Starting from the actual demand for new energy vehicles, Shougang Zhixin has successively conquered the ultra-low iron loss and magnetic induction enhancement control technology of high-grade non-oriented silicon steel, as well as the key manufacturing technology of ultra-high strength electrical steel. It has successfully developed 5 series, including low iron loss series, high magnetic induction series, ultra-high magnetic induction series, high-strength low iron loss series, and more than 20 specialized non-oriented silicon steel products, and has achieved the world’s first in the 35SWYS900 and 25SW1250H brand products. Applied research showed that the use of new development non-oriented silicon steel products in the drive motors of EV’s can help improve the efficiency, torque, and power density of the drive motors.

The influence of continuous casting electromagnetic stirring process on the magnetic properties, secondary recrystallization, and primary recrystallization of 0.30 mm thick high magnetic induction oriented silicon steel were studied in this paper. The results showed that the final product samples using electromagnetic stirring process have a lower iron loss of P1.7/50 by 0.04 W/kg and a higher induction of B800 by 0.03 T compared to those without electromagnetic stirring. With electromagnetic stirring process, the high magnetic induction oriented silicon steel has a better magnetic property. The main reason is that for samples under electromagnetic stirring process the grain size of the primary recrystallization is smaller, the temperature of the secondary recrystallization is lower, the proportion of small angle Goss texture of the primary recrystallization is higher, and the deviation angle of the <100> texture around the ND direction is smaller after secondary recrystallization.

With the strengthening of environmental policies, the production of non-oriented silicon steel and chromium free coating products has rapidly increased in recent years. There are certain differences in performance and quality stability between early chromium free coating products and chromium containing coatings. This article showed that adding additives to the coating solution can significantly improve the surface quality of the coating. Meanwhile, through resin selection and modification adjustments, the product’s weldability, rust resistance, insulation, and heat resistance have been improved. The quality and performance of chromium free coating products have been significantly improved, and they exhibit different characteristics in different application scenarios, leading to rapid development of chromium free coating products.

From the perspective of engineering practicality and effectiveness, product level iron core models were designed and manufactured. Based on a physical model, the influence of harmonic phase difference on no-load loss was studied. When the phase difference is π, the performance of the iron core is the worst. The finite element simulation obtained the magnetic density distribution of the iron core under complex working conditions of harmonic and DC bias, and analyzed the reasons for the increase in no-load loss. Comparative experiments were conducted on the 0.20-0.27 mm oriented silicon steel iron core model under complex working conditions. The results showed that the additional loss of the 20SQGD070 iron core model was reduced by 31 % compared to the 27SQGD090 iron core model when the working magnetic density was 1.7 T and 10 % third harmonic was added. The additional losses of silicon steel core models with different thickness specifications under DC bias are comparable. Considering the service conditions of oriented silicon steel materials in transformers, suggestions for selecting oriented silicon steel materials under complex working conditions are proposed.

Based on engineering practice, the influences of welding groove size, shape, position, and quantity on the three-phase induced potential imbalance of permanent magnet synchronous motors for 6-pole 54 groove new energy vehicles were firstly simulated and analyzed in this paper. And secondly, the variation law of the three-phase induced potential imbalance of the motor was simulated and analyzed under different stator slot numbers and motor pole numbers. Finally, prototype production and testing verification were carried out. Through simulation analysis and experimental verification, it is pointed out that for permanent magnet synchronous motors used in 6-pole 54 slot new energy vehicles, the width and depth of the welding groove will affect the imbalance of the three-phase induced potential of the motor. The imbalance of the three-phase induced potential of the motor is directly proportional to the size of the welding groove. At the same time, it was pointed out that for permanent magnet synchronous motors, from the perspective of reducing the imbalance of three-phase induced potential, the number of stator welding slots should not be an integer multiple of the number of poles. In addition, the corresponding relationship between the balance of three-phase voltage and current of the motor and the torque output and operating efficiency of the motor was also pointed out.

When the cold rolled silicon steel is subjected to decarburization and recrystallization annealing in a continuous annealing furnace, nodules often appear on the surface of carbon sleeve rollers. The nodules can easily cause pitting defects in the strip steel at high temperatures and affect the stacking coefficient of silicon steel sheets, so they are fatal defects in silicon steel finished products. The mechanism of carbon sleeve nodulation in silicon steel annealing furnace rollers were researched and analyzed in-depth in this paper, and solutions were proposed to control carbon sleeve nodulation.