kh12MFL of pearlitic and ledeburitic classes is studied under the conditions of abrasive wear after different variants of heat treatment. The working surfaces of the steels are subjected to electron microscope transmission analysis. It is shown that the retained austenite formed as a result of high-temperature quenching (1100

The structure, the hardness, and the thickness of the hardened surface layer of normalized steel 45 are studied after electromechanical treatment (EMT) with dynamic application of the forming force. The effect of the density of the current of the pulsed EMT on the structure, the microhardness and the thickness of the hardened surface layer is determined. The properties of the hardened layer of the

Steel AISI4140 is studied after plasma nitriding and preliminary oxidation. The structure of the preliminarily oxidized surfaces after the nitriding is studied by scanning electron microscopy (SEM). The free surface energy is computed from the results of the measurement of the angle of contact between a liquid drop and the surface studied. The thickness of the nitrided layer is determined. The phase

The effect of ion nitriding in glow discharge on the structure and mechanical properties of steel R6M5 after quenching from 1200°C and tempering at 560°C with preliminary severe plastic deformation (SPD) is studied. Application of ion nitriding in glow discharge is shown to be effective for hardening the high-speed steel RM5 after SPD.

The microstructure and mechanical properties of maraging steel 350 is studied after aging at 500 – 650°C. The yield strength, the ultimate strength, the impact energy, and the hardness of the steel are determined. The volume fraction of reverted austenite after the aging is assessed. The impact energy, the elongation, and the product of the ultimate strength by the elongation are shown to depend on

Processes of formation of structure and properties in the functional layer from chromium-nickel cast iron of two-layer centrifugally cast indefinite forming rolls under crystallization and subsequent tempering are investigated. The temperatures of the start and finish of the phase transformations, the phase composition, and the contents of martensite and retained austenite in the material of the functional

The structure of a coating based on a mixture of particles of Cu and Zn deposited by the method of gas dynamic spraying is studied. An x-ray diffraction analysis and a microscopic spectrum analysis are used to determine the structure and the elemental composition of the coating. Development of diffusion after the formation of the coating is shown to yield a solid solution of copper and zinc in it.

Mg – HA (magnesium-hydroxyapatite) composites obtained by powder metallurgy and subjected to sintering at three different temperatures and subsequent hot extrusion for making orthopedic implants are studied. The relative density, the hardness and the properties after tensile and impact tests are determined with the use of optical and scanning electron microscopy.

Titanium carbosilicide is synthesized by the method of spark plasma sintering (SPS) from a powder mixture of plain elements (Ti, Si, C). The stages of the synthesis process are considered, i.e., pressing of the powder mixture, melting of the constituents, chemical reactions, and phase transformations. The materials synthesized at 1000, 1300, 1500 and 1600°C are studied by the methods of phase, diffraction

Sparingly alloyed high-manganese austenitic steels 40G20 and 25G20S3 are studied. The phase composition, the structure and the mechanical properties of the steels are determined after quenching from the austenitic range, and their variation during tension of standard specimens is studied by the methods of transmission electron microscopy and x-ray diffraction analysis. The characteristics of strain

Amorphous alloys Fe81Zr5Nb4B10 and Fe40.5Co40.5Zr5Nb4B10 obtained by melt spinning and subjected to annealing at different temperatures are studied. The activation energy of crystallization of the alloys is determined for different heating rates. It is shown that the primary product of crystallization of amorphous alloy Fe81Zr5Nb4B10 is an α-Fe phase and a phase with a structure of type α-Mn. In the

RGO/Cu – Zr – La alloy produced by repeated pressing and sintering is studied. The effect of the reduced graphene oxide (RGO), Zr and La components on the microstructure, mechanical properties, conductivity, and oxidation resistance of the alloy is studied. It is shown that precipitation of RGO and Zr on grain boundaries hinders displacement of the grain boundaries. The mechanical characteristics of

The microstructure and the wear resistance of precision nickel alloy 40KhNYu-VI used for the production of paramagnetic bearings are studied after glow discharge nitriding. It is shown that the continuous layer of CrN nitride formed under the nitriding provides substantial elevation of the wear resistance of the surface of the parts. The wear intensity after the nitriding decreases by a factor of 5

The effect of artificial aging on the mechanical properties of Al6082 alloy and Al6082/(2 – 10%)Al2O3 composite produced by stir casting is studied. The structure is studied with the help of a field emission scanning electron microscope (FESEM). The stress-strain curves, the impact energy and the hardness are measured. It is shown that growth in the fraction of the hardening phase and artificial aging

Tough-pitch copper M1 is studied after deformation by the method of equal channel angular pressing (ECAP) in a die with parallel channels with the use of cryogenic cooling in liquid nitrogen. Comparative analysis of the properties of the copper after the ECAP with cooling in liquid nitrogen and at room temperature is performed. Special features of formation of ultrafine-grained structure in quenched

The properties of steel parts after carburizing in low-pressure acetylene are studied. The thickness of the carburized layer, its hardness, the microstructure, and the hardness of the core are determined after carburizing at 900 – 960°C with simultaneous shortening of the process from 104 to 44 min. The data obtained for the diffusion of carbon make it possible to predict the profiles of carbon distribution

The effect of annealing and SiC additions on the process of wear of electrolytic nickel-phosphorus (NiP) coatings under different friction conditions (sliding, fretting and fretting-corrosion) is studied. It is shown that the sliding friction causes much lower wear than the fretting wear and the fretting corrosion. The lowest wear under the friction conditions considered is exhibited by the heat treated

We carried out structural and tribological investigations of steels and alloys after different modes of their nitriding. On the basis of the results of tribological tests and metal-physics investigations, we estimated the efficiency of each applied procedure of treatment and determined the characteristics of the structural state of nitrided layer, promoting the improvement of the wear resistance of