Abstract: In this paper, the samples of a highgrade nonoriented silicon steel with different thickness of C6 coating were prepared and tested to compare their conventional magnetic properties. The results showed that the magnetic polarization decreased monotonously, and the iron loss increased monotonously, as the thickness of the samples' coating gradually increased, and the more accurate correction value of those data was also obtained. The work in this paper has certain reference significance for the design of large motor and the application of highgrade nonoriented silicon steel with C6 coating.

Key words: high grade non oriented silicon steel, C6 insulating coatings, Epstein frame