Abstract: With a hot-rolled steel sheet for electrical steel sheet production having a scale layer on the surface, where the surface of the steel sheet has a lightness L* as defined in JIS Z 8781-4: 2013 satisfying 30?L*?50, and chromaticities a* and b* as defined in JIS Z 8781-4: 2013 satisfying ?1?a*?2 and ?5?b*?3 respectively, and with one end portion in the longitudinal direction of a coil as a reference, a color difference ?Eab* as defined in JIS Z 8781-4: 2013 at the central portion and at the opposite end portion satisfies ?Eab*?8, it is possible to obtain a grain-oriented electrical steel sheet where the variation of properties in a product coil is small.

Abstract: Provided is a method for manufacturing a grain-oriented electrical steel sheet. A steel slab having a specific chemical composition is heated and hot rolled. A hot-rolled steel sheet thus obtained is subjected to hot band annealing to obtain a cold-rolled steel sheet, which is then subjected to primary recrystallization annealing to obtain a primary recrystallized steel sheet. An annealing separator is applied to the primary recrystallized steel sheet, which is then coiled. The coil is subjected to secondary recrystallization annealing to obtain a grain-oriented electrical steel sheet having an average value of a deviation angle (?2+?2)1/2 calculated from a deviation angle ? from ideal Goss orientation around an ND rotation axis and a deviation angle ? from ideal Goss orientation around a TD rotation axis of 4.5° or less, and an area ratio R? of crystal grains with ??0.50° of 15% or less.

Abstract: Provided is a grain-oriented electrical steel sheet that has excellent magnetic properties and can be manufactured by secondary recrystallization orientation control using coil annealing with high productivity. A grain-oriented electrical steel sheet comprises a specific chemical composition, wherein an average value of a deviation angle (?2+?2)1/2 calculated from a deviation angle ? from ideal Goss orientation around an ND rotation axis and a deviation angle ? from ideal Goss orientation around a TD rotation axis is 5.0° or less, and an area ratio R? of crystal grains with ??0.50° is 20% or less.

Abstract: To improve and stabilize magnetic properties, a steel sheet is soaked in a temperature range of 1000° C. or more and 1120° C. or less for 200 sec or less and then soaked in a temperature range of 650° C. or more and 1000° C. or less for 200 sec or less in annealing before final cold rolling, and the amount of Al in precipitates after the annealing before the final cold rolling is limited to 50% or more of the total amount of Al contained in the steel slab.

Abstract: In a production of a grain-oriented electrical steel sheet by subjecting a steel slab containing a particular composition and further including an inhibitor-forming ingredient to hot rolling, hot-band annealing, cold rolling, primary recrystallization annealing combined with decarburization annealing and finish annealing, the steel slab satisfies a given relation between a content ratio of sol. Al to N and a final sheet thickness, and, in the finish annealing, the steel sheet is kept at a temperature zone of higher than 850° C. but not higher than 950° C. in heating process for 5 to 200 hours, heated to a temperature zone of 950 to 1050° C. at 5 to 30° C./hr and further subjected to purification treatment of keeping a temperature of not lower than 1100° C. for not less than 2 hours to provide a secondary recrystallization structure that has an average value of a diameter equivalent to a circle of 10 to 100 mm.

Abstract: Provided is a method of producing a hot-rolled steel sheet for a grain-oriented electrical steel sheet. The method comprising: preparing a steel slab having a chemical composition containing, by mass %, C: 0.002% or more and 0.080% or less, Si: 2.00% or more and 8.00% or less, Mn: 0.02% or more and 0.50% or less, acid-soluble Al: 0.003% or more and less than 0.010%, and at least one of S or Se: 0.001% or more and 0.010% or less in total, with N limited to less than 0.006%, and the balance being Fe and inevitable impurities; heating the steel slab to 1300° C. or lower; and subjecting the steel slab to hot rolling, wherein a friction coefficient in final pass of the hot rolling is 0.35 or less.

Abstract: 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.

Abstract: 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 ?m or less, and a number of neck parts of 5 ?m2 or less in area is 0.06/?m2 or less and a number of neck parts of 10 ?m2 to 40 ?m2 in area is 0.005/?m2 or more and 0.011/?m2 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.

Abstract: 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.

Abstract: In a grain-oriented electrical steel sheet which is manufactured from a thin slab without using an inhibitor forming component, excellent magnetic properties are stably achieved. In a method for manufacturing a grain-oriented electrical steel sheet, a slab heating and annealing are performed under specific conditions.

Abstract: In the production of a grain-oriented electrical steel sheet by hot rolling a slab containing Si: 2.0-8.0 mass % and no inhibitor-forming ingredients, cold rolling, subjecting to a decarburization annealing, applying an annealing separator composed mainly of MgO and containing a Ti compound(s) and subjecting to a finish annealing, an atmosphere in the heating process of the decarburization annealing is rendered into a dry atmosphere having a dew point of not higher than 0° C. and a Ti amount (Ti(a)) and a N amount (N(a)) contained in an iron matrix after the removal of a forsterite coating and a Ti amount (Ti(b)) and a N amount (N(b)) contained in the steel sheet having a forsterite coating are made to satisfy relationships as N(b)?0.0050 mass %, N(b)/N(a)?4, and Ti(b)/Ti(a)?4.

Abstract: Provided are a grain-oriented electrical steel sheet with low iron loss even when including at least one grain boundary segregation element among Sb, Sn, Mo, Cu, and P, and a method for manufacturing the same. In our method, Pr is controlled to satisfy Pr??0.075T+18, where T>10, 5<Pr, T (hr) is the time required after final annealing to reduce the temperature of a secondary recrystallized sheet from 800° C. to 400° C., and Pr (MPa) is the line tension on the secondary recrystallized sheet during flattening annealing. As a result, a grain-oriented electrical steel sheet in which iron loss is low and a dislocation density near crystal grain boundaries of the steel substrate is 1.0×1013 m?2 or less can be obtained even when the grain-oriented electrical steel sheet contains at least one of Sb, Sn, Mo, Cu, and P.

Abstract: The disclosure contains, in mass % or mass ppm: C: 0.005% or less, Si: 2.0% to 5.0%, Mn: 0.01% to 0.5%, sol.Al: 10 ppm or less, N: 15 ppm or less, S and Se: each 10 ppm or less, and three or more selected from Sn, Sb, Cr, P, Mo and B whose contents satisfy a relational expression of 0.16?[% Sn]+[% Sb]+[% Cr]+2×[% P]+[% Mo]+[% B]?0.50, the balance being Fe and inevitable impurities, where a number of times of repeated bending in a bend test is 10 or more.

Abstract: In a production of a grain-oriented electrical steel sheet by subjecting a steel slab containing a particular composition and further including an inhibitor-forming ingredient to hot rolling, hot-band annealing, cold rolling, primary recrystallization annealing combined with decarburization annealing and finish annealing, the steel slab satisfies a given relation between a content ratio of sol. Al to N and a final sheet thickness, and, in the finish annealing, the steel sheet is kept at a temperature zone of higher than 850° C. but not higher than 950° C. in heating process for 5 to 200 hours, heated to a temperature zone of 950 to 1050° C. at 5 to 30° C./hr and further subjected to purification treatment of keeping a temperature of not lower than 1100° C. for not less than 2 hours to provide a secondary recrystallization structure that has an average value of a diameter equivalent to a circle of 10 to 100 mm.

Abstract: In a grain-oriented electrical steel sheet which is manufactured from a thin slab without using an inhibitor forming component, excellent magnetic properties are stably achieved. In a method for manufacturing a grain-oriented electrical steel sheet, a slab heating and annealing are performed under specific conditions.

Abstract: Excellent magnetic properties can be stably obtained in grain-oriented electrical steel sheets produced from thin slabs without using inhibitor forming components. Provided is a method for producing a grain-oriented electrical steel sheet comprising: subjecting a molten steel to continuous casting to form a slab with 25 to 100 mm in thickness, the molten steel having a chemical composition containing, in mass %, C: 0.002 to 0.100%, Si: 2.00 to 8.00%, Mn: 0.005 to 1.000%, Al: <0.0100%, N: <0.0050%, S: <0.0050% and Se: <0.0050%, and the balance being Fe and inevitable impurities; heating and then hot rolling the slab to form a hot-rolled steel sheet; wherein the step of heating the slab is performed at 1000 to 1300° C. for 10 to 600 seconds.

Abstract: 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.

Abstract: Excellent magnetic properties can be stably obtained in grain-oriented electrical steel sheets produced from thin slabs without using inhibitor forming components. Provided is a method for producing a grain-oriented electrical steel sheet comprising: subjecting a molten steel to continuous casting to form a slab with 25-100 mm in thickness, the molten steel having a chemical composition containing, in mass %, C: 0.002-0.100%, Si: 2.00-8.00% and Mn: 0.005-1.000%, Al: <0.0100%, N: <0.0050%, S: <0.0050% and Se: <0.0050%, and the balance being Fe and inevitable impurities; heating and then hot rolling the slab to form a hot-rolled steel sheet; wherein the step of heating the slab is performed at 1000-1300° C. for 10-600 seconds, and the hot rolling is started within 30 seconds after the heating.

Abstract: With a hot-rolled steel sheet for electrical steel sheet production having a scale layer on the surface, where the surface of the steel sheet has a lightness L* as defined in JIS Z 8781-4: 2013 satisfying 30?L*?50, and chromaticities a* and b* as defined in JIS Z 8781-4: 2013 satisfying ?1?a*?2 and ?5?b*?3 respectively, and with one end portion in the longitudinal direction of a coil as a reference, a color difference ?Eab* as defined in JIS Z 8781-4: 2013 at the central portion and at the opposite end portion satisfies ?Eab*?8, it is possible to obtain a grain-oriented electrical steel sheet where the variation of properties in a product coil is small.

Abstract: Provided is a grain-oriented electrical steel sheet that has excellent magnetic properties and can be manufactured by secondary recrystallization orientation control using coil annealing with high productivity. A grain-oriented electrical steel sheet comprises a specific chemical composition, wherein an average value of a deviation angle (?2+?2)1/2 calculated from a deviation angle ? from ideal Goss orientation around an ND rotation axis and a deviation angle ? from ideal Goss orientation around a TD rotation axis is 5.0° or less, and an area ratio R? of crystal grains with ??0.50° is 20% or less.