Electromagnetic performance parameters are the core technical indicators for silicon steel coils and sheets; they directly determine equipment energy consumption and operating efficiency and serve as the primary basis for grade classification. Core loss is a critical parameter among these, representing the energy loss within the iron core at specific magnetic flux densities and frequencies. Standard industry testing metrics include P17/50 (at a power frequency of 50 Hz) and P10/400 (at a high frequency of 400 Hz). Non-oriented silicon steel typically exhibits core loss values between 3.0 and 19.0 W/kg, while high-end, ultra-thin silicon steel for new energy applications can achieve values below 9.0 W/kg. Oriented silicon steel offers even lower core loss, making it suitable for the long-term no-load operation of high-voltage transformers. Other key parameters include magnetic polarization and saturation magnetic flux density. Conventional silicon steel generally achieves magnetic polarization exceeding 1.6 T, with premium grades reaching 1.66 T; higher values indicate superior magnetic permeability, higher electromagnetic conversion efficiency, and better magnetization performance. Additionally, the electrical resistivity of silicon steel is typically controlled between 45 and 60 μΩ·cm-far higher than that of ordinary carbon steel. This material-level property effectively suppresses eddy currents and significantly reduces heat loss in alternating magnetic fields, ensuring stable and energy-efficient operation of electrical equipment.
Dimensional accuracy and lamination parameters are core technical standards governing the processability of silicon steel, directly influencing core manufacturing precision and equipment assembly quality. Silicon steel coils and sheets are available in a comprehensive range of thicknesses; common industrial specifications include 0.35 mm and 0.5 mm, while mainstream thicknesses for oriented silicon steel are 0.27 mm and 0.3 mm. Ultra-thin silicon steel designed for high-frequency motors in new energy vehicles can be as thin as 0.1 mm or 0.2 mm. Thickness tolerances are strictly controlled within ±1%, and the material features excellent surface flatness without warping or deformation. Length, width, and slitting tolerances comply with both national and industry standards, meeting the requirements for various precision stamping and lamination processes. The lamination factor is a crucial practical parameter; for standard silicon steel, this factor-representing the ratio of effective magnetic flux area after stacking multiple sheets-can reach 0.95–0.98. A higher factor indicates superior overall magnetic utilization efficiency for the core and allows for a more compact equipment design. The material's nominal density is standardized at 7.6–7.7 kg/dm³, serving as fundamental data for structural design, weight calculation, and operational matching.
Mechanical properties and insulation coating parameters determine the material's processability, service life, and operational safety. Regarding mechanical properties, conventional silicon steel exhibits a yield strength of 350–450 MPa, stable tensile strength, and moderate elongation. It offers excellent performance in stamping, shearing, and bending, resisting cracking, spring-back, and deformation during deep processing, making it suitable for fabricating complex core structures. Insulation coating parameters are particularly critical; the finished sheets feature a specialized high-temperature-resistant coating characterized by strong adhesion and uniformity. With a temperature rating exceeding 200°C and superior resistance to friction, corrosion, and aging, the coating effectively blocks eddy currents between laminations and prevents inter-laminar short circuits. Additionally, the silicon steel possesses an extremely low magnetostriction coefficient, resulting in minimal vibration and noise during operation. Its excellent weather and oxidation resistance ensure reliable, low-noise, and energy-efficient performance for electrical equipment, even under demanding industrial conditions involving high temperatures, vibration, and humidity.
