Electrical Steel Research Articles

Establishment of Multivalent Molybdenum Salt System and Its Effect on the Anti-Corrosion Performance of Insulating Coatings for Oriented Silicon Steel

Chromium salt fillers commonly used in current anti-corrosion coatings are highly toxic. However, due to the unique high–low valence transformation and passivation mechanisms of chromium-based functional fillers and their wide applicability, chromium-free coatings find it challenging to achieve the same performance and industry acceptance. This study introduces an innovative approach that uses zinc to reduce molybdate (MoO42−) in an acidic solution, thereby forming a multivalent MoO42− system (PMZ system), and applies it to chromium-free insulating coating for oriented silicon steel. The effects of reductant dosage on the valence composition of molybdenum in the PMZ system and the corrosion resistance of the coating were investigated. Additionally, the difference in the valence composition of molybdenum between the PMZ system and the multivalent phosphomolybdate system (PMNZ system) and its impact on corrosion resistance were studied. The results indicate that the PMZ system contains trivalent molybdenum and hexavalent molybdenum, while the PMNZ system contains pentavalent molybdenum and hexavalent molybdenum. The systems leverage the reactivity of lower-valence molybdenum to delay the corrosion by reacting with oxygen while maintaining the original mechanism of molybdenum salt fillers and forming sediment with iron ions to form a passivation layer. As the content of trivalent molybdenum in the PMZ system increases, the corrosion resistance of the insulating coating improves. When the amount of zinc added in the PMZ system is 0.006 g, the relative proportion of trivalent molybdenum reaches 20.52%, and the salt spray resistance of the coating developed with the PMZ system reaches 248 h with a corrosion area of less than 5%. When the contents of the main components and sodium molybdate in the PMZ coating and the PMNZ coating are the same, the corrosion resistance of the PMZ coating, which contains trivalent molybdenum, is better than that of the PMNZ coating, and the salt spray resistance exceeds 192 h.

Effect of time of a two-step annealing on the microstructure and magnetic properties of non-oriented electrical steels

Effect of time of a two-step annealing on the microstructure and magnetic properties of non-oriented electrical steels

Induction Heating Features in Electrical Steel Hot Rolling Mills

Induction Heating Features in Electrical Steel Hot Rolling Mills

Performance Improvement of Wound Field Synchronous Motor for EV Propulsion Applying Grain-Oriented Electrical Steel

Performance Improvement of Wound Field Synchronous Motor for EV Propulsion Applying Grain-Oriented Electrical Steel

Predicting Compressive Strength of Oil Well Cement Slurries: Novel Moduli‐Based Analysis of Chemical Composition at Different Temperature Condition

ABSTRACTThis study evaluates the impact of cement chemical composition on the compressive strength (CS) of cement slurries, utilizing silica fume (SF) and fly ash (FA) as additional materials. A comprehensive analysis was conducted on 317 datasets from the literature, focusing on factors including silicon dioxide (SiO₂), aluminum oxide (Al₂O₃), calcium oxide (CaO), iron oxide (Fe₂O₃), water‐to‐binder (w/b) ratio, and SF and FA content, as well as curing time and temperature. The research presents three geochemical moduli, namely, silicate modulus (SM), aluminate modulus (AM), and hydraulic modulus (HM), to assess and forecast CS. The investigation utilizing full quadratic (FQ) and cubic (CUB) models underscores the precision of prediction models corroborated by statistical metrics, such as scatter index (SI), root mean squared error (RMSE), and correlation coefficient (R2). Univariate, bivariate, and multivariate evaluations indicate that SM, AM, and HM significantly decrease input parameters while preserving or enhancing model accuracy. The ideal replacement percentages for SF and FA to maximize strength were determined to be 14.6% and 11.6%, respectively. The optimal values for SM, AM, and HM were 2.62, 1.38, and 2.21, respectively. The results establish a solid framework for optimizing cement formulations, presenting sustainable alternatives for improved mechanical performance and decreased material consumption in oil well cementing and building applications.

Correlation Between Soft Magnetic Properties and Microstructure According to Heat Treatment in FeCo-2V Electrical Steel

Correlation Between Soft Magnetic Properties and Microstructure According to Heat Treatment in FeCo-2V Electrical Steel

Design and Analysis of Double‐Sided U‐Shaped Linear Primary Permanent Magnet Vernier Motor

This paper introduces a new double‐sided U‐shaped linear primary permanent magnet Vernier (U‐LPPMV) motor, whose most important feature is a U‐shaped Halbach structure in which the magnetization direction of five permanent magnets is concentrated at the center point, which provides more than twice the thrust density compared with existing single‐sided motors. The secondary stage adopts a convex pole structure consisting of laminated silicon steel sheets, which has the advantages of a simple structure and low cost. The no‐load counter‐electromotive force and magnetic chain are made more sinusoidal by changing the side end structure at both ends of the primary. Next, the air‐gap magnetic density of the motor is analyzed analytically by establishing the magnetomotive force potential‐magnetic conductance model, and the accuracy is verified by simulation analysis. In addition, a global optimization of the motor is performed to increase the average thrust and improve the electromagnetic performance based on the optimized structural parameters. Finally, the accuracy of the theory is demonstrated by prototype design and fabrication as well as by building a test platform, and the motor is more suitable for long‐stroke, high‐load, and high‐precision application scenarios. © 2025 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC.

Carbon Footprint Analysis of Distribution Network Transformers Based on Life Cycle Assessment

Transformers in the distribution network must have their carbon emissions analyzed in order to meet the “double carbon” goal. Using an oil-immersed distribution transformer as the research object, this paper develops a “cradle-to-grave” carbon accounting model. A life cycle assessment (LCA)-based methodology is proposed to account for carbon emissions and total energy demand over the full life cycle and further analyze the carbon emissions within each stage. A case study is presented using data from a 200 kVA transformer manufactured by a transformer plant in Xinjiang. According to the data, there are 112.18 t of carbon emissions and 798.21 GJ of total energy consumed. Distribution network transformers have carbon emissions of 282 kg, 782 kg, 122.96 kg, 11,079.64 kg, and −88.6 kg throughout the manufacture and manufacturing stage, transportation stage, construction and installation stage, operation stage, and waste recycling stage, respectively. There are 4.12 GJ, 9.06 GJ, 1.34 GJ, 785.97 GJ, and −0.28 GJ in total energy requirements. According to the study, which covered 99.03% of the entire life cycle, the operation stage had the largest percentage of carbon emissions. In addition to streamlining the production process and using more energy-efficient equipment, the waste recovery stage successfully decreased the environmental impact of carbon emissions. Sensitivity analysis shows that the silicon steel sheet and transformer oil has a significant impact on the carbon emissions of distribution network transformers during the life cycle, and the higher the grade of silicon steel sheet, the lower the carbon emissions, and the synthetic ester transformer oil has the most comprehensive performance and the lowest carbon emissions.

Effect of Annealing Process on Microstructure and Magnetic Properties of Fe-3.0 Wt Pct Si Non-oriented Silicon Steel Ultra-Thin Ribbons Prepared with Planer Flow Casting

Effect of Annealing Process on Microstructure and Magnetic Properties of Fe-3.0 Wt Pct Si Non-oriented Silicon Steel Ultra-Thin Ribbons Prepared with Planer Flow Casting

Calculation of Stray-Field Loss of TEAM P21 Model Under Complex Excitations Based on the Improved Energetic Hysteresis Model

An efficient numerical calculation method of stray-field loss is investigated for typical magnetic load components (grain-oriented silicon steel sheets (GO), magnetic steel plate, and combined components of both materials) under non-sinusoidal excitations (NSE) containing symmetrical harmonic and DC to avoid the local overheating caused by high stray-field loss density. The paper investigates the stray-field loss with different types of load components and working conditions based on the leakage flux complementary-based measurement method, derives an analytical formulation calculating the energetic hysteresis model parameters under different magnetic flux densities to reduce the dependence on measurement data, establishes a loss calculation method considering the influence of non-sinusoidal magnetization on magnetic loss, and discusses the advantages and limitations of existing numerical approaches of additional loss to establish an effective computational strategy of stray-field loss. Finally, the effectiveness of the proposed method is verified by simulations and experiments.

Utilizing Flexible Magnetic-Alloy Sheet with Rolling-to-Attaching Method to Fabricate a Smart Nail for Electromagnetic Screw-Hole Targeting in Intramedullary Interlocking-Nail Surgery

Abstract In this paper, we present a novel method to fabricate a smart nail for electromagnetic targeting of distal screw-holes in intramedullary interlocking-nail surgery. The nail is fabricated by using a flexible magnetic-alloy Metglas sheet with a rolling-to-attaching method. That is, among most high permeable magnetic materials, the Metglas sheet has superior features in flexibility and bendability and therefore can be rolled and inserted inside the nail to accordingly conform to curvature of inner surface of the nail. Regarding the targeting system, we used a conventional c-shaped electromagnet (consisting of a c-shaped silicon steel core, emitting coil, and receiving coil) with measurement electronics as the targeting system. At first, an AC input voltage is applied to the emitting coil to generate magnetic flux in the air-gap between emitting coil and receiving coil. Consequently, by electromagnetic induction, an AC voltage is induced in the receiving coil. As the nail is axially moved or rotated within the air-gap between the emitting and receiving coils, the magnetic flux between the coils is influenced, leading to a change in the voltage output of the receiving coil. This voltage change is further analyzed to determine location and orientation of the Metglas sheet (as well as screw holes). Based on this targeting principle, we conduct location and orientation targeting tests. Results show that our method not only can successfully achieve these targeting, but also significantly simplifies the complexity of both targeting system and surgical procedure, in practical perspective.

Effect of nitrogen content and cerium treatment on the characteristics of inclusions in non-oriented silicon steel

The electric arc furnace (EAF) short process is an important technical path for the future production of green steel, while the higher nitrogen content limits the production of high-grade steel plates, represented by non-oriented silicon steel (NOSS). Under this background, the influence of nitrogen content and cerium treatment on the characteristics of inclusions in NOSS was investigated. Thermodynamic analysis reveals that increasing nitrogen content raises both the initial precipitation temperature and the mass fraction of AlN. NOSS with varying nitrogen contents were smelted in a resistance furnace by top-blowing nitrogen gas (simulating high nitrogen content NOSS produced using EAF), and then cerium treatment was performed on the high nitrogen content NOSS. The inclusions were qualitatively and quantitatively characterised by scanning electron microscope (SEM, Sigma 300). The results indicate that as nitrogen content increases from 0.0013 to 0.0043 wt%, the number density of submicron-sized inclusions, which are more harmful to NOSS properties, increases from 95.43 to 126.64 mm−2. These inclusions are mainly pure MnS and nitrides (AlN and AlN + MnS). After cerium treatment, the modification of sulphides and coarsening of AlN resulted in a decrease in the number density of submicron inclusions. With 0.0086 wt% cerium, the lowest observed number density of submicron-sized inclusions is 14.58 mm−2. The heterogeneous nucleation between AlN and Ce-S was confirmed using the edge-to-edge matching model combined with electron backscattered diffraction.

The Mechanism of Heating Rate on the Secondary Recrystallization Evolution in Grain Oriented Silicon Steel

The Mechanism of Heating Rate on the Secondary Recrystallization Evolution in Grain Oriented Silicon Steel

The Multiple Effects of RE Element Addition in Non-Oriented Silicon Steel.

High-grade non-oriented silicon steel with high magnetic induction and low iron loss produced with low carbon emissions is crucial for the development of new energy and energy-saving motors. In this paper, the trace mixed rare earth (RE) elements exhibit a great potential to enhance magnetic properties in a lower carbon emission process by multiple effects on microstructure, texture, and inclusion in non-oriented silicon steel. With the trace-doped RE elements (0.004-0.030%), RE-rich precipitates preferentially form and subsequently adsorb fine inclusions below 1 μm to transform into spherical or ellipsoidal shape, which results in a significant increase in final recrystallization grain size. Moreover, the favorable λ texture (<001>//ND) is promoted while the detrimental γ texture (<111>//ND) is reduced, owing to the advantages in size and quantity of λ grains during the nucleation process. The improved magnetic properties of higher B50 and lower P15/50 are achieved with 0.004% RE at lower annealing temperature ranges. The increased λ texture is attributed to the heterogeneity in microstructure and texture as well as the grain boundary segregation of RE elements. However, a higher RE content (0.072%) leads to a deterioration in magnetic performance due to the formation of more stable RE-rich precipitates, smaller grains, and stronger γ texture. An iron loss calculation model was also proposed to guide the design of high-grade non-oriented silicon steel by incorporating the multiple effects of RE elements on grain size, recrystallization texture, and inclusion.

Tensile deformation behavior and constitutive modeling of cold-rolled non-oriented silicon steel with 2.5 wt% Si

Tensile deformation behavior and constitutive modeling of cold-rolled non-oriented silicon steel with 2.5 wt% Si

Prediction model for hot rolling force in electrical steel involving phase transformation using SSA-LSTM network and mathematical model

To enhance the rolling force prediction accuracy of non-oriented electrical steel involving phase transformation, a high-precision RFPM (rolling force prediction model) that combines the RFOM (rolling force optimisation model) with the SSA-LSTM (sparrow search algorithm and long short-term memory) network was established. The RFOM was developed by optimising the important influencing parameters, including the deformation resistance model in the phase separation region and stress state coefficient model, of rolling force. The SSA-LSTM network was proposed, which utilises the SSA to optimise the hyperparameters of the double-layer LSTM network, it enables learning the complex spatial data correlation of the rolling force and improves its prediction accuracy. The superiority of the proposed high-precision RFPM was verified, which adopts multiple evaluation indicators, by comparing the RFOM, the BP, the LSTM, and the SSA-LSTM models. The results manifest that the high-precision RFPM has better prediction performance, which has reached 94.40%, and it has better rolling force calculation accuracy, which the error ratio of δ≤5%, δ≤8%, and δ≤10% is 80.35%, 93.21%, and 97.14%, respectively. In addition, the proposed high-precision RFPM prediction time can meet the requirements of online real-time rolling force prediction. The rolling force accuracy of wide strips, especially non-oriented electrical steel involving phase transformation, can be significantly improved by optimising the factors affecting the rolling force of phase transformation electrical steel. The industrial data test shows that the high-precision RFPM based on the theoretical model and data-driven model can meet the requirements of on-site accuracy and online real-time control during the actual production in the large 1450 mm 4-high hot strip mills.

Changes in the heterogeneous deformation structure and texture with cold rolling reduction in {110}&lt;110&gt; oriented coarse grained 3% silicon steel

Changes in the heterogeneous deformation structure and texture with cold rolling reduction in {110}&lt;110&gt; oriented coarse grained 3% silicon steel

Effect of the scanning strategy on texture of grain-oriented electrical steel (Fe-4wt%Si) processed via laser powder-bed fusion and subsequent thermomechanical processing

Effect of the scanning strategy on texture of grain-oriented electrical steel (Fe-4wt%Si) processed via laser powder-bed fusion and subsequent thermomechanical processing

Synthesis of semi sintered nickel bronze electrode for electric discharge surface alloying of silicon steel and the properties of coated surface

Synthesis of semi sintered nickel bronze electrode for electric discharge surface alloying of silicon steel and the properties of coated surface

Microstructure evolution of forsterite film during the high-temperature annealing process in grain-oriented silicon steel

Microstructure evolution of forsterite film during the high-temperature annealing process in grain-oriented silicon steel