scholarly journals Influence of recrystallization annealing regime on the formation of a fine-grained structure in structural steels

2020 ◽  
Vol 164 ◽  
pp. 08021
Author(s):  
Valeriy Gordienko ◽  
Alexandr Chernykh ◽  
Sergei Repin
Keyword(s):  
Heating Temperature ◽  
Recrystallization Annealing ◽  
Initial Structure ◽  
Factors Affecting ◽  
Metal Structures ◽  
Term Operation ◽  
Fine Grained ◽  
Degree Of Dispersion ◽  
Fine Grained Structure ◽  
Main Factors

The analysis of the main factors affecting the reliability and safety of welded metal structures in long-term operation is carried out. The features of obtaining a fine-grained structure due to recrystallization annealing and the main factors affecting the degree of dispersion of the formed microstructure are considered. For low-carbon steel 08ps and low-alloy steel 09G2S, optimal recrystallization annealing regimes have been developed with the aim of obtaining final structures with a given degree of dispersion, typical for real building metal structures. It was found that the degree of dispersion of the obtained microstructures depends on the heating temperature, the initial structure, and the chemical composition of the steels.

A Study of the Factors Affecting the Separation Force of Artificial Leather Laminating Process

2017 ◽  
Vol 728 ◽  
pp. 307-312
Author(s):  
Kusol Pimapunsri ◽  
Teeradej Wuttipornpun ◽  
Darawan Veeranant
Keyword(s):  
Transverse Direction ◽  
Heating Temperature ◽  
Machine Direction ◽  
Factors Affecting ◽  
Artificial Leather ◽  
Optimal Setting ◽  
Main Factors ◽  
Potential Factors ◽  
Separation Force ◽  
Temperature Heating

The separation force is one of the most important properties of artificial leather industries. This paper aims to determine an optimal setting of artificial leather laminating process in order to obtain the desired separation force. There are three potential factors directly influence the separation force for both machine direction (MD) and transverse direction (TD). These factors are take-off temperature, heating temperature, and embossing pressure. To study the effect of these factors on the separation force, a 23 factorial design with six replicates is then conducted, and the result is analyzed at a significant level of 0.05. The result shows that all main factors have significant effects to MD and TD. The optimal setting of the laminating process for artificial leather to obtain the desired MD and TD is that using take-off temperature, heating temperature and embossing pressure at 175°C, 150°C and 40 Bar respectively.

scholarly journals Surface preparation as one of the main factors for ensuring the durability of anti-corrosion coatings

2020 ◽  
Vol 7 (2) ◽  
Author(s):  
Aleksei Bezgodov ◽  
Ilya Ovchinnikov
Keyword(s):  
Surface Treatment ◽  
Protective Coatings ◽  
Surface Preparation ◽  
Negative Consequences ◽  
Treatment Methods ◽  
Factors Affecting ◽  
Metal Structures ◽  
Optimal Processing ◽  
Main Factors ◽  
Paint Coatings

This article is devoted to the protection of bridge metal structures from corrosion. The article was written with the aim of studying one of the stages of anti-corrosion treatment, namely the preparation of the surface before applying a protective coating. In the article, the authors address the problem of the durability of paint coatings, and point to the main reasons, to a greater extent, affecting the service life. Studying the problem of the durability of protective coatings, the authors distinguish such a stage as preparing the metal surface of the bridge structure before applying the paintwork. The authors tell how important the preparation of the surface is and what negative consequences are possible if it is disturbed or not. For a more detailed study of the problem, the authors consider several methods of preparing the surface of the structure, such as: abrasive blast cleaning, phosphating the surface and heat treatment. When studying the above mentioned methods, the authors describe the technology of the work, the main factors affecting the final result of processing, as well as the positive and negative sides of each of the methods. For each of the surface treatment methods, the authors present illustrations that clearly show the basic concept of the selected treatment option. Summing up the comparative analysis of surface treatment methods before applying anti-corrosion coatings, the authors chose the most optimal processing method, as well as concluded that the importance of this stage and the possibility of its further improvement.

scholarly journals Thermocyclic treatment (tcт) of metals - way for getting optimum structures and properties

2019 ◽  
pp. 238-252
Author(s):  
O.N. Perkov ◽  
I.A. Vakulenko ◽  
V.M Kuzmychov
Keyword(s):  
Heat Treatment ◽  
Heating Temperature ◽  
Rapid Heating ◽  
Metal Structure ◽  
Treatment Method ◽  
Repeated Heating ◽  
Fine Grained ◽  
Heating And Cooling ◽  
Fine Grained Structure ◽  
Rapid Coarsening

The aim of this work is to study the basic principles of thermal cyclic processing (TCТ) of metals to obtain structures that determine the optimal complex of mechanical properties. The basic provisions of metal heating centers using periodically repeated heating and cooling cycles are given. The TCТ method, as a heat treatment method, is based on constant accumulation from cycle to cycle of positive changes in the structure of metals. Studies have shown that with rapid heating, the growth of austenitic grain occurs slowly and, therefore, heating to high temperatures (up to 10000C) does not lead to an intensive increase in grain. It has been established that grain size increases at a variable heating temperature 3 times slower than under isothermal conditions at the corresponding temperature. Provided that the growth rate of the new phase (austenite) is small and the nucleation rate of grains is significant, it turns out that by the end of the a®g transformation, a fine-grained structure is retained. Further heating or holding at a constant temperature leads to a rapid coarsening of austenite grains. If cooling (for example, in air) of rapidly heated steel is performed 10–150C higher than the temperature of the Ас1 point, then fine perlite grain is formed due to reverse recrystallization. With one thermal cycle, ferrite in subeutectoid steels almost does not undergo changes. But if several such heating and cooling are performed, then the entire ferrite-pearlite structure undergoes a change. It has been established that the higher the heating rate during heating and heating and the less overheating above Ас1, the finer the grain in carbon structural steel. However, this increases the need to increase the number of heat treatment cycles. The mechanism of structure formation explaining these phenomena and practical recommendations on the implementation of the process of the technical and economic process are presented. This approach makes it possible to form the optimal metal structure. At the same time, opportunities can be significantly expanded in terms of obtaining materials with desired properties and improving on this basis machines, structures, individual units and parts. All this puts TCТ in the category of promising areas in metalworking.

The effect of structure and texture on pure magnesium properties

2021 ◽  
Vol 112 (1) ◽  
pp. 57-62
Author(s):  
Bartosz Sułkowski
Keyword(s):  
Deformation Mode ◽  
Pure Magnesium ◽  
Coarse Grained ◽  
Initial Structure ◽  
Fine Grained ◽  
Compression Direction ◽  
First Case ◽  
Axis Parallel ◽  
Fine Grained Structure ◽  
Deformation Modes

Abstract Deformation modes and twin hardening of pure magnesium under compression in respect of the initial structure and texture were studied in the present work. In general, samples had two types of texture with different alignment of c-axis in respect to a compression direction. In the first case, most of the grains have the c-axis parallel to the compression direction and in the second case, the c-axis was perpendicular with the compression direction. It was found that coarse grained material deformed by slip despite the type of the texture, while the fine grained samples, with c-axis perpendicular to the compression direction, deformed by twinning. The samples which deform by twinning exhibited the highest yield point. It was concluded that combination of the fine grained structure and hard type texture components may introduce twinning as the main deformation mode and may increase the mechanical properties of magnesium and its alloys. The model for twin induced hardening is proposed where twins act as the grain refinement factor.

Changing of Mechanical and Technological Properties of Cast Metal as a Result of Pulse-Magnetic Processing of Melts

2017 ◽  
Vol 746 ◽  
pp. 255-261
Author(s):  
Dmitrij Chernikov ◽  
Vladimir Glushchenkov
Keyword(s):  
New Method ◽  
Structure And Properties ◽  
Technological Properties ◽  
Cast Metal ◽  
Fine Grained ◽  
Fine Grained Structure ◽  
Main Factors ◽  
Experimental Researches ◽  
Magnetic Processing

A new method of action on melts is proposed which is based on pulse-magnetic processing them with the aim to form a homogeneous fine-grained structure and improved technological properties of cast metal. The results of experimental researches of influence of main factors of treatment on the structure and properties of binary and commercial alloys of the system Al-Si are given.

Recent Rapid Climate Changes in Antarctic and their Influence on Low Diversity Ecosystems

2010 ◽  
Vol 17 (1) ◽  
pp. 17-30 ◽  
Author(s):  
Katarzyna J. Chwedorzewska
Keyword(s):  
Environmental Variables ◽  
Climate Changes ◽  
Biological Significance ◽  
Global Changes ◽  
Factors Affecting ◽  
Low Diversity ◽  
Main Factors ◽  
The Antarctic ◽  
High Diversity ◽  
Temperature Water

ABSTRACTThe geographic position, astronomic factors (e.g. the Earth’s maximum distance from the Sun during winter), ice cover and altitude are the main factors affecting the climate of the Antarctic, which is the coldest place on Earth. Parts of Antarctica are facing the most rapid rates of anthropogenic climate change currently seen on the planet. Climate changes are occurring throughout Antarctica, affecting three major groups of environmental variables of considerable biological significance: temperature, water, UV-B radiation.Low diversity ecosystems are expected to be more vulnerable to global changes than high diversity ecosystems

Pitting Corrosion of Biomedical Titanium and Titanium Alloys: A Brief Review

2020 ◽  
Vol 16 ◽  
Author(s):  
Yu-Wei Cui ◽  
Liang-Yu Chen ◽  
Xin-Xin Liu
Keyword(s):  
Corrosion Resistance ◽  
Pitting Corrosion ◽  
Potential Temperature ◽  
Growth Stages ◽  
Factors Affecting ◽  
Ti Alloys ◽  
Pitting Corrosion Resistance ◽  
Superior Mechanical Properties ◽  
Good Biocompatibility ◽  
Main Factors

Abstract:: Thanks to their excellent corrosion resistance, superior mechanical properties and good biocompatibility, titanium (Ti) and Ti alloys are extensively applied in biomedical fields. Pitting corrosion is a critical consideration for the reliability of Ti and Ti alloys used in the human body. Therefore, this article focuses on the pitting corrosion of Ti and Ti alloys, which introduces the growth stages of pitting corrosion and its main influencing factors. Three stages, i.e. (1) breakdown of passive film, (1) metastable pitting, and (3) propagation of pitting, are roughly divided to introduce the pitting corrosion. As reviewed, corrosive environment, applied potential, temperature and alloy compositions are the main factors affecting the pitting corrosion of Ti and Ti alloys. Moreover, the pitting corrosion of different types Ti alloys are also reviewed to correlate the types of Ti alloys and the main factors of pitting corrosion. Roughly speaking, β-type Ti alloys have the best pitting corrosion resistance among the three types of Ti alloys.

scholarly journals Measuring the Efficiency of Football Clubs Using Data Envelopment Analysis: Empirical Evidence From Spanish Professional Football

SAGE Open ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 215824402198925
Author(s):  
Isidoro Guzmán-Raja ◽  
Manuela Guzmán-Raja
Keyword(s):  
Data Envelopment Analysis ◽  
High Efficiency ◽  
Sport Performance ◽  
Data Envelopment ◽  
Professional Football ◽  
Efficiency Measure ◽  
Factors Affecting ◽  
Football Clubs ◽  
Main Factors ◽  
Using Data

Professional football clubs have a special characteristic not shared by other types of companies: their sport performance (on the field) is important, in addition to their financial performance (off the field). The aim of this paper is to calculate an efficiency measure using a model that combines performance (sport and economic) based on data envelopment analysis (DEA). The main factors affecting teams’ efficiency levels are investigated using cluster analysis. For a sample of Spanish football clubs, the findings indicate that clubs achieved a relatively high efficiency level for the period studied, and that the oldest teams with the most assets had the highest efficiency scores. These results could help club managers to improve the performance of their teams.

scholarly journals Enzymatic Process for Cystoseira barbata Valorization: Ethanol Production and Additional By-Products

Processes ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 741
Author(s):  
Doinita-Roxana Cioroiu Tirpan ◽  
Ancaelena Eliza Sterpu ◽  
Claudia Irina Koncsag ◽  
Alina Georgiana Ciufu ◽  
Tănase Dobre
Keyword(s):  
Ethanol Production ◽  
Alcoholic Fermentation ◽  
Ethanol Yield ◽  
Product Yield ◽  
Liquid Ratio ◽  
Experimental Conditions ◽  
Factors Affecting ◽  
Cystoseira Barbata ◽  
Main Factors ◽  
Process Factors

The aim of this study is to evaluate the potential of dried Cystoseira barbata alga for ethanol production through alcoholic fermentation. The influence of the main factors affecting the fermentation are studied in the frame of a 23 factorial experimental plan. The main factors influencing the process are the fermentation temperature (t from 25 °C to 35 °C), the solid to liquid ratio (S/L from 0.040 g/g to 0.080 g/g), and the cellulase ratio (R from 8 U/g d.m to 16 U/g d.m.). The maximum volatile compounds yield of 0.2808 g/g d.m and ethanol yield of 0.0158 g/g d.m were favored by the following experimental conditions: process temperature of 35 °C, solid to liquid ratio of 0.0415, and enzyme ratio of 16 U/g d.m. A statistical model was used to correlate the product yield with the process factors. Additionally, 19 interesting bioactive compounds were found in the enzymatic hydrolysis and alcoholic fermentation broths which seem likely to maintain natural defence mechanisms against diseases and physical disorders.

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