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: 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: 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: 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: When a grain-oriented electrical steel sheet is produced by heating a steel slab containing, by mass %, C: 0.020 to 0.10%, Si: 2.0 to 4.0%, Mn: 0.005 to 0.50%, Al: less than 0.010%, N, S and Se: less than 0.0050% each to a temperature of not higher than 1280° C., subjecting slab to hot rolling, hot-band annealing, single cold rolling or two or more cold rollings having intermediate annealing between each cold rolling and a primary recrystallization annealing combined with decarburization annealing, applying annealing separator onto steel sheet surface, and subjecting steel sheet to 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 cooling process from maximum achieving temperature in at least one of hot band annealing and intermediate annealing, whereby grain-oriented electrical steel sheet having excellent magnetic properties is stably produced.

Abstract: To provide a grain-oriented electrical steel sheet that has better magnetic property than conventional ones, in hot band annealing of the hot rolled steel sheet obtained by a predetermined step, an average heating rate from ordinary temperature to 400° C. is set to 50° C./s or more, and a time to reach 900° C. from 400° C. is set to 100 sec or less.

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: A grain-oriented electrical steel sheet has magnetic properties improved over conventional grain-oriented electrical steel sheets. A method of producing a grain-oriented electrical steel sheet comprises: heating a steel slab at 1300° C. or less, the steel slab having a chemical composition containing C, Si, Mn, acid-soluble Al, S and/or Se, Sn and/or Sb, N, and a balance being Fe and inevitable impurities; subjecting the steel slab to hot rolling to obtain a hot rolled steel sheet; subjecting the hot rolled steel sheet to cold rolling once, or twice or more with intermediate annealing performed therebetween, to obtain a cold rolled steel sheet with a final sheet thickness; subjecting the cold rolled steel sheet to primary recrystallization annealing; applying an annealing separator to a surface of the cold rolled steel sheet after the primary recrystallization annealing; and then subjecting the cold rolled steel sheet to secondary recrystallization annealing.

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: To provide a grain-oriented electrical steel sheet that has better magnetic property than conventional ones, in hot band annealing of the hot rolled steel sheet obtained by a predetermined step, an average heating rate from ordinary temperature to 400° C. is set to 50° C./s or more, and a time to reach 900° C. from 400° C. is set to 100 sec or less.