Patent Number: 6,309,473

Title: Method of making grain-oriented magnetic steel sheet having low iron loss

Abstract: Grain-oriented magnetic steel sheet made by the method-including hot rolling and final finish annealing, wherein (1) the O content in the steel slab is limited to up to about 30 ppm; (2) for the entire steel sheet having final thickness including an oxide film before final finish annealing, from among impurities, the Al content is limited to up to about 100 wtppm, and the respective contents of B, V, Nb, Se, S, P, and N, to up to about 50 wtppm each; and (3) during final finish annealing, the N content in the steel is, at least in the temperature region of from about 850 to C., limited within the range of from about 6 to 80 wtppm.

Inventors: Hayakawa; Yasuyuki (Okayama, JP), Kurosawa; Mitsumasa (Okayama, JP), Komatsubara; Michiro (Okayama, JP)

Assignee: Kawasaki Steel Corporation

International Classification: C22C 38/60 (20060101); C22C 38/08 (20060101); C22C 38/02 (20060101); C21D 8/12 (20060101); H01F 001/147 ()

Expiration Date: 10/30/2018