Abstract: When joining end faces of a plurality of soft magnetic sheets which are superposed in the sheet thickness direction and which are bent at parts forming corner areas of a core, offset of positions of the end faces from the desired positions is suppressed. In a region of a window part comprised of a region inside of a first part 110 and second part 120, a third part 130 with a length in a longitudinal direction (X-axial direction) the same as a length in the X-axial direction of the window part at the position where the third part 130 is arranged is arranged so as to contact the region of the inner circumferential surface between the first corner area 101 and third corner area 103.

Abstract: When joining end faces of a plurality of soft magnetic sheets which are superposed in the sheet thickness direction and which are bent at parts forming corner areas of a core, offset of positions of the end faces from the desired positions is suppressed. In a region of a window part comprised of a region inside of a first part 110 and second part 120, a third part 130 with a length in a longitudinal direction (X-axial direction) the same as a length in the X-axial direction of the window part at the position where the third part 130 is arranged is arranged so as to contact the region of the inner circumferential surface between the first corner area 101 and third corner area 103.

Abstract: A wound core (10) in which, in a laminating direction, when the surface roughness of a steel sheet portion in a direction connecting a center in a sheet thickness direction of a grain-oriented electrical steel sheet (1) positioned on the innermost periphery of the wound core among the laminated grain-oriented electrical steel sheets (1) and a center in the sheet thickness direction of the grain-oriented electrical steel sheet (1) positioned on the outermost periphery of the wound core (10) is Ral, and the surface roughness of the grain-oriented electrical steel sheet (1) in a direction parallel to a longitudinal direction on an end surface of a planar portion (4) of the laminated grain-oriented electrical steel sheet (1) is Rac, a ratio Ral/Rac between Rat and Rac satisfies the relationship of 1.5?Ral/Rac?12.0.

Abstract: A wound core (10) is a wound core having a wound shape (10) including a rectangular hollow portion (15) in a center and a portion in which grain-oriented electrical steel sheets (1) in which planar portions (4) and bent portions (5) are alternately continuous in a longitudinal direction are stacked in a sheet thickness direction, which is a wound core formed by stacking the grain-oriented electrical steel sheets(1) that have been individually bent in layers and assembled into a wound shape and in which the plurality of grain-oriented electrical steel sheets are connected to each other via at least one joining part (6) for each roll, wherein the bent portion (5) of the laminated grain-oriented electrical steel sheet (1) has an average Vickers hardness of 190 to 250 HV in an L cross section in the longitudinal direction which is a cross section of the grain-oriented electrical steel sheet (1) in a thickness direction.

Abstract: Provided is a wound core formed by laminating a plurality of bent bodies obtained by forming a coated grain-oriented electrical steel sheet in which a coating is formed on at least one surface of a grain-oriented electrical steel sheet so that the coating is on an outside, in a sheet thickness direction, in which the bent body has a bent region obtained by bending the coated grain-oriented electrical steel sheet and a flat region adjacent to the bent region, the number of deformation twins present in the bent region in a side view is five or less per 1 mm of a length of a center line in the sheet thickness direction in the bent region, and when a region extending 40 times a sheet thickness to both sides in a circumferential direction from a center of the bent region on an outer circumferential surface of the bent body is defined as a strain affected region, a proportion of an area where the coating is not damaged at any position along the circumferential direction in a flat region within the strain affected r

Abstract: A grain-oriented electrical steel sheet according to the present invention includes a silicon steel sheet as a base steel sheet, and when an average value of amplitudes in a wavelength range of 20 to 100 ?m among wavelength components obtained by performing Fourier analysis on a measured cross-sectional curve parallel to a sheet width direction of the silicon steel sheet is set as ave-AMPC100, ave-AMPC100 is 0.0001 to 0.050 ?m.

Abstract: Provided is a wound core formed by laminating a plurality of bent bodies obtained by forming a coated grain-oriented electrical steel sheet in which a coating is formed on at least one surface of a grain-oriented electrical steel sheet so that the coating is on an outside, in a sheet thickness direction, in which the bent body has a bent region obtained by bending the coated grain-oriented electrical steel sheet and a flat region adjacent to the bent region, the number of deformation twins present in the bent region in a side view is five or less per 1 mm of a length of a center line in the sheet thickness direction in the bent region, and when a region extending 40 times a sheet thickness to both sides in a circumferential direction from a center of the bent region on an outer circumferential surface of the bent body is defined as a strain affected region, a proportion of an area where the coating is not damaged at any position along the circumferential direction in a flat region within the strain affected r

Abstract: A grain-oriented electrical steel sheet includes: a steel sheet and optionally an insulation coating formed on the steel sheet, in which, in a case where a heat treatment of performing retention at 800° C. for 2 hours is performed, regarding a time-magnetostriction waveform (t?? waveform) when magnetized to 1.7 T, a peak value of a difference waveform obtained by subtracting the time-magnetostriction waveform after the heat treatment from the time-magnetostriction waveform before the heat treatment is 0.01×10?6 or more and 0.20×10?6 or less, and a difference obtained by subtracting an iron, loss before the heat treatment from an iron loss after the heat treatment is 0.03 W/kg or more and 0.17 W/kg or less.

Abstract: A grain-oriented electrical steel sheet according to the present invention includes a silicon steel sheet as a base steel sheet, and when an average value of amplitudes in a wavelength range of 20 to 100 ?m among wavelength components obtained by performing Fourier analysis on a measured cross-sectional curve parallel to a sheet width direction of the silicon steel sheet is set as ave-AMPC100, ave-AMPC100 is 0.0001 to 0.050 ?m.

Abstract: When joining end faces of a plurality of soft magnetic sheets which are superposed in the sheet thickness direction and which are bent at parts forming corner areas of a core, offset of positions of the end faces from the desired positions is suppressed. In a region of a window part comprised of a region inside of a first part 110 and second part 120, a third part 130 with a length in a longitudinal direction (X-axial direction) the same as a length in the X-axial direction of the window part at the position where the third part 130 is arranged is arranged so as to contact the region of the inner circumferential surface between the first corner area 101 and third corner area 103.

Abstract: A wound core is formed by laminating a plurality of bent bodies formed from a grain-oriented electrical steel sheet having a coating containing phosphorus formed on a surface, in a sheet thickness direction of the grain-oriented electrical steel sheet, in which the bent body is formed in a rectangular shape by having four flat portions and four corner portions adjacent to the flat portions, the corner portion has a bent region having a total bending angle of approximately 90° in a side view, the number of deformation twins present in the bent region in the side view is five or less per 1 mm of a length of a center line in the bent region in the sheet thickness direction, and the amount of phosphorus eluted from the corner portion in a case of being boiled in water for 30 minutes is 6.0 mg or less per 1 m2 of a surface area of the corner portion.

Abstract: A grain-oriented electrical steel sheet comprising a steel sheet having a surface on which grooves, in which an extending direction crosses a rolling direction and a depth direction is parallel to a sheet thickness direction, are formed, and wherein a molten solidified substance ranging in parallel to the groove exists on both sides of the groove on the surface of the steel sheet, and a height becoming a maximum frequency in a height distribution of height data in which the surface of the steel sheet in a specific area including the groove is measured at regular intervals is set as a virtual plane, and a value of V2/V1 is more than 0.10 and less than 0.80, wherein V1 is a space volume of recess parts recessed from the virtual plane and V2 is a volume of projection parts projected from the virtual plane.

Abstract: A wound core is formed by laminating a plurality of bent bodies formed from a grain-oriented electrical steel sheet having a coating containing phosphorus formed on a surface, in a sheet thickness direction of the grain-oriented electrical steel sheet, in which the bent body is formed in a rectangular shape by having four flat portions and four corner portions adjacent to the flat portions, the corner portion has a bent region having a total bending angle of approximately 90° in a side view, the number of deformation twins present in the bent region in the side view is five or less per 1 mm of a length of a center line in the bent region in the sheet thickness direction, and the amount of phosphorus eluted from the corner portion in a case of being boiled in water for 30 minutes is 6.0 mg or less per 1 m2 of a surface area of the corner portion.

Abstract: A grain-oriented electrical steel sheet includes: a base steel sheet; a primary film formed on a surface of the base steel sheet; and a tension insulation coating formed on a surface of the primary film, in which a magnetic domain control is performed by irradiating the tension insulation coating with a laser from above. When a strip-like sample having a length of 300 mm in a direction parallel to a rolling direction of the grain-oriented electrical steel sheet and a length of 60 mm in a direction parallel to a transverse direction is extracted from the grain-oriented electrical steel sheet, a range from a surface of the tension insulation coating to a depth position of 5 ?m toward the base steel sheet side from an interface between the base steel sheet and the primary film is removed by pickling at least one surface of the sample, and a warpage amount of the sample is thereafter measured, the warpage amount satisfies predetermined conditions.

Abstract: A grain-oriented electrical steel sheet includes a steel sheet having a surface on which grooves in which an extending direction crosses a rolling direction and a depth direction is parallel to a sheet thickness direction are formed. A molten solidified substance ranging in parallel to the groove exists on both sides of the groove on a surface of the steel sheet. A height becoming a maximum frequency in a height distribution of height data in which the surface of the steel sheet in a specific area including the groove is measured at regular intervals is set as a virtual plane, and when a space volume of recess parts recessed from the virtual plane is set as V1 and a volume of projection parts projected from the virtual plane is set as V2, a value of V2/V1 is more than 0.10 and less than 0.80. A plurality of projections are formed in the specific area, and among the plurality of projections, a width of a projection closest to the groove is larger than widths of the other projections.

Abstract: A grain-oriented electrical steel sheet includes: a base steel sheet; a primary film formed on a surface of the base steel sheet; and a tension insulation coating formed on a surface of the primary film, in which a magnetic domain control is performed by irradiating the tension insulation coating with a laser from above. When a strip-like sample having a length of 300 mm in a direction parallel to a rolling direction of the grain-oriented electrical steel sheet and a length of 60 mm in a direction parallel to a transverse direction is extracted from the grain-oriented electrical steel sheet, a range from a surface of the tension insulation coating to a depth position of 5 ?m toward the base steel sheet side from an interface between the base steel sheet and the primary film is removed by pickling at least one surface of the sample, and a warpage amount of the sample is thereafter measured, the warpage amount satisfies predetermined conditions.

Abstract: The present invention provides an electrical steel sheet core for a low-noise transformer capable of effectively lowering noise by suppressing vibration perpendicular to the surfaces of the steel sheets and reducing vibration, and relates to an electrical steel sheet for a low-noise transformer characterized by randomly inserting viscoelastic layers with both viscosity and elasticity into the gaps of the steel sheet lamination layers, and a low-noise transformer formed by using said electrical steel sheet.

Abstract: The object of the present invention is to provide a low iron loss and low noise grain-oriented electrical steel sheet for securing both low core loss and low noise of a transformer at the same time. The present invention relates to a grain-oriented electrical steel sheet containing Si: 1.0-4.0 wt % produced by controlling, with regard to ?O, which is defined as a 0-p value when a grain-oriented electrical steel sheet is magnetized up to a saturated magnetic flux density, and ?17, which is defined as the value obtained by subtracting a 0-p value at the magnetization magnetic flux density of 1.7 T from a 0-p value at a saturated magnetic flux density, ?OC and ?17L, which are absolute values deviated by forming a tension film and a forsterite film, and ?OL and ?17L, which are absolute values deviated by irradiating laser after the film formation, in adequate ranges respectively, and further controlling ?17, which is a 0-p value at the magnetization magnetic flux density of 1.

Abstract: The present invention provides an electrical steel sheet core for a low-noise transformer capable of effectively lowering noise by suppressing vibration perpendicular to the surfaces of the steel sheets and reducing vibration, and relates to an electrical steel sheet for a low-noise transformer characterized by randomly inserting viscoelastic layers with both viscosity and elasticity into the gaps of the steel sheet lamination layers, and a low-noise transformer formed by using said electrical steel sheet.

Abstract: The object of the present invention is to provide a low iron loss and low noise grain-oriented electrical steel sheet for securing both low core loss and low noise of a transformer at the same time. The present invention relates to a grain-oriented electrical steel sheet containing Si: 1.0-4.0 wt % produced by controlling, with regard to &egr;O, which is defined as a 0-p value when a grain-oriented electrical steel sheet is magnetized up to a saturated magnetic flux density, and &egr;17, which is defined as the value obtained by subtracting a 0-p value at the magnetization magnetic flux density of 1.7 T from a 0-p value at a saturated magnetic flux density, &egr;OC and &egr;17L, which are absolute values deviated by forming a tension film and a forsterite film, and &egr;OL and &egr;17L, which are absolute values deviated by irradiating laser after the film formation, in adequate ranges respectively, and further controlling &lgr;17, which is a 0-p value at the magnetization magnetic flux density of 1.