


Том 58, № 9-10 (2017)
- Жылы: 2017
- Мақалалар: 26
- URL: https://journal-vniispk.ru/0026-0673/issue/view/14662
Structural Steels
Strength of “Light” Ferritic and Austenitic Steels Based on the Fe – Mn – Al – C System
Аннотация
The phase composition, the hardness, the mechanical properties at room temperature, and the resistance to hot (950 – 1000°C) and warm (550°C) deformation are studied for cast deformable “light” ferritic and austenitic steels of the Fe – (12 – 25)% Mn – (0 – 15)% Al – (0 – 2)% C system alloyed additionally with about 5% Ni. The high-aluminum high-manganese low-carbon and carbonless ferritic steels at a temperature of about 0.5Tmelt have a specific strength close to that of the austenitic steels and may be used as weldable scale-resistant and wear-resistant materials. The high-carbon Fe – (20 – 24)% Mn – (5 – 9)% Al – 5% Ni – 1.5% C austenitic steels may be applied as light high-strength materials operating at cryogenic temperatures after a solution treatment and as scale- and heat-resistant materials in an aged condition.



Titanium Alloys
Modern Sparingly Alloyed Titanium Alloys: Application and Prospects
Аннотация
Comparative analysis of the properties of domestic and foreign sparingly alloyed titanium alloys is preformed, and the main tendencies and prospects of their development are considered. Recent works of FGUP “VIAM” in the field of creation and approbation of various-purpose low-alloy titanium alloys are reviewed.



Aluminum Alloys
Effect of Annealing on the Electrical Resistivity and Strengthening of Low-Alloy Alloys of the Al – Zr – Si System
Аннотация
The effect of annealing at up to 550°C on the electrical resistivity ρ and HB hardness of low-alloy alloys of the Al – Zr – Si system containing up to 0.3% Zr and 0.3% Si is studied. The Thermo-Calc software is used to analyze the phase composition of the system. The computed and experimental data are used to determine the lower and upper limits for heating of cast preforms from Al – Zr alloys (shaped castings and ingots). It is shown that heating below 400°C and above 450°C is not expedient, because it increases the duration of the annealing in the former case and lowers the hardening effect due to coarsening of the Zr-containing particles in the latter case.



Article
A Study of Structural Changes in Pressed Semiproducts from Aluminum Alloy V95ochT2 in the Range of Dark Spots
Аннотация
Seven heats of alloy V95ochT2 are studied after a heat treatment imitating the conditions of the appearance of dark spots in the production process and anodic oxidizing (anodizing). The mechanical properties, the hardness, the structure, and the electrical conductivity of the alloy are determined. The causes and conditions of the appearance of dark spots are analyzed. The transparence of the film is shown to worsen upon formation of particles of second phase in the alloy.



Effect of Low Additions of Y, Sm, Gd, Hf and Er on the Structure and Hardness of Alloy Al – 0.2% Zr – 0.1% Sc
Аннотация
The structure and phase composition of addition alloys based on aluminum with Hf, Er, Gd, Yand Sm and the effect of low additions of these transition metals on the structure and properties of alloy Al – 0.2% Zr – 0.1% Sc are studied. It is shown that individual introduction of Y, Sm, Er, and Gd in an amount of 0.1% each causes formation of eutectic phases Al3Y, Al3Sm, Al3Er and Al3Gd, respectively. An indirect inference is that the additions of Y, Sm, Hf, Er and Gd raise the thermal stability of the Al3 (Sc, Zr) dispersoids after annealing at 250°C with a hold of up to 100 h; softening at 370°C starts after holding for 54 h. Maximum hardening is detected in the case of 0.1% Er and attains 50 HV after a 54-h hold at 370°C.



Formation of Fine-Grained Structure and Superplasticity in Commercial Aluminum Alloy 1565ch
Аннотация
A process for fabricating 5-mm-thick sheets from alloy 1565ch with recrystallized grains less than 10 μm in size is developed, which involves superplastic forming and provides elevated mechanical properties at room temperature. The parameters of superplasticity and the mechanical properties of alloy 1565ch are determined. Test forming of a dome-shape model part is performed.



Laws of Formation of Nanostructured Condition in Single Crystals of Highly Refractory Alloy VZhM4-VI Microalloyed with Lanthanum
Аннотация
Results of metallographic studies of the microstructure of single crystals of alloy VZhM4-VI with residual content of lanthanum varied from 0.0002 to 0.026% after a complete heat treatment and after testing for long-term strength are presented. The mechanism of the action of lanthanum on the formation of nanostructure in single crystals of VZhM4-VI is studied. It is shown that creation of nanostructure in the alloy raises its high-temperature properties.



Formation of Multiphase Microstructure in Steel 35CrMnSi by Intercritical Annealing – Quenching – Partitioning Heat Treatment
Аннотация
Low-alloy steel 35CrMnSi (0.37% C, 1.18% Cr, 0.85% Mn, 1.24% Si) is studied after an annealing – quenching – partitioning heat treatment. The steel with an initially martensitic structure is subjected to 15-min austenitizing in the intercritical temperature range of 790 – 810°C, quenching to a temperature below Ms (240°C), 100-sec holding at this temperature for redistributing the carbon between the phases, and water cooling. The mechanical properties of the steel are determined in tensile tests and the microstructure is studied by light and scanning electron microscopy. Fracture surfaces are investigated. A mode of annealing – quenching – partitioning heat treatment is suggested for creating an optimum microstructure raising the elongation without worsening the high strength properties of the steel.



Development of Casting Process for Pressings of Pistons of Car Augmented Engines
Аннотация
Results of a study aimed at formation of a single-phase fine-grained structure in pistons during their production process involving isostatic pressing of liquid metal prior to the start of crystallization, pressing of the crystallizing metal, and holding under pressure in the process of cooling to the shop temperature are presented.



Effect of the Temperature of Hot Rolling on Formation of Microdiscontinuities on Nonmetallic Inclusions in Steel ShKh15SG
Аннотация
Formation of micropores near nonmetallic inclusions under fatigue fracture of a bearing steel is considered. Dependences of pore formation on the temperature of hot rolling of the steel and relations between the number of pores and the deformation temperature are presented. Recommendations are given on the deformation temperature ranges.



Analysis of Magnetization Curves and Magnetocrystalline Anisotropy of Uniaxial Ferromagnets
Аннотация
Theoretical analysis of the processes of magnetization of uniaxial ferromagnetic materials is performed within the Neel theory of magnetic phases. Relations are obtained for the constants of magnetic crystal anisotropy K1, K2, the form factor N, and the saturation magnetization Is, at which the magnetization curves exhibit jumps (FOMP). Formulas for computing the saturation fields Hs and the jump fields HFOMP are derived for crystals with different types of magnetocrystalline anisotropy MCA. It is shown that the Sucksmith–Thompson method is applicable for computing the first too MCAconstants of uniaxial ferromagnets with any type of MCA. Constants K1 and K2 are computed with allowance for the form factor of the specimen. Model magnetization curves are plotted for uniaxial ferromagnets with different types of MCA along and perpendicularly to crystallographic axis c. The analytical results match the model curves well.



Domain Structure of R2Fe17 Intermetallic Compounds with Planar-Type Anisotropy
Аннотация
Magnetic domain structure is studied in single crystals of R2Fe17 (R = Tb, Dy, Ho, Er) intermetallic compounds in a wide range of temperatures (10 – 300 K) and magnetic fields (μ0H = 0 – 0.1 T). It is shown that single crystal specimens of hexagonal magnetics with planar-type anisotropy acquire domain structures containing not only 180-degree domain boundaries but also 60- and 120-degree ones.



Effect of the Crystallization Conditions of Alloy Mn54Al43C3 on the Magnetic Properties of Mechanically Milled Powder
Аннотация
Results of formation of a ferromagnetic τ-phase and an antiferromagnetic ε-phase in alloys of type Mn54Al43C3 obtained by induction and arc melting and by rapid hardening of the melt are presented. The magnetic hysteresis properties of powders produced by high-power mechanical milling of the synthesized alloys are studied. The optimum temperature conditions for transformation of the ε-phase into a ferromagnetic τ-phase are determined for the alloys and for their ultrafine powders. The resulting powders of Mn54Al43C3 have an ultimate specific magnetization σm = 81 (G · cm3)/g and a coercive force Hc = 3 kOe in a magnetic field of 12 kOe.



Microstructure of an Ingot of Sm2Fe17 Intermetallic and its Homogenization
Аннотация
The phase composition and microstructure of Sm – Fe alloys obtained by vacuum induction melting of the elements are studied near the stoichiometry of Sm2F17 by the methods of scanning electron microscopy, local microanalysis and x-ray analysis. The possibility of coherent junction of all the phase components of an ingot is analyzed with the help of representation of the crystal structures of all intermetallics of the Sm – Fe system in terms of coordination polyhedrons. It is shown that long-term annealing at a high temperature (for 30 h at 1150°C) does not remove from the structure of the ingot the regions of metallic samarium formed due to the peritectic type of solidification of the Sm2Fe17 intermetallic.



Effect of Partial Substitution of Neodymium with Praseodymium on the Magnetic and Process Properties of Sintered Magnets of Type NdFeB
Аннотация
The effect of substitution of neodymium with praseodymium in sintered magnets of type NdFeB on their magnetic and process properties in the concentration range of [Pr] = 0 – 13 wt.% is studied. The special features of milling of the alloys, sintering processes and heat treatments in the production of magnets containing praseodymium are discussed. Hysteresis characteristics of Br ≥ 1.2 T, HcJ ≥ 1200 kA/m, Hcb ≥ 880 kA/m, Hk ≥ 960 kA/m, and BHmax ≥ 280 kJ/m3 are obtained for magnets with composition (in wt.%) 33 Nd, 10 Pr, 1.5 (Ti + Al + Cu), 1.3 B, the remainder Fe.



Magnetic Properties of Hard Magnetic Alloy Fe – 28% Cr – 13.4% Co – 2% Mo – 0.5% Si
Аннотация
The method of regression analysis is used to obtain equations describing the dependences of magnetic hysteresis properties of magnetically hard powder alloy Fe – 28% Cr – 13.4% Co – 2% Mo – 0.5% Si on regimes of thermomagnetic treatment (the temperatures of the start of the treatment and the rates of cooling in magnetic field). The determined treatment modes make it possible to obtain in an alloy with a coercive force Hc up to 40 kA/m, a residual induction Br up to 1.2 T, and a maximum energy product (BH)max up to 25 kJ/m3. The alloy may find application in the production of rotors of synchronous hysteresis-reluctance motors.



System for Rapid Control of Magnetic Characteristics of Sheet Electrical Steel
Аннотация
Asystem for rapid control of magnetic characteristics of sheet electrical steel is suggested. Implementation of the full-scale-model method employing an original measuring magnetic induction transducer does not require preparation of special test specimens. The system makes it possible to inspect regions of sheets of electrical steel, preforms and parts of electrical devices. Results of determination of magnetic characteristics of sheet electrical steels 2212 and 3413 are presented.



Magnetic and Mechanical Properties of Hard Magnetic Alloys 30Kh21K3M and 30Kh20K2M2V
Аннотация
The magnetic and mechanical properties of two hard magnetic alloys (30Kh21K3M and 30Kh20K2M2V) of the Fe – Cr – Co system in anisotropic and isotropic conditions produced by traditional induction melting and by the method of powder metallurgy with subsequent pressure treatment of the metal are studied. The obtained regression equations for Br, HcB and (BH )max describe the quantities adequately in the used range of variation of factors. The response surfaces and their sections in the phase space of the heat treatment factors are plotted. The results of the analysis of the proportion of residual induction in anisotropic and isotropic states are used to infer that the model of the mechanism of magnetization reversal of hard magnetic alloys of the class considered needs amending.



Mirror Effect in Measuring Systems with Variable Geometry of the Electromagnet Interpole Space
Аннотация
The dynamics of variation of the signal of the data measured in a study of hysteretic characteristics of magnetically hard materials in magnetic circuits (open, incompletely closed and closed) with variable geometry of the interpole space of the electromagnet used for obtaining the magnetic characteristics of the materials is studied.



Method of Harmonic Balance in Full-Scale-Model Tests of Electrical Devices
Аннотация
Methods for determining the weber-ampere characteristics of electrical devices, one of which is based on solution of direct problem of harmonic balance and the other on solution of inverse problem of harmonic balance by the method of full-scale-model tests, are suggested. The mathematical model of the device is constructed using the describing function and simplex optimization methods. The presented results of experimental applications of the method show its efficiency. The advantage of the method is the possibility of application for nondestructive inspection of electrical devices in the processes of their production and operation.



Effect of the Error of Measurement of Current Harmonics on the Accuracy of Determination of Magnetic Characteristics
Аннотация
The effect of the error of measurement of the form of current harmonics on the accuracy of determination of weber-ampere characteristics of electrical devices is studied. The developed method for determining weber-ampere characteristics makes it possible to plot them for ac electrical devices in terms of the amplitude and frequency of the input voltage and of the measured current waveform. The effect of the error of measurement of the waveform on the weber-ampere characteristic obtained is studied.



Refractory Alloys
Evolution of Dislocation Structure in a Ni3Al Single Crystal Under the Conditions of High-Temperature Superplasticity
Аннотация
The evolution of defective structure in a single crystal of a Ni3Al-base intermetallic with iron and chromium additives under the conditions of superplasticity (δ = 140%) is studied by transmission electron microscopy. The tensile deformation is performed a 1150°C. Planar flaws and recrystallized grains are detected in the fractured zone of the metal. The mechanisms of high-temperature superplasticity of alloys based on Ni3Al intermetallic are discussed.



Heat Treatment
Heat Treatment of Parts and Castings from High-Manganese Steel of Type 110G13L and its Special Features
Аннотация
Transformations that occur under heating in the structure of high-manganese steel 110G13L are studied. The carbon content in the steel is shown to affect the optimum temperature of heating the high-manganese castings for quenching. An empirical formula for determining the total duration of heating and holding of this type of castings for quenching is obtained.



Technical Information
Effect of Shot Peening on the High-Cycle Fatigue Behavior of High-Strength Cast Iron with Nodular Graphite
Аннотация
The effect of shot peening treatment on high-cycle fatigue of high-strength cast iron with globular graphite is studied. The fatigue curves are plotted, the microhardness and the surface roughness are measured. An analysis of fracture surfaces is performed, and the thickness of the hardened layer is determined. The shot peening is shown to affect favorably the fatigue resistance of the iron but to worsen the condition of the surface.



XX International Conference on Permanent Magnets
Phenomenological Theory of the Processes of Magnetization Reversal of Permanent Magnets From Alloys of Types SmCo5 and Nd2Fe14B
Аннотация
Amethod for simulating the hysteretic properties and the process of magnetization reversal of uniaxial highly anisotropic ferromagnets is developed with allowance for the presence of magnetostatic interaction between microvolumes of the material. It is based on the phenomenological approach to an elementary act of the process of magnetization reversal of these materials. Computer simulation is used to explain and illustrate the phenomenon of “thermal magnetization,” the formation of “channels of reversal magnetization,” the interrelation between the degree of crystal texture and the spin reorientation transfer, the coarsening of the domain structure in rapidly hardened powders, and the behavior of permanent magnets in a magnetic system in contact with a magnetically soft material.



Erratum
Erratum to: Crystal Geometry Mechanism of Intergrowth of Spinel and Manganese Sulfide into a Complex Nonmetallic Inclusion


