According to an exemplary embodiment of the present invention, a method for manufacturing a grain-oriented electrical steel sheet includes: a step of hot-rolling a slab to manufacture a hot-rolled steel sheet; a step of performing hot-rolled sheet annealing on the hot-rolled steel sheet; a step of performing primary cold-rolling on the hot-rolled sheet annealed hot-rolled steel sheet; a step of performing primary decarburization annealing on the primarily cold-rolled steel sheet; a step of performing secondary cold-rolling on the decarburization-annealed steel sheet; a step of performing secondary decarburization annealing on the secondarily cold-rolled steel sheet; and a step of performing continuous annealing on the secondarily decarburization-annealed steel sheet.

A laminated core (100) has a plurality of legs having an extension direction in a direction perpendicular to a lamination direction of electrical steel sheets and a plurality of yokes having an extension direction in a direction orthogonal to the lamination direction of the electrical steel sheets and the extension direction of the legs, and, in the same position of the electrical steel sheet in the lamination direction, at least a partial region of the legs and at least a partial region of the yokes are configured by the same electrical steel sheet. The electrical steel sheet is disposed such that a first direction of directions of easy magnetization of the electrical steel sheet is along the extension direction of the legs and a second direction of the directions of easy magnetization of the electrical steel sheet is along the extension direction of the yokes.

An elastic matrix determination method and a vibration analysis method for a laminated iron core, with which it is possible to optimally determine an elastic modulus of a laminated iron core. When a vibration analysis of a laminated iron core obtained by laminating steel sheets is performed by using a configuration expression indicating a relationship between stress and strain in a matrix display by using an elastic matrix, a shear modulus in two surfaces including a laminating direction of the laminated iron core included in the elastic matrix in the configuration expression is determined in consideration of slip between laminated steel sheets.

A grain-oriented electrical steel sheet having a metallographic structure after secondary-recrystallized annealing including matrix grains of Goss-oriented secondary recrystallized grains, wherein an existence frequency of Goss-oriented crystal grains having a major diameter of 5 mm or less in the matrix grains is 1.5 grains/cm.sup.2 or more and 8 grains/cm.sup.2 or less, and the magnetic flux density B8 is 1.88 T or more, and wherein deviation angles from a rolling direction of [001] direction of the Goss-oriented crystal grains having the major diameter of 5 mm or less are 7″ or less and 5° or less, in terms of a simple or arithmetic average of α angle and β angle, respectively, wherein the α angle represents an angle formed by a longitudinal direction and a projection of the [001] on a specimen surface, and the β angle represents a tilt of the [001] out of the specimen surface.

Provides is a non-oriented electrical steel sheet suitable for use in a rotor of an IPM motor that has excellent magnetic flux density B.sub.50 and high-frequency iron loss properties, high tensile strength and fatigue strength, and little variation in tensile strength. The non-oriented electrical steel sheet has a predetermined steel sheet chemical composition and a microstructure in which a ratio of non-recrystallized microstructure is 5% or more and 70% or less and the number of inclusion having a diameter of 5 μm or more is not more than 5 counts/mm.sup.2.

Provides is a non-oriented electrical steel sheet suitable for use in a rotor of an IPM motor that has excellent magnetic flux density B.sub.50 and high-frequency iron loss properties, high tensile strength and fatigue strength, and little variation in tensile strength. The non-oriented electrical steel sheet has a predetermined steel sheet chemical composition and a microstructure in which a ratio of non-recrystallized microstructure is 5% or more and 70% or less and the number of inclusion having a diameter of 5 μm or more is not more than 5 counts/mm.sup.2.

The present invention has been made in an effort to provide an adhesive coating composition capable of adhering (fastening) a non-oriented electrical steel sheet without using a conventional fastening method such as welding, clamping, or interlocking, a non-oriented electrical steel sheet stack to which the same is applied, and a manufacturing method thereof. According to an exemplary embodiment of the present invention, an adhesive coating composition includes: 40 to 99 wt % of a first component containing a water-soluble resin; and 1 to 60 wt % of a second component containing a composite metal phosphate.

Grain-oriented electrical steel sheet excellent in magnetic properties and excellent in adhesion of a primary coating to the steel sheet is provided. The grain-oriented electrical steel sheet is provided with a base steel sheet having a chemical composition containing C: 0.005% or less, Si: 2.5 to 4.5%, Mn: 0.050 to 1.000%, a total of S and Se: 0.005% or less, sol. Al: 0.005% or less, and N: 0.005% or less and having a balance of Fe and impurities and a primary coating having Mg.sub.2 SiO.sub.4 as a main constituent formed on a surface of the base steel sheet. A peak position of Al emission intensity obtained when conducting elemental analysis by glow discharge spectrometry from a surface of the primary coating in a thickness direction is present in a range of 2.0 to 12.0 μm from a surface of the primary coating to the thickness direction. A sum of perimeters of the Al oxides at the peak position of Al emission intensity is 0.20 to 1.00 μm/μm.sup.2, and a number density of Al oxides is 0.02 to 0.20/μm.sup.2.

A grain-oriented electrical steel sheet according to an exemplary embodiment of the present invention includes: a linear groove formed in one or both surfaces of the electrical steel sheet in a direction intersecting with a rolling direction; and a linear thermal shock portion formed in the one or both surfaces of the electrical steel sheet in a direction intersecting with the rolling direction. An angle between a longitudinal direction of the groove and a longitudinal direction of the thermal shock portion is 1 to 5°.

A grain-oriented electrical steel sheet according to an exemplary embodiment of the present invention includes: a linear groove formed in one or both surfaces of the electrical steel sheet in a direction intersecting with a rolling direction; and a linear thermal shock portion formed in the one or both surfaces of the electrical steel sheet in a direction intersecting with the rolling direction. An angle between a longitudinal direction of the groove and a longitudinal direction of the thermal shock portion is 1 to 5°.