Grain-oriented electrical steel sheet, method for manufacturing grain-oriented electrical steel sheet, and annealing separator utilized for manufacture of grain-oriented electrical steel sheet

Abstract

An annealing separator used for manufacture of the grain-oriented electrical steel sheet according to the present invention contains MgO, at least one or more types of compounds of metal selected from a group comprised of Y, La, and Ce, at least one or more types of compounds of metal selected from a group comprised of Ti, Zr, and Hf, and at least one or more types of compounds of metal selected from a group comprised of Ca, Sr, and Ba, when a content of the MgO in the annealing separator is defined as 100% by mass %, a total content of the compounds selected from a group comprised of Y, La, and Ce converted to oxides is 0.8 to 8.0%, a total content of the compounds of metal selected from a group comprised of Ti, Zr, and Hf converted to oxides is 0.5 to 9.0%, and a total content of the compounds of metal selected from a group comprised of Ca, Sr, and Ba converted to sulfates is 0.5 to 8.0%, a mean particle size of the compounds of metal selected from a group comprised of Ca, Sr, and Ba is 12 μm or less, a ratio of the mean particle size of the compounds of metal selected from a group comprised of Ca, Sr, and Ba to the mean particle size of the compounds of metal selected from a group comprised of Y, La, and Ce is 0.1 to 3.0, a total of the total content of the compounds of metal selected from a group comprised of Y, La, and Ce converted to oxides and the total content of the compounds of metal selected from a group comprised of Ti, Zr, and Hf converted to oxides is 2.0 to 12.5%, a ratio of a sum of the numbers of Y, La, and Ce atoms to a sum of the numbers of Ti, Zr, and Hf atoms contained in the annealing separator is 0.18 to 4.0, still further a number density of particles of the compounds of metal selected from the group comprised of Y, La, and Ce which are particles of a spherical equivalent diameter based on volume of 0.1 μm or more is 2,000,000,000/g or more, still further a number density of particles of the compounds of metal selected from the group comprised of Ti, Zr, and Hf which are particles of a spherical equivalent diameter based on volume of 0.1 μm or more is 2,000,000,000/g or more, and still further a number density of particles of the compounds of metal selected from the group comprised of Ca, Sr, and Ba which are particles of a spherical equivalent diameter based on volume of 0.1 μm or more is 2,000,000,000/g or more.

Dependencies are inferred from the claim text.