Patent ID: 11884988
Assignee: NIPPON STEEL CORPORATION
Field: Materials, metallurgy (Chemistry)
Classification: CPC C  H | IPC C

Claim 11:
12. A method of manufacturing the base sheet for a grain-oriented electrical steel sheet according to claim 3, the method comprising:
adjusting an amount of surface oxygen per one surface of a final-annealed grain-oriented silicon steel sheet to more than 0.01 g/m2 and 0.05 g/m2 or less, or more than 0.05 g/m2 and 0.10 g/m2 or less; and
performing thermal oxidation annealing on the final-annealed grain-oriented silicon steel sheet in an atmosphere in which an oxidation potential represented by a ratio PH2O/PH2 of water vapor pressure to hydrogen pressure is 0.0081 or less in a case where the amount of surface oxygen is more than 0.01 g/m2 and 0.05 g/m2 or less, or in an atmosphere in which the oxidation potential is 0.005 or less in a case where the amount of surface oxygen is more than 0.05 g/m2 and 0.10 g/m2 or less, at a soaking temperature of 1000° C. or lower to form an externally oxidized layer on a surface of the grain-oriented silicon steel sheet;
thereby producing the base sheet for a grain-oriented electrical steel sheet of claim 3.