Non-oriented electrical steel is the core magnetic material for stator and rotor laminations in traction motors for new energy vehicles. Its magnetic, mechanical, processing and coating properties jointly determine motor power density, efficiency, thermal behavior and high-speed service reliability. This paper focused on the coupled route of high-frequency low loss, high magnetic induction, high strength and ultra-thin gauge manufacturing. The origins and control strategies of high-frequency iron loss were discussed from the perspectives of grain size, texture, precipitates, residual stress and thickness effect. Strengthening strategies, including solid-solution strengthening, precipitation strengthening, grain refinement and dislocation strengthening, were compared with emphasis on their influence on magnetic properties. Frontier topics such as ultra-thin strip rolling, punching and stacking, self-bonding coatings and multi-field service evaluation were further summarized. The analysis indicates that the key issue for traction-motor-grade non-oriented electrical steel is no longer the improvement of a single property, but the establishment of a coordinated relationship among composition, process, microstructure, coating and service evaluation under specific motor operating conditions. Future research should focus on physical modeling of high-frequency iron loss, magneto-mechanical co-design, stable manufacturing of ultra-thin gauges, self-bonded core technology and multi-field coupled evaluation systems.

New energy vehicle drive motors often operate under elevated-temperature conditions and non-uniform temperature fields during service. Their electromagnetic performance is closely related to the temperature dependence of the magnetic properties of the non-oriented silicon steel core material. To systematically investigate the influence of temperature variations on the magnetization behavior and iron loss characteristics of non-oriented silicon steel, three commercial grades with representative thicknesses of 0.20 mm, 0.35 mm, and 0.50 mm were selected for study. Based on the Epstein coil testing method, systematic experimental investigations were conducted across a broad temperature range from -70 ℃ to 150 ℃. Experimental results indicate that in the low magnetic field range, the magnetic permeability of the material increases with rising temperature. In contrast, in the high magnetic field range, it exhibits a decreasing trend. Meanwhile, the saturation magnetic flux density decreases slightly with increasing temperature, while the remanence and coercivity decline significantly. Regarding the characteristics of iron loss, at low frequencies, iron loss exhibits low sensitivity to temperature changes. However, at high frequencies, iron loss shows a pronounced decrease as temperature rises.

Aiming at frequent sudden strip shape variation and rolling instability occurring during speed-up single-pass rolling of high-silicon non-oriented silicon steel on a 20-high reversible cold rolling mill, field comparative tests and single-variable experimental investigations were carried out with fixed process parameters including roll surface roughness, reduction ratio and emulsion temperature to systematically clarify the formation mechanism of the above defects. The results reveal that offset of spray header position deteriorates the spreading uniformity of emulsion, resulting in mismatching between lubrication/cooling conditions at rolling interface and rolling speed, as well as abnormal fluctuation of roll thermal crown, which serves as the dominant trigger for abrupt strip shape defects. Based on the revealed mechanism, the optimal opening rate of 20% for roll cooling pipeline valves was determined via optimization, and a standardized adjustment specification of 10-15 mm for spray header clearance was formulated. Practical industrial application verifies that the proposed optimization completely eliminates strip shape defects during acceleration, raises the stable single-pass rolling speed by 25% and improves I-Unit flatness control precision by 74.7%, substantially enhancing rolling stability and production efficiency. This study fills the adaptability gap of existing theories under on-site special rolling conditions and develops a practically implementable flatness control process, which provides valuable engineering references for stable cold rolling production of high-silicon non-oriented silicon steel and troubleshooting of analogous rolling defects.

Grain-oriented silicon steel and iron-based amorphous alloy are two core functional materials for the manufacturing of transformer cores. Differences in their production processes and material properties directly determine the overall performance of transformers. This paper conducts an in-depth comparative analysis of the two types of materials from key dimensions including strip production process, transformer operating performance, whole-life cycle economy and scenario applicability. Under the guidance of the national "Dual Carbon" strategy and the upgrading of industrial technology, transformers made of the two materials will develop collaboratively toward high performance, large capacity, green low-carbon and scenario customization in the future. An industrial pattern featuring complementary materials and coordinated scenario division will be formed, jointly supporting the low-carbon and high-efficiency transformation and upgrading of the power equipment industry.

Based on the potential interfering elements specified in GB/T 4336—2016, T/CSTM 00010.2—2017 and ASTM E 415—08 standards, elemental interference effects were investigated in the determination of niobium content in high-grade non-oriented silicon steel. The results show that acid-soluble aluminum is identified as the major unconsidered interfering element affecting accurate measurement of niobium in high-grade non-oriented electrical steel. Combined with experimental tests and data analysis, an interference correction model is established for the niobium detection method. Comparative analysis and precision verification tests confirm the reliability and stability of the proposed model. The optimized analytical method integrated with the novel interference correction model enables the deviation between spectrometric determined values and chemical analysis results of niobium to be controlled within ±0.0002%, which fully satisfies the technical requirements of routine industrial inspection.

To address the insufficient detection accuracy in the ultra-low content range for carbon and sulfur elements in non-oriented silicon steel using the conventional infrared absorption method, this study systematically investigated the determination of ultra-low carbon and sulfur detection limits and the factors significantly affecting detection accuracy, and proposed a set of optimal configuration parameters. The method detection limits of carbon 0.6×10?? and sulfur 0.5×10?? were determined by the blank test standard deviation method (3σ criterion), extending the detection limit from the conventional 10×10?? to below 5×10??. Key influencing factors including crucible pretreatment, carrier gas, fluxing agent, sample preparation, and analysis power were optimized, with both carbon and sulfur dual-element data used as evaluation criteria throughout all optimization experiments. The optimal parameters were obtained: crucible pretreatment at 1100 ℃ for 30 min; in-plant pipeline oxygen (99.99% purity) with oxygen purifier; domestic W-Sn flux added before sample; no sample pretreatment needed; analysis power at 80%. Verification using reference materials with carbon 3.4×10?? and sulfur 4.4×10?? demonstrated accurate results and good precision, meeting the quality control requirements for high-grade non-oriented silicon steel production.

This paper systematically analyzed the influence mechanism of welding parameters of Miebach laser welder on the weld quality of electrical steel (silicon steel). Through the study of key process parameters such as laser power, welding speed, focus position and butt joint process, the influence laws of each parameter on weld formation, penetration depth, microstructure properties and defect generation were revealed. The research found that the matching of laser power and welding speed was the core factor determining weld quality. Precise control of the focus position directly affects the laser energy density distribution, and the zero-gap butt joint process adopted in cold-rolled electrical steel welding can effectively ensure the butt joint accuracy of strip steel and fundamentally reduce weld defects. Furthermore, this paper introduced the application of the quality control and detection system (QCDS) in quality monitoring of electrical steel normalizing and pickling production line, and proposed a multi-objective parameter optimization method based on Taguchi-Grey relational analysis, providing theoretical basis and practical guidance for process adjustment in actual production of electrical steel.