Electrical Steel Sheets Research Articles

Structure and Mechanical Properties of the Molybdenum–Steel Bimetal Fabricated by Hot Isostatic Pressing

Abstract—The structure and the ultimate tensile strength of the bimetallic joints of a TsM2A (Mo–Ti–Zr system) molybdenum alloy and a corrosion-resistant 12Kh18N10T steel are studied. These joints are formed by diffusion welding under hot isostatic pressing conditions using the following combined intermediate layers: vanadium–electrical sheet steel, vanadium–copper, and titanium–niobium–copper. The highest strength of the joint (419 MPa) is reached when a combination intermediate layer of titanium, niobium, and copper is used.

Non-Oriented Silicon Iron Alloys Used in Efficient Electrical Motor Production

In this paper four non-oriented electrical steel grades M400-50A, M400-65A, M300-35A and NO20, utilizing a laboratory single sheet tester, were analyzed. For the magnetic measurements the peak magnetic polarization of 1 T was chosen. The frequency was variated between 3 Hz and 400 Hz. The isotropic electrical steel sheets were cut through punching technology, along the rolling direction. The experimentally determined energy losses were decomposed, using the loss separation theory, into hysteresis, classical and excess components. The relative magnetic permeability was analyzed and its parts, real and imaginary permeability were computed. The non-oriented alloy magnetic properties’ variation as a function of frequency was plotted and explained in the paper.

Rotating magnetic properties of electrical steel sheet under DC-biased field

Rotating magnetic properties of electrical steel sheet under DC-biased field

The Effects of Induction Motor’s Steel Sheet Thickness on Efficiency, Losses and Electrical Cost

Application of the induction motor in industry is common transversely the world. Performance evaluation of its energy efficient was increased the attention as it will convey important energy and commercial funds. This research considered the effects of electrical steel sheet’s thickness for rotor material of 0.5Hp 3-phase induction motor on energy efficiency, losses reductions and utility bill cost. The outcome for this research work is thru reducing the lamination thickness of steel sheet (from 0.50mm to 0.35mm) for rotor frame, the energy efficiency was increased by 1.4% and 13.27Watt of losses have been decreased. Uncertainty the new design is applied to 100, 000 pieces a new rotor of motor, it is assessed that 40.32kWh/year of energy might be saved also the utility bill will be saved up to RM 1.35million.

Performance prediction of surface‐mounted permanent magnet synchronous motor based on ring specimen test result

The B-H curve and iron loss of electrical steel sheets are essential data for predicting the performance of electric motors. The Epstein frame test is widely adopted to acquire these magnetic properties. However, for rotating electric machines with relatively small geometry, the ring specimen test is preferred because of its simplicity and geometric similarity. This study deals with the experimental verification of the ring specimen test. The B-H curve and iron loss of non-oriented electrical steel sheets are measured via the Epstein frame test and the ring specimen test. Each result is applied in finite element analysis (FEA) of the fabricated electric motor. Furthermore, using these FEA results and the d-q -axis equivalent circuit, the performance of the electric motor is predicted. For experimental verification, electric motor tests are performed under no-load and load conditions.

Quasi in-situ EBSD characterization of the evolution of microtexture and microstructure in non-oriented electrical steels during cold rolling and annealing

Non-oriented electrical steel sheets are extensively used to manufacture core laminations for electric motors. The microstructure and crystallographic texture of the final thin sheets have a significant effect on the magnetic quality of the lamination core. Controlling the development of microstructure and texture during thermomechanical processing of these steels is of great practical importance. Although the final microstructure and texture of the steel sheets are affected by all the processing procedures employed, cold rolling and final annealing have the most direct effect since these are usually the final steps to process the steel. Although much effort has been made to study the evolution of microstructure and texture in non-oriented electrical steels, the formation mechanisms of the final microstructure and texture during annealing (especially grain growth) are still not completely understood, which is partially due to the fact that it is very difficult to directly investigate these processes using conventional characterization techniques. In this research, a quasi in-situ electron backscatter diffraction (EBSD) technique was presented, which enabled the tracking of the changes of the morphology and orientation of individual grains during cold rolling and the subsequent annealing process. The experiments revealed the rotations of individual grains under plane strain compression, and tracked the formation of nuclei from the deformed matrix and the growth of new grains during the recrystallization process. The results provided valuable insights into the evolution of microstructure and microtexture during cold rolling and annealing of non-oriented electrical steels, and helped understand the mechanisms that govern the nucleation and grain growth during recrystallization.

An Enhanced Electrical Steel Sheet Model Integrating the Effects of Rotating Magnetic Properties and DC-Biased Field

An Enhanced Electrical Steel Sheet Model Integrating the Effects of Rotating Magnetic Properties and DC-Biased Field

Improving magnetic properties of non-oriented electrical steels by controlling grain size prior to cold rolling

Abstract The 0.5 mm-thick Fe-0.9 wt%Si-0.3 wt%Al non-oriented electrical steel sheets were successfully produced with one-stage and two-stage cold rolling methods. The comparative investigations were conducted on the relationships between the processing routes, microstructures, textures and magnetic properties. This study mainly focused on how to increase the grain sizes prior to cold rolling and its influences on subsequent microstructure and texture evolution. The results showed that the fine microstructure prior to final cold rolling led to the pronounced γ-fiber texture, fine recrystallized grains and deteriorated magnetic properties after final annealing. Nevertheless, by introducing a low-reduction cold rolling and intermediate annealing, coarse grains could be generated prior to the final cold rolling. When the cold rolling reduction was 11%, a relatively homogeneous microstructure composed of fully coarse grains was produced. The increased grain sizes promoted the generation of dense shear bands during final cold rolling, which served as the nucleation sites for λ-grains and Goss grains. This resulted in the improved magnetic properties due to the weakened γ-fiber texture, strengthened λ-fiber texture and Goss texture and increased grain sizes in the final annealed sheets. This work provided a new way to improve the magnetic properties of non-oriented electrical steels by controlling the grain sizes prior to final cold rolling.

High-resolution measurement method for magnetostriction of electrical steel sheets using an open-type single sheet tester

One of the main cause of acoustic noise from iron core in electrical machines is magnetostriction. However, good reproducibility of magnetostriction measurement cannot be expected due to its ppm-order value. To measure the magnetostriction accurately

Optimization of a single strip tester to measure magnetic properties of electrical sheet steel at medium frequencies

Optimization of a single strip tester to measure magnetic properties of electrical sheet steel at medium frequencies

Calculations of eddy currents in electrical steel sheets taking into account their magnetic hysteresis

PurposeThe purpose of this paper is to present the method which relatively easily allows to approximate the hysteresis loop of the dynamo or transformer steel sheets. The paper also looks into the formulation of an equation allowing determination of distribution of the flux density and eddy currents in cross-section of these sheets.Design/methodology/approachAn exponential function was applied in the presented method relating to the approximation of the hysteresis loop. When the field strength changes its value, then, the flux density are the sum or difference of a function, describing the lower or upper hysteresis curve and some “ransient” component. On the basis of Maxwell’s equations and Amper’s law, one non-linear differential equation was formulated which allows to calculate the flux density and eddy currents in a cross-section of a transformer sheet.FindingsThe method which relatively easily allows approximation of the hysteresis loop of ferromagnetic material is presented in the paper. The paper presents the derivation of one non-linear differential equation, allowing calculation of the flux density and eddy currents in the cross-section of the transformer sheets, taking into account the hysteresis phenomenon.Practical implicationsThe paper presents the method that can be used in modeling of the hysteresis loops of dynamo or transformer sheets, and the final non-linear differential equation can be applied in calculations of the magnetic field and eddy currents in cross-section of the transformer sheets.Originality/valueThe paper refers to important issues of modeling and calculations of the magnetic and eddy current field distribution in transformer steel sheets.

Effect of Material Characteristics on PMDC Motors based on the Grade of Electrical Steel Sheet

In this study, the effect of the material characteristics of electrical steel sheet on permanent magnet direct current (PMDC) motors is investigated using finite-element analysis. The motor design and test results are examined and verified through fabrication. The characterizations of brushless direct current (BLDC) motors according to the materials used in their cores have been actively studied. On the other hand, the effect of material characteristics on a PMDC motor consisting of brushes and commutators has not been studied as much. In the case of the PMDC motors, electrical steel sheets are infrequently used because this motor is relatively smaller than the BLDC motor. However, the iron loss characteristics, which are proportional to the frequency and the magnetic flux density, affect the efficiency even in small motors. Further, the output of the motor changes owing to saturation due to iron loss. The outcome presented in this study provides core materials selection guidelines to improve motor efficiency.

An Improved Anisotropic Vector Preisach Hysteresis Model Taking Account of Rotating Magnetic Fields

This paper presents an identification algorithm of the scalar Preisach model by using a set of symmetric minor hysteresis loops and suggests an improved vector Preisach model to describe the vector and anisotropic hysteresis behavior of a non-oriented (NO) electrical steel sheet (ESS) under rotating magnetic fields. Symmetric minor hysteresis loop is quite easy measured, so an identification algorithm based on symmetric minor hysteresis loop instead of first-order reverse curve is presented in this paper. The vector Preisach model employs a nonlinear coefficient, which is a function of magnitude and a direction of magnetic flux density, to describe the anisotropic property of the NO ESS and increases the numerical accuracy. The validity of the suggested vector Preisach model is investigated through comparisons with the experimental results under various magnetic field conditions.

Modeling of Magnetostrictive Property of Electrical Steel Sheet Under Vectorial Excitation

An accurate estimation for the magnetostrictive effect in an electrical steel sheet is helpful for determining the deformation and noise originating from magnetostriction during the design stages of electric devices. Because of limited measurement conditions, the rotational magnetostrictive modeling has been left aside during the calculations of core deformations. In this paper, the dynamic hysteresis properties of magnetostriction under different elliptic magnetization loci in a grain-oriented electrical steel sheet are investigated based on a rotational magnetic properties tester. A dynamic magnetostrictive model is proposed, in which the principal strains of magnetostrictions are time-dependent on variations of magnetic flux density, and the influences of past magnetization histories of material on the magnetostrictive strains are taken into account. Finally, magnetostrictive characteristics of a single-phase transformer core model built with uncut cores are analyzed and verified by experimental results. The results show that the rotational magnetostriction in the corner area is found to have a major contribution to core vibration and the proposed model can be employed to estimate the rotational magnetostrictions effectively.

Simple Numerical Calculation Method of Rotational Iron Loss in Silicon Steel Sheets

To evaluate the iron losses of motors and three-phase transformers, the rotational iron loss should be considered. A simple numerical calculation method of the rotational iron losses under rotational flux with high flux density and different axis ratios is proposed in this paper. First, it is shown that the method of decomposing the rotational flux into the directions of the major and minor axes of the rotational flux is effective in calculating the rotational iron losses of the non-oriented and grain-oriented electrical steel sheets in low magnetization region. Then, the simple iron loss calculation method is improved to consider the decrease of rotational hysteresis and anomalous eddy current losses in high magnetization region under circular rotational flux and verified by comparing with measurement results. Furthermore, it is improved to be applicable to rotational iron loss calculation under rotational flux with different axis ratios and verified by comparing with measurement results.

Analyses of Circulating-current Loss in Armature Windings and In-plane Eddy-current Loss in Electrical Steel Sheets of Permanent-magnet Synchronous Machines

Analyses of Circulating-current Loss in Armature Windings and In-plane Eddy-current Loss in Electrical Steel Sheets of Permanent-magnet Synchronous Machines

Investigation of the impact of the magnetic system configuration on the magnetic gear torque characteristics

Magnetic gears based on permanent magnets become very popular and promising because they are able to transmit torque without mechanical contact, do not create additional noise, do not require lubrication, have high efficiency and reliability, are more durable, which makes it possible to use them instead of mechanical gearboxes, including for motor-wheels of electric vehicles. Due to the design features of the magnetic gearbox, during its operation, pulsations of the transmitted torque occur. The main cause of pulsations is the presence of a cogging torque. When designing a magnetic gearbox, one should strive to ensure that the amount of cogging torque is minimal, since it causes vibrations and noise in the equipment and leads to a deterioration in the performance of the magnetic gearbox, and therefore decreases the efficiency of the motor-wheel. As a result of numerical studies, it was found that with an integer value of the reduction coefficient, the cogging torque is several times larger than for a non-integer value. For the given dimensions of the gearbox (outer diameter, axial length), the configuration and dimensions of the magnetic gearbox system are determined, at which the specified values of the gearbox moments are achieved at the minimum values of the cogging torque. It seems highly technological to produce a magnetic gear modulator consisting of fixed steel segments as a single unit, steel segments in which are connected by arches and the modulator can be made by stamping or laser cutting electrical steel sheets. As a result of numerical studies, the optimum thickness of the connecting arches and their location between the steel elements of the modulator are determined, at which the specified value of the gearbox torque and the technological effectiveness of its manufacture and assembly are provided. The calculation of the characteristics of the researching magnetic gear was made in the software package Infolytica Magnet.

Measuring Iron Loss of the Electrical Steel Sheets with Different Grades under Compressive Stress Normal to the Surface

Measuring Iron Loss of the Electrical Steel Sheets with Different Grades under Compressive Stress Normal to the Surface

Study of transformer magnetic field considering different temperature and DC bias of electrical steel sheet

Study of transformer magnetic field considering different temperature and DC bias of electrical steel sheet

Development of Through-Thickness Cube Recrystallization Texture in Non-oriented Electrical Steels by Optimizing Nucleation Environment

Texture evolution of 2.1 wt pct Si non-oriented electrical steel sheets was investigated using macro- and micro-texture analysis. The desirable cube ({001}〈100〉) component successfully dominates the recrystallization texture through sheet thickness. The nucleation sites of cube grains are mainly identified at the interfaces of {001}〈230〉-{001}〈130〉 and {223}〈362〉-{114}〈481〉 oriented deformation bands. The formation of through-thickness cube recrystallization texture can be attributed to the optimization of nucleation environment, featuring quantitative advantage of cube nuclei at both strong plane strain and strong shear strain layers under the superiority of locally low density of cube nuclei.