Based on wire-cut samples including cast slab, hot-rolled, normalized, cold-rolled and decarburized plates of 0.27 mm thickness high permeability grainoriented silicon steel by both Bi-bearing high-temperature and low-temperature slab reheating processes, the Bi particles were observed by BSE model of SEM and the semi quantitative analysis to the distribution of Bi was conducted by auger electron spectroscopy. The results showed that the undissolved Bi in molten steel would exist in the form of elemental particles as sphericity during the following different procedure processes, and both processes had the highest precipitate percentages of Bi after decarburizing anneal. In addition, both processes had the general same segregation regularity of Bi, each procedure process having obvious grain boundary segregation, and the Bi’s relative amount of grain boundary segregation up to the highest after decarburizing anneal.

In order to improve the stability of magnetic properties of grain-oriented silicon steel, the effects of basic alloying elements C, Si, Mn, S, Al and N on the γ phase transition temperature, the γ phase maximum content and its corresponding temperature were analyzed by Thermo-Calc software system. And the effects to the precipitation temperature, maximum precipitation amount of AlN and MnS phases were also analyzed. The results showed that with the increase of C content, the transition temperature, the maximum content and the temperature corresponding to the maximum content of γ phase are all increased. With the increase of Si content, the transition temperature, the maximum content and the corresponding temperature of maximum content of γ phase are all decreased. The maximum precipitation amount of MnS phase is mainly affected by the content of S. The maximum precipitation of AlN phase is increased greatly with the increase of N content.

Based on the experience of developing HiB grain-oriented silicon steel with thickness of 0.27 mm in Ansteel, the changes and evolutions of microstructures and textures in hot rolling, normalizing, cold rolling, decarburizing annealing and high temperature annealing processes were studied in this paper. The results showed that the surface layer structures of the hot rolled plate were recrystallized structures, and the central layer structures were incomplete recrystallized banded structures. Recrystallization of the grain-orientated silicon steel and the growth of the recrystallized structures were occurred after normalization. And after cold rolling and decarburization annealing, the structures of the grain-orientated silicon steel transformed into equiaxed ferrite grains. The surface layer grain of the hot rolled plate was {110}〈001〉 Goss grain, which was strengthened in situ after normalization. After cold rolling, the Goss textures were changed to {111}〈112〉 textures and some of them were remained in the shear zone of deformation, which then grew up to the textures with Goss textures as the main texture components during secondary recrystallization.

The effect of normalization process on the microstructure, texture and magnetic properties of 1.8 % Si non-oriented electrical steel were investigated, and the recrystallization of cold rolled sheets under different normalization processes was also studied. The results showed that normalization eliminated the deformation of hot rolled sheets and then affected the microstructures and textures of cold rolled sheets and final annealed sheets. The cold rolled sheets subjected to normalization process had a much lower nucleation rate, and the abundant shear bands and coarse deformed grains were conducive to the nucleation and growth of λ-fiber grains, which helped to increase the grain size and improve the texture. After normalization, the grain size increased and the favorable λ-fiber texture enhanced in the final annealed sheets.Compared to that without normalization, the average magnetic induction (B50) increased by 0.029 T and the iron loss (P1.5/50) decreased by 0.227 W/kg when normalizing at 1 000 ℃. Normalization is an effective way to improve magnetic properties.

The influence of coating liquid with solid content of 19.5 %-35 % on the coating amount, insulation, corrosion resistance, heat resistance and micro morphology of the coating were studied by means of interlayer resistance meter, RX-400 film thickness/weight meter, neutral salt spray test, high temperature furnace and scanning electron microscope. The results showed that the coating film thickness was directly proportional to the solid content,and the corresponding coating thickness range for solid content is 0.65-2.33 μm under the conditions of this experiment.The maximum heat resistance temperature of the coating was 800 ℃. After the heat resistance test, the insulation resistance decreased by about 50 %.The maximum corrosion resistance time could reach 12 hours, and thin coatings were easily penetrated by chloridion(Cl-), resulting in poor corrosion resistance compared to thick coatings. Thick coatings were prone to drying holes under high temperatures drying, which reduced the corrosion resistance.The coating with the solid content of 25.27 % has better performance under this process.

3D wound core transformer has a special symmetry structure for three phase. It has several advantages, such as low core loss, light weight and better heat dissipation effect. Due to the structure of the core as well as the nonlinear magnetization of the silicon steel sheet, the magnetic field in the core has stronger 3rd harmonic waves, which make every frame of the core in non-sinusoidal excitation condition. Therefore it is impossible to measure the core loss of the frame of 3D wound core directly. In this paper three-dimensional finite element analysis model was established to analyze the distribution characters of 3D wound core. On this basis, non-sinusoidal exciting voltages of 3D wound core were measured, and a rapid test method of single frame core loss of 3D wound core was proposed and its availability was verified.

Hitachi Metals is the world's largest manufacturer of amorphous ribbons and renamed as Proterial in 2023. In this paper, the development of Hitachi metals’ amorphous ribbon was reviewed. The process features of single furnace production and continuous multi-furnaces production were compared. In the process of continuous multi-furnaces production, the realizable continuous casting and coiling can greatly enhance the production efficiency and yield, but require high stability of production equipment and process control. Furthermore the development of new products, new application field and new standards about amorphous ribbons were also introduced. The new production HB1M with high saturation induction and magnetic domain controlled low iron loss Fe-based amorphous alloys “MaDC-A^TM”can effectively reduce the core loss. A recycling plant to handle the amorphous metal cores used in amorphous transformers was established. The recyclings are used as raw materials for amorphous ribbons to achieve low production cost and recycling of products. They also expand in other areas of application such as amorphous motor, amorphous block core for solar power generation and Ni-based amorphous brazing materials.

The overview, differences, market supply and demand of amorphous alloy threedimensional coil core dry-type transformers and silicon steel three-dimensional coil core dry-type transformers were introduced, and the advantages and disadvantages of these transformers were analyzed. At present, the procurement of transformers for State Grid and Southern Grid presents a structure mainly consisting of silicon steel transformers and supplemented by amorphous alloy transformers. The current development mode is to form complementary advantages and mutual cooperation between amorphous alloy three-dimensional coil core dry-type transformers and silicon steel three-dimensional coil core dry-type transformers.

The structure and the principle of the blade gap adjustment mechanism of TMEIC laser welder were analyzed, and the methods to improve the double shear’s cutting quality were studied. The results showed that the straightness of the cutting section and the blade gap adjustment were the key factors to improve the double shear’s cutting quality. The breakage rate of weld joint can be reduced by improving the shearing accuracy.