Investigation of the Operational Reliability of the Rolled Rails According to the Various Technologies

2015 ◽  
Vol 651-653 ◽  
pp. 317-321 ◽  
Author(s):  
Nicolay G. Kolbasnikov ◽  
Oleg G. Zotov ◽  
Aleksey A. Lukyanov
Keyword(s):  
Mechanical Properties ◽  
Chemical Composition ◽  
Production Technology ◽  
Experimental Studies ◽  
Operational Reliability ◽  
Temperature Deformation ◽  
Current Production ◽  
Cooling Speed ◽  
Deformation Modes

Based on experimental studies of the complex mechanical properties and microstructure, as well as simulation of rails rolling modes made from different steel manufacturers are shown the main technological approaches to obtain rails with high operational reliability . Found that, under the current production technology of domestic steel rails the adjustment of the chemical composition, temperature-deformation modes of rolling and cooling speed rate of the rails is suitable for reducing the negative free ferrite influence on rails durability.

Effect of Thermo-Mechanical Treatment on Mechanical Properties of AlCuMg Alloys

2013 ◽  
Vol 199 ◽  
pp. 407-411
Author(s):  
Teresa Bajor ◽  
Marlena Krakowiak ◽  
Dariusz Rydz
Keyword(s):  
Mechanical Properties ◽  
Internal Combustion Engines ◽  
Large Scale ◽  
Research Work ◽  
Experimental Studies ◽  
Construction Materials ◽  
High Strength ◽  
Effect Of Temperature ◽  
High Temperature Deformation ◽  
Temperature Deformation

Technology development and new grades of alloys creation put before construction materials the number of requirements in range of durability and reliability of created constructions. Receivers expect materials with high strength properties, low production cost of the finished product, availability, corrosion resistance and low specific gravity. So the specific needs of customers mean that studies are constantly associated with the exploration of new materials and technologies that could meet made requirements [1,2,. In large scale this demand is met through the use of non-ferrous metals and their alloys. Selection of appropriate manufacturing techniques and the use of heat treatment procedures allow to obtain materials with better mechanical properties. Here the leading role has the aluminium and its alloys. Due to specific mechanical properties aluminium based materials are used in almost each field of industry. In aircraft industry they are used for the manufacture of fuselage elements in automobile industry the light alloys are used to make cylinder blocks, and other elements of internal combustion engines. In the construction industry they are used to manufacture windows and doors, as well as beautiful self-supporting lightweight facades. While the aluminium alloy products such as films or cans are also used in the food industry. The combination of physico-chemical and mechanical properties of aluminium alloys makes them the optimal solution for innovative design, thanks to them engineers can provide high strength associated with very low gravity. This allows to minimize the costs of subsequent use of the product, and while achieving good strength parameters. As part of this work the analysis of strain rate and temperature impact on mechanical properties of the tested alloy will be carried out. The experimental studies conducted in the temperature range of recrystallization (test temperature: 400°C, 450°C, 480°C, 500°C) using two strain rates 1 s-1 and 0,1 s-1. This paper present the analysis of the application of high-temperature deformation changes in structure mainly caused by the dynamic recrystallization processes, which determine the optimal parameters of AlCuMg deformation process [. The proposed methodology of the research work made it possible to determine the effect of temperature-velocity parameters to changes in mechanical properties (inter alia: microhardness measurements) and changes in the structure of the material, which are closely related to the level achieved in mechanical properties.

scholarly journals The Effect of Chemical Composition and Production Technology on the Mechanical Properties of EN AW-8006 Alloy

2021 ◽  
Vol 4 (1) ◽  
pp. 45-50
Author(s):  
Judit Pázmán ◽  
Jánosné Fehér ◽  
Viktor Gonda ◽  
Balázs Verő
Keyword(s):  
Mechanical Properties ◽  
Chemical Composition ◽  
Aluminum Alloys ◽  
Reference Material ◽  
Cold Rolling ◽  
Production Technology ◽  
Iron Content ◽  
Tensile Testing ◽  
Grain Structure ◽  
Test Results

Abstract Aluminum alloys en AW-8006 with three different Fe:Mn ratios were studied. In the experiments, the temperature of the intermediate soft-annealing between the cold rolling processes and the final soft-annealing at the end of the production technology were varied. The processed samples were subjected to tensile testing and hardness measurements. The effect of chemical composition, based on the test results, showed that for samples without intermediate softening, only the increase of iron content has a significant effect on the yield stress, and the change of iron content refined the final grain structure compared to the reference material.

Methodology of studying the mechanical properties of composite materials (reinforced concrete)

2018 ◽  
Vol 84 (12) ◽  
pp. 61-67
Author(s):  
V. A. Eryshev
Keyword(s):  
Mechanical Properties ◽  
Reinforced Concrete ◽  
Experimental Studies ◽  
Analytical Relationship ◽  
Hardened Concrete ◽  
Deformation Model ◽  
Joint Work ◽  
Concrete Shrinkage ◽  
Axial Tension ◽  
Tension And Compression

The mechanical properties of a complex composite material formed by steel and hardened concrete, are studied. A technique of operative quality control of new credible concrete and reinforcement, both in laboratory and field conditions is developed for determination of the strength and strain characteristics of materials, as well as cohesion forces determining their joint operation under load. The design of the mobile unit is presented. The unit provides a possibility of changing the direction of loading and testing the reinforced element of the given shape both for tension and compression. Moreover, the nomenclature of testing equipment and the number of molds for manufacturing concrete samples substantially decrease. Using the values of forcing resulting in concrete cracking when the joint work of concrete and reinforcement is disrupted the values of the inherent stresses and strains attributed to the concrete shrinkage are determined. An analytical relationship between the forces and deformations of the reinforced concrete sample with central reinforcement is derived for axial tension and compression, with allowance for strains and stresses in the reinforcement and concrete resulted from concrete shrinkage. The results of experimental studies are presented, including tension diagrams and diagrams of developing axial deformations with an increase in the load under the central loading of the reinforced elements. A methodology of accounting for stresses and deformations resulted from concrete shrinkage is developed. The applicability of the derived analytical relationships between stresses and deformations on the material diagrams to calculations of the reinforced concrete structures in the framework of the deformation model is estimated.

Calculation-and-experimental estimation of the role of the frequency ratio in changing the endurance at two-frequency deformation modes

2019 ◽  
Vol 85 (1(I)) ◽  
pp. 64-71 ◽  
Author(s):  
M. M. Gadenin
Keyword(s):  
High Frequency ◽  
Experimental Studies ◽  
Low Frequency ◽  
Reduction Factor ◽  
Single Frequency ◽  
Cyclic Loads ◽  
Small Ratio ◽  
Harmonic Components ◽  
Deformation Modes

The cycle configuration at two-frequency loading regimes depends on the number of parameters including the absolute values of the frequencies and amplitudes of the low-frequency and high-frequency loads added during this mode, the ratio of their frequencies and amplitudes, as well as the phase shift between these harmonic components, the latter having a significant effect only with a small ratio of frequencies. Presence of such two-frequency regimes or service loading conditions for parts of machines and structures schematized by them can significantly reduce their endurance. Using the results of experimental studies of changes in the endurance of a two-frequency loading of specimens of cyclically stable, cyclically softened and cyclically hardened steels under rigid conditions we have shown that decrease in the endurance under the aforementioned conditions depends on the ratio of frequencies and amplitudes of operation low-frequency low-cycle and high-frequency vibration stresses, and, moreover, the higher the level of the ratios of amplitudes and frequencies of those stacked harmonic processes of loading the greater the effect. It is shown that estimation of such a decrease in the endurance compared to a single frequency loading equal in the total stress (strains) amplitudes can be carried out using an exponential expression coupling those endurances through a parameter (reduction factor) containing the ratio of frequencies and amplitudes of operation cyclic loads and characteristic of the material. The reduction is illustrated by a set of calculation-experimental curves on the corresponding diagrams for each of the considered types of materials and compared with the experimental data.

Study of the character and causes of destruction of the cardan shaft of the propeller engine

2019 ◽  
Vol 85 (12) ◽  
pp. 43-50
Author(s):  
D. A. Movenko ◽  
L. V. Morozova ◽  
S. V. Shurtakov
Keyword(s):  
Mechanical Properties ◽  
Chemical Composition ◽  
Yield Point ◽  
Protective Coating ◽  
Fracture Pattern ◽  
Corrosion Cracking ◽  
Tempered Martensite ◽  
Neck Formation ◽  
Static Mechanism ◽  
Shaft Surface

The results of studying operational destruction of a high-loaded cardan shaft of the propeller engine made of steel 38KhN3MFA are presented to elucidate the cause of damage and develop a set of recommendations and measures aimed at elimination of adverse factors. Methods of scanning electron and optical microscopy, as well as X-ray spectral microanalysis are used to determine the mechanical properties, chemical composition, microstructure, and fracture pattern of cardan shaft fragments. It is shown that the mechanical properties and chemical composition of the material correspond to the requirements of the regulatory documentation, defects of metallurgical origin both in the shaft metal and in the fractures are absent. The microstructure of the studied shaft fragments is tempered martensite. Fractographic analysis revealed that the destruction of cardan shaft occurred by a static mechanism. The fracture surface is coated with corrosion products. The revealed cracks developed by the mechanism of corrosion cracking due to violation of the protective coating on the shaft. The results of the study showed that the destruction of the cardan shaft of a propeller engine made of steel 38Kh3MFA occurred due to formation and development of spiral cracks by the mechanism of stress corrosion cracking under loads below the yield point of steel. The reason for «neck» formation upon destruction of the shaft fragment is attributed to the yield point of steel attained during operation. Regular preventive inspections are recommended to assess the safety of the protective coating on the shaft surface to exclude formation and development of corrosion cracks.

Structural features and strength behavior of TRIP/TWIP steels

2020 ◽  
pp. 5-18
Author(s):  
D. V. Prosvirnin ◽  
◽  
M. S. Larionov ◽  
S. V. Pivovarchik ◽  
A. G. Kolmakov ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Chemical Composition ◽  
Thermomechanical Processing ◽  
Maximum Load ◽  
Structural Features ◽  
Stacking Fault ◽  
Stacking Fault Energy ◽  
Structural And Functional Properties ◽  
Twip Steels ◽  
The Creation

A review of the literature data on the structural features of TRIP / TWIP steels, their relationship with mechanical properties and the relationship of strength parameters under static and cyclic loading was carried out. It is shown that the level of mechanical properties of such steels is determined by the chemical composition and processing technology (thermal and thermomechanical processing, hot and cold pressure treatment), aimed at achieving a favorable phase composition. At the atomic level, the most important factor is stacking fault energy, the level of which will be decisive in the formation of austenite twins and / or the formation of strain martensite. By selecting the chemical composition, it is possible to set the stacking fault energy corresponding to the necessary mechanical characteristics. In the case of cyclic loads, an important role is played by the strain rate and the maximum load during testing. So at high loading rates and a load approaching the yield strength under tension, the intensity of the twinning processes and the formation of martensite increases. It is shown that one of the relevant ways to further increase of the structural and functional properties of TRIP and TWIP steels is the creation of composite materials on their basis. At present, surface modification and coating, especially by ion-vacuum methods, can be considered the most promising direction for the creation of such composites.

Weldability - Behavior of Welded Reinforcement

2019 ◽  
Vol 70 (10) ◽  
pp. 3469-3472
Keyword(s):  
Mechanical Properties ◽  
Chemical Composition ◽  
Mechanical Characteristics ◽  
Mechanical Performance ◽  
Current Work ◽  
Carbon Equivalent ◽  
Work Process ◽  
Ultimate Limit

Weldability involves two aspects: welding behavior of components and safety in operation. The two aspects will be reduced to the mechanical characteristics of the elements and to the chemical composition. In the case of steel reinforcing rebar’s, it is reduces to the percentage of Cech(carbon equivalent) and to the mechanical characteristics: the yielding limit, the ultimate limit, and the elongations which after that represent the ductility class in which the re-bars is framed. The paper will present some types of steel reinforcing rebar’s with its mechanical characteristics and the welding behavior of those elements. In the current work, process-related behavior of welded reinforcement, joint local and global mechanical properties, and their correlation with behavior of normal reinforcement and also the mechanical performance resulted in this type of joints. Keywords: welding behavior, ultimate limit, reinforcing rebar’s

Development of Combined Machining Modes, Investigation of Mechanical Properties and Structure of Deformed Semi-Finished Products from Alloy 01417

2020 ◽  
Vol 992 ◽  
pp. 498-503
Author(s):  
S. Sidelnikov ◽  
D. Voroshilov ◽  
M. Motkov ◽  
M. Voroshilova ◽  
V. Bespalov
Keyword(s):  
Mechanical Properties ◽  
Rare Earth Metals ◽  
Electrophysical Properties ◽  
Intermediate Annealing ◽  
Plastic Properties ◽  
Bar Rolling ◽  
Annealing Temperatures ◽  
Continuous Ingot ◽  
The Wire ◽  
Deformation Modes

The article presents the results of studies on the production of wire with a diameter of 0.5 mm from aluminum alloy 01417 with a content of rare-earth metals (REM) in the amount of 7-9% for aircraft construction needs. The deformation modes, the experimental technique and equipment for the implementation of the proposed technology described. The wire was obtained by drawing and bar rolling with subsequent drawing from a rod with a diameter of 5 mm, obtained previously using the process of combined rolling-extruding (CRE) from a continuous ingot with a diameter of 12 mm, cast in an electromagnetic mold (EMM). The wire obtained by the presented technology was subjected to 4 different heat treatment modes with annealing temperatures from 350 to 500 °C and holding time of 1 h in the furnace to achieve mechanical and electrophysical properties corresponding to TS 1-809-1038-2018. The level of strength and plastic properties obtained in the course of research required only one intermediate annealing. The microstructure of the wire was investigated and the modes were revealed that made it possible to obtain the required level of mechanical properties and electrical resistivity, satisfying TS 1-809-1038-2018.

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