Investigation of consequences of violation of technology of manufacture of individ-ual elements of BMP-2 track tape

2021 ◽  
pp. 61-68
Author(s):  
R. Kuzmenko ◽  
М. Kovba ◽  
O. Popovchenko ◽  
Т. Kovbasiuk ◽  
S. Shvachko
Keyword(s):  
Heat Treatment ◽  
Spectral Analysis ◽  
Chemical Composition ◽  
Materials Science ◽  
Density Measurement ◽  
Science Research ◽  
Steel Grade ◽  
Military Equipment ◽  
Steel Grades ◽  
The Military

The operation of the BMP-2 infantry fighting vehicle was accompanied by periodic failures of the tracked belts. This is due to the breakage of the fixing bolts of the track pins fastening bracket, and thus the military equipment became stationary. Establishing the causes of the destruction of the bolt fixing the staple of the track fingers of the tracked belt of military equipment was carried out using a complex of instrumental materials science research. In particular, the chemical composition of the material from which the bolts and staples were made was determined by the spectral analysis; the fracture surface of the fixing bolt was investigated by the macroanalysis; the microstructure of the bolts was examined using optical microscopy; the microhardness and density of the bolt material was measured. The bolts were made from steel grades 30XM and 33XC, and not from the recommended steel grade 38XC. The macrostructure of the broken bolt corresponds to the shearing structure. The microstructure showed rolling and heat treatment defects. Density measurement confirmed the presence of heat treatment defects. The imperfection of the applied heat treatment was confirmed by measuring the microhardness. A complex of metallurgical research has established the main cause of the destruction of the bolts. It consists in an unsuccessful design of bolts and brackets, an incorrectly selected steel grade with defects in rolling and heat treatment.

Application of Computer Simulation in Materials Science

2012 ◽  
Vol 189 ◽  
pp. 453-456
Author(s):  
Su Ping You
Keyword(s):  
Heat Treatment ◽  
Computer Simulation ◽  
Materials Science ◽  
Material Design ◽  
Science Research ◽  
Research Process ◽  
Simulation Methods ◽  
Simulation Technology ◽  
Material Microstructure ◽  
Qualitative Estimate

The computer simulation methods have become more and more widely used technique in materials science research. This paper discusses the importance of the application of computer simulation in the field of materials science. There are many application areas of computer simulation in materials science including the heat treatment, material microstructure, corrosion and protection, casting, and material design areas. It can be seen from the results of these applications that computer simulation technology is an efficient, realistic way to fully reflect the variation of the sample in a variety of research process. It can get rid of a rough qualitative estimate of production of the backward state.

The Prediction of Hardenability using Neural Networks

2014 ◽  
Vol 59 (1) ◽  
pp. 133-136 ◽  
Author(s):  
M. Knap ◽  
J. Falkus ◽  
A. Rozman ◽  
K. Konopka ◽  
J. Lamut
Keyword(s):  
Neural Networks ◽  
Chemical Composition ◽  
Steel Grade ◽  
Chemical Compositions ◽  
Heterogeneous Database ◽  
High Quality ◽  
Model Predictions ◽  
Steel Grades ◽  
Improved Model ◽  
Influential Parameters

Abstract The objective of the research that has been presented was to model the effect of differences in chemical composition within one steel grade on hardenability, with a very broad and heterogeneous database used for studying hardness predictions. This article presents the second part of research conducted with neural networks. In the previous article [1] the most influential parameters were defined along with their weights and on the basis of these results, an improved model for predicting hardenability was developed. These developed neural networks were applied to model predictions of hardenability for three steel grades VCNMO150, CT270 and 42CrMoS4. The results proved that the correlation between the chemical composition differences within a chosen steel grade and the hardness changes can be modeled. If the database is big enough, predictions would be accurate and of high quality. But for a less comprehensive database, the differences in hardness predictions for various chemical compositions of the steel grade concernedwere observable.

scholarly journals Development of actions on optimization of chemical composition of carburized steel grade 16MnCrS5 to eliminate the causes of the growth of large austenite grains

2019 ◽  
pp. 49-56 ◽  
Author(s):  
I. A. Kovaleva ◽  
I. A. Ovchinnikova ◽  
S. V. Stefanovitch
Keyword(s):  
Grain Size ◽  
Chemical Composition ◽  
High Performance ◽  
Internal Combustion Engines ◽  
Cutting Tools ◽  
Steel Grade ◽  
Fine Grained ◽  
Carburized Steel ◽  
Fine Grained Structure ◽  
Steel Grades

The problem of friction, wear of machine parts and cutting tools, the need to increase the life of machines makes the task of creating new high-performance, energy-saving technologies of hardening one of the main in engineering. In mechanical engineering, the problem of improving the physical, mechanical and operational properties in thin surface layers (~10 microns) of such parts as shafts, gears, measuring tools, drills, cylinders of internal combustion engines, etc. is important. Currently, these tasks are often solved by applying reinforcing coatings. Cementation is economical. The technology of cemented steels smelting, which is currently used by metallurgical plants, does not ensure stable production of fine-grained structure in products. At the same time, the capacity of machines and units are growing, and to obtain parts that can withstand higher loads while maintaining their overall dimensions, new steel grades are needed. The complexity of the configuration of gears with a thin tooth and a massive sleeve, and the need for minimal warping make heat treatment as difficult and responsible as a complex tool, such as shaped cutters. Therefore, for the manufacture of gears you want to assign steel with small hereditary grain size. In this article we will focus on the development and production of cemented steel in the conditions of OJSC «BSW – Management Company of Holding «BMC», in particular, the steel brand 16MnCrS5 commissioned by the European manufacturer of gearboxes and motors. To determine the grain size of the metal must be subjected to special types of processing for the manifestation of certain characteristics. These results allow us to draw conclusions about the need to adjust the chemical composition of steel grade 16MnCrS5 by introducing a system of modifying elements, which will reduce the tendency of steel to overheating, therefore, reduce the size of austenitic grains. On the basis of the revealed regularities on the influence of carbide-forming elements, a further system of steel modification is determined, which includes a complex of elements V, Nb, Ti.

scholarly journals FORMATION OF A MULTI-LAYERED TITANO-STEEL INTERMETALLIC COMPOSITE

2020 ◽  
pp. 6-14
Author(s):  
V. N. Arisova ◽  
L. M. Gurevich ◽  
V. O. Kharlamov ◽  
D. D. Tverdysheva ◽  
V. A. Izyumsky
Keyword(s):  
Electron Microscopy ◽  
Heat Treatment ◽  
Spectral Analysis ◽  
Chemical Composition ◽  
X Ray ◽  
Intermetallic Composite ◽  
Intermetallic Layers

The work presents the results of studies on the formation of intermetallic layers in a five-layer explosion-welded composite titanium VT-20+steel 08Cr18Ni10Ti after heat treatment at temperatures of 800, 850 and 900 °C and holding times of 4 and 10 hours. The structure, microhardness, chemical composition of the diffusion zones of the composite were studied using optic, electron microscopy and X-ray spectral analysis.

scholarly journals STUDY OF DIFFUSION PROCESSES IN A MULTILAYER TITANIUM-STEEL COMPOSITE UNDER LONG HEATING

2021 ◽  
pp. 14-21
Author(s):  
V. N. Arisova ◽  
L. M. Gurevich ◽  
A. F. Trudov ◽  
V. O. Kharlamov ◽  
D. D. Tverdysheva
Keyword(s):  
Electron Microscopy ◽  
Heat Treatment ◽  
Spectral Analysis ◽  
Chemical Composition ◽  
Diffusion Processes ◽  
X Ray ◽  
Optical And Electron Microscopy ◽  
Steel Composite

The paper presents the results of studies of diffusion processes in a five-layer explosion-welded composite titanium VT-20+steel 08Cr18Ni10Ti after heat treatment at temperatures of 850 and 900 ° C and holding times of 20-100 hours. The features of the formation of the microstructure, microhardness, and the chemical composition of the diffusion zones of the composite have been studied using optical and electron microscopy and X-ray spectral analysis.

Plasma parameters in atomic-emission spectral analysis of phosphate concentrates of the fission products

2019 ◽  
Vol 85 (2) ◽  
pp. 17-22
Author(s):  
M. I. Khamdeev ◽  
E. A. Erin
Keyword(s):  
Spectral Analysis ◽  
Chemical Composition ◽  
Reference Materials ◽  
Fission Products ◽  
Atomic Emission ◽  
Electric Arc ◽  
Physical Parameters ◽  
Arc Plasma ◽  
Atomic Emission Spectral Analysis ◽  
Excitation Processes

Physical parameters of electric arc plasma as well as their time dependences are calculated when analyzing phosphate precipitates of the fission products of irradiated nuclear fuel. Phosphate concentrates of the fission products are known for their complex chemical composition and high thermal and chemical stability. Hence, direct atomic emission spectral analysis of phosphate powders without transferring them into solutions is advisable. Different conditions of sample preparation and synthesis of the reference materials determine the different chemical forms of the elements to be determined. This, in turn, affects the kinetics of their evaporation in the electrode crate and excitation processes in the plasma. The known mechanisms of those processes cannot always be transferred to specific conditions of the given method of analysis thus entailing the necessity of studying the effect of the samples chemical composition on the results of determination, proper choice of spectroscopic carriers, detailed study of spectra excitation processes in spectral analysis, and analysis of the physical parameters of the electric arc plasma. We used the lines Zn I 307.206 nm and Zn I 307.589 nm to measure the effective temperature of the central hot sections of the arc in a range of4500 - 6500 K. NaCl, BaCl2 and NaCl + T1C1 were studied to reduce the effect of the sample elemental composition on excitation conditions of the spectra and their stabilization as a spectroscopic carrier. In control experiments we used carrier-free samples. The coincidence of the values of the plasma physical parameters within the measurement error not exceeding 20%, as well as the identity of the nature of the kinetic curves for samples of phosphate precipitates and synthetic reference materials prove their correctness. The result of the study substantiate correctness of the direct atomic-emission spectral procedure in analysis of phosphate concentrates of fission when using synthetic reference materials.

BÖHLER W403 VMR

Alloy Digest ◽  
2013 ◽  
Vol 62 (9) ◽  
Keyword(s):  
Heat Treatment ◽  
Chemical Composition ◽  
Physical Properties ◽  
Tool Steel ◽  
Raw Materials ◽  
Heat Treating ◽  
Diffusion Annealing ◽  
Selection Of

Abstract Böhler (or Boehler) W403 VMR is a tool steel with outstanding properties, based not only on a modified chemical composition, but on the selection of highly clean raw materials for melting, remelting under vacuum (VMF), optimized diffusion annealing, and a special heat treatment. This datasheet provides information on composition, physical properties, and elasticity. It also includes information on forming and heat treating. Filing Code: TS-721. Producer or source: Böhler Edelstahl GmbH.

Structure and chemical composition of exopolysaccharides of frost-damaged sugar beet

2020 ◽  
pp. 34-39
Author(s):  
Aneta Antczak-Chrobot ◽  
Maciej Wojtczak
Keyword(s):  
Spectral Analysis ◽  
Chemical Composition ◽  
Sugar Beet ◽  
Total Acid ◽  
Average Molecular Mass ◽  
Central European ◽  
Composition And Structure ◽  
Monomeric Composition ◽  
Branched Structure ◽  
Different Origin

In this research paper, development of a procedure of isolation of exopolysaccharides from frost-damaged beet and an analysis of structural and chemical composition of polymers isolated from sugar beet of different origin are presented. Total acid hydrolysis degradation integrated with HPAEC-ED analysis has been utilized to confirm the monomeric composition of the separated polysaccharides. The implementation of NMR spectral analysis and SEC chromatography of the structure of exopolysaccharides has been investigated. The results demonstrate that the chemical composition and structure of exopolysaccharides depend on their origin. Typical exopolysaccharides from Central European beet roots consist mainly of glucose monomers – and they have low branched structure – about 90% of α-1,6 linkage which is typical for dextran. The exopolysaccharides isolated from Swedish beet are characterized by 50–60% fructose monomers. They contain only about 65% α-1,6 linkages. Exopolysaccharides extracted from various origin beet differ in average molecular mass. The molecular distribution is not normal.

DETERMINATION OF THE DISTRIBUTION FUNCTION OF THE TIME BETWEEN FAILURES OF A WEAPON MODEL WITHOUT TAKING INTO ACCOUNT THE ENEMY’S FIRE IMPACT

2019 ◽  
pp. 39-45
Author(s):  
M. Sliusarenko ◽  
O. Semenenko ◽  
T. Akinina ◽  
O. Zaritsky ◽  
V. Ivanov
Keyword(s):  
Distribution Function ◽  
Analytical Description ◽  
Time To Failure ◽  
Missile Defense ◽  
Incorrect Choice ◽  
Military Equipment ◽  
Time Between Failures ◽  
The Military ◽  
Fire Impact

In the article, based on the analysis of the requirements for the readiness of weapons and military equipment during combat use and the reliability of their operation in the course of combat operations, it was discovered that one of the reasons that causes a discrepancy between the declared failures and real ones may be the incorrect choice and justification of the time distribution function up to the refusal of military means. As a rule, during the development of these tools, the function of distribution of time to failure is chosen by analogy with similar patterns of weapons and military equipment. In the theory of reliability, special attention is given to choosing the function of time-breaking non-response (failures or failures). Therefore, the article deals with the questions of evaluating the effectiveness of functioning of complex systems and methods of modeling the processes of their functioning, taking into account the laws of the distribution of random variables. The discrepancy between the declared irregularity of the military apparatus and the fact that is actually observed in the troops can be explained by the incorrectly accepted hypothesis about the distribution of time to failure. Therefore, the article analyzes the order of the justification of such a function without taking into account the enemy's fire impact and the proposed variant of determining the function of distribution of the time of work until the refusal of the model of military equipment. The article also cites the reasons for the discrepancy between the claimed missile defense equipment and what is actually observed in the troops. The proposed mathematical model of faultlessness, which at stages of designing and design will allow to set requirements to the model of technology with the help of analytical description. The sequence of calculations of non-failure indexes based on the use of Weibull distribution is substantiated.

scholarly journals Solvent-Controlled Self-Assembled Oligopyrrolic Receptor

Molecules ◽  
2021 ◽  
Vol 26 (6) ◽  
pp. 1771
Author(s):  
Fei Wang ◽  
Kejiang Liang ◽  
Mads Christian Larsen ◽  
Steffen Bähring ◽  
Masatoshi Ishida ◽  
...  
Keyword(s):  
Materials Science ◽  
Science Research ◽  
Polymeric Chain ◽  
Supramolecular System ◽  
Receptor System ◽  
One Dimensional ◽  
X Ray ◽  
Host Guest Complex ◽  
Colorimetric Response ◽  
Strong Acids

We report a fully organic pyridine-tetrapyrrolic U-shaped acyclic receptor 10, which prefers a supramolecular pseudo-macrocyclic dimeric structure (10)2 in a less polar, non-coordinating solvent (e.g., CHCl3). Conversely, when it is crystalized from a polar, coordinating solvent (e.g., N,N-dimethylformamide, DMF), it exhibited an infinite supramolecular one-dimensional (1D) “zig-zag” polymeric chain, as inferred from the single-crystal X-ray structures. This supramolecular system acts as a potential receptor for strong acids, e.g., p-toluenesulfonic acid (PTSA), methane sulfonic acid (MSA), H2SO4, HNO3, and HCl, with a prominent colorimetric response from pale yellow to deep red. The receptor can easily be recovered from the organic solution of the host–guest complex by simple aqueous washing. It was observed that relatively stronger acids with pKa < −1.92 in water were able to interact with the receptor, as inferred from 1H NMR titration in tetrahydrofuran-d8 (THF-d8) and ultraviolet–visible (UV–vis) spectroscopic titrations in anhydrous THF at 298 K. Therefore, this new dynamic supramolecular receptor system may have potentiality in materials science research.

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