A manufacturing method of a grain-oriented electrical steel sheet according to an embodiment of the present invention includes: manufacturing a cold-rolled sheet; forming a groove in the cold-rolled sheet; removing an Fe—O oxide formed on a surface of the cold-rolled sheet; primary recrystallization annealing the cold-rolled sheet; and applying an annealing separating agent to the primary recrystallized cold-rolled sheet, and secondary recrystallization annealing it, wherein a close contacting property coefficient calculated by Formula 1 below is 0.016 to 1.13.

close contacting property coefficient (S.sub.ad)=(0.8×R)/H.sub.hill-up  [Formula 1] (In Formula 1, R represents the average roughness (μm) of the surface of the cold-rolled sheet after the removing of the oxide, and H.sub.hill-up represents the average height (μm) of the hill-up present on the surface of the cold-rolled sheet after the removing of the oxide.)

An oriented electrical steel sheet according to an exemplary embodiment of the present invention includes C: 0.01% or less (excluding 0%), Si: 2.0%-4.0%, Mn: 0.01%-0.20%, acid soluble Al: 0.040% or less (excluding 0%), N: 0.008% (excluding 0%), S: 0.008% (excluding 0%), Se: 0.0001-0.008%, Cu: 0.002-0.1%, Ni: 0.005-0.1%, Cr: 0.005-0.1%, P: 0.005%-0.1% and Sn: 0.005%-0.20%, one or more among Sb: 0.0005%-0.10%, Ge: 0.0005%-0.10%, As: 0.0005%-0.10%, Pb: 0.0001%-0.10%, Bi: 0.0001%-0.10% and Mo: 0.001-0.1% as wt %, and consisting of the balance of Fe and other inevitable impurities, and after final secondary recrystallization, a magnetic flux density B8 is 1.92 Tesla or more.

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 %.   Expression (2)

A non-oriented electrical steel sheet is produced by subjecting a steel slab containing, in mass %, C: not more than 0.0050%, Si: 1.0 to 6.5%, Mn: 0.05 to 2.0%, S: not more than 0.0050%, Al: not more than 0.01%, N: not more than 0.0050%, Ti: not more than 0.0030%, Nb: not more than 0.0030% and O: not more than 0.0050% to a hot rolling, a cold rolling and a finish annealing, the finish annealing conducted under conditions that a soaking temperature T (° C.) satisfies the following equation (1):

[00001]$\begin{array}{cc}\frac{\left(8000+400\times \mathrm{Si}\left(\mathrm{mass}\%\right)\right)}{\{\left(-\log \left(\mathrm{Al}\left(\mathrm{mass}\%\right)\times N\left(\mathrm{mass}\%\right)\right)+1.7+0.2\times \mathrm{Si}\left(\mathrm{mass}\%\right)\right\}}-273.15\le T\le 1200,& \left(1\right)\end{array}$

and an atmosphere in the finish annealing is a mixed gas composed of one or more selected from nitrogen, hydrogen and noble gas with a nitrogen content of not more than 50 vol % and a dew point of not higher than −20° C., whereby a non-oriented electrical steel sheet achieving a high magnetic flux density and a low iron loss is produced.

A grain oriented electrical steel sheet is produced by heating a steel slab containing, by mass %, C:0.02-0.10%, Si:2.0-5.0%, Mn:0.01-1.00%, sol. Al:0.01-0.04%, N:0.004-0.020% and S+Se:0.002-0.040% to a temperature of higher than 1280° C., and subjecting the sheet to a hot rolling, a hot-band annealing, a single cold rolling or two or more cold rollings having an intermediate annealing between each cold rolling and a primary recrystallization annealing combined with a decarburization annealing, applying an annealing separator onto a steel sheet surface, and subjecting the sheet to a finish annealing and a flattening annealing, a rapid cooling is conducted at an average cooling rate of not less than 200° C./s from 800° C. to 300° C. in the cooling process from a maximum achieving temperature in at least one annealing of the hot-band annealing and the intermediate annealing.

This electrical steel sheet contains, as a chemical composition, by mass %, C: 0.0035% or less, Si: 2.00% to 3.50%, Mn: 2.00% to 5.00%, P: 0.050% or less, S: 0.0070% or less, Al: 0.15% or less, N: 0.0030% or less, Ni: 0% to 1.00%, Cu: 0% to 0.10%, and a remainder: Fe and impurities, in which an X-ray random intensity ratio in a {100} <011> crystal orientation on a sheet surface is 15.0 to 50.0, and magnetic flux densities in 0°, 22.5°, and 45° directions from a rolling direction each satisfy [1.005×(B.sub.50 (0°)+B.sub.50 (45°))/2≥B.sub.50 (22.5°)].

A method for producing a non-oriented electrical steel sheet used as an iron core material for a motor or transformer and having excellent magnetic properties including subjecting a raw steel material including, by mass %, C: not more than 0.005%, Si: 1.0 to 5.0%, Mn: 0.04 to 3.0%, sol. Al: not more than 0.005%, P: not more than 0.2%, S: not more than 0.005%, N: not more than 0.005% and the remainder being Fe and impurities forming a hot-rolled sheet, subjecting the hot-rolled sheet to hot-band annealing and a single or two or more cold rollings including an intermediate annealing between each rolling forming a cold-rolled sheet having a final sheet thickness and subjecting the cold-rolled sheet to a finish annealing, wherein at least one pass in the final cold rolling at a friction coefficient μ of not less than 0.030 and a rolling reduction of not less than 15%.

A laser-scribed grain-oriented silicon steel resistant to stress-relief annealing and a manufacturing method therefor. Parallel linear grooves (20) are formed on one or both sides of grain-oriented silicon steel (10) by laser etching. The linear grooves (20) are perpendicular to, or at an angle to, the rolling direction of the steel plate. A maximum height of edge protrusions of the linear grooves (20) does not exceed 5 μm, and a maximum height of spatters in etch-free regions between adjacent linear grooves (20) does not exceed 5 μm, and the proportion of an area occupied by spatters in the vicinity of the linear grooves (20) does not exceed 5%. The steel has low manufacturing costs, and the etching effect of the finished steel is retained during a stress-relief annealing process. The steel is suitable for manufacturing of wound iron core transformers.

Provided is a grain-oriented electrical steel sheet having a film that is effective for the magnetic properties of the steel sheet and particularly effective for iron loss reduction and has favorable adhesion. In a grain-oriented electrical steel sheet, an insulating film partially enters into a steel substrate to form an anchor part, a depth of the anchor part from the surface of the steel substrate is 3.5 μm or less, and a number of neck parts of 5 μm.sup.2 or less in area is 0.06/μm.sup.2 or less and a number of neck parts of 10 μm.sup.2 to 40 μm.sup.2 in area is 0.005/μm.sup.2 or more and 0.011/μm.sup.2 or less, where each neck part is a remaining part of the insulating film on the surface of the steel substrate when peeling the insulating film from the steel substrate in a bend test for the grain-oriented electrical steel sheet.

To provide a grain-oriented electrical steel sheet that has better magnetic property than conventional ones without requiring high-temperature slab heating, in the case of not performing intermediate annealing, the hot rolled steel sheet obtained by a predetermined step is subjected to hot band annealing, and, in a heating process in the hot band annealing, heating is performed at a heating rate of 10° C./s or less for 10 sec or more and 120 sec or less in a temperature range of 700° C. or more and 950° C. or less, and in the case of performing the intermediate annealing, in a heating process in final intermediate annealing, heating is performed at a heating rate of 10° C./s or less for 10 sec or more and 120 sec or less in a temperature range of 700° C. or more and 950° C. or less.