Manufacturing methods and grain-oriented electrical steel sheet and grain-oriented electrical steel sheet for surface glass coating of grain-oriented electrical steel sheet

摘要

PROBLEM TO BE SOLVED: To provide a manufacturing method of a directional electromagnetic steel plate having an excellent magnetic property, where nitrogen is added to a steel plate before secondary recrystallization for the purpose of forming silicon nitride, and then the nitrogen is diffused into the steel plate to participate the silicon nitride in a grain boundary.;SOLUTION: An annealing separation agent includes MgO: 50% or more, and oxide of M which is any one of Ti, Mn, Si, Cr, Al, or B, wherein the oxide of M is 5 mass parts or more and 20 mass parts of less to 100 mass parts of an annealing separation agent in terms of MOx. In addition, a glass coating liquid includes phosphorus oxide and one or more of oxide of A which is any one of Al, Ca, Ti, Nd, Mo, Cr, B, Ta, Cu, or Mn. Mole ratio (Z/P) of the total of metallic component A: Z(mol) of the oxide, and the phosphor: P (mol) of the phosphorus oxide satisfies a relation of 0.08≤Z/P≤0.8.;COPYRIGHT: (C)2014,JPO&INPIT