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1

Modelling of magnetisation processes in transformer steel sheets

Sierżęga Michał, Mazgaj Witold

Archives of Electrical Engineering

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2023

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Vol. 72, nr 4

855--870

EN

This study describes a method that allows the modelling of magnetisation processes in transformer steel sheets for any direction of the magnetic field strength. In the proposed approach, limiting hysteresis loops for the rolling and transverse directions were used. These loops are modified depending on the magnetisation angle between the direction of the field strength vector and rolling direction. For this purpose, unique correction coefficients, which are functions of the magnetisation angle, were applied for both hysteresis loops. An algorithm for determining the limiting hysteresis loops for any magnetisation angle is presented herein. The calculation results for several cases of magnetisation were compared with the measured hysteresis loops.

2

A Comparative Study of Nanocrystalline Fe38.5Co38.5 Nb7 P15Cu1 Alloys Obtained by Mechanical Alloying and Rapid Quenching

Cotai Ana, Miraglia Salvatore, Neamtu Bogdan Viorel, Marinca Traian Florin, Chicinaș Horea F., Isnard Olivier, Chicinaș Ionel

Archives of Metallurgy and Materials

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2022

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Vol. 67, iss. 2

555--561

EN

This paper presents a comparative study of the preparation and characterisation of Fe38.5Co38.5 Nb7 P15Cu1 alloy produced by mechanical alloying (MA) and rapid quenching (RQ) method. In order to obtain the starting mixture (SS) in the present study, we opted for the replacement of elemental Nb and P powders with ferroalloy powders of niobium and phosphorus. Benzene was used as a control agent of the process (PCA) for wet MA. The samples obtained (powders and ribbons) were characterised by X-ray diffraction (XRD), differential scanning calorimetry (DSC), scanning electron microscopy (SEM), X-ray microanalysis (EDX), magnetic measurements M(H) and thermomagnetic measurements M(T). After 40 h of wet MA, the alloy was partially amorphous, and the ribbons obtained by RQ do not show an amorphous state. Also, the magnetic measurements show the influence of the method used on the magnetic properties.

3

Effect of Annealing, Stoichiometry, and Surface on Magnetism of (Pr,Dy)FeCoB Microparticles Ensemble

Kablov E. N., Ospennikova O. G., Kunitsyna E. I., Piskorskii V. P., Korolev D. V., Morgunov R. B.

Archives of Metallurgy and Materials

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2017

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Vol. 62, iss. 3

1923--1930

EN

Magnetic properties of powder (Pr,Dy)FeCoB ferrimagnetic alloys and effects of annealing, surface states were analyzed. X-ray photoelectron spectroscopy and Mössbauer spectra of powders indicate the effect of surface states on phase composition and magnetic properties of the studied powder, if particles average size is smaller than 10 μm. Effect of stoichiometry on magnetic anisotropy was found. Thermal stability of anisotropy field was proved by replacement of Fe atoms with Co atoms.

4

Effect of the Magnetisation of Covered Electrodes on the Quality and Properties of Underwater Wet Welded Joints

Rogalski G., Fydrych D., Prokop-Strzelczyńska K.

Biuletyn Instytutu Spawalnictwa w Gliwicach

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2016

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Vol. 60, No. 3

34--41

EN

The article analyses the effect of the magnetisation of covered electrodes on the geometry and properties of T-joints with fillet welds made of steel S235JR in watery environment. It was established that as regards the conditions and parameters used in the tests, the magnetisation of electrodes affected the stability of arc burning and the formation of shape-related welding imperfections but it did not influence the microstructure and hardness of the test joints.

PL

Dokonano analizy wpływu namagnesowania elektrod otulonych na geometrię i właściwości złączy teowych ze spoinami pachwinowymi wykonanych ze stali S235JR w środowisku wodnym. Stwierdzono, że dla zastosowanych warunków i parametrów spawania namagnesowanie elektrod wpływa na stabilność jarzenia się łuku, powstawanie niezgodności spawalniczych typu błędy kształtu, natomiast nie ma wpływu na budowę mikrostrukturalną i twardość złączy próbnych.

5

Impact of plate dimensions on time and space distributionof magnetic field induction inside the plate magnetized with C-core at various frequencies

Augustyniak M., Augustyniak B., Chmielewski M., Sadowski W.

Przegląd Elektrotechniczny

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2007

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R. 83, nr 6

48-49

EN

The study is dedicated to the numerical method of calculating with good accuracy of space and time distribution of magnetic field (both B and H), in ferritic steel plates of various geometries. Indirect methods of experimental verification of simulations are presented, including the Hall effect measurements along the surface of the plates. Simulations are made at frequencies from 0.1 Hz (quasi-static) up to 25 Hz, and the measurements at frequencies from 0.1 to 5 Hz.

PL

Badania dotyczyły numerycznego ilościowego modelowania czasoprzestrzennego rozkładu pola magnetycznego (B, H, jak również gęstości prądów wirowych) w ferrytycznych stalowych płytach o różnych geometriach. Zaprezentowano pośrednią procedurę weryfikacji wyników modelowania za pomocą pomiarów pola rozproszonego. Symulacje przeprowadzone są dla częstotliwości zawartych między 0.1 (przypadek quasi-statyczny) oraz 25 Hz, natomiast pomiary przeprowadzone są w zakresie 0.1 – 5 Hz. Uzyskano dobrą zgodność jakościową; pewne rozbieżności ilościowe tłumaczone są niemodelowaniem procesu histerezy oraz zgrubnym doborem własności materiałowych użytych w modelu.

6

The influence of substrate and cap layer on magnetic characteristics of some multilayers

Staniucha I., Urbaniak-Kucharczyk A.

Materials Science Poland

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2007

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Vol. 25, No. 2

371--375

EN

The influence of non-symmetrical boundary conditions, caused by different materials of the substrate and covering, on some properties of the systems consisting of magnetic layers separated by nonmagnetic spacer have been considered. Magnetic properties like spin wave patterns, FMR spectra, Curie temperature, magnetization and spin wave parameter B have been investigated for symmetrical and nonsymmetrical structures like: Cu(111)/(Fe/Cu)n/Fe/Cu/Si(111), vacuum/(Fe/Cu(111))n/Fe/vacuum, vacuum/( Fe/Cu)n/Si(111) and Cu/(Fe/Cu)n/Fe/GaAs, vacuum/(Fe/Cu)n/Fe/GaAs, where n is equal 1 or 2. Influence of roughness on selected characteristics of magnetic systems with non-symmetrical conditions on external surfaces has been also investigated.

7

O metodzie magnetycznej pamięci metalu

Lisiecki J.

Prace Naukowe Instytutu Technicznego Wojsk Lotniczych. Technika Lotnicza

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2004

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nr 18

51-84

PL

Przedstawiono podstawowe zagadnienia fizyczne dotyczące metody magnetycznej pamięci metalu należącej do grupy metod badań nieniszczących. Pokazano i omówiono wyniki pomiarów składowej normalnej rozproszonego pola magnetycznego H y p na próbkach ze stali 08X i Bw14G rozciąganych w zakresie do granicy plastyczności. Pokazano przebiegi pola rozproszonego na próbce poddanej silnemu odkształceniu plastycznemu oraz na próbkach z wprowadzonymi sztucznymi wadami w postaci otworów o różnej średnicy.

EN

Most essential physical aspects of the method of magnetic memory of metals have been presented. This method is one of NDT (non-destructive testing) methods. Measurements of the normal component of a magnetic leakage field H y p have also been presented, using specimens of the 08X and Bw14G steels exposed to tensile tests, i.e. to stretching, until the yield point was reached. Changes of the field of leakage have been shown using a specimen subjected to heavy plastic strain and specimens with artiticial detects, e.g. boreholes of different diameters.

8

Integrals of Lipschitz-Hankel type in analysis of magnetostatic fields

Pawluk K.

Journal of Technical Physics

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2003

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Vol. 44, no 2

133-144

EN

A boundary-integral model of the static magnetic field due to cylindrical permanent magnets that is put in free space is considered. Magnetic scalar potential quantities created by a virtual quantity "surface magnetic charge density" is expressed by means of Lipschitz-Hankel integrals that for the considered case are reducible (by the way of hypergeometric series) to some algebraic expressions, in which elliptic integrals of various kinds occur. This approach seems to be more effective than that can be reached by the use of a typical professional software for the field problems in which numerical integration, being not quite conform to the considered case, is common. The magnet subjected to the analysis has to be virtually subdivided in some number of elementary pieces, inside of which the uniform distribution of the inherent magnetization is supposed.

9

Rotating field in induction motor under consideration of anisotropy and cutting strains of steel sheets

Zagradisnik I., Slemnik B.

Journal of Technical Physics

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2002

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Vol. 43, no 4

521-525

EN

The rotating magnetic field in a symmetrical induction machine supplied with a sine-shaped and balanced system shows an asymmetrical shape if the magnetic medium is anisotropic. The shape of the air gap magnetic flux distribution is repeated twice per one revolution of the rotating field in a two-pole machine. The harmonic analyses show that all components rotate with variable magnitudes and non-uniform speeds. The variations are greater if the order of the component is higher. Only odd harmonics occur. Due to the spatial dependence of reluctance and the electric voltage balance in an induction machine, the magnetizing current also shows a spatial dependence.

10

Magneto-static field distribution due to inherent magnetisation of permanent magnets

Pawluk K.

Journal of Technical Physics

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2002

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Vol. 43, no 4

443-452

EN

A boundary-integral model of the static magnetic field due to cylindrical permanent magnets that is put in free space is considered. Magnetic scalar potential quantities created by a virtual quantity "surface magnetic charge density" is expressed by means of Lipschitz-Hankel integrals that for the considered case are reducible (by the way of hypergeometric series) to some algebraic expressions, in which elliptic integrals of various kinds occur. This approach seems to be more effective than that can be reached by the use of a typical professional software for the field problems in which numerical integration, being not quite conform to the considered case, is common. The magnet subjected to the analysis has to be virtually subdivided in some number of elementary pieces, inside of which the uniform distribution of the inherent magnetization is supposed.