International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

During operation, under the influence of mechanical stress, temperature, and external environment, the initial structure of a railway wheel undergoes changes that lead to its fatigue-corrosion wear.
The wheels with different tread profiles that were removed from operation due to the maximum wear of the rims were studied. The studies were carried out using the metallographic method (Neophot-21) and scanning electron microscope JSM-35.
The causes of cracks and wear particles formation near the tread surface of railway wheels associated with phase and structural changes occurring during operation were analyzed. The possibilities of changing the tread profile due to uneven wear were established. It was shown that structural and phase changes near the tread surface are associated with the development of plastic shifts due to the action of external loads, thermal stresses during braking, and the formation of “white layers” when the metal is heated by the heat of braking and abrupt cooling when the brakes are turned off. The role of non-metallic inclusions and corrosion products of wheel steel in the formation of cracks near tread of railway wheels has been established.

The features of the chemical and phase composition, structure and transformations in boride inclusions in the steel 04H14Т3R1F, used for the manufacture of hexagonal pipe covers used during transportation to the place of regeneration and storage of spent fuel assemblies (FA) of nuclear power plants, have been studied. It has been established that steel 04H14Т3R1F contains two types of boride inclusions (Ti,Fe,Cr,V)2B with a shell of (Ti,Cr,V)2B and (Fe,Cr)2B, which have significant chemical heterogeneity. It is shown that in the process of hot deformation the phase and structural transformations occur: a change in the composition of borides due to the redistribution of elements, dynamic diffusion fragmentation and release of “satellite” particles, brittle destruction of borides, boride transformation. The behavior of boride inclusions and their influence on the mechanical properties of 04H14T3R1F steel at different plastic deformation temperatures was studied.

Current construction practice often implies the need to carry out specific actions related to the specification of current operating characteristics of existing and operated in different periods in different ways fibre-reinforced industrial concrete internal floorings and external pavements. Such problems are most often related to a planned change in the operating load, or to estimate their service life in the future. In this regard, specific parameters of a system approach proposed by the author are specified below, including the necessary preliminary field, laboratory and analytical activities related to establishing the current strength-deformation and other essential characteristics of existing industrial concrete floorings and pavements, as follows: concrete cross-section thickness, concrete strengthdeformation characteristics, type and amount of reinforcement used (including fibres), deformation characteristics of the crushed-stone base – according to the dynamic penetration in number of test points, static calculations for the new load conditions, restoring their integrity after sampling, etc. Given the lack of any normative documents on the subject, the proposed systematic approach to the assessment of the residual operational resource of existing fibre-reinforced industrial concrete floorings/pavements is of important methodological importance and fully corresponds to the needs of real construction practice. Its practical use has been approved by the author through a number of successfully conducted systematic expert procedures at a number of sites in the country and abroad.

The features of the chemical and phase composition, structure and transformations in boride inclusions in the steel 04H14Т3R1F, used for the manufacture of hexagonal pipe covers used during transportation to the place of regeneration and storage of spent fuel assemblies (FA) of nuclear power plants, have been studied. It has been established that steel 04H14Т3R1F contains two types of boride inclusions (Ti,Fe,Cr,V)2B with a shell of (Ti,Cr,V)2B and (Fe,Cr)2B, which have significant chemical heterogeneity. It is shown that in the process of hot deformation the phase and structural transformations occur: a change in the composition of borides due to the redistribution of elements, dynamic diffusion fragmentation and release of “satellite” particles, brittle destruction of borides, boride transformation. The behavior of boride inclusions and their influence on the mechanical properties of 04H14T3R1F steel at different plastic deformation temperatures was studied.

The influence of non-metallic inclusions on the formation of defects in deformed steels and their role in providing crack resistance are considered. It is shown that non-metallic inclusions as stress and strain concentrators are one of the most dangerous sources of defect initiation in steels during pressure treatment. It has been established that the nature of cracks and the features of their growth near nonmetallic inclusions are determined by the type of inclusions, as well as by the scheme of the local stress state, which depends on the loading conditions. An analysis was made of the features of the initiation and development of the cracks near non-metallic inclusions of various types during tensile strain, compressive and bending deformation. It is shown that the most severe way of deformation for the inclusion-matrix system is tensile strain, the softest is compression.

The results of finite element modeling of a new method with an increased metal processing level were considered. The improvement of the drawing process was achieved by changing the usual scheme of metal movement during deformation, which made it possible to achieve large strains compared to the standard drawing scheme. It is established that step drawing has the advantage of an increased processing level, but it leads to the formation of an inhomogeneous gradient strain.

This report presents the photonic effect in the deformation of matter by amplifying the emission of hydrogen gas by electromagnetic waves. Presents real experimental facts which upheld the principle (law) that the substance of deformation (pressure and tension) intenifitsirat appointing photon gas (electromagnetic waves. End the final justification of substances in treatment (stress, strain and friction) substances form of electromagnetic matter and emphasis.

Using computer modelling with originally developed semi empirical physical grounded models a study was carried out to investigate influence of previous hot deformation on carbonitrides formation from austenite in low-carbon micro-alloyed steel. Studied in the article is an influence of degree and rate of the deformation on processes of nucleation and growth of Nb and Ti carbonitride particles. The model helps to predict not only process of changing in number and average size of the particles but also to estimate their final size distribution. One of additional peculiarities of the developed model is its ability to predict composition of the cabinetries formed in certain conditions. The model takes into account process of recrystallization and returning, which affect carbonitrides precipitation and are influenced by it. Acceleration was shown of both nucleation and growth rates of the particles due to increasing of deformation degree and strain rate. Another result is that previous deformation significantly affects size distribution function of the particles precipitated with rather lesser effect on their average size. Kinetic curves and final size distribution plots are given.

The results of the effect of preliminary thermal-cyclic deformation on the microstructure of hot-rolled low-carbon steel Ст3пс are presented. It is shown that the regime of thermal-cyclic rolling leads to a decrease in the average grain size of ferrite from 8 to 6 microns in comparison with the structure of steel after industrial production. There is a decrease in the size of pearlite colonies and their volume fraction in the structure of steel after using thermal-cyclic deformation. The results of the effect of heat treatment: normalization and tempering on the electrical resistivity of the hot-rolled carbon steel sheet Ст3пс produced using thermal-cyclic mode of deformation processing (DTCT). DTCT preliminary thermal-cyclic was rolled (5 cycles at a reduction of 10-15 % in each cycle and cooled to a temperature below the Ar1). And normalizing annealing was carried out in the range from 100 to 900 °C increments to 100 °C for 1 hour. The possibility to reduce the magnitude of the specific electrical resistance of the hot-rolled steel manufactured using DTCT mode through the use of subsequent normalizing at 700 °C on average 10 %, and by annealing – no more than 5 %. A further increase in the time of normalization at 700 °C to 3, 5 and 10 hours has no significant effect on the value of the electrical resistance of the steel subjected DTCT. However, the downward trend in resistivity is maintained. Overall reduction of electrical resistivity of the hot-rolled steel Ст3пс by using
mode DTCT and subsequent normalizing at 700 °C for 1 hour is more than 12 %.

The potential of using the ultrafine dispersion powder material obtained by the ECA pressing from a copper powder have considered for the production of fast-acting fuse links. The dependences of the density and microhardness along the length of the sample under different deformation conditions obtained. A deformation zone of constant density is determined and recommended for using in the production of fuse links. The dependence of the electrical resistance along the sample cross-section and across the deformation axis has determined. The fuse links calculation procedure has proposed.

This paper investigations detail analysis of the influence the type of construction and the way of fixing seat bearers on basic bus construction and its superstructure. Before performing experimental investigations it was modeling of tension-deformation condition of across frame made by using Finite Element Methods. During experimental investigations on basis of this analysis it was founded three measuring points where deformations were measuring. According results from experimental investigations it was third type of seat bearers allowing raise of safety area of bus passenger’s.

In this paper are presented some macrofractographic and microfractographic analysis of welded joint fracture surfaces, respectively welded seam (W), heat affected zone (HAZ) and base metal (BM), of spiral and longitudinal steel welded pipes after conducting the laboratory destructive testing. Destructive testing are conducted to assess the quality of the steel welded pipes and besides the numerical results, the fracture surface of the tested samples offers additional information, very important for assessing the quality of steel welded pipes. Given this, in the paper are treated the macrofractographic and microfractographic analysis (LOM-Light Optical Microscopy and Scanning Microscopy-SEM) of the fracture surfaces of samples which are fractured after destructive testing. The morphology of the fracture surfaces is compared with the numerical results and it concludes that there is a direct correlation between the obtained results and deformation that causes fracture, providing thus additional information for assessing the quality of the welded pipes.