scholarly journals Optimization of chemical composition of steel for gearweels of agricultural industry engineering

2020 ◽  
Vol 11 (4) ◽  
pp. 123-129
Author(s):  
O. Ye. Semenovskyi ◽  
◽  
L. L. Titova ◽  

Development of new steels in mechanical engineering to create alloys with predetermined properties that can minimize material and labor costs during their processing. Optimization of the chemical composition of the alloy based on the analysis of the impact of complex alloying on the structure and consequently on the manufacturability of steel. This will reduce the level of internal intensities in the heat treatment process. Based on the analysis of existing trends in mechanical engineering, it is established that the complexity of modern parts of gearweels imposes on the material increasing technological requirements for stamping, machinability, weldability, hardenability, cementation and gouging in the hardening process which explains the need for alloying steel via a certain group of chemical elements. The influence of different compositions of steels for gearweels on the level of internal intensities occurring in parts during heat treatment is studied. The optimal composition of complex-alloyed cementing steel is established.

2020 ◽  
Vol 192 ◽  
pp. 02009
Author(s):  
Valery Predein ◽  
Artyom Popov ◽  
Oleg Komarov ◽  
Sergey Zhilin

The paper considers the possibility of reducing the use of crude ore for metal product by using aluminothermy, which facilitates effective integrated processing of metal waste generated by engineering and metallurgy facilities in the form of mill scale, ferrous and non-ferrous metal swarf with simultaneous castings production. The paper studies the impact patterns of thermite components ratios on the parameters of extracting chemical elements from the source components, metal phase output and its chemical composition. The possible applications for experimental alloys resulting from controlled exothermic reactions are determined for supplying castings and melting stock to blank production for mechanical engineering facilities.


Author(s):  
Oleksandr Babachenko ◽  
Ganna Kononenko ◽  
Katerina Domina ◽  
Rostislav Podolskyi ◽  
Olena Safronova

A review of research in the field of modeling experiments on heat treatment and pressure treatment of metal and the impact on the physical and mechanical properties of steel with a chemical composition of 0.59% C, 0.31% Si, 0.73% Mn. A mathematical model for calculating the physical and mechanical properties of steel in the process of hot plastic deformation has been developed and prospects for further development of research in this area have been identified. As a result of modeling, the following functions were obtained: the amount of deformation in the direction of the applied force divided by the initial length of the material. The coefficient of elongation of the material with the actual chemical composition at a temperature of 1250 ± 10 ° C, which was 0.32. When comparing the values of the load that was applied to the GPA in the laboratory and the results of calculations using the developed model, it was found that they have close values of about 45 MPa. This confirms the adequacy of the obtained model.A review of research in the field of modeling experiments on heat treatment and pressure treatment of metal and the impact on the physical and mechanical properties of steel with a chemical composition of 0.59% C, 0.31% Si, 0.73% Mn. A mathematical model for calculating the physical and mechanical properties of steel in the process of hot plastic deformation has been developed and prospects for further development of research in this area have been identified. As a result of modeling, the following functions were obtained: the amount of deformation in the direction of the applied force divided by the initial length of the material. The coefficient of elongation of the material with the actual chemical composition at a temperature of 1250 ± 10 ° C, which was 0.32. When comparing the values of the load that was applied to the GPA in the laboratory and the results of calculations using the developed model, it was found that they have close values of about 45 MPa. This confirms the adequacy of the obtained model.


Author(s):  
Radiy Kh. Gimaletdinov ◽  
Andrey A. Gulakov ◽  
Ildar Kh. Tukhvatulin

Problem Statement (Relevance): An urgent task of rolling mill operators includes minimizing the cost of manufactured products while ensuring the required quality. To accomplish the task, measures are being taken to optimize the rolling process aimed at increasing the duration of the rolling campaigns and reducing the number of roll regrinds. The performance of the rolls is influenced by the properties of the working layer material which determine wear resistance, formation and development of fire cracks, as well as resistance to metal sticking. Finishing mill rolls dictate the surface quality of the rolled steel. That is why it is important to make timely regrinds in order to completely remove the fire crack layer. The removal depth and the acceptable duration of the campaigns depend on the properties of the roll working layer material. To improve the properties of the rolls, the roll manufacturers need the actual roll operation data to be able to analyze how the chemical composition and the structure of the roll working layer is related to the roll performance. Such analysis will help improve the structure and properties of the materials used, as well as develop new ones. Objectives: The objective of this research is to understand how the chemical composition of the working layer of indefinite chilled cast iron rolls used in finishing mills dictates the roll performance, to evaluate the effect of each chemical element, and to determine what concentrations of the chemical elements could most effectively benefit the performance of indefinite chilled cast iron rolls. Methods Applied: The methods applied include building a database of the finishing mill indefinite chilled cast iron rolls and using artificial neural networks based on a dual-function algorithm. Originality: The authors built a neuromodel which can help understand the effect of the chemical composition of the roll working layer and predict the performance of indefinite chilled cast iron rolls. The authors studied the effect of carbon, silicon, manganese, chromium, nickel, molybdenum, vanadium, niobium and boron on the performance of indefinite chilled cast iron rolls. Findings: Graphic diagrams were built which demonstrate the effect of each chemical element on the performance of indefinite chilled cast iron rolls at constant concentrations of the remaining elements. The authors looked at the relationship between the chemical elements and the roll performance in terms of the impact of the former on the structure of indefinite chilled cast iron rolls. The effective concentrations of the chemical elements were also determined. Practical Relevance: The authors developed a new chemical composition of indefinite chilled cast iron to be used for the working layer of finishing mill rolls. As a result, a 12–14% increase in the roll performance was achieved.


2020 ◽  
Vol 163 ◽  
pp. 05011
Author(s):  
Marina Opekunova ◽  
Anatoly Opekunov ◽  
Stepan Kukushkin ◽  
Sergey Lisenkov

This study describes the changes in the chemical composition of soil waters under the influence of natural and anthropogenic factors in the area of development of oil and gas condensate fields in the north of Western Siberia. The concentration of chemical elements (Na, K, Ca, Cu, Zn, Fe, Pb, Cd, Ni, Co, Cr, Ba, Sr, Cd, and Mn) in soils, ground and soil waters was determined. Pollution of soil water and soil is local in nature and it is characteristic of areas located in the immediate vicinity of industrial facilities. A set of indicators is proposed for assessing the transformation of natural complexes under the influence of oil and gas production. The increased pH values, concentrations of petroleum hydrocarbons, nitrates, chlorides, sodium, potassium, calcium, barium, strontium, iron and manganese, as well as zinc, vanadium, cobalt and nickel are observed. In the impact zones in soil waters and soils. Mechanical disturbances of the soil and vegetation cover lead to an increase in defrost, secondary waterlogging and are accompanied by an increase in the migration of chemical elements in the catenary structure of landscapes.


2020 ◽  
Vol 643 ◽  
pp. A108
Author(s):  
A. Coutens ◽  
B. Commerçon ◽  
V. Wakelam

Context. The chemical composition of protoplanetary disks is expected to impact the composition of the forming planets. Characterizing the diversity of chemical composition in disks and the physicochemical factors that lead to this diversity is consequently of high interest. Aims. The aim of this study is to investigate the chemical evolution from the prestellar phase to the formation of the disk, and to determine the impact that the chemical composition of the cold and dense core has on the final composition of the disk. Methods. We performed 3D nonideal magneto-hydrodynamic (MHD) simulations of a dense core collapse using the adaptive-mesh-refinement RAMSES code. For each particle ending in the young rotationally supported disk, we ran chemical simulations with the three-phase gas-grain chemistry code Nautilus. Two different sets of initial abundances, which are characteristic of cold cores, were considered. The final distributions of the abundances of common species were compared to each other, as well as with the initial abundances of the cold core. Results. We find that the spatial distributions of molecules reflect their sensitivity to the temperature distribution. The main carriers of the chemical elements in the disk are usually the same as the ones in the cold core, except for the S-bearing species, where HS is replaced by H2S3, and the P-bearing species, where atomic P leads to the formation of PO, PN, HCP, and CP. However, the abundances of less abundant species change over time. This is especially the case for “large” complex organic molecules (COMs) such as CH3CHO, CH3NH2, CH3OCH3, and HCOOCH3 which see their abundances significantly increase during the collapse. These COMs often present similar abundances in the disk despite significantly different abundances in the cold core. In contrast, the abundances of many radicals decrease with time. A significant number of species still show the same abundances in the cold core and the disk, which indicates efficient formation of these molecules in the cold core. This includes H2O, H2CO, HNCO, and “small” COMs such as CH3OH, CH3CN, and NH2CHO. We computed the MHD resistivities within the disk for the full gas–grain chemical evolution and find results in qualitative agreement with the literature assuming simpler chemical networks. Conclusions. In conclusion, the chemical content of prestellar cores is expected to affect the chemical composition of disks. The impact is more or less important depending on the type of species. Users of stand-alone chemical models of disks should pay special attention to the initial abundances they choose.


This paper includes the study of heat treatment process that we carried out on En 19 steel in cryogenic atmosphere. Cryogenic treatments of alloy steels have been significantly increase wear resistance and toughness. These investigations of warmth treatment cryogenic medicines of amalgam steels have been asserted to altogether expand wear protection and sturdiness. Cryogenic handling is a supplementary procedure to customary warmth treatment process in steels. The cryogenic treatment on apparatus materials builds the life of instruments, gear, parts and materials by boosting elasticity, sturdiness and strength. This cryogenic hardening process is an onetime treatment influencing the whole part — not only the surface. Cryogenic treatment has been broadly embraced as a cost decrease and execution upgrading innovation. Cryogenic treatment is likewise utilized as an empowering innovation, when its pressure alleviating benefits are used to allow the manufacture (or machining) of basic resistance parts. With regards to great outcomes about the use of profound cryogenic treatment (DCT) on materials, the impact on the microstructure and properties (hardness, strength and the substance of held austenite) are observed to be made strides. Cryogenic treatment has been distinguished to improve the properties of Tools steels. It is discovered that cryogenic treatment confers almost 110% change in apparatus life.


2021 ◽  
Vol 40 (5) ◽  
pp. 104-114
Author(s):  
G.A. Chelnokov ◽  
◽  
I.V. Bragin ◽  
N.A. Kharitonova ◽  
◽  
...  

The article presents the results of isotope-chemical research of the Tavatum thermal water deposit (coast of the Sea of Okhotsk, Magadanskaya Oblast), as well as surrounding underground and surface waters. For the first time, data on the content of isotopes of oxygen and hydrogen in the underground and surface waters were obtained, and the analysis of trace elements was performed. The results show that the chloride sodium-calcium mesohalinous thermal waters of the Tavatum deposit are atmogenic; two processes can be considered as the main processes of the chemical composition formation: 1) involvement of deep brines (including cryopeg waters) and 2) cationic exchange in the interaction of sea waters (buried during marine transgressions in the Holocene) with rocks. In the chemical composition of thermal waters, there are indicator chemical elements reflecting the impact of deep high-temperature processes. The temperature of the deep fluid estimated by different geothermometers is 117 to 128°C, and the depth of formation is at least three kilometers.


Author(s):  
I. I. Lube ◽  
N. V. Trutnev ◽  
S. V. Tumashev ◽  
A. V. Krasikov ◽  
A. G. Ul’yanov ◽  
...  

At production of pipes of type 13Cr grade steel used at development of oil and gas deposits in areas with aggressive environment, intensive wear of instrument takes place, first of all, piercing mill mandrels. Factors, influencing the resistivity of the piercing mandrels considered, including chemical composition of the material, the mandrel is made of and its design. Based on industrial experience it was shown, that chrome content in the mandrel material practically does not affect on the increase of its resistivity, since the formed thin protective oxides having high melting temperature, are quickly failed and practically are not restored in the process of piercing. To increase the resistivity of piercing mandrels at production of casing tubes of type 13Cr grade steel, a work was accomplished to select a new material for their manufacturing. The chemical composition of steel presented, which was traditionally used for piercing mandrels manufacturing, as well as a steel grade proposed to increase their resistivity. First, molybdenum content was increased, which increases the characteristics of steel strength and ductility at high temperatures and results in grain refining. Second, tungsten content was also increased, which forms carbides in the steel resulting in an increase of its hardness and “red resistivity”, as well as in preventing grains growth during heating. Third, cobalt content was also increased, which increases heat resistivity and shock loads resistivity. The three elements increase enabled to increase the mandrels resistivity by two times. Results of mandrel test of steel 20ХН2МВ3КБ presented, the mandrel having corrugation on the working cone surface, which enabled to reach the resistivity growth to 12 passes without significant change of instrument cost. Microstructure of mandrels made of steels 20Х2Н4МФА and 20ХН2МВ3КБ shown. Application of the centering pin of special design was tested, which provided forming of a rounding edge on the front billet ends, eliminated undercut of mandrel external surface in the process of secondary billet grip and increase the service life of the piercing mill mandrels. At production of seamless pipes of martensite class type 13Cr stainless steels having L80 group of strength, an increase of piercing mandrel resistivity was reached by more than four times, which together with other technical solutions enabled to increase the hourly productivity of the hot rolling section of Volzhsky pipe plant ТПА 159-426 line by more than two times.


Author(s):  
Kulwant Singh ◽  
Gurbhinder Singh ◽  
Harmeet Singh

The weight reduction concept is most effective to reduce the emissions of greenhouse gases from vehicles, which also improves fuel efficiency. Amongst lightweight materials, magnesium alloys are attractive to the automotive sector as a structural material. Welding feasibility of magnesium alloys acts as an influential role in its usage for lightweight prospects. Friction stir welding (FSW) is an appropriate technique as compared to other welding techniques to join magnesium alloys. Field of friction stir welding is emerging in the current scenario. The friction stir welding technique has been selected to weld AZ91 magnesium alloys in the current research work. The microstructure and mechanical characteristics of the produced FSW butt joints have been investigated. Further, the influence of post welding heat treatment (at 260 °C for 1 h) on these properties has also been examined. Post welding heat treatment (PWHT) resulted in the improvement of the grain structure of weld zones which affected the mechanical performance of the joints. After heat treatment, the tensile strength and elongation of the joint increased by 12.6 % and 31.9 % respectively. It is proven that after PWHT, the microhardness of the stir zone reduced and a comparatively smoothened microhardness profile of the FSW joint obtained. No considerable variation in the location of the tensile fracture was witnessed after PWHT. The results show that the impact toughness of the weld joints further decreases after post welding heat treatment.


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