| 摘要 |
PURPOSE:To produce a non-oriented silicon steel sheet in which core loss is effectively reduced without deterioration in magnetic flux density in a high-frequency magnetization region of a specified range. CONSTITUTION:This steel is the one having 1.7 to 4.5wt%. total content of Si and Al and in which contents of C, Mn, S, P, N and O other than those in nitride and/or inside oxide contg. layer on the sheet surface layer is regulated to prescribed ranges. On the surface layer part of the steel sheet, the nitride and/or inside oxide-contg. layer in which the depth from the steel sheet surface layer, the average grain size of nitrides and/or inside oxides and the area ratios in the section of the steel thickness are regulated to prescribed ranges is formed, and the area ratios of nitrides and inside oxides present in the regions other than the nitride and/or inside oxide-contg. layer in the section of the sheet thickness and the average grain size D of the steel sheet are regulated to prescribed ranges. In this way, the silicon steel sheet usable at the frequency of 200Hz to 5kHz can be obtd. |
