Influence of Zirconium Alloy Chemical Composition on Microstructure Formation and Irradiation Induced Growth

2009 ◽  
pp. 758-758-22 ◽  
Author(s):  
VN Shishov ◽  
MM Peregud ◽  
AV Nikulina ◽  
PV Shebaldov ◽  
AV Tselischev ◽  
...  
Keyword(s):  
Chemical Composition ◽  
Zirconium Alloy ◽  
Microstructure Formation

Effects of Cellulosic and Basic Flux on the Structure, Composition and Hardness of SMAW Welds on Steel X42

2016 ◽  
Vol 27 ◽  
pp. 11-19 ◽  
Author(s):  
Farida Khamouli ◽  
Mosbah Zidani ◽  
Hichem Farh ◽  
Adel Saoudi ◽  
L'hadi Atoui
Keyword(s):  
Chemical Composition ◽  
Carbon Content ◽  
Acicular Ferrite ◽  
Mass Concentration ◽  
Chemical Compositions ◽  
Low Carbon ◽  
Micro Hardness ◽  
Microstructure Formation ◽  
Basic Flux ◽  
Metallic Inclusions

This paper studied the effects of cellulosic and basic flux on the chemical composition, microstructure, formation of inclusions and micro hardness of X42 steel SMAW welds. The commercialized chemical compositions of flux used are: E6010, E8010-P1 and E8018-G, with electrodes of low carbon content. Welding conditions are not constant. The microstructure of the fusion zone for each flux consists mainly of acicular ferrite. It is found that manganese increases in the fusion zones (C, B and A) respectively .The change in mass concentration of manganese is homogeneous through the three points with all the used flux. Regardless of the flux used, the non-metallic inclusions observed are of two types: white and black. The micro-hardness decreasing values were obtained in the fusion zones (C, B and A).

INVESTIGATION OF A BRAZED JOINT MICROSTRUCTURE FORMATION, MADE OF DISSIMILAR NICKEL SUPER ALLOYS AND THE COMPLEX BRAZING ALLOY

2021 ◽  
pp. 3-12
Author(s):  
O.G. Ospennikova ◽  
◽  
A.N. Afanasyev-Khodykin ◽  
I.A. Galushka ◽  
◽  
...  
Keyword(s):  
Heat Treatment ◽  
Chemical Composition ◽  
Microstructure Formation ◽  
Heat Resistant Alloy ◽  
Joint Microstructure ◽  
Resistant Alloy ◽  
Heat Resistant ◽  
Brazed Joint

Presents the results of studies on the microstructure an opposite combination of nickel heat-resistant alloys of a brazed joint. The chemical composition of the phases formed as a result of the interaction of the mono-crystal alloy VKNA-25, heat-resistant alloy EP975 and complex alloyed solder VPr56 was investigated. The main regularities of the microstructure of the brazed joint changes during heat treatment were established. The dependence is established and the formula is derived for obtaining the optimal microstructure of the brazed seam with different duration of heat treatment and the size of the assembly gap.

Influence of Cellulosic Fluxes on the Chemical Composition, Microstructure, Inclusions and Micro-Hardness of SMAW Multi-Pass Welds of X42 Steel

2019 ◽  
Vol 297 ◽  
pp. 62-70
Author(s):  
Farida Khamouli ◽  
Mosbah Zidani ◽  
Kaltoum Digheche ◽  
Adel Saoudi ◽  
L'Hadi Atoui
Keyword(s):  
Chemical Composition ◽  
Fusion Zone ◽  
Chemical Compositions ◽  
Low Carbon ◽  
Micro Hardness ◽  
Microstructure Formation ◽  
Welded Steel ◽  
Metallic Inclusions ◽  
Si Content ◽  
Ti Content

This paper studied the influence of cellulosic flux on the chemical composition, microstructure, formation of inclusions and micro hardness of X42 welded steel. The chemical compositions of the used fluxes are FA: E6010 and FB: E8010-P1, with electrodes has low carbon content. The welding conditions are not constant. The fluxes (FA and FB) have a high content of TiO2 and SiO2 and a low Ti and Si content was also detected in the internal (P1) and external (P3) passes. But there was an increase in the Ti content in the fusion zone (P1, P2 and P3) of the different passes gradually, compared to the base metal. The microstructure of the fusion zone (P1, P2 and P3) for each flux is mainly composed of acicular ferrite. The mass concentration variation of Mn is more elevated through the centers of the fusion zone passes (P1, P2 and P3) with the used fluxes. White and black non-metallic inclusions are observed, regardless of used flux. The micro-hardness in fusion zone varies according to the variation of the equivalent carbon in the different electrodes.

Multiscale Modeling of Ductile Iron Solidification With Continuous Nucleation by a Cellular Automaton

2010 ◽  
Author(s):  
Andriy A. Burbelko ◽  
Daniel Gurgul ◽  
Edward Fras´ ◽  
Edward Guzik
Keyword(s):  
Chemical Composition ◽  
Cellular Automaton ◽  
Source Function ◽  
Distribution Curve ◽  
Heat Diffusion ◽  
Cumulative Distribution ◽  
Microstructure Formation ◽  
Time Step ◽  
Solid Phases ◽  
Continuous Nucleation

The solidification of metals and alloys is a typical example of multiphysics and multiscale engineering systems. The phenomenon of different time and spatial scales should be taken into consideration in the modeling of a microstructure formation: heat diffusion, the components diffusion in the liquid and solid phases, the thermodynamics of phase transformation under a condition of inhomogeneous chemical composition of growing and vanishing phases, phase interface kinetics, and grains nucleation. The results of a two-dimensional modeling of the microstructure formation in a ductile cast iron are presented. The cellular automaton model (CA) was used for the simulation. The model takes into account the nucleation of two kinds of grains that appear inside of the liquid during solidification: austenite and graphite. The six states of CA cells correspond to the above-mentioned three phases (liquid, austenite and graphite) and to the three two-phase interfaces. A numerical solution was used for the modeling of concentration and temperature fields. The parabolic nonlinear differential equations with a source function were solved by using the finite element method and explicit scheme. In the mono-phase cells the source function is equal to zero. In the interface cells the value of the source function varies depending on the local undercooling. The undercooling value depends on the front curvature, the local temperature and the local chemical composition of the phases. Overlapping lattices with the same spatial step were used for concentration field modeling and for the CA. The time scale of the temperature field for this lattice is about 104 times shorter. Due to the above reasons, another lattice was used with a multiple spatial step and the same time step. The new grain nucleation of solid phases from a liquid is a phenomenon which must be taken into account for correct simulation of a polycrystalline structure formation. The cumulative distribution curve approach was used to calculate the number of substrates on which nucleation takes place as a function of under-cooling below the equilibrium temperature. An algorithm of continuous nucleation modeling during solidification is presented. The undercooling of solid phase grain nucleation was calculated on the basis of the inverse function of the above-mentioned cumulative distribution curve (fractile) with the argument equal to the random number generated in the interval 0…1 with uniform density. The domain of correct usage of this algorithm was analyzed.

The Origin of the Moon

1962 ◽  
Vol 14 ◽  
pp. 149-155 ◽  
Author(s):  
E. L. Ruskol
Keyword(s):  
Chemical Composition ◽  
Solar System ◽  
The Moon ◽  
The Earth ◽  
The Difference ◽  
Origin Of The Moon

The difference between average densities of the Moon and Earth was interpreted in the preceding report by Professor H. Urey as indicating a difference in their chemical composition. Therefore, Urey assumes the Moon's formation to have taken place far away from the Earth, under conditions differing substantially from the conditions of Earth's formation. In such a case, the Earth should have captured the Moon. As is admitted by Professor Urey himself, such a capture is a very improbable event. In addition, an assumption that the “lunar” dimensions were representative of protoplanetary bodies in the entire solar system encounters great difficulties.

On the Inhomogeneity of Chemical Composition over the Surface of 21 Per

1976 ◽  
Vol 32 ◽  
pp. 343-349
Author(s):  
Yu.V. Glagolevsky ◽  
K.I. Kozlova ◽  
V.S. Lebedev ◽  
N.S. Polosukhina
Keyword(s):  
Chemical Composition ◽  
Spectral Line ◽  
Variable Star ◽  
Radial Velocities ◽  
Crimean Astrophysical Observatory ◽  
Line Intensities ◽  
Magnetic Variable

SummaryThe magnetic variable star 21 Per has been studied from 4 and 8 Å/mm spectra obtained with the 2.6 - meter reflector of the Crimean Astrophysical Observatory. Spectral line intensities (Wλ) and radial velocities (Vr) have been measured.

Structural Studies on Mitotic Spindle Fibres

1978 ◽  
Vol 36 (3) ◽  
pp. 615-626
Author(s):  
J.R. Mcintosh
Keyword(s):  
Chemical Composition ◽  
Mitotic Spindle ◽  
Structural Studies ◽  
Mitotic Apparatus ◽  
Chemical Studies ◽  
Medical Interest ◽  
Spindle Fibres

The mitotic apparatus is a structure of obvious biological and medical interest, but it has proved to be a difficult cellular machine to understand. The chemical composition of the spindle is only slightly elucidated, largely because of the difficulties in preparing useful isolates of the structure. Chemical studies of the mitotic spindle have been reviewed elsewhere (Mcintosh, 1977), and will not be discussed further here. One would think that structural studies on the mitotic apparatus (MA) in situ would be straightforward, but even with this approach there is some disagreement in the results obtained with various methods and by different investigators. In this paper I will review briefly the approaches which have been used in structural studies of the MA, pointing out the strengths and problems of each approach. I will summarize the principal findings of the different methods, and identify what seem to be fruitful avenues for further work.

Effects of 5-5'-Diphenyl-2-thiohydantoin (DPTH) and Thyroxine on the Ultrastructure and Chemical Composition of Rat Liver

1971 ◽  
Vol 29 ◽  
pp. 570-571
Author(s):  
E. A. Elfont ◽  
R. B. Tobin ◽  
D. G. Colton ◽  
M. A. Mehlman
Keyword(s):  
Chemical Composition ◽  
Rat Liver ◽  
Future Study ◽  
Mode Of Action ◽  
Liver Mitochondria ◽  
Rat Liver Mitochondria ◽  
Effective Inhibitor ◽  
Biochemical Effects ◽  
Glycerophosphate Dehydrogenase ◽  
Stimulation Of

Summary5,-5'-diphenyl-2-thiohydantoin (DPTH) is an effective inhibitor of thyroxine (T4) stimulation of α-glycerophosphate dehydrogenase in rat liver mitochondria. Because this finding indicated a possible tool for future study of the mode of action of thyroxine, the ultrastructural and biochemical effects of DPTH and/or thyroxine on rat liver mere investigated.Rats were fed either standard or DPTH (0.06%) diet for 30 days before T4 (250 ug/kg/day) was injected. Injection of T4 occurred daily for 10 days prior to sacrifice. After removal of the liver and kidneys, part of the tissue was frozen at -50°C for later biocheailcal analyses, while the rest was prefixed in buffered 3.5X glutaraldehyde (390 mOs) and post-fixed in buffered 1Z OsO4 (376 mOs). Tissues were embedded in Araldlte 502 and the sections examined in a Zeiss EM 9S.Hepatocytes from hyperthyroid rats (Fig. 2) demonstrated enlarged and more numerous mitochondria than those of controls (Fig. 1). Glycogen was almost totally absent from the cytoplasm of the T4-treated rats.

Applications of Photoelectron Microscopy

1976 ◽  
Vol 34 ◽  
pp. 506-507
Author(s):  
William J. Baxter
Keyword(s):  
Electron Microscopy ◽  
Thermal Decomposition ◽  
Chemical Composition ◽  
Ultraviolet Radiation ◽  
Thin Layer ◽  
Edge Effects ◽  
Electron Optics ◽  
Surface Layers ◽  
Crystalline Orientation ◽  
Fluorescent Screen

In this form of electron microscopy, photoelectrons emitted from a metal by ultraviolet radiation are accelerated and imaged onto a fluorescent screen by conventional electron optics. image contrast is determined by spatial variations in the intensity of the photoemission. The dominant source of contrast is due to changes in the photoelectric work function, between surfaces of different crystalline orientation, or different chemical composition. Topographical variations produce a relatively weak contrast due to shadowing and edge effects.Since the photoelectrons originate from the surface layers (e.g. ∼5-10 nm for metals), photoelectron microscopy is surface sensitive. Thus to see the microstructure of a metal the thin layer (∼3 nm) of surface oxide must be removed, either by ion bombardment or by thermal decomposition in the vacuum of the microscope.

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