Abstract: The present invention has as its object to provide grain-oriented electrical steel sheet further improved in core loss in control of magnetic domains by forming laser grooves in steel sheet after decarburization annealing and before finish annealing. The grain-oriented electrical steel sheet according to the present invention is a grain-oriented electrical steel sheet having a plurality of grooves on the surface of the steel sheet and provided with a glass coating on that surface, which grain-oriented electrical steel sheet characterized in that an absolute value of an angle ? formed by a direction perpendicular to both a rolling direction and sheet thickness direction of the steel sheet and a longitudinal direction of the grooves is 0 to 40°, a width W of the grooves is 20 to 300 ?m, a depth D of the grooves is 10 to 40 ?m, and a pitch P of the grooves in the rolling direction is 1.

Abstract: This grain-oriented electrical steel sheet includes a base steel sheet, a glass coating formed on the base steel sheet, and a tension-applied insulation coating formed on the glass coating, in which, in the base steel sheet, a plurality of linear strain regions that extend continuously or intermittently in a direction intersecting with a rolling direction are present, the plurality of linear strain regions are each 210 ?m or less in width in the rolling direction, the plurality of linear strain regions are parallel to each other, intervals of linear strain regions adjacent to each other in the rolling direction are 10 mm or less, and magnetostriction ?0-pb in a unit of ?m/m when the grain-oriented electrical steel sheet is excited up to 1.7 T and magnetostriction ?0-pa in a unit of ?m/m when the grain-oriented electrical steel sheet is heat-treated at 800° C. for 4 hours and then excited up to 1.7 T satisfy 0.02??0-pb??0-pa?0.20.

Abstract: The steel sheet processing apparatus includes a laser irradiation unit configured to form a groove on a surface of a steel sheet, an illumination unit configured to irradiate the groove with pulsed light, an imaging unit configured to image the groove irradiated with the pulsed light with an exposure time longer than an irradiation time of the pulsed light to generate a captured image, a determination unit configured to make a determination based on the captured image, and a processing control unit configured to control an operation of the laser irradiation unit. The determination unit determines whether the groove satisfies a first standard on the basis of the captured image. In a case where the determination unit determines that the groove does not satisfy the first standard, the processing control unit controls the laser irradiation unit so that the groove formed by the laser irradiation unit satisfies the first standard.

Abstract: This grain-oriented electrical steel sheet includes a base steel sheet having a predetermined chemical composition, a glass coating formed on the base steel sheet, and a tension-applied insulation coating formed on the glass coating, on a front surface of the base steel sheet, a plurality of linear strains that extend continuously or intermittently in a direction intersecting with a rolling direction are present, intervals p in the rolling direction of the plurality of linear strains adjacent to each other are 3.0 to 9.0 mm, widths of the linear strains are 10 to 250 ?m, and, in an X-ray topographic spectrum in a range of 1.50 mm in the rolling direction that is obtained from an X-ray topographic image of the front surface and includes the linear strain at a center, a full width at half maximum of a peak of the X-ray topographic spectrum including a maximum value of a spectral intensity is 0.02 mm or more and 0.10 mm or less.

Abstract: A groove processing device that forms a groove in an object's surface using laser beams includes: a light source device that outputs the laser beams; a polygon mirror that reflects the laser beams that are output; a condensing optical system provided on an optical path of the laser beams that are reflected and focuses the laser beams; and a shielding plate provided between the condensing optical system and the object at a position which blocks some of the laser beams and blocks some of the laser beams. Among the laser beams that are focused, some that are not blocked form the groove in the surface of the object at a focus. The shielding plate is provided closer to the condensing optical system than the focus and is rotated with respect to the object's surface to block the laser beams that do not form the groove.

Abstract: This method for manufacturing a grain-oriented electrical steel sheet includes: a cold rolling step of manufacturing a cold-rolled steel sheet; a final annealing step of performing final annealing accompanied by secondary recrystallization on the cold-rolled steel sheet; a groove forming step of linearly forming a groove in a direction intersecting a rolling direction of the cold-rolled steel sheet with respect to the cold-rolled steel sheet before or after the final annealing step; and a tension coating applying step of forming a tension coating on a groove forming surface by applying and baking a coating solution containing a compound of phosphoric acid, phosphate, chromic anhydride, chromate, alumina, or silica, in a state where the groove forming surface of the cold-rolled steel sheet faces downward.

Abstract: The present invention has as its object to provide grain-oriented electrical steel sheet better improved in core loss in control of magnetic domains for forming laser grooves in cold rolled steel sheet. The present invention provides grain-oriented electrical steel sheet meeting the following requirements for achieving the object: That is, it provides grain-oriented electrical steel sheet comprising a base material steel sheet having a plurality of grooves on the surface of the steel sheet and a glass coating on the surface of the base material steel sheet, in which grain-oriented electrical steel sheet, an absolute value of an angle ? formed by a direction perpendicular to a rolling direction and a sheet thickness direction of the base material steel sheet and a longitudinal direction of the grooves is 0 to 40°, a width W of the grooves is 20 ?m to 300 ?m, a depth D of the grooves is 10 ?m to 40 ?m, and a pitch P of the grooves in the rolling direction is 1.

Abstract: The present invention has as its object to provide grain-oriented electrical steel sheet better improved in core loss in control of magnetic domains for forming laser grooves in cold rolled steel sheet. The present invention provides grain-oriented electrical steel sheet meeting the following requirements for achieving the object: That is, it provides grain-oriented electrical steel sheet comprising a base material steel sheet having a plurality of grooves on its surface and a glass coating on the surface of the base material steel sheet, in which grain-oriented electrical steel sheet, an absolute value of an angle ? formed by a direction perpendicular to a rolling direction and a sheet thickness direction of the base material steel sheet and a longitudinal direction of the grooves is 0 to 40°, a width W of the grooves is 20 ?m to 300 ?m, a depth D of the grooves is 10 ?m to 40 ?m, and a pitch P of the grooves in the rolling direction is 1.0 mm to 30.

Abstract: The present steel sheet processing apparatus includes one or more support rolls and a laser irradiation unit. The laser irradiation unit includes a laser output unit, a laser scanning unit, a focusing optical unit, a housing, and an angle adjustment unit that changes an angle of the housing with respect to a steel sheet. When a surface of the steel sheet is scanned with a laser beam, the angle adjustment unit changes the angle of the housing in a plane formed by a normal direction of the steel sheet surface and a scanning direction so that a distance from the focusing optical unit to the surface of the steel sheet of the laser beam focused by the focusing optical unit is equal over a total length of a scanning region of the laser beam on the surface of the steel sheet. The laser irradiation unit irradiates the laser beam in a state in which the angle of the housing is changed by the angle adjustment unit to form grooves or residual stress regions on the surface of the steel sheet.

Abstract: The method for manufacturing a grain-oriented electrical steel sheet is a method for manufacturing a grain-oriented electrical steel sheet including a strain region forming process of irradiating the grain-oriented electrical steel sheet having a base steel sheet (1), an intermediate layer (4) disposed to be in contact with the base steel sheet (1), and an insulation coating (3) disposed to be in contact with the intermediate layer (4) with an electron beam and forming a strain region (D) which extends in a direction intersecting a rolling direction of the base steel sheet (1) on a surface of the base steel sheet (1), wherein, in the strain region forming process, a temperature of a central portion of the strain region (D) in the rolling direction of the base steel sheet (1) and an extension direction of the strain region (D) is heated to 800° C. or higher and 2000° C. or lower.

Abstract: A laser processing device includes: a laser light source unit that irradiates, with laser light, a surface of a steel sheet conveyed in a predetermined conveyance direction; a first nozzle that injects gas toward an irradiation site of the laser light, parallel to an optical axis direction of the laser light; and a dust collection mechanism unit that is provided only at one of an upstream side or a downstream side of the irradiation site, in the conveyance direction, and that collects, from a dust collection port, laser sputter generated from the irradiation site.

Abstract: This grain-oriented electrical steel sheet includes a base steel sheet, a forsterite-based primary film disposed on a surface of the base steel sheet, and a phosphate-based tension-imparting film containing no chromium, which is disposed on a surface of the primary film. In a case where a Ti content and a S content are respectively expressed as XTi and XS, by mass %, the forsterite-based primary film satisfies Expression (1) and Expression (2). A strain-introduced magnetic domain control is performed on the grain-oriented electrical steel sheet 0.10?XTi/XS?10.00??Expression (1) XTi+XS?0.10 mass %.

Abstract: This grain-oriented electrical steel sheet includes a base steel sheet having a predetermined chemical composition, a glass coating formed on the base steel sheet, and a tension-applied insulation coating formed on the glass coating, on a front surface of the base steel sheet, a plurality of linear strains that extend continuously or intermittently in a direction intersecting with a rolling direction are present, intervals p in the rolling direction of the plurality of linear strains adjacent to each other are 3.0 to 9.0 mm, widths of the linear strains are 10 to 250 ?m, and, in an X-ray topographic spectrum in a range of 1.50 mm in the rolling direction that is obtained from an X-ray topographic image of the front surface and includes the linear strain at a center, a full width at half maximum of a peak of the X-ray topographic spectrum including a maximum value of a spectral intensity is 0.02 mm or more and 0.10 mm or less.

Abstract: This grain-oriented electrical steel sheet includes a base steel sheet, a glass coating formed on the base steel sheet, and a tension-applied insulation coating formed on the glass coating, in which, in the base steel sheet, a plurality of linear strain regions that extend continuously or intermittently in a direction intersecting with a rolling direction are present, the plurality of linear strain regions are each 210 ?m or less in width in the rolling direction, the plurality of linear strain regions are parallel to each other, intervals of linear strain regions adjacent to each other in the rolling direction are 10 mm or less, and magnetostriction ?0-pb in a unit of ?m/m when the grain-oriented electrical steel sheet is excited up to 1.7 T and magnetostriction ?0-pa in a unit of ?m/m when the grain-oriented electrical steel sheet is heat-treated at 800° C. for 4 hours and then excited up to 1.7 T satisfy 0.02??0-pb??0-pa?0.20.

Abstract: This grain-oriented electrical steel sheet includes a base steel sheet, a glass coating formed on the base steel sheet, and a tension-applied insulation coating formed on the glass coating, in the base steel sheet, a plurality of linear strains that extend continuously or intermittently in a direction intersecting with a rolling direction are present, and intervals in the rolling direction of the plurality of linear strains adjacent to each other are 10 mm or less, in a region where the strains are present, a closure domain is present, a length d of the closure domain in a sheet thickness direction from a surface of the base steel sheet is 30 to 60 ?m, a length w in the rolling direction is 200 ?m or less, and a ratio mid of a depth m from the surface of the base steel sheet where a compressive strain in the rolling direction present in the closure domain exhibits a maximum value to the length d is in a range of more than 0.30 and less than 0.90.

Abstract: Provided is a laser scanning device that scans a surface of an electrical steel sheet with a laser beam, and includes: a laser beam output unit which irradiates the laser beam; a polygon mirror which has a polygonal shape including a top surface and a bottom surface that are polygonal, in which at least any one surface excluding the top surface and the bottom surface is formed as a mirror, which rotates about an axis serving as a rotation axis and penetrating the top surface and the bottom surface, and which causes the laser beam irradiated from the laser beam output unit to be reflected at the mirror; and an optical system which guides the laser beam reflected at the polygon mirror to the surface of an electrical steel sheet, the rotation axis of the polygon mirror being parallel to the surface of the electrical steel sheet and substantially parallel to a direction in which the laser beam is scanned.

Abstract: The grain-oriented electrical steel sheet according to the present embodiment is a grain-oriented electrical steel sheet having a base steel sheet (1), an intermediate layer (4) disposed to be in contact with the base steel sheet (1), and an insulation coating (3) disposed to be in contact with the intermediate layer (4). The grain-oriented electrical steel sheet according to the present embodiment includes a surface of the base steel sheet (1) having a strain region (D) which extends in a direction intersecting a rolling direction of the base steel sheet (1), and a crystalline phosphorus oxide M2P4O13 present in the insulation coating (3) on the strain region (D) in a cross-sectional view of a surface parallel to the rolling direction and a sheet thickness direction of the base steel sheet (1). (M means at least one or both of Fe and Cr.

Abstract: The grain-oriented electrical steel sheet according to the present invention is a grain-oriented electrical steel sheet having a base steel sheet (1), an intermediate layer (4) disposed to be in contact with the base steel sheet (1), and an insulation coating (3) disposed to be in contact with the intermediate layer (4), and the grain-oriented electrical steel sheet includes a surface of the base steel sheet (1) having a groove (G) which extends in a direction intersecting a rolling direction of the base steel sheet (1), in which in a cross-sectional view of a plane parallel to the rolling direction and a sheet thickness direction of the base steel sheet (1), when a region between end portions of the groove (G) is defined as a groove part (RG), an average thickness of the intermediate layer (4) of the groove part (RG) is 0.5 times or more and 3.

Abstract: A grain-oriented electrical steel sheet according to the present invention includes a base steel sheet having plural grooves on a surface and a glass film formed on the surface of the base steel sheet.

Abstract: A method for manufacturing a grain-oriented electrical steel sheet according to an aspect of the present invention includes a step of obtaining a hot-rolled steel sheet by carrying out hot rolling on a slab containing a predetermined component composition with a remainder including Fe and impurities, a step of obtaining a hot-rolled annealed sheet by carrying out hot-rolled sheet annealing as necessary, a step of carrying out pickling to obtain a pickled sheet, a step of carrying out cold rolling to obtain a cold-rolled steel sheet, a step of carrying out primary recrystallization annealing, a step of applying an annealing separating agent including MgO to a surface and then carrying out final annealing to obtain a final-annealed sheet, and a step of applying an insulating coating and then carrying out flattening annealing.