Distribution of Magnetic Field Parameters in the Surface Layer of the Material of Reaction Furnace Coils after Operation Period

2019 ◽  
Vol 945 ◽  
pp. 653-659 ◽  
Author(s):  
E.A. Naumkin ◽  
J.N. Shermatov ◽  
A.I. Gaysina
Keyword(s):  
Magnetic Field ◽  
Magnetic Properties ◽  
Service Life ◽  
Field Intensity ◽  
Constant Magnetic Field ◽  
Magnetic Field Intensity ◽  
Surface Layers ◽  
Life Period ◽  
Carburized Layer ◽  
Reaction Furnace

One of the main reasons for the limited service life period of the reaction furnace coils is the carburization of the surface layers, which leads to a decrease in the performance characteristics of the pipe material, decrease in plasticity, generation of internal stresses, change in the metal structure. Therefore, monitoring the state of coils surface in order to detect critical parameters of the carburized layer thickness, using non-destructive methods of control is relevant. The results of the distribution of magnetic parameters over the depth of the carburized layer in the fragments of pipes made of steel 20Х25Н20C2, operated under furnace conditions at high temperatures, for 1300, 6000, 8000, 10000 hours are presented in the article. Analysis of the results showed that the magnetic properties are manifested only in the surface layers of the reaction furnace tubes. At the same time, the longer the service life period, the deeper is the layer exercising the magnetic properties and the higher in this layer the values ​of the constant magnetic field intensity. Analysis of magnetic properties distribution in all studied pipe fragments, both from the inner and from the outer side, showed the non-uniformity of the constant magnetic field intensity distribution, while zones of extremely high values ​are observed. The layer-by-layer surface removal in these zones with the determination of the resultant constant magnetic field intensity showed that there are critical values of the carburization depth, after which a sharp increase of this parameter is registered. These results can be used as a method for carburization depth determination, and also used to develop criterion for rejecting coils of reaction furnaces.

The effects of magnetic field intensity on the magnetic properties of Fe80Si9B11 amorphous alloys during magnetic annealing

2021 ◽  
Vol 134 ◽  
pp. 107200
Author(s):  
Yin Zhang ◽  
Yong Yang ◽  
Zhongyuan Wu ◽  
Xiaomeng Feng ◽  
Chenxu Wang ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Properties ◽  
Field Intensity ◽  
Amorphous Alloys ◽  
Magnetic Field Intensity ◽  
Magnetic Annealing

Magnetic and Piezoelectric Properties of the Fe3+ Doped PLZT Electroceramics

2012 ◽  
Vol 730-732 ◽  
pp. 117-122 ◽  
Author(s):  
Lucjan Kozielski ◽  
M. Płońska
Keyword(s):  
Magnetic Field ◽  
Magnetic Properties ◽  
Field Intensity ◽  
Magnetic Field Intensity ◽  
Piezoelectric Properties ◽  
Magnetic Measurements ◽  
Iron Ions ◽  
Two Samples ◽  
Fe Ions

For the growing interest in developing of more attractive multiferroic and magnetoelectric ceramics an alternative is a double-doped Pb(Zr1-xTix)O3- material with trivalent lanthanum and iron ions. Such material has a structure based on ABO3perovskite and properties depending on the chemical and structural composition. In the present work the results of the preparation and characterization of Fe3+- modified 9/65/35 PLZT ceramics have been reported. Two samples of Pb0,91(La1-zFez)0,09(Zr0,65Ti0,35)0,9775O3ceramics, for different Fe ions concentration (z = 0,0 and 0,5 at.%), were prepared from the MOM derived powders and sintered by the hot uniaxial pressing methods. To analyze the obtained ceramics properties the XRD, SEM and also application oriented dielectric and magnetic measurements were performed. The Fe3+substitution at the La-site of PLZT has shown many interesting and unusual dielectric, piezoelectric and magnetic properties. The obtained material was proposed to implement into Piezoelectric Transformer structure to change gain characteristics proportionally to magnetic field intensity.

scholarly journals Distribution of magnetic field intensity on surface of ferromagnetic specimen with specimen getting thinner

2021 ◽  
Vol 2094 (4) ◽  
pp. 042076
Author(s):  
V Yu Pivovarov ◽  
I R Kuzeyev
Keyword(s):  
Magnetic Field ◽  
Field Intensity ◽  
Magnetic Field Intensity ◽  
Test Methods ◽  
Specimen Thickness ◽  
Surface Layers ◽  
Wide Range ◽  
Intensity Changes ◽  
The Magnetic Field ◽  
Ferromagnetic Specimen

Abstract Contemporary achievements of the physics of surfaces allow to define dramatic differences between the surface layers and the underneath part of the same material. Even though there is a wide range of test methods and scientific findings, so far all the peculiarities of the surface phenomena have not been figured out. The article considers a hypothesis of the surface layer fractal structure. The hypothesis is based on the fact that the transition from a 3D plane to a 2D plane happens through a number of intermediary structures (transition or small-fraction layer). In order to check this hypothesis, we carried out an experiment aimed at studying the intensity of the magnetic field of a ferromagnetic specimen with the specimen getting thinner. The idea of the experiment was in the assumption that if the specimen has a certain thickness the surface layers will become comparable with the underneath material and this will influence the way the magnetic field intensity changes. The conducted measurements allowed to build a correlation between the magnetic field intensity components and the specimen thickness. The measurements showed that the thinner the specimen is, the ‘closer’ the correlation is. These findings display how the small fraction layer reacts to the change of the underneath material. This confirms it is possible to obtain information about the state of the structural material underneath by measuring the surface properties.

scholarly journals Effect of Citrate on the Size and the Magnetic Properties of Primary Fe3O4 Nanoparticles and Their Aggregates

2021 ◽  
Vol 11 (15) ◽  
pp. 6974
Author(s):  
Andrea Atrei ◽  
Fariba Fahmideh Mahdizadeh ◽  
Maria Camilla Baratto ◽  
Andrea Scala
Keyword(s):  
Magnetic Field ◽  
Magnetic Properties ◽  
Field Intensity ◽  
Magnetic Field Intensity ◽  
Magnetic Domains ◽  
X Ray Diffraction ◽  
Paramagnetic Resonance ◽  
Co Precipitation ◽  
Post Synthesis ◽  
Electron Paramagnetic

The size, size distribution and magnetic properties of magnetite nanoparticles (NPs) prepared by co-precipitation without citrate, in the presence of citrate and citrate adsorbed post-synthesis were studied by X-ray Diffraction (XRD), Dynamic Light Scattering (DLS), Electron Paramagnetic Resonance (EPR) and magnetization measurements. The aim of this investigation was to clarify the effect of citrate ions on the size and magnetic properties of magnetite NPs. The size of the primary NPs, as determined by analysing the width of diffraction peaks using various methods, was ca. 10 nm for bare magnetite NPs and with citrate adsorbed post-synthesis, whereas it was around 5 nm for the NPs co-precipitated in the presence of citrate. DLS measurements show that the three types of NPs form aggregates (100–200 nm in diameter) but the dispersions of the citrate-coated NPs are more stable against sedimentation than those of bare NPs. The sizes and size distributions determined by XRD are in good agreement with those of the magnetic domains obtained by fitting of the magnetization vs. magnetic field intensity curves. Magnetization vs. magnetic field intensity curves show that the three kinds of sample are superparamagnetic.

scholarly journals Multi-point ground-based ULF magnetic field observations in Europe during seismic active periods in 2004 and 2005

2008 ◽  
Vol 8 (3) ◽  
pp. 501-507 ◽  
Author(s):  
G. Prattes ◽  
K. Schwingenschuh ◽  
H. U. Eichelberger ◽  
W. Magnes ◽  
M. Boudjada ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Field Intensity ◽  
Seismic Activity ◽  
Magnetic Field Intensity ◽  
Field Measurements ◽  
Fluxgate Magnetometer ◽  
Vertical Magnetic Field ◽  
Earthquake Epicenter ◽  
Electromagnetic Noise ◽  
Horizontal Magnetic Field

Abstract. We present the results of ground-based Ultra Low Frequency (ULF) magnetic field measurements observed from June to August 2004 during the Bovec earthquake on 12 July 2004. Further we give information about the seismic activity in the local observatory region for an extended time span 2004 and 2005. ULF magnetic field data are provided by the South European Geomagnetic Array (SEGMA) where the experience and heritage from the CHInese MAGnetometer (CHIMAG) fluxgate magnetometer comes to application. The intensities of the horizontal H and vertical Z magnetic field and the polarization ratio R of the vertical and horizontal magnetic field intensity are analyzed taking into consideration three SEGMA observatories located at different close distances and directions from the earthquake epicenter. We observed a significant increase of high polarization ratios during strong seismic activity at the observatory nearest to the Bovec earthquake epicenter. Apart from indirect ionospheric effects electromagnetic noise could be emitted in the lithosphere due to tectonic effects in the earthquake focus region causing anomalies of the vertical magnetic field intensity. Assuming that the measured vertical magnetic field intensities are of lithospheric origin, we roughly estimate the amplitude of electromagnetic noise in the Earths crust considering an average electrical conductivity of <σ>=10−3 S/m and a certain distance of the observatory to the earthquake epicenter.

Numerical Investigations on Rotatry Micropolar Fluid in Hydromagnetics Permeated with Suspended Particles Saturating Porous Medium

2021 ◽  
pp. 57-69
Author(s):  
Pushap Lata Sharma ◽  
Sumit Gupta
Keyword(s):  
Magnetic Field ◽  
Porous Medium ◽  
Field Intensity ◽  
Magnetic Field Intensity ◽  
Suspended Particles ◽  
Rotation Parameter ◽  
Wave Number ◽  
Stationary Convection ◽  
Micropolar Fluids ◽  
Medium Permeability

This paper deals with the convection of micropolar fluids heated and soluted from below in the presence of suspended particles (fine dust) and uniform vertical rotation and uniform vertical magnetic field in a porous medium. Using the Boussinesq approximation, the linearized stability theory and normal mode analysis, the exact solutions are obtained for the case of two free boundaries. It is found that the presence of the suspended particles number density, the rotation parameter, stable solute, magnetic field intensity and medium permeability bring oscillatory modes which were non–existent in their absence. It is found that the presence of coupling between thermal and micropolar effects, rotation parameter, solute parameter and suspended particles may introduce overstability in the system. Graphs have been plotted by giving numerical values to the parameters accounting for rotation parameter , magnetic field solute parameter, the dynamic microrotation viscosity and coefficient of angular viscosity to depict the stability characteristics, for both the cases of stationary convection and overstability. It is found that Rayleigh number for the case of overstability and stationary convection increases with increase in rotation parameter, as well as with magnetic field intensity, solute parameter and decreases with increase in micropolar coefficients and medium permeability, for a fixed wave number, implying thereby the stabilizing effect of rotation parameter, magnetic field intensity ,solute parameter and destabilizing effect of micropolar coefficients and medium permeability on the thermosolutal convection of micropolar fluids.

Tunable amplified spontaneous emission based on liquid magnetically responsive photonic crystals

2019 ◽  
Vol 7 (13) ◽  
pp. 3740-3743 ◽  
Author(s):  
Ying Li ◽  
Yue Long ◽  
Guoqiang Yang ◽  
Chen-Ho Tung ◽  
Kai Song
Keyword(s):  
Magnetic Field ◽  
Photonic Crystals ◽  
Spontaneous Emission ◽  
Field Intensity ◽  
Magnetic Field Intensity ◽  
Amplified Spontaneous Emission ◽  
The Magnetic Field

The wavelength of amplified spontaneous emission based on liquid magnetically responsive photonic crystals can be tuned by simply changing the magnetic field intensity.

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