A method for manufacturing a grain-oriented electrical steel sheet according to an embodiment of the present invention comprises the steps of: hot-rolling a slab to prepare a hot-rolled sheet, the slab containing, in wt %, 2.0 to 6.0% of Si, 0.04 to 0.12% of Mn, 0.001 to 0.022% of N, 0.027 to 0.060% of C, 0.01 to 0.08% of Nb, 0.01% or less of Ti, and the balance of Fe and other inevitable impurities; cold-rolling the hot-rolled sheet to prepare a cold-rolled sheet; and subjecting the primarily recrystallization-annealed cold-rolled sheet to secondary recrystallization annealing.

An exemplary embodiment in the present disclosure provides a grain-oriented electrical steel sheet containing, by wt %: 3.0 to 4.5% of Si; 0.05 to 0.2% of Mn; 0.015 to 0.035% of Al; 0.0015% or less (excluding 0%) of C; 0.0015% or less (excluding 0%) of N; 0.0015% or less (excluding 0%) of S; and a balance of Fe and other unavoidable impurities, wherein the grain-oriented electrical steel sheet satisfies the following Relational Expressions 1 and 2:

(W.sub.13/50/W.sub.17/50)≤0.57  [Relational Expression 1]

(W.sub.15/50/W.sub.17/50)≤0.76  [Relational Expression 2] where Wx/y represents a core loss value under conditions in which a magnitude of an applied magnetic field is x/10 T and a frequency is y Hz.

Provided are a Ni-based superalloy for stably obtaining high tensile strength and a method for manufacturing the same. Provided are: a Ni-based superalloy having a composition comprising, in mass %, C: up to 0.10%, Si: up to 0.5%, Mn: up to 0.5%, P: up to 0.05%, S: up to 0.050%, Fe: up to 45%, Cr: 14.0 to 22.0%, Co: up to 18.0%, Mo: up to 8.0%, W: up to 5.0%, Al: 0.10 to 2.80%, Ti: 0.50 to 5.50%, Nb: up to 5.8%, Ta: up to 2.0%, V: up to 1.0%, B: up to 0.030%, Zr: up to 0.10%, Mg: up to 0.005%, and the balance of Ni with inevitable impurities, and has a grain orientation spread (GOS) of at least 0.7° as an intragranular misorientation parameter measured by an SEM-EBSD technique; and a method for manufacturing the same.

A grain-oriented electrical steel sheet includes: a base steel sheet having a predetermined chemical composition; a glass coating provided on the surface of the base steel sheet; and a tension-applying insulation coating provided on the surface of the glass coating, in which linear thermal strains having, a predetermined angle (φ) with respect to a transverse direction which is a direction orthogonal to a rolling direction are periodically formed on the surface of the tension-applying insulation coating at predetermined intervals along the rolling direction, a full width at half maximum F1 on the linear thermal strain and a full width at half maximum F2 at an intermediate position between the two linear thermal strains adjacent to each other satisfy 0.00<(F1−F2)/F2≤0.15, the width of the linear thermal strain is 10 μm or more and 300 μm or less, and in the base steel sheet, an orientation distribution angle γ around a rolling direction axis of secondary recrystallization grains, an orientation distribution angle α around an axis parallel to a normal direction, and an orientation distribution angle β around an axis perpendicular to each of the RD axis and the ND axis in units of ° satisfy 1.0≤γ≤8.0 and 0.0≤(α.sup.2+β.sup.2).sup.0.5≤10.0.

A non-oriented electrical steel sheet according to an embodiment of the present invention includes, in wt %, Si: 1.5 to 4.0%, Al: 0.1 to 1.5%, Mn: 0.05 to 1.5%, Sn: 0.015 to 0.1%, P: 0.005 to 0.05%, Ga: 0.001 to 0.004%, and Bi: 0.0005 to 0.003%, and the balance of Fe and inevitable impurities. An area fraction of texture in a {118}//ND orientation is higher than that of texture in a {111}///ND orientation.

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)

A grain-oriented electrical steel sheet according to the present invention has a steel sheet surface provided with grooves. An average protrusion height of the surface protrusion extending along a longitudinal direction of the groove is more than 5 μm and not more than 10 μm. When the surface protrusion is viewed in a cross section including the longitudinal direction of the groove and a normal direction of the steel sheet surface, the surface protrusion includes specific portions each having a height of 50% or more with respect to a height of each peak point appearing on a profile line of the surface protrusion. In the longitudinal direction of the groove, the total length of the specific portions is a length of 30% or more with respect to an overall length of the surface protrusion.

Disclosed is a multi-layer rolled composite board, comprising a transition layer provided between two adjacent composite layers, wherein the transition layer is an anisotropic steel sheet. Also disclosed is a manufacturing method for the multi-layer rolled composite board, the method comprising the following steps: (1) providing a transition layer between adjacent composite layers to assemble a blank, and creating a vacuum between the layers; and (2) performing composite rolling, comprising: heating the blank to 1100-1260° C. and maintaining the temperature for 0.6 h or above, then performing hot rolling at a temperature of Ar3 or above, with the final rolling temperature being controlled to be higher than 820° C., cooling at a speed of 30-100° C./s after rolling, and then coiling, with the coiling temperature being controlled to be 20-750° C. The multi-layer rolled composite board of the present invention can be greatly transformed according to different compositions and processes so as to achieve different strength grades ranging from 150 MPa to 1700 MPa, thereby providing the basis for different specific mechanical properties for the whole steel sheet.

The present invention relates to a grain-oriented electrical steel sheet including 2.0 to 6.0 wt % of Si, 0.01 wt % or less (excluding 0 wt %) of C, 0.01 wt % or less (excluding 0 wt %) of N, and 0.005 to 0.1 wt % of Co, and including a balance of Fe and other inevitable impurities.

Disclosed is a grain-oriented electrical steel sheet that has excellent high-frequency iron loss properties and blanking workability. The steel sheet includes: steel components including, by mass %, Si: 1.5-8.0%, Mn: 0.02-1.0%, and at least one selected from Sn: 0.010-0.400%, Sb: 0.010-0.400%, Mo: 0.010-0.200%, and P: 0.010-0.200%; and crystal grains including coarse secondary recrystallized grains having an average grain size of 5 mm or more and fine grains having a grain size of 0.1-2.0 mm, wherein at least some of the coarse secondary recrystallized grains penetrate the steel sheet in a thickness direction and are respectively exposed on front and back surfaces of the steel sheet such that projection planes of the exposed surfaces of these coarse secondary recrystallized grains on the front and back surfaces form an overlapping region, and the fine grains are present at a number density per unit area of 0.6-40 pieces/cm.sup.2.