What is provided is a steel sheet for a non-oriented electrical steel sheet containing, in mass %, C: 0.0040% or less, Si: 1.9% or more and 3.5% or less, Al: 0.10% or more and 3.0% or less, Mn: 0.10% or more and 2.0% or less, P: 0.09% or less, S: 0.005% or less, N: 0.0040% or less, B: 0.0060% or less, and the remainder consisting of Fe and impurities, in which the recrystallization rate of the structure of a sheet thickness-direction cross section at each position 10 mm apart toward the sheet width center from each of both end portions in the sheet width direction is less than 50%, and, when the sheet width is represented by W, the recrystallization rate of the structure of a sheet thickness-direction cross section at the position of ¼W from each of both end portions in the sheet width direction is 50% or more.

Provided is a grain-oriented electrical steel sheet having both low iron loss and good magnetostrictive properties, with which a transformer having excellent properties can be manufactured. The grain-oriented electrical steel sheet of the present disclosure has a linear strain region extending linearly in a direction intersecting the rolling direction, where the linear strain region has a region having compressive stress in the rolling direction, and a region adjacent in a rolling direction to the region having compressive stress has a region having tensile stress in the rolling direction.

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. In case of viewing region including grooves in cross section orthogonal to groove longitudinal direction, a straight line passing through peak point present on profile line of glass film and parallel to groove width direction orthogonal to sheet thickness direction in cross section is defined as reference line, a point present on boundary line between glass film and base steel sheet and present at lowest location in sheet thickness direction is defined as deepest point, and a point present on boundary line and present at the highest location in the sheet thickness direction in region having the deepest point in a center and having length of 2 μm in groove width direction is defined as shallowest point, a relationship between shortest distance A between reference line and deepest point and shortest distance B between reference line and shallowest point satisfies Expression (1).
0.1 μm≤A−B≤5.0 μm  (1)

To form linear grooves of desired groove width on a metal strip surface and provide a grain-oriented electrical steel sheet having excellent magnetic properties, a linear groove formation method comprises: forming a resist coating on at least one surface of a metal strip; thereafter irradiating the resist coating with a laser while scanning the laser in a direction crossing a rolling direction of the metal strip, to remove the resist coating in a part irradiated with the laser; and thereafter performing etching treatment to form a linear groove in a part of the metal strip in which the resist coating is removed, wherein the resist coating contains a predetermined amount of an inorganic compound, and on the surface of the metal strip, the laser has a predetermined elliptic beam shape.

Provided is a grain-oriented electrical steel sheet which has been subjected to heat-resistant magnetic domain refining treatment and can effectively suppress carburizing and nitriding during stress relief annealing. The grain-oriented electrical steel sheet has a plurality of grooves on one side that extend linearly across the rolling direction and are lined up at intervals in the rolling direction, and has at least a forsterite film on a surface of the steel sheet, where an average thickness of the forsterite film formed on the floor of the grooves is 0.45 μm or more, and a standard deviation a of the thickness is 0.34 μm or less.

A grain-oriented electrical steel sheet according to an embodiment of the present invention has an average degree of orientation difference of 0.5 to 10° between recrystallized grains that are in contact with a groove present on the surface of the electrical steel sheet and the bottom of the groove, and other recrystallized grains.

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°.

An Fe-based amorphous alloy ribbon reduced in iron loss, less deformed, and highly productive in a condition of a magnetic flux density of 1.45 T is provided. One aspect of the present disclosure provides an Fe-based amorphous alloy ribbon having first and second surfaces, and is provided with continuous linear laser irradiation marks on at least the first surface. Each linear laser irradiation mark is formed along a direction orthogonal to a casting direction of the Fe-based amorphous alloy ribbon, and has unevenness on its surface. When the unevenness is evaluated in the casting direction, a height difference HL×width WA calculated from the height difference HL between a highest point and a lowest point in a thickness direction of the Fe-based amorphous alloy ribbon and the width WA which is a length of the linear irradiation mark on the first surface is 6.0 to 180 μm.sup.2.

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°.

A grain oriented electrical steel sheet includes the texture aligned with Goss orientation. In the grain oriented electrical steel sheet, when a grain size RAα.sub.C, a grain size RAβ.sub.C, and a grain size RAγ.sub.C are defined in a transverse direction C, the grain sizes satisfy RAγ.sub.C<RAα.sub.C and RAγ.sub.C<RAβ.sub.C.