Abstract: Provided is a grain-oriented electrical steel sheet including a steel sheet having a steel sheet surface in which a groove, which extends in a direction intersecting a rolling direction and of which a groove depth direction matches a sheet thickness direction, is formed. In a case where the steel sheet surface is seen from the sheet thickness direction, the steel sheet surface is provided with a groove group that is constituted by a plurality of the grooves arranged in a sheet width direction, the grooves, which constitute the groove group, arc arranged in such a manner that adjacent grooves overlap each other on a projection plane perpendicular to the rolling direction, and a plurality of the groove groups are arranged with an interval in the rolling direction.

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 separator production method in accordance with an embodiment of the present invention includes a coated article winding off step of winding off, from a core, a separator original sheet which has been taken up in a coated article taking up step of winding the separator original sheet on an outer peripheral surface of the core while oscillating the core in a rotation axis direction, and the core is oscillated in the rotation axis direction in the coated article winding off step.

Abstract: The separator production method in accordance with an embodiment of the present invention includes a coated article taking up step of taking up a separator original sheet by winding the separator original sheet on an outer peripheral surface of a core while oscillating the core in the rotation axis direction; a coated article winding off step of winding off the separator original sheet, which has been taken up in the coated article taking up step, from the core; and a transferring step of transferring the separator original sheet, which has been wound off in the coated article winding off step, such that a state of being distorted in a wavelike manner in the transverse direction is maintained.

Abstract: In a laser processing apparatus for refining magnetic domains of a grain-oriented electromagnetic steel sheet by setting a laser beam to be focused on the grain-oriented electromagnetic steel sheet and scanned in a scanning direction, the laser beam focused on the grain-oriented electromagnetic steel sheet is linearly polarized light, and the angle between the linear polarization direction and the scanning direction is equal to or higher than 0° and lower than 45°.

Abstract: In a laser processing apparatus for refining magnetic domains of a grain-oriented electromagnetic steel sheet by setting a laser beam to be focused on the grain-oriented electromagnetic steel sheet and scanned in a scanning direction, the laser beam focused on the grain-oriented electromagnetic steel sheet is linearly polarized light, and an angle between a linear polarization direction and the scanning direction is higher than 45° and equal to or lower than 90°.

Abstract: A laser processing apparatus includes a laser irradiation unit has a structure providing an intensity distribution of the laser beam focused on the grain-oriented electrical steel sheet on a cross-section in a direction perpendicular to the scanning direction on the grain-oriented electrical steel sheet so as to satisfy Ib/Ia?2, where Ra1 and Ra2 are distances between the centroid of the intensity distribution and positions at which the intensity integration value from the centroid of the intensity distribution is 43% of the total intensity integration value, beam intensities Ia1 and Ia2 are intensities of the laser beam corresponding to Ra1 and Ra2, respectively, Ia is the average value of Ia1 and Ia2 and Ib is the beam intensity at the centroid of the intensity distribution.

Abstract: A laser processing apparatus includes a laser irradiation unit has a structure providing an intensity distribution of the laser beam focused on the grain-oriented electrical steel sheet on a cross-section in a direction perpendicular to the scanning direction on the grain-oriented electrical steel sheet so as to satisfy Ib/Ia?2, where Ra1 and Ra2 are distances between the centroid of the intensity distribution and positions at which the intensity integration value from the centroid of the intensity distribution is 43% of the total intensity integration value, beam intensities Ia1 and Ia2 are intensities of the laser beam corresponding to Ra1 and Ra2, respectively, Ia is the average value of Ia1 and Ia2 and Ib is the beam intensity at the centroid of the intensity distribution.

Abstract: In a method for producing a grain-oriented electrical steel sheet, grooves each having a given length and extending in a direction including a direction perpendicular to a transportation direction of the grain-oriented electrical steel sheet are formed at given intervals in the transportation direction by irradiating the surface of the grain-oriented electrical steel sheet with a laser beam while scanning the surface of the grain-oriented electrical steel sheet with the laser beam. Further, in the method for manufacturing a grain-oriented electrical steel sheet, the laser beam is a continuous-wave laser beam having a laser wavelength ? of 1.0 ?m to 2.1 ?m, power density Pd [W/mm2] which is obtained by dividing laser beam intensity P by a focused beam area S is 5×105 W/mm2 or more, and the power density Pd [W/mm2] and scanning speed V [mm/s] of a focused spot of the laser beam on the surface of the grain-oriented electrical steel sheet satisfy a relationship of 0.005×Pd+3000?V?0.005×Pd+40000.

Abstract: A grain-oriented magnetic steel sheet includes grooves each of which extends in a direction intersecting a transportation direction, the grooves being formed at predetermined pitches PL in the transportation direction by laser beam irradiation, in which a relationship between a standard deviation value D and the pitch PL satisfies the following expression (1), the standard deviation value D being a standard deviation of distances between a linear approximation line, which is obtained from a center line of each of the grooves in a groove width direction by a least-squares method, and respective positions on the center line, and an average angle formed between tangent lines of the respective positions on the center line and a direction perpendicular to the transportation direction is more than 0° to 30°. [Expression 1] 0.

Abstract: This method of manufacturing a grain-oriented electrical steel sheet includes, between a cold rolling process and a winding process, a groove formation process of irradiating the surface of a silicon steel sheet with a laser beam multiple times at predetermined intervals in a sheet passing direction, over an area from one end edge to the other end edge, in a sheet width direction of the silicon steel sheet, thereby forming a groove along a locus of the laser beam.

Abstract: This method of manufacturing a grain-oriented electrical steel sheet includes, between a cold rolling process and a winding process, a groove formation process of irradiating the surface of a silicon steel sheet with a laser beam multiple times at predetermined intervals in a sheet passing direction, over an area from one end edge to the other end edge, in a sheet width direction of the silicon steel sheet, thereby forming a groove along a locus of the laser beam.

Abstract: In a method for producing a grain-oriented electrical steel sheet, grooves each having a given length and extending in a direction including a direction perpendicular to a transportation direction of the grain-oriented electrical steel sheet are formed at given intervals in the transportation direction by irradiating the surface of the grain-oriented electrical steel sheet with a laser beam while scanning the surface of the grain-oriented electrical steel sheet with the laser beam. Further, in the method for manufacturing a grain-oriented electrical steel sheet, the laser beam is a continuous-wave laser beam having a laser wavelength ? of 1.0 ?m to 2.1 ?m, power density Pd [W/mm2] which is obtained by dividing laser beam intensity P by a focused beam area S is 5×105 W/mm2 or more, and the power density Pd [W/mm2] and scanning speed V [mm/s] of a focused spot of the laser beam on the surface of the grain-oriented electrical steel sheet satisfy a relationship of 0.005×Pd+3000?V?0.005×Pd+40000.

Abstract: There is provided a method for manufacturing a grain-oriented electromagnetic steel sheet whose iron losses are reduced by laser beam irradiation, capable of improving the iron losses in both the L-direction and the C-direction while easily ensuring high productivity. The method for manufacturing a grain-oriented electromagnetic steel sheet reduces iron losses by scanning and irradiating a grain-oriented electromagnetic steel sheet with a continuous-wave laser beam condensed into a circular or elliptical shape at constant intervals in a direction substantially perpendicular to a rolling direction of the grain-oriented electromagnetic steel sheet, wherein when an average irradiation energy density Ua is defined as Ua=P/(Vc×PL) (mJ/mm2), where P (W) is average power of the laser beam, Vc (m/s) is a beam scanning velocity, and PL (mm) is an irradiation interval in a rolling direction, PL and Ua are in the following ranges: 1.0 mm?PL?3.0 mm, 0.8 mJ/mm2?Ua?2.0 mJ/mm2.

Abstract: A grain-oriented electrical steel plate is characterized in that grooves having a width of 10 ?m to 200 ?m and a depth of 10 ?m to 30 ?m exist in at least one of a front surface and a rear surface of a steel plate at intervals of 1 mm to 10 mm, an angle between a direction in which the grooves extend and a rolling direction of the steel plate is 60 degrees to 120 degrees, and tensile stresses having a maximum value of 20 MPa to 300 MPa act in the rolling direction within ranges of 10 ?m to 300 ?m from side surfaces of the grooves.

Abstract: An object of the present invention is to provide a grain-oriented electrical steel sheet with low core loss and low magnetostriction and a method for producing the same. The grain-oriented electrical steel sheet is excellent in reduced core loss and magnetostriction while under a high flux density of 1.9 T, comprises a refined magnetic domain comprising a laser irradiated portion which has melted and resolidified to form a solidified layer, wherein the thickness of the solidified layer is 4 ?m or less. The grain-oriented electrical steel sheet may further comprise a laser irradiated portion where a surface roughness Rz is small and a cross section viewed from a transverse direction has a concave portion having a width of 200 ?m or less and a depth of 10 ?m or less for further improvement.

Abstract: Technology scanning and irradiating grain-oriented electrical steel sheet moving in a rolling direction at a speed Vl with an elliptical spot formed by a laser beam in the width direction at Vc to improve the core loss of the grain-oriented electrical steel sheet, which adjusts the angle ?s formed by the scan direction of the elliptical beam and the long axis of the ellipse based on the equation ?s=tan?1(Vl/Vc) and which constructs the system for adjusting the ?s by an optical system for laser irradiation comprised of a cylindrical lens telescope, scan mirror, and f? lens arranged in that order, a system for changing the angle of the cylindrical lens telescope with respect to the scan direction of the scan mirror, and a system for changing the distance between lenses.

Abstract: A grain-oriented electrical steel plate is characterized in that grooves having a width of 10 ?m to 200 ?m and a depth of 10 ?m to 30 ?m exist in at least one of a front surface and a rear surface of a steel plate at intervals of 1 mm to 10 mm, an angle between a direction in which the grooves extend and a rolling direction of the steel plate is 60 degrees to 120 degrees, and tensile stresses having a maximum value of 20 MPa to 300 MPa act in the rolling direction within ranges of 10 ?m to 300 ?m from side surfaces of the grooves.

Abstract: There is provided a method for manufacturing a grain-oriented electromagnetic steel sheet whose iron losses are reduced by laser beam irradiation, capable of improving the iron losses in both the L-direction and the C-direction while easily ensuring high productivity. The method for manufacturing a grain-oriented electromagnetic steel sheet reduces iron losses by scanning and irradiating a grain-oriented electromagnetic steel sheet with a continuous-wave laser beam condensed into a circular or elliptical shape at constant intervals in a direction substantially perpendicular to a rolling direction of the grain-oriented electromagnetic steel sheet, wherein when an average irradiation energy density Ua is defined as Ua=P/(Vc×PL) (mJ/mm2), where P (W) is average power of the laser beam, Vc (m/s) is a beam scanning velocity, and PL (mm) is an irradiation interval in a rolling direction, PL and Ua are in the following ranges: 1.0 mm?PL?3.0 mm, 0.8 mJ/mm2?Ua?2.0 mJ/mm2.

Abstract: The present invention provides a method of production of grain-oriented electrical steel sheet greatly reducing the Watt loss of the grain-oriented electrical steel sheet and making the magnetostriction as small as possible, that is, a method of production of grain-oriented electrical steel sheet with small magnetostriction by improving the magnetic properties by irradiation by a finely focused laser beam comprising using a power modulated laser controlled in maximum power density to 1×102 to 1×104 W/mm2 to optimize the amount of strain given by laser irradiation in both the sheet width direction and rolling direction and, in particular, to make the modulation duty 70% to less than 100%.