scholarly journals V. Development of new powder wires for building-up. A powder wire based on dust of gas cleaning systems of silicomanganese

2018 ◽  
pp. 101-106
Author(s):  
N. A. Коzyrev ◽  
R. E. Kryukov ◽  
A. S. Nepomnyaschikh ◽  
A. A. Usol’tsev ◽  
М. V. Popova
Keyword(s):  
Chemical Composition ◽  
Nonmetallic Inclusions ◽  
Statistical Processing ◽  
Optical Microscope ◽  
Aluminum Production ◽  
Production Plant ◽  
Powder Wire ◽  
Gas Cleaning ◽  
Study Results ◽  
Wear Tests

A new powder wire developed by using dust of gas cleaning systems of silicomanganese production plant and powder of gas cleaning systems of aluminum production at different proportion of components. As components the following was used: dust of gas cleaning systems of aluminum production plant, % (mas.): 21–46.23 Al2O3; 18–27 F; 8–15 Na2O; 0.4–6 K2O; 0.7–2.3 CaO; 0.5–2.48 Si2O; 2.1–3.27 Fe2O3; 12.5–30.2 Ctotal; 0.07–0.9 MnO; 0.06–0.9 MgO; 0.09–0.19 S; 0.1–0.18 P, and dust of gas cleaning systems of silicomanganese production plant, % (mas.): 2.43 Al2O3; 1.32 Na2O; 5.56 K2O; 6.4 CaO; 29.19 SiO2; 0.137 BaO; 7.54 MgO; 0.23 S; 0.04 P; 1.067 Fe; 27.69 Mn; 2.687 Zn; 3.833 Pb.The building-up was done under a flux, made of slag of silicomanganese plant of Zapadno-Sibirsky steel-works, havin the chemical composition (%, mas.): 6.91–9.62 Al2O3; 22.85–31.70 CaO; 46.46–48.16 SiO2; 0.27–0.81 FeO; 6.48–7.92 MgO; 8.01–8.43 MnO; 0.28–0.76 F; 0.26–0.36 Na2O; 0.62 K2O; 0.15–0.17 S; 0.01 P. The building-up mode selected. Samples wear tests were carried out at machine 2070 СМТ-1. Chemical composition of the built-up metal was determined at spectrometer ДФС-71. The hardness of built-up layers was measured by hardness meter МЕТ-ДУ. The estimation of nonmetallic inclusions was made as per GOST 1778– 70 by optical microscope Olympus GX-51.Quality indices studied and coefficients of manganese recovery at different proportions of components calculated. Statistical processing of the study results was made, statistical curves of influence of component compositions on properties of built-up layer constructed.

scholarly journals Study of properties of cored wire based on ferrochrome gas-cleaning dust

2019 ◽  
Vol 75 (3) ◽  
pp. 365-372 ◽  
Author(s):  
N. A. Kozyrev ◽  
A. A. Usol’tsev ◽  
A. N. Prudnikov ◽  
R. E. Kryukov ◽  
A.. R. Mikhno
Keyword(s):  
Wear Resistance ◽  
Chemical Composition ◽  
Statistical Processing ◽  
Aluminum Production ◽  
Recovery Coefficient ◽  
Cored Wire ◽  
Gas Cleaning ◽  
Filling Materials ◽  
Study Results ◽  
Cored Wires

Applying of wear-resistant alloyed coatings by build-up welding is one of methods to provide high operation properties of technological, metallurgical in particular equipment. Technologies of strengthening by direct alloying or reducing of alloying materials from oxide phases by reducing agent directly in the arc during building-up are most efficient ones. For build-up, cored wires are used frequently nowadays. A possibility to manufacture cored wires based on ferrochrome production gas-cleaning dust and powders of silicon, aluminum, and aluminum production gas-cleaning dust as reducing agents considered. Chemical composition and relation between cored wires components quoted. Manufacturing of 5 mm diameter wire accomplished at laboratory facility by running through draw plate. Duringestimation of efficiency of the manufactured cored wires application a regime of build-up was selected, study of chemical composition of built-up metal carried-out, wearing tests made, measuring of built-up samples hardness carried-out. Coefficients of chrome recovery coefficient at different relation between filling materials were calculated. Statistical processing of the study results accomplished statistical dependences of components content influence onthe built-up layer properties plotted. Study of the built-up showed, that chrome recovery in the built-up layer depends completely on the cored wire filling coefficient. At that under other conditions being equal, the hardness always correlates with the wear, and increase of chrome concentration results in reduction of the surface wear. Dependents of mass share elements comprising the cored wire content on built-up layer hardness and its wear resistance determined. The dependences obtained can be used for forecasting of builtup layer hardness and its wear resistance while built-up metal chemical composition varying.

scholarly journals TUNGSTEN RECOVERY FROM OXIDE DURING FLUX CORD WIRE SURFACING

2019 ◽  
Vol 62 (3) ◽  
pp. 215-221
Author(s):  
N. A. Kozyrev ◽  
R. E. Kryukov ◽  
V. M. Shurupov ◽  
N. V. Kibko ◽  
L. P. Bashchenko
Keyword(s):  
Chemical Composition ◽  
Nonmetallic Inclusions ◽  
Tungsten Powder ◽  
Aluminum Production ◽  
Metallographic Analysis ◽  
Austenite Grain Size ◽  
Cored Wire ◽  
Gas Cleaning ◽  
Primary Austenite ◽  
Austenite Grain

 Influence of introduction of tungsten powder and tungsten concentrate into surfacing flux-cored wire on structure, structural components microhardness, hardness and wear of the surfacing layer has been studied. Flux cored tungsten-containing wires of H- and E-types according to the IIW classification were manufactured for surfacing in laboratory. Powders of silicon KR-1 (GOST 2169 – 69), manganese MR-0 (GOST 6008 – 82), chromium PKhA-1M (industrial standard TU 14-1-1474 – 75), vanadium VEL-1 (industrial standard TU 48-0533 – 71), nickel PNK-1l5 (GOST 9722 – 97), aluminum PAP-1 (GOST 5494 – 95), tungsten PVT (industrial standard TU 48-19-72 – 92) and iron powder PZhV-1 (GOST 9849 – 86) were used as fillers. In some wires tungsten concentrate KSh-4 (GOST 213 – 83) produced by “AIR” mining company” JSC was used instead of tungsten powder. Gas cleaning dust of aluminum production of the following chemical composition: 21.00 – 43.27 % Al2O3; 18 – 27 % F; 8 – 13 % Na2O; 0.4 – 6.0 % K2O; 0.7 – 2.1 % CaO; 0.50 – 2.48 % SiO2; 2.1 – 2.3 % Fe2O3; 12.5 – 28.2 % Cgen; 0.03 – – 0.90 % MnO %; 0.04 – 0.90 % MgO; 0.09 – 0.46 % S; 0.10 – – 0.18 % P (by weight) was used as a carbon-containing reducing agent. Wire with diameter of 5mm manufactured at laboratory installation ASAW 1250 tractor was used for surfacing. Surfacing modes were: Is = 400 – 450 A; Ud = 32 ÷ 36 V; Vs = 24 ÷ 30 m/h. Surfacing was performed under a layer of AN-26S flux and flux made of silicomanganese slag; number of deposited layers – 5. Chemical composition of deposited metal was determined, metallographic analysis of deposited layer was carried out: size of the former austenite grain, size of martensite needles, degree of contamination by nonmetallic inclusions were stated and wear tests were carried out, hardness and microhardness were measured. The possibility in principal of using tungsten concentrate instead of tungsten powder in studied flux cored wires is shown, degree of tungsten extraction was calculated. For H-type fluxcored wire, introduction of tungsten concentrate instead of tungsten powder into the charge of wire does not increase contamination of deposited layers with nonmetallic inclusions and reduces size of the primary austenite grain. Use of tungsten concentrate in E-type flux-cored wire manufacturing helps to reduce size of the primary austenite grain and size of martensite needles, increasing microhardness of martensite in structure of deposited layer. Introduction of tungsten concentrate instead of tungsten powder into the composition of the charge of H-type wire provides a significant increase in hardness and wear resistance of deposited layer.

Effects of Etching on Zircon Grains and its Implications for the Fission Track Method

2012 ◽  
Vol 66 (5) ◽  
pp. 545-551 ◽  
Author(s):  
Carlos Alberto Tello Sáenz ◽  
Eduardo Augusto Campos Curvo ◽  
Airton Natanael Coelho Dias ◽  
Cleber José Soares ◽  
Carlos José Leopoldo Constantino ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Crystal Lattice ◽  
Fission Track ◽  
Surface Characteristics ◽  
Optical Microscope ◽  
Etching Time ◽  
X Ray ◽  
Track Method ◽  
Zircon Fission Track ◽  
Natural Zircon

Studies of zircon grains using optical microscopy, micro-Raman spectroscopy, and scanning electron microscopy (SEM) have been carried out to characterize the surface of natural zircon as a function of etching time. According to the surface characteristics observed using an optical microscope after etching, the zircon grains were classified as: (i) homogeneous; (ii) anomalous, and (iii) hybrid. Micro-Raman results showed that, as etching time increases, the crystal lattice is slightly altered for homogeneous grains, it is completely damaged for anomalous grains, and it is altered in some areas for hybrid grains. The SEM (energy dispersive X-ray spectroscopy, EDS) results indicated that, independent of the grain types, where the crystallinity remains after etching, the chemical composition of zircon is approximately 33% SiO2:65% ZrO2 (standard natural zircon), and for areas where the grain does not have a crystalline structure, there are variations of ZrO2 and, mainly, SiO2. In addition, it is possible to observe a uniform surface density of fission tracks in grain areas where the determined crystal lattice and chemical composition are those of zircon. Regarding hybrid grains, we discuss whether the areas slightly altered by the chemical etching can be analyzed by the fission track method (FTM) or not. Results of zircon fission track and U-Pb dating show that hybrid and homogeneous grains can be used for dating, and not only homogeneous grains. More than 50 sedimentary samples from the Bauru Basin (southeast Brazil) were analyzed and show that only a small amount of grains are homogeneous (10%), questioning the validity of the rest of the grains for thermo-chronological evolution studies using zircon FTM dating.

scholarly journals INCREASING KNOWLEDGE ABOUT FACTORS OF QUALITY OF EDUCATION

2014 ◽  
Vol 2 (2) ◽  
pp. 99-105
Author(s):  
Peter Madzík ◽  
Miroslav Hrnčiar ◽  
Zuzana Škutchanová
Keyword(s):  
Customer Satisfaction ◽  
Statistical Processing ◽  
Perceived Quality ◽  
Quality Of Education ◽  
Satisfaction Index ◽  
Customer Satisfaction Index ◽  
Study Results ◽  
Perception Of Quality ◽  
Increasing Knowledge

This article presents a study of an important attribute that influences students' perception of quality of education – their own study results. The influence of this attribute on the perceived quality of education is examined by formulating hypothesis and statistical processing of data acquired by menas of a survey among graduates. The hypothesis consisted of two researched attributes – study results of students, and graduates' satisfaction with their studies. Questions concerning the second attribute were formulated using methods for calculation of the customer satisfaction index. Statistical examination proved dependence of these two attributes.

scholarly journals Effect of Rosemary (Rosmarinus officinalis L.) Supplementation on Probiotic Yoghurt: Physicochemical Properties, Microbial Content, and Sensory Attributes

Foods ◽  
2021 ◽  
Vol 10 (10) ◽  
pp. 2393
Author(s):  
Haider I. Ali ◽  
Mithun Dey ◽  
Azalldeen Kazal Alzubaidi ◽  
Sadiq Jaafir Aziz Alneamah ◽  
Ammar B. Altemimi ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Bifidobacterium Longum ◽  
Sensory Attributes ◽  
Rosmarinus Officinalis ◽  
Sensory Properties ◽  
Lactobacillus Delbrueckii ◽  
Rosemary Extract ◽  
Total Phenolic ◽  
Study Results ◽  
Rosmarinus Officinalis L

Rosemary (Rosmarinus officinalis L.) is a natural aromatic plant that belongs to the family of Lamiaceae. The rosemary plant has been utilized to preserve food due to its ability to prevent oxidation and microbial contamination. This study aimed to investigate the effect of fortifying yoghurt with rosemary extracts and probiotic bacteria (LAB) (Bifidobacterium longum ATCC15707 and two lactic acid bacteria, Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus) on its chemical composition, total phenolic compounds, antioxidant capacity, and sensory properties. The study results revealed significant differences in the total solids, protein, and ash content when rosemary concentration increased beyond 2%. However, there were no significant differences among the treatments in acidity and pH value. The sensory evaluation results indicated that the addition of aqueous extract of rosemary affected the sensory properties of yoghurt (flavour, body and texture, appearance, and overall grade), wherein an increasing concentration of rosemary extract increased score of flavour, body and texture, appearance, and overall grade. On the other hand, rosemary extract did not affect the sensory properties and chemical composition. To sum up, it can be stated that rosemary was used in the preparation of yoghurt with increased health benefits, acceptable sensory attributes, and the production of synbiotic yogurt.

Water Quality of Lake Iskanderkul and Its Tributaries

2020 ◽  
Vol 6 (2) ◽  
pp. 79-88
Author(s):  
Z.O. Normakhmedova ◽  
◽  
A.V. Mitusov
Keyword(s):  
Water Pollution ◽  
Water Quality ◽  
Chemical Composition ◽  
Fish Farming ◽  
Natural Phenomena ◽  
Change Dynamics ◽  
Chemical Composition Of Water ◽  
Study Results ◽  
Copper Zinc

This article presents the study results of the change dynamics in the chemical composition of water in Lake Iskanderkul and the rivers flowing into it, as well as the comparison of water quality in the water bodies of the Iskanderkul Basin and several mid-stream tributaries of the Zarafshan River. It was established that the chemical composition of water in Lake Iskanderkul and its tributaries meets the requirements of the corresponding state standard (GOST 2874-82 “Drinking Water”). However, in terms of dissolved oxygen, copper, zinc, lead and iron the water in Lake Iskanderkul does not satisfy fish farming requirements. The main water pollution sources in the area include such natural phenomena as floods, avalanches, mudslides, and rock dissolution.

Tarczyca bocznokwiatowa (Scutellaria lateriflora) – znaczenie w medycynie tradycyjnej i pozycja we współczesnej fitoterapii

2019 ◽  
Vol 20 (1) ◽  
Author(s):  
Inga Kwiecień ◽  
Beata Kawka ◽  
Halina Ekiert
Keyword(s):  
Chemical Composition ◽  
North American ◽  
Folk Medicine ◽  
Raw Material ◽  
Study Results ◽  
Phenylpropanoid Glycosides ◽  
Scutellaria Lateriflora ◽  
Sedative Action ◽  
Main Components

American skullcap (Scutellaria lateriflora L.) has long been used as a medicine by North American Indian tribes. A monograph of Scutellariae lateriflorae herba was included in the American Herbal Pharmacopoeia in 2009. This raw material is very popular in North America because of its sedative action. It is also highly valued in Australia, while in Europe, it has been widely used until now in the United Kingdom. The main components of the herb of this plant species include flavonoids specific for the Scutellaria genus, mostly baicalein, baicalin, wogonin, scutellarin. They are accompanied by other groups of compounds: diterpenoids – neoclerodan derivatives, γ-aminobutyric acid, melatonin, serotonin, catalpol, phenolic acids, phenylpropanoid glycosides (mostly verbascoside) and essential oil. Studies of chemical composition and investigation of medicinal activity of this raw material confirmed its uses known from North American folk medicine. Study results proved most of all a significance of flavonoid compounds present in the raw material for its documented biological activity. The aim of the paper is to review the present knowledge on chemical composition and medicinal significance of this very valuable plant. The research team from the Department of Pharmaceutical Botany JU MC initiated biotechnological studies of this species. Its microshoots successfully grown in vitro produce considerable amounts of specific flavonoids (mostly baicalin and wogonoside) and verbascoside, and in future they can be an alternative rich source of these compounds for pharmaceutical and cosmetic applications.

Mathematical Modeling оf the Silicon Production Process from Pelletized Charge

2020 ◽  
Vol 989 ◽  
pp. 394-399
Author(s):  
Nina V. Nemchinova ◽  
Andrey A. Tyutrin ◽  
Sergei N. Fedorov
Keyword(s):  
Chemical Composition ◽  
Crystalline Silicon ◽  
Raw Materials ◽  
Smelting Process ◽  
Aluminum Production ◽  
Molten Silicon ◽  
Product Modeling ◽  
Silicon Phase ◽  
Silicon Production ◽  
Metallurgical Silicon

The paper considers the problem of recycling the dust waste resulting from metallurgical silicon production; such dust contains considerable amounts of valuable silica. The problem is solved by redirecting this byproduct to the silicon smelting process. We herein propose using the dust left in silicon and aluminum production as a component of pelletized charge, used for silicon smelting in ore-thermal furnaces (OTF). Mathematical (physico-chemical) modeling was applied to study the behavior of pelletized-charge components, in order to predict the chemical composition of smelting-produced silicon. We generated a model that simulated the four temperature zones of a furnace, as well as the crystalline-silicon phase (25°С). The model contained 17 elements entering the furnace, due to being contained in raw materials, electrodes, and the air. Modeling produced molten silicon, 91.73 wt% of which was the target product. Modeling showed that, when using the proposed combined charge, silicon extraction factor would amount to 69.25%, which agrees well with practical data. Results of modeling the chemical composition of crystalline silicon agreed well with the chemical analysis of actually produced silicon.

Investigation of the chemical composition of nonmetallic inclusions utilizing ternary phase diagrams

2002 ◽  
Vol 49 (5) ◽  
pp. 437-443 ◽  
Author(s):  
Marcolino Fernandes ◽  
José Carlos Pires ◽  
Noé Cheung ◽  
Amauri Garcia
Keyword(s):  
Chemical Composition ◽  
Phase Diagrams ◽  
Ternary Phase ◽  
Nonmetallic Inclusions ◽  
Ternary Phase Diagrams

Fracture Failure Analysis of 304 Stainless Steel Elbow

2018 ◽  
Author(s):  
Yian Wang ◽  
Guoshan Xie ◽  
Libin Song ◽  
Meng He ◽  
Fakun Zhuang ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Chemical Composition ◽  
Hydrogen Embrittlement ◽  
Failure Analysis ◽  
Hydrogen Content ◽  
Fracture Morphology ◽  
Optical Microscope ◽  
304 Stainless Steel ◽  
High Hydrogen ◽  
Delayed Cracking

A cracking incident of a 304 stainless steel elbow serving in the synthesis gas purification device occurred during running. In order to get an understanding of the failure mechanism, a failure analysis was performed on the cracked elbow in this paper. The chemical composition, mechanical properties of strength, toughness and hardness, hydrogen content were identified and determined. The metallographical structure was observed and analyzed by optical microscope (OM) and X-Ray Diffraction (XRD), while the fracture morphology was observed by scanning electron microscope (SEM). The results showed that the chemical composition of the cracked elbow meet the requirements for China standard, while comparing with GB/T 14976-2012 standards, the strength and elongation of the leaked elbow are higher and lower respectively, and the hardness of the leaked elbow was higher than quality certificate documents that of HB ⩽ 187. Large quantities of martensite and δ-ferrite were observed in elbow, which indicated that the elbow was not well solid solution heat treated required by specification (1050°C,30min). The fracture morphology presents typical brittle fracture. The hydrogen content of cracked elbow was significant higher than that of other 304 stainless steel elbow serving in the environment without hydrogen. It is acknowledged that martensite showed higher sensitivity of hydrogen embrittlement compared with austenite. Furthermore, the operating temperature of cracked elbow was in the range of high hydrogen embrittlement sensitivity. Depending on the metallographical structure, strength, service environment, hydrogen content and fracture morphology, it can be concluded that hydrogen induced delayed cracking was the dominant mechanism of the failure.

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