Electrical Steel Research Articles

The mechanism of citric acid and oxalic acid on dissolution of high-silicon iron tailings

In the indoor static environment, citric acid and oxalic acid, two kinds of low molecular weight organic acids were used to dissolve silicon and iron, which were two valuable elements in iron tailings. The results showed that the iron tailings used in this study were high silicon type iron tailings with 76.1 % silicon content and 11.31 % iron content. Both acids were soluble to ferrosilicon, but their solubility to iron was higher. Compared with the two, oxalic acid had stronger silicon solubility, reaching 35.98 μg/mL after 24d. The solubility of citric acid to iron was stronger, reaching 483.51 μg/mL after 24d. The dissolution of silicon and total iron in iron tailings by oxalic acid, citric acid and mixed acid conforms to first-order kinetics and belongs to surface dissolution reaction. After the dissolution of oxalic acid, silicon and iron ions might exist in the form of metasilic acid, iron oxalate and trioxalate potassium ferrite. Oxalic acid reacted with Fe2+ to precipitate, which might be the reason for the higher Fe3+ in the solution. The silicon and iron ions after citric acid dissolution might exist in the form of ferric citrate, ferric citrate complex, ferrous hexafluorosilicate, and more Fe2+ products might be the reason for the higher Fe2+ in the solution.

Measurement equipment and result analysis of B-H curve of current transformer core material under mixing frequency.

To examine the effect of mixed-frequency excitation conditions on the hysteresis and loss characteristics of ferromagnetic materials, this paper shows how to construct magnetic property test equipment for electrical steel using Epstein's square circle. Experiments were carried out to assess the hysteresis and loss properties of oriented silicon steel wafers under mixed-frequency sinusoidal operating conditions with different occupancy ratios. It used heterodyne extraction to investigate the effect of different occupancy ratios of industry and magnetization frequency on the hysteresis and loss characteristics of oriented silicon steel sheets.

Comparative analysis of silicon and steel technologies: Shaping societal evolution and prospects

Lives have completely changed in the past few decades in light of the application of integrated circuits which are based on silicon. This paper conducts a comparative analysis of the impact of silicon technology and steel on human societies, both pivotal in advancing social productivity. It delves into their evolution, highlighting the transformation from antiquity to modernity for steel and the maturation of silicon from a natural element to a semiconductor cornerstone. Key developments in steel, such as the Bessemer process and electric arc furnaces, are explored alongside silicons journey from basic electronic components to complex integrated circuits. The paper also investigates the influence of these materials in various industries, notably the automotive sector, where steels structural integrity complements silicons role in digitization and automation. Furthermore, it examines the future prospects of these industries, emphasizing sustainable practices in steel production and the potential of silicon in emerging fields like quantum computing. The analysis aims to underscore the similarities and interplay between the roles of silicon and steel in shaping modern society, providing insights into their enduring significance and evolving applications.

Electrical Capacitors Based on Silicone Oil and Iron Oxide Microfibers: Effects of the Magnetic Field on the Electrical Susceptance and Conductance.

This paper presents the fabrication and characterization of plane capacitors utilizing magnetodielectric materials composed of magnetizable microfibers dispersed within a silicone oil matrix. The microfibers, with a mean diameter of about 0.94 μm, comprise hematite (α-Fe2O3), maghemite (γ-Fe2O3), and magnetite (Fe3O4). This study investigates the electrical behavior of these capacitors under the influence of an external magnetic field superimposed on a medium-frequency alternating electric field, across four distinct volume concentrations of microfibers. Electrical capacitance and resistance measurements were conducted every second over a 60-s interval, revealing significant dependencies on both the quantity of magnetizable phase and the applied magnetic flux density. Furthermore, the temporal stability of the capacitors' characteristics is demonstrated. The obtained data are analyzed to determine the electrical conductance and susceptance of the capacitors, elucidating their sensitivity to variations in microfiber concentration and magnetic field strength. To provide theoretical insight into the observed phenomena, a model based on dipolar approximations is proposed. This model effectively explains the underlying physical mechanisms governing the electrical properties of the capacitors. These findings offer valuable insights into the design and optimization of magnetodielectric-based capacitors for diverse applications in microelectronics and sensor technologies.

A new approach for improving the properties of tailings sand autoclaved aerated concrete - From a mineralogical perspective

This study proposed a new method to improve the performance of tailings sand autoclaved aerated concrete (SAAC). Firstly, high silicon iron tailings from the Anqian area and low silicon molybdenum tailings from the Weinan area were selected, and the mineral composition of these two tailings was analyzed. Then, the single mineral in the two tailings were used instead of siliceous raw materials to prepare mineral autoclaved concrete (MAC). The autoclaved reactivities of these minerals were analyzed through compressive strength, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TG-DTG), and scanning electron microscopy (SEM), and which minerals were beneficial for the preparation of SAAC were determined. On this basis, magnetic separation and gravity-magnetic separation processes were used to pretreat Anqian iron tailings and Weinan molybdenum tailings, respectively. Finally, the effectiveness of this method was verified by preparing SAAC made with tailings before and after pretreated. The tested results showed that the autoclaved activities of siliceous minerals were in the following order: quartz hornblende, feldspar, chlorite, while the montmorillonite and biotite, and the metal mine (hematite and pyrite) did not have autoclaved reactivities. The main crystalline phase of hydration products in MAC made with single mineral without autoclaved reactivities were C-S-H, Ca(OH)2, CaCO3, and hibschite, and that in MAC made with quartz, hornblende, feldspar, and chlorite were C-S-H, tobermorite, Ca(OH)2, CaCO3, and hibschite (except quartz). After 1.3 T strong magnetic separation treatment, the content of Fe2O3 in iron tailings decreased from 11.11 % to 4.16 %, and the compressive strength of SAAC made with iron tailings with magnetic separation pretreated increased by 11.43 % comparted to that of SAAC made with original iron tailings. After gravity separation and 1.1 T strong magnetic separation pretreated, the content of SiO2 in molybdenum tailings increased from 63.97 % to 84.03 %, and the mineral content of biotite decreased from 40.5 % to 11.2 %. The compressive strength of SAAC made with molybdenum tailings with gravity-magnetic separation pretreated increased by 24.09 % comparted to that of SAAC made with original molybdenum tailings.

Comparisons of {100} texture improvement and formability in hot-rolled non-oriented electrical steel by austenite–ferrite phase transformation and shear deformation

Comparisons of {100} texture improvement and formability in hot-rolled non-oriented electrical steel by austenite–ferrite phase transformation and shear deformation

Fully Consolidated Deposits from Oxide Dispersion Strengthened and Silicon Steel Powders via Friction Surfacing

Abstract The objective of this work is to study the ability of friction surfacing to deposit metal alloys that are difficult to process with traditional methods. Creep and neutron irradiation resistant oxide dispersion strengthened (ODS) materials cannot be produced via conventional casting route due to insolubility of the oxidic and metallic alloy constituents, causing unintended inhomogeneous oxide dispersion and material behavior. Increasing silicon content of Iron-Silicon (Fe-Si) improves electromagnetic properties but embrittles the material significantly and the fusion based manufacturing methods unable to process this steel. The solid-state nature of the friction surfacing process offers a potential alternative processing route to enable wider usage of difficult to process alloy systems. Both ODS and Fe-Si materials are available in powder forms. While the existing literature in friction surfacing focuses on depositing composites by incorporating small quantities powders through holes in consumable rod, this is a first study that shows a large charge of powder can be converted to a homogeneous fully consolidated deposit in friction surfacing. A novel methodology is used that incorporates the high portion of powder feedstock into hollow consumable friction surfacing rods (up to 35% volume fraction). It was found that fully consolidated deposits can be produced with powder feedstocks using proposed methodology. A recrystallized, homogeneous, equiaxed microstructure was observed in Fe-Si 6.8 wt% and a new generation FeAlOY ODS alloy deposits processed with hollow stainless-steel friction surfacing rods. Both powder and rod material plasticize and deposit without bulk intermixing.

The method of reducing energy consumption in large blast furnace smelting by low-silicon smelting

Currently, achieving carbon peaking and neutrality poses significant challenges for China's iron and steel industry. Low-carbon smelting in large blast furnaces (BFs) is poised to be a pivotal element in attaining the “double carbon” goal. This study, grounded in the fundamental process theory of blast furnace ironmaking, employs data analysis to investigate production technology across 25 large blast furnaces in China exceeding 4000 m3 in 2021. It specifically examines the correlation between pig iron silicon content and fuel consumption, elucidating strategies and techniques for low-silicon smelting. By exemplifying the reduction of silicon content in a 5050 m3 blast furnace of a Chinese enterprise, the study systematically delineates the low-silicon smelting process, including specific parameters and standards concerning fuel consumption, raw material conditions, and operational systems. The findings demonstrate that a reduction of 0.1% in pig iron silicon content can decrease carbonaceous fuel consumption by at least 5 kg/t. Given current raw material conditions and equipment levels, it is feasible to reduce the silicon content of iron in large-scale blast furnaces exceeding 4000 m3 in China to 0.3%.

Effect of adhesion promoters on rheokinetics and roll peel strength of electrical steel stacks

Epoxy varnishes for stacked electrical steel are of high relevance for renewable energy and electric mobility technologies. Water-borne epoxy varnish systems are still under development, especially with regards to the improvement of the adherence to the steel substrate. The main objective of this study was to assess the potential of low molar mass, silane-based adhesion promoters (AP) with amine or glycidyl functional groups as to their effect on the crosslinking kinetics of coatings and the mechanical performance of electrical steel laminates.Model formulations with different types and contents of silane AP or in combination with a pre-crosslinker were based on a Bisphenol A diglycidyl ether, a dicyandiamide (DICY) crosslinking agent and an emulsifier. The amount of water was fixed to 45 m%. Model varnishes were prepared by shear emulsification at elevated temperatures. Varnishes were applied onto electrical steel sheets and partly crosslinked to the B-stage. Finally, coated steel sheets were stacked and laminated in a heated press.To examine the crosslinking kinetics under non-isothermal conditions, rheokinetic measurements were performed. While the curing onset temperature of formulations with amine-based AP dropped by ∼10 °C, the effect of the epoxysilane AP was less pronounced (drop by ∼5 °C). Pre-conditioning of the varnishes in A-stage revealed a further reduction of the curing onset temperature associated with significantly higher initial viscosity. This was a clear indication for pronounced pre-crosslinking in A-stage and hence, a limited shelf life of silane-modified varnishes. The glass transition range in the fully cured state was solely affected by the diamine-based AP. Interestingly, the investigated low molar mass silane APs had no significant positive effect on the roll peel strength of the laminates.

High‐Strength Nonoriented Electrical Steel with Excellent Magnetic Properties Accomplished by Cu–Ni Multialloying

High‐Strength Nonoriented Electrical Steel with Excellent Magnetic Properties Accomplished by Cu–Ni Multialloying

An enhanced Energy-Based hysteresis model for electrical steel sheets considering mechanical stress

Mechanical stress significantly influences the hysteresis characteristics of silicon steel, which are crucial for the design of electrical equipment cores. This study develops an improved Energy-based hysteresis model that integrates the effects of mechanical stress by modifying the anhysteretic magnetization model to include total average anisotropy energy density and introducing a linear relationship between coercive force and mechanical stress. The model’s performance is demonstrated using 30QG120 oriented silicon steel sheets, where the hysteresis loops under varying stress conditions are successfully simulated and validated against experimental data. The results confirm the model’s accuracy and practical utility in predicting material behavior under mechanical stress, offering a valuable tool for optimizing electrical steel sheet design.

Investigation of Inclusion Characteristics in Ferrosilicon Killed High Silicon Steels

Industrially, the silicon requirement of liquid steel is often met with ferrosilicon (FeSi) instead of high‐purity silicon addition. FeSi, a silicon‐rich alloy, contains impurities typically inherited from its manufacturing stage. Therefore, FeSi addition results in the formation of complex inclusions in the liquid steel. Herein, a detailed inclusion characterization of the samples obtained from the melting experiments for a wide range of silicon concentrations has been carried out to examine the effect of FeSi impurities. Pure silica inclusions evolve to silica‐ and/or alumina‐based Si–Al–(Ti)–O–(TiN) complex inclusions with the increasing addition of FeSi to the steel melt. Reduction of silica by aluminum or titanium, the presence of titanium in the steel melt, and/or TiN inclusions formed at the periphery of oxide inclusions restrict the growth of oxide inclusions, resulting in small‐sized (average) oxide inclusions. The underlying mechanism of such complex (Si–Al–Ti–O–N)‐based inclusions has been explained with the aid of microstructural characterization and thermodynamic calculations. Moreover, the steel–crucible (alumina) interface has also been investigated for inclusion deposits and crucible–steel interaction.

Development and characterization of powder metallurgy processed Al/Fe/SiC/MoS2 hybrid composites

This study explores hybrid aluminum matrix composites through powder metallurgy, incorporating silicon carbide, iron, and molybdenum disulfide at varying weight percentages (5%, 10%, and 15%). Defect-free hybrid composites with a uniform distribution of reinforcing particles were fabricated and characterized for microstructure, hardness, density, and wear. The EDX spectra show peaks consistent with Al, Fe, SiC, and MoS2, confirming their presence in developed hybrid composites. The pure aluminum sample presents a relative density higher than that of hybrid composites, while its hardness is lower (25%–41%) than that of hybrid composites. The wear rate decreased with the amount of reinforcing particles. The presence of hard silicon carbide, iron, particles, and lubrication by molybdenum disulfide effectively enhanced the wear behavior of hybrid composites.

Viscosity, Density, Surface Tension, and Crystallization Behavior of Commercial Mold Fluxes

This study investigates the viscosity, density, surface tension, and crystallization behavior of two commercial mold fluxes that are utilized to cast ultralow‐carbon, low‐carbon, and medium‐carbon steel grades, as well as electric steels (high‐B magnetic and grain‐oriented steels). Experiments are performed in the temperature range of 1073–1673 K using the rotating bob method, maximum bubble pressure method, buoyancy method, and single hot thermocouple technique. The phase structure is investigated via scanning electron microscopy and X‐ray powder diffraction. The results indicate that viscosity and density exhibit nonlinear temperature dependence. Increased basicity (CaO/SiO2) results in reduced viscosity and elevates the break temperature of the mold fluxes. Furthermore, the incubation time required for phase formation decreases with increasing basicity. Finally, time–temperature transformation and continuous cooling transformation diagrams are constructed.

Shaping society: The evolution and impact of silicon and steel technologies—Building the future: A comparative analysis of silicon and steel technologies

Abstract In the ever-changing technical world, this article compares the societal implications of two technological behemoths: silicon technology and steel technology. Silicon technology, best recognized for its role in integrated circuits and electronics, ushered in the digital age, revolutionizing the way people communicate, calculate, and conduct business. Steel technology, on the other hand, has formed the foundation of contemporary infrastructure and industries due to its strength and versatility. This research thoroughly investigates their economic, environmental, and social implications, providing light on their distinct and common contributions to society. It also looks into the astonishing history of silicon integrated circuit technology, tracking its route from Moore’s Law-driven aggressive growth to the current emphasis on energy efficiency and power consumption reduction. The paper’s investigation is critical in understanding the delicate interplay between innovation and social advancement, and it provides insights into technology’s transformational capacity. As we stand at the crossroads of these two technical domains, this research emphasizes the historical relevance of silicon and steel technologies, as well as their ability to shape our technological future. It enables readers to study the dynamic interplay between silicon and steel via a comparative perspective, exposing their revolutionary contributions and the intricate web of societal advancement they have woven throughout history.

A grader for fresh jujube with electromagnetic synchronous actuator assembly

AbstractIn recent years, the post‐harvest commercialization of fresh jujube sorting technology is backward, the efficiency of manual grading is low, and the application of machine vision technology in fruit grading has been a research hotspot. To improve the grading accuracy and speed of the fresh jujube machine vision grading machine, this study designs a method of fresh jujube machine vision grading using an electromagnetic synchronous actuator. The grading machine consists of an automatic distribution and arrangement system, an image acquisition and processing system, and a synchronous actuator assembly, which uses a sensitive electromagnet to adsorb a silicon steel switching buckling plate to execute the action. The image processing process includes an image color component, Sobel operator filtering, Otsu method binarization, and ellipse fitting to extract the color and size eigenvalues. The experimental results show that the date images can be acquired quickly and processed accurately with a processing speed of 50 ms per frame. In addition, the proposed actuator can be sensitively triggered with a response time of 40 ms. The grader successfully classified jujube into five size classes and one color class. The grading accuracy and non‐destructive rate reached 93.7% and 100%, respectively. The grading efficiency is 20 jujubes per second, with a maximum production rate of 1400 kilograms per hour. This grading machine realizes the requirements of high accuracy, high speed, and non‐destructive grading of fresh jujube and provides an important technical and theoretical basis for the development of machine vision jujube rapid grading technology.Practical applicationsIn recent years, sorting technology in the post‐harvest commercialization of fruits has been outdated, and manual grading has been inefficient. The application of machine vision technology in fruit grading has been a research hotspot in recent years. This study designs a machine vision grading of fresh dates with an electromagnetic synchronous actuator. The grader was composed of a roller conveyor, synchronous actuator assembly, image main processor, and actuator controlling co‐processor. Experimental results indicated that jujube images could be acquired rapidly and processed accurately, with a processing speed of 50 ms per frame. In addition, the proposed actuator could be sensitively triggered with a response time of 40 ms. Finally, the grader successfully sorted jujubes into five size classes and one color class. The grading accuracy rate and non‐destructive rate reached 93.7% and 100%, respectively. The grading efficiency was 20 jujubes per second, and the maximum productivity was 1400 kg/h.

Iron Loss Analysis of High-Speed AFPM Motor With Ultra-Thin Silicon Steel Considering Bending Stress

Iron Loss Analysis of High-Speed AFPM Motor With Ultra-Thin Silicon Steel Considering Bending Stress

Error analysis and correction strategy for measuring oriented silicon steel by SST method

AbstractTo accurately determine the relationship between magnetic polarisation and magnetic field strength in oriented silicon steel, the magnetic properties, such as power loss, were measured under different magnetisation conditions. This facilitates for the precise selection of iron core materials for distribution transformers. The deviation rate of measurement results for different magnetisation conditions in oriented silicon steel with varying thicknesses was analysed using the SST method. Additionally, the finite element simulation of MagNet was employed to further investigate this relationship. The causes of measurement errors in oriented silicon steel by the SST method are thoroughly studied, with a focus on 0.18 mm oriented silicon steel as an example. It is found that the main reason for the measurement error is the deviation between the actual effective magnetic path length and the conventional effective magnetic path length, which is caused by the uneven distribution of magnetic polarisation in oriented silicon steel. The main reason for the difference of magnetisation conditions is the change in the actual effective magnetic path length, which is mainly affected by changes in permeability. Combined with the magnetic field distribution inside the oriented silicon steel, the distribution coefficient of magnetic polarisation can be calculated, the actual effective magnetic path length under each condition can be calculated, and then the measurement results of the SST method can be modified. This research is expected to significantly contribute to the practical applications of oriented silicon steel in engineering.

Recent development of grain oriented electrical steel in Shougang steel

Shougang Steel has been pursuing the development of low iron loss and high permeability grain oriented electrical steels for more than a decade. Grain oriented electrical steel requires a very strong Goss {110}〈001〉 texture and as such a comprehensive control of thermo-mechanical processing parameters is required to achieve a strict control of texture. In this paper the key metallurgical problems associated with manufacture of grain oriented electrical steel are discussed, including the factors that affect both primary recrystallization and secondary recrystallization leading to the development of a strongly textured final sheet. The metallurgical factors affecting magnetostriction of electrical steels are also analyzed, and a technological approach for domain refinement, and its effect on magnetic properties, is described. Examples of magnetic properties under non-sinusoidal magnetization conditions are also reported and analyzed. As a result of continuous research and development efforts the high permeability low iron loss grain oriented electrical steel of thin gauge products of 0.2 mm/0.18 mm thickness have recently been developed to meet the requirements of the new China national standard of energy efficiency grades for power transformers.

Hot Deformation Behavior of Free-Al 2.43 wt.% Si Electrical Steel Strip Produced by Twin-Roll Strip Casting and Its Effect on Microstructure and Texture.

Twin-roll strip casting (TRSC) technology has unique advantages in the production of non-oriented electrical steel. However, the hot deformation behavior of high-grade electrical steel produced by TRSC has hardly been reported. This work systematically studied the hot deformation behavior of free-Al 2.43 wt.% Si electrical steel strip produced by twin-roll strip casting. During the simulated hot rolling test, deformation reduction was set as 30%, and the ranges of deformation temperature and strain rate were 750~950 °C and 0.01~5 s-1, respectively. The obtained true stress-strain curves show that the peak true stress decreased with an increase in the deformation temperature and with a decrease in the strain rate. Then, the effect of hot deformation parameters on microstructure and texture was analyzed using optical microstructure observation, X-ray diffraction, and electron backscattered diffraction examination. In addition, based on the obtained true stress-strain curves of the strip cast during hot deformation, the constitutive equation for the studied silicon steel strip was established, from which it can be found that the deformation activation energy of the studied steel strip is 83.367 kJ/mol. Finally, the kinetics model of dynamic recrystallization for predicting the recrystallization volume percent was established and was verified by a hot rolling experiment conducted on a rolling mill.