Development of non-oriented and grain-oriented silicon steel

This paper described recently devloped non-oriented electrical steel products for both rotating machines and ballast cores of fluorescent lamps and effective measures to achieve lower core loss for grain-oriented silicon steel for transformers. H6, the highest grade of non-oriented electrical steel produced by Nippon Steel Corp. for large rotating electric machines, has been developed by applying special process techniques to cleanly refined 3% silicon steel. The typical core loss of 0.50mm H6 is 2.20 watt/kg, in W15/50 . NC-M1 and NC-B1 have been developed as high efficiency core materials for small motors and ballast cores by using very clean low silicon steel with 1.0% Mn. Typical properties of NC-M1 0.47mm are 1.93 watt/lb in W15/60 and 2745 in μ15/60. Recently developed techniques in the refinement of the magnetic domain in highly oriented silicon steel shall be reviewed. The principal subjects of discussion will be magnetic domain refining techniques for materials used in stacked and wound cores. Our conclusion is that the guiding principle for low core loss silicon steel in stacked and wound cores is to increase the degree of (110) (001) orientation and to develop a domain refining technique for highly oriented material.