Annealing separator having excellent reactivity for grain-oriented electrical steel sheet and method of use the same

Annealing separator having excellent reactivity for grain-oriented silicon steel sheet, which consists essentially of at least one solid solution metallic oxide compound selected from the following general formulas:

• (Mg.sub.1-x M.sup.3+.sub.x).Ay, (Mg.sub.1-x M.sup.2+.sub.x)O.Ay or (Mg.sub.1-x M.sup.2+.sub.x1 M.sup.3+.sub.x2).Ay
• where
• M.sup.2+ is one or more bivalent metals selected from the group consisting of Be, Ca, Ba, Sr, Sn, Mn, Fe, Co, Ni, Cu or Zn;
• M.sup.3+ is one or more tervalent metals selected from the group consisting of Al, Fe, Cr, Co, B, Ti or Sb;
• 0.01.ltoreq.x.ltoreq.0.40;
• x=x1+x2;
• A is at least one of the following:
• F, Cl, Br, Co.sub.3, SiO.sub.3, PO.sub.3 or CrO.sub.3
• 0.001.ltoreq.y.ltoreq.2.0 (y is weight percentage with respect to 100 parts by weight of solid solution metallic oxide compound).

Annealing separator having excellent reactivity for grain-oriented silicon steel sheet, which consists essentially of at least one solid solution metallic oxide compound selected from the following general formula:

• (Mg.sub.1-x X.sup.a.sub.x1 X.sup.b.sub.x2)O.Ay
• where
• X.sup.a consists of Fe.sup.2+ and/or Fe.sup.3+ ;
• X.sup.b consists of M.sup.2+ and/or M.sup.3+ ;
• M.sup.2+ is one or more bivalent metal selected from the group consisting of Be, Ca, Ba, Sr, Sn, Mn, Fe, Co, Ni, Cu or Zn;
• M.sup.3+ is one or more tervalent metal selected from the group consisting of Al, Fe, Cr, Co, B, Ti or Sb;
• 0.01.ltoreq.x.ltoreq.0.40;
• x=x1+x2;
• A is at least one of the following:
• F, Cl, Br, Co.sub.3, SiO.sub.3, PO.sub.3 or CrO.sub.3 ;
• 0.001.ltoreq.y.ltoreq.2.0 (y is weight percentage with respect to 100 parts by weight of solid solution metallic oxide compound).

Method of applying an annealing separator in a production of grain-oriented silicon steel sheet which comprises

• cold rolling to obtain a final thickness, decarburization annealing, forming an oxide film mainly containing SiO.sub.2, coating an annealing separator, final annealing, forming an insulation coating and heat-flattening treatment, the improvement wherein said annealing separator consisting essentially of at least one solid solution metallic oxide compound selected from the following general formulas;
• (Mg.sub.1-x M.sup.3+.sub.x)O, (Mg.sub.1-x M.sup.2+.sub.x)O or (Mg.sub.1-x M.sup.2+.sub.x1 M.sup.3+.sub.x2)O,
• where
• M.sup.2+ is one or more bivalent metal selected from the group consisting of Be, Ca, Ba, Sr, Sn, Mn, Fe, Co, Ni, Cu or Zn;
• M.sup.3+ is one or more tervalent metal selected from the group consisting of Al, Fe, Cr, Co, B, Ti or Sb;
• 0.01.ltoreq.x.ltoreq.0.40;
• x=x1+x2.

Method of applying an annealing separator in a production of grain-oriented silicon steel sheet which comprises

• cold rolling to obtain a final thickness, decarburization annealing, forming an oxide film mainly containing SiO.sub.2, coating an annealing separator, final annealing, forming an insulation coating and heat-flattening treatment, the improvement wherein said annealing separator consisting essentially of at least one solid solution metallic oxide compound selected from the following general formulas;
• (Mg.sub.1-x M.sup.3+.sub.x)O.Ay, (Mg.sub.1-x M.sup.2+.sub.x)O.Ay or (Mg.sub.1-x M.sup.2+.sub.x1 M.sup.3+.sub.x2)O.Ay
• where
• M.sup.2+ is one or more bivalent metal selected from the group consisting of Be, Ca, Ba, Sr, Sn, Mn, Fe, Co, Ni, Cu or Zn;
• M.sup.3+ is one or more tervalent metal selected from the group consisting of Al, Fe, Cr, Co, B, Ti or Sb;
• 0.01.ltoreq.x23 0.40;
• x=x1+x2;
• A is at least one of the following;
• F, Cl, Br, CO.sub.3, SiO.sub.3, PO.sub.3 or CrO.sub.3
• 0.001.ltoreq.y.ltoreq.2.0 (y is weight percent with respect to 100 parts by weight of solid solution metallic oxide compound).

Method of applying an annealing separator in a production of grain-oriented silicon steel sheet which comprises

• cold rolling to obtain a final thickness, decarburization annealing, forming an oxide film mainly containing SiO.sub.2, coating an annealing separator, final annealing, forming an insulation coating and heat-flattening treatment, the improvement wherein said annealing separator consisting essentially of at least one solid solution metallic oxide compound selected from the following general formula;
• (Mg.sub.1-x X.sup.a.sub.x1 X.sup.b.sub.x2)O.Ay
• where
• X.sup.a consists of Fe.sup.2+ and/or Fe.sup.3+ ;
• X.sup.b consists of M.sup.2+ and/or M.sup.3+ ;
• M.sup.2+ is one or more bivalent metal selected from the group consisting of Be, Ca, Ba, Sr, Sr, Mn, Fe, Co, Ni, Cu or Zn;
• M.sup.3+ is one or more tervalent metal selected from the group consisting of Al, Fe, Cr, Co, B, Ti or Sb;
• 0.01.ltoreq.x.ltoreq.0.40;
• x=x1+x2;
• A is at least one of the following;
• F, Cl, Br, Co.sub.3, SiO.sub.3, PO.sub.3 or CrO.sub.3 ;
• 0.001.ltoreq.y.ltoreq.2.0 (y is weight percent with respect to 100 parts by weight of solid solution metallic oxide compound).