The microstructure, the phase composition, the microhardness and the wear resistance of hypoeutectic white cast irons with different contents of chromium are studied. It is shown that the wear resistance of the iron depends substantially on the type of the carbide phase and on the morphology of the ledeburitic eutectic, which is determined in its turn by the content of chromium.

The influence of preliminary low-cycle overloads on the fatigue fracture resistance in the stages of formation and propagation of cracks in cyclically hardened steels is studied. The regular features of changes in the structural state under the overloads and its relation to the stress-strain diagram are determined using metallographic and x-ray diffraction analyses. The prehistory of the process of

The characteristics of the oxide layer deposited by microarc oxidation (MAO) on Al – Si alloys in a silicate-alkaline electrolyte are studied. The thermal conductivity of the layer at 50 – 120°C is determined using a special facility by the method of stationary heat flow. The thickness, the porosity, the elemental composition, the content of the amorphous phase, and the size of the crystallites in

The structural types of copper, diamond and tungsten are represented by a linear union of four tetrahedrons over faces within solution of a general problem of representation of a crystal structure as a union of special atomic clusters. This union (a tetrablock) plays the role of a universal building unit, because it determines the generating clusters (building units) of the basic structural types considered

A process of manufacturing of rolled sheets from a new high-strength wear-resistant weldable steel H500 MAGSTRONG® with wear resistance, strength and impact toughness parameters at negative temperatures not inferior to those of the best world counterparts is described. Transmission electron microscopy is used to study the structure of a sheet with a thickness of 12 mm formed as a result of hot rolling

Examination of fractures of rolling bearings from steel 8Kh4V9F2-Sh (ÉI347-Sh) is used to assess the effect of production factors on the operating capacity of bearings under elevated loads. The microstructure and fractures of the steel are analyzed. The compressive stresses and the contents of the general and diffusion-mobile hydrogen are determined. It is shown that a fatigue crack appears in the

The main mechanisms of structure formation in zones of welded joints of unlike metals (steel – aluminum) obtained by friction stir welding in the mode of structural superplasticity are considered. Sheet billets of different steels (St3ps, 12Kh18N10T) and deformable aluminum alloys (AD1, AMg6) with a thickness of 3 mm are butt- and lap-welded by the friction stir technique. The microstructures, the

The methods of optical and electron microscopy and x-ray spectrum microanalysis are used to study the microstructure and phase composition of a tubular welded joint from alloy HP40NbTi based on the Fe – 25Cr – 35Ni system. Short-term and long-term mechanical properties of the alloy are determined. The joint is characterized by structural inhomogeneity and formation of silicon segregations and G-phase

The structure, phase composition and impact toughness of specimens cut from different-thickness regions of a billet with cross section 160 × 160 mm from continuously cast high-speed steel R6M5 are studied. It is shown that the macro- and microstructure, phase composition, and process ductility of the continuously cast high-speed steel R6M5 are substantially higher than those of the steel obtained by

The effect of heat treatment parameters (the temperature of 850 – 930°C and the cooling rate of 1 – 20 K/min) on the microstructure and mechanical properties of carbon steel with 1.95 wt.% C is studied. The temperatures of the phase transformations in the steel are determined. X-ray diffractometry is performed. A heat treatment mode preventing the formation of ledeburite in the structure of the steel

Long-length bimetallic conductors with a copper core and a shell from an aluminum alloy up to 2.4 mm in diameter with enhanced strength are obtained by swaging. The effect of the swaging strain on the structure, phase composition and mechanical properties of the bimetallic conductors is studied.

An approach to description of the structural types of phases is suggested, in accordance with which the structural types A15, C15 and C14 of Frank–Kasper phases are described as the densest packing of chains of special unions of tetrahedrons-tetrablocks. A tetrablock is a seven-vertex union of four tetrahedrons over faces. For the packing to be the densest, the ideal tetrahedrons in the tetrablocks

The process of formation of a multilevel multilayer B4C – Ti-6Al-4V cermet coating by the method of SLM is studied. The coating is characterized by presence of heterogeneous zones differing in the mechanical properties. It is shown that the use of the B4C – Ti-6Al-4V powder mixture with ceramics concentration 20 wt.% is not expedient, because it causes deficit of the metallic matrix and formation of

The relative magnetic permeability and electric conductivity in the temperature range from room one to 800°C are determined for steel 18CrNiMo7-6 with different structures, i.e., martensitic, bainitic and ferritic-pearlitic ones. The variation of the magnetic properties of the steel as a function of the temperature and of the microstructure and their effect of the depth of penetration of eddy currents

The methods of scanning electron microscopy and x-ray diffractometry are used to study the microstructure and mechanical properties of welded joints from alloy Ti60 after laser welding and subsequent heat treatment (PWHT). It is shown that the microstructure of the welded joint consists of three zones, i.e., a fusion zone (FZ), a heat-affected zone (HAZ) and base metal (BM). The PWHT lowers considerably

The methods of transmission and scanning electron microscopy are used to study the evolution of the structure of a welded joint of steels 32G2 and 40KhN in the thermomechanically affected zone (TAZ) under rotary friction welding (RFW). EBSD analysis is used to certify the microstructure in different parts of the TAZ and to calculate the densities of the low- and high-angle boundaries. It is shown that

Parts and billets produced from aluminum alloys and carbon steels using different methods of control, i.e., ultrasonic and radiographic inspection, computer tomography and metallographic analysis, are studied. Computer tomography is shown to be more advantageous than the other methods of nondestructive inspection.

The parameters of the process of production of flawless bimetallic billets from powder steel R6M5 (the external layer) and 5KhNM (the core) are assessed by mathematical simulation. The bimetal has mechanical properties comparable to those of cast and deformed high-speed steel, a more homogeneous structure, and a much lower cost.

The causes of reversible variation of coercivity in alloys for permanent magnets as a result of cyclic heat treatments are analyzed including the effect of magnetostatic interaction between microvolumes on the processes of magnetization reversal and on the magnitude of the reversibility of the coercivity. A scheme of the processes occurring in alloys of the Sm – Co – Cu – Fe – Zr system is suggested

The effect of the chemical composition of the alloys on the magnetic properties of sintered Sm – Co – Fe – Cu – Zr magnets produced with mixing of alloy powders is studied. Elevation of (BH )max of Sm – Co – Fe – Cu – Zr magnets due to increase of the concentration of Fe to 20 wt.% requires observation of a strict proportion of the components and precision choice of the modes of heat treatment. Optimization

Structural and phase transformations at elevated temperatures in α-titanium containing trace nonmetallic impurities are studied by the methods of differential scanning calorimetry and x-ray diffraction analysis. The microstructural and energy characteristics of such transformations are determined.

The possibility of raising the wear resistance and prolonging the service of forging die inserts is analyzed with the aim to elevate the efficiency of the production process and to reduce the cost of forgings. Three sets of inserts fabricated from the same grade of die steel and subjected to the same heat treatment are studied. Additional nitriding (gas or ion plasma one) is applied to two sets for

The effect of the chemical composition and microstructural parameters on the corrosion resistance of low-alloy steels serving in oilfield pipelines is studied. The causes of lowering of the corrosion resistance of the steels are determined. Recommendations are given for raising this characteristic without lowering the strength of the steels.

Results of a study of the fine structure of an alloy of the Mg – Zn – Zr – REE system proving the presence of nanosize plates of self-organizing LPSO-phases after deformation are presented. The Zn and Y hardening elements are redistributed in the periodic rows of the LPSO phases under the effect of the deformation process parameters. The optimum deformation mode of the new alloy provides formation

The effects of the dislocation density and of the concentration of vacancies in the β-solid solution on the processes of aging of intermetallic titanium alloy VTI-4 yielding a Ti2AlNb orthorhombic O-phase are studied. It is shown that the influence of the nonequilibrium concentration of vacancies in the solid solution is decisive for acceleration of the diffusion process and abrupt growth of the sizes

X-ray diffractometry with mathematical processing of the diffraction patterns by the Tikhonov method of regularization, which enhances the resolution, is used to study the phase state in Nd – Fe – Co – B – Zr-base alloys during the reverse reaction of HDDR process at different hydrogen pressures. The range of hydrogen pressures in which the reverse reaction (recombination) of the HDDR process develops

Deformations of straight-sided splines (changes in the width of the hubs) of steels 16MnCr5, AMS6265 and 17CrNiMo7-6 are studied after different treatments, i.e., a hold at 1050°C without carburizing and with slow cooling to room temperature, vacuum carburizing with subsequent slow cooling to room temperature, and vacuum carburizing with subsequent oil quenching. The sizes of the deformations are shown

The effect of long-term thermocycling and mechanical loads on the corrosion resistance of novel nitrogen austenitic Cr – Ni – Mn steels melted under laboratory conditions is studied in various aggressive environments. The steels are subjected to 400 thermal cycles in the temperature range from –100 to 100°C and to cyclic mechanical loading during 1 × 106 cycles. The structure and the mechanical properties

Ametallographic study of advanced low-carbon martensitic steel with high resistance of the supercooled austenite to the transformations by pearlitic and bainitic mechanisms under continuous cooling is performed. The critical temperatures of the transformations occurring under heating and cooling are determined. The kinetics of the isothermal transformation of the austenite in the temperature range

The phenomenon of post-aging retrogression in magnesium alloys containing two rare-earth metals belonging to different groups, i.e., yttrium Y (the yttrium group) and samarium Sm (the cerium group), is investigated. It is shown that retrogression may occur in alloys with different proportions of yttrium and samarium aged at 200°C for maximum hardness and then annealed at somewhat higher temperatures

The structure and magnetic hysteresis properties of nanocrystallized melt-spun ribbons with composition (Sm0.8Zr0.2)(Fe0.72Co0.24Ti0.04)z ( z = 10 – 12) are studied. It is shown that substitution of a part of iron in the composition of the alloy by cobalt raises substantially the Curie temperature but almost halves the coercivity. The decrease is connected with growth in the volume fraction of the

The effect of laser surface alloying with copper on the structure, phase composition and microhardness of surface layers of titanium is studied. Treatment modes improving the structure and special properties of the surface are determined.

A process of hardening of steel 16Kh3NVFMB-Sh involving vacuum carburizing and subsequent hardening heat treatment is studied. It is shown that in order to obtain an optimum phase composition and, as a consequence, high operating properties, the steel should be subjected after carburizing to high tempering for formation of a fine ferrite-carbide structure. The treatment should be finished with quenching

Special features of the process of recrystallization of austenite under hot deformation and its effect on the physical and mechanical properties of rolled sections from bearing and structural steels under the conditions of thermal deformation treatment are studied.

Structural changes occurring in the surface layer as a result of the hardening produced by various variants cyclic loading in high-strength high-quality steel 30KhGSN2A are considered. The sizes of the hardened zone are determined. It is shown that the hardening occurs in the early loading stages and is then followed by a durable state of saturation until failure. The differences in the deformation

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