Grain oriented electrical steel sheet and method of manufacturing the same

Abstract

A method of manufacturing a grain oriented electrical steel sheet includes subjecting a slab to rolling to a final sheet thickness; subjecting the sheet to subsequent decarburization; applying an annealing separator composed mainly of MgO to a surface of the sheet before subjecting the sheet to final annealing; subjecting the sheet to subsequent tension coating; and subjecting, after the final annealing or the tension coating, the sheet to magnetic domain refining treatment by electron beam irradiation, wherein a degree of vacuum during the electron beam irradiation is 0.1 to 5 Pa, and a tension to be exerted on the steel sheet during flattening annealing is 5 to 15 MPa.

1 . A method of manufacturing a grain oriented electrical steel sheet comprising:
 subjecting a slab to rolling to a final sheet thickness;   subjecting the sheet to subsequent decarburization;   applying an annealing separator composed mainly of MgO to a surface of the sheet before subjecting the sheet to final annealing;   subjecting the sheet to subsequent tension coating; and   subjecting, after the final annealing or the tension coating, the sheet to magnetic domain refining treatment by electron beam irradiation, wherein
 (1) a degree of vacuum during the electron beam irradiation is 0.1 to 5 Pa, and 
 (2) a tension to be exerted on the steel sheet during flattening annealing is 5 to 15 MPa. 
   
     
     
         2 . The method according to  claim 1 , wherein the slab for the grain oriented electrical steel sheet is subjected to hot rolling and, optionally, hot rolled sheet annealing, and subsequently subjected to cold rolling once, or twice or more with intermediate annealing performed therebetween, to be finished to a final sheet thickness.