Abstract: An electrical steel sheet has a component composition including, by mass %, C: 0.007% or less, Si: 4% to 10%, and Mn: 0.005% to 1.0%, the balance being Fe and incidental impurities, as well as a sheet thickness within a range of 0.01 mm or more to 0.10 mm or less, and a profile roughness. Pa of 1.0 ?m or less. The electrical steel sheet exhibits excellent iron loss properties whereby the magnetic property is free from deterioration, and degradation of the stacking factor can be avoided, even when the steel sheet with a thickness of 0.10 mm or less has been subjected to siliconizing treatment to increase the Si content in the steel.

Abstract: A treatment solution for an insulation coating of grain-oriented electrical steel sheets includes at least one selected from phosphates of Mg, Ca, Ba, Sr, Zn, Al and Mn; colloidal silica in a proportion of 0.5 to 10 mol in terms of SiO2; and a water-soluble vanadium compound in a proportion of 0.1 to 2.0 mol in terms of V, relative to PO4:1 mol in the phosphates.

Abstract: A treatment solution for insulation coating for grain-oriented electrical steel sheets contains at least one selected from phosphates of Mg, Ca, Ba, Sr, Zn, Al, and Mn; colloidal silica in a proportion of 0.5 to 10 mol in terms of SiO2 and a water-soluble vanadium compound in a proportion of 0.1 to 2.0 mol in terms of V, relative to PO4:1 mol in the phosphates.

Abstract: A grain oriented electrical steel sheet has grooves on one surface of the steel sheet formed for magnetic domain refining, the steel sheet including a forsterite film and a tension coating on front and back surfaces of the steel sheet, wherein the tension coating is applied on a surface with the grooves in a coating amount A (g/m2) and is applied on a surface with no grooves in a coating amount B (g/m2), the coating amounts A and B satisfying (1) and (2): 3?A?8??(1); and 1.0<B/A?1.8??(2).

Abstract: A treatment solution for an insulation coating for a grain oriented electrical steel sheet includes at least one member selected from phosphates of Mg, Ca, Ba, Sr, Zn, Al, and Mn, and colloidal silica in a proportion of 0.5 to 10 mol in terms of SiO2 and at least one member selected from permanganates of Mg, Sr, Zn, Ba, and Ca in a proportion of 0.02 to 2.5 mol in terms of metal elements in the permanganates, relative to PO4:1 mol in the phosphates.

Abstract: A grain oriented electrical steel sheet has grooves on one surface of the steel sheet formed for magnetic domain refining, the steel sheet including a forsterite film and a tension coating on front and back surfaces of the steel sheet, wherein the tension coating is applied on a surface with the grooves in a coating amount A (g/m2) and is applied on a surface with no grooves in a coating amount B (g/m2), the coating amounts A and B satisfying (1) and (2): 3?A?8??(1); and 1.0<B/A?1.8??(2).

Abstract: A grain oriented electrical steel sheet has sufficiently low iron loss and having less conventionally-concerned warpage of the steel sheet even after the steel sheet is subjected to artificial magnetic domain refining treatment, where strain-introducing treatment is conducted with high energy so that an iron loss-reducing effect can be maximized. The grain oriented electrical steel sheet is obtained by adjusting tension to be applied to a tension-applying insulating coating, or to both surfaces of the steel sheet by the tension-applying insulating coating, before strain-introducing treatment in the range of Formula (1): 1.0?(tension applied to non-strain-introduced surface)/(tension applied to strain-introduced surface)?2.0??(1), and by controlling the amount of warpage of the steel sheet toward the strain-introduced surface side after strain-introducing treatment in the range of 1 mm or more and 10 mm or less.

Abstract: The present invention provides a method for manufacturing a grain oriented electrical steel sheet, including preparing as a material a steel slab having a predetermined composition and carrying out at least two cold rolling operations, characterized in that a thermal treatment is carried out, prior to any one of cold rolling operations other than final cold rolling, at temperature in the range of 500° C. to 750° C. for a period in the range of 10 minutes to 480 hours. The grain oriented electrical steel sheet of the present invention exhibits through utilization of austenite-ferrite transformation superior magnetic properties after secondary recrystallization.

Abstract: A treatment solution for insulation coating for grain oriented electrical steel sheet includes at least one member selected from phosphates of Mg, Ca, Ba, Sr, Zn, Al, and Mn, and colloidal silica in a proportion of 0.2 to 10 mol in terms of SiO2 and a titanium chelate compound in a proportion of 0.01 to 4.0 mol in terms of Ti, relative to PO4: 1 mol in the phosphates.

Abstract: The present invention provides a grain-oriented electrical steel sheet produced by a method for promoting secondary recrystallization without an inhibitor, the grain-oriented electrical steel sheet including 2.0% or more and 4.5% or less of Si and 0.01% or more and 0.5% or less of Mn on a mass % basis, wherein the number of oxide particles having a diameter of 1 to 3 ?m among that (oxide particles) of containing Ca and/or Mg is 400 or less per unit area (1 cm2) in a transverse cross-section perpendicular to a rolling direction. Therefore, the grain-oriented electrical steel sheet has excellent stable magnetic properties throughout the length of a coil.

Abstract: A treatment solution for insulation coating for grain-oriented electrical steel sheets contains at least one selected from phosphates of Mg, Ca, Ba, Sr, Zn, Al, and Mn; colloidal silica in a proportion of 0.5 to 10 mol in terms of SiO2 and a water-soluble vanadium compound in a proportion of 0.1 to 2.0 mol in terms of V, relative to PO4:1 mol in the phosphates.

Abstract: A treatment solution for an insulation coating for a grain oriented electrical steel sheet includes at least one member selected from phosphates of Mg, Ca, Ba, Sr, Zn, Al, and Mn, and colloidal silica in a proportion of 0.5 to 10 mol in terms of SiO2 and at least one member selected from permanganates of Mg, Sr, Zn, Ba, and Ca in a proportion of 0.02 to 2.5 mol in terms of metal elements in the permanganates, relative to PO4:1 mol in the phosphates.

Abstract: A treatment solution for insulation coating for grain oriented electrical steel sheet includes at least one member selected from phosphates of Mg, Ca, Ba, Sr, Zn, Al, and Mn, and colloidal silica in a proportion of 0.2 to 10 mol in terms of SiO2 and a titanium chelate compound in a proportion of 0.01 to 4.0 mol in terms of Ti, relative to PO4: 1 mol in the phosphates.

Abstract: The present invention provides a grain-oriented electrical steel sheet produced by a method for promoting secondary recrystallization without an inhibitor, the grain-oriented electrical steel sheet including 2.0% or more and 4.5% or less of Si and 0.01% or more and 0.5% or less of Mn on a mass % basis, wherein the number of oxide particles having a diameter of 1 to 3 ?m among that (oxide particles) of containing Ca and/or Mg is 400 or less per unit area (1 cm2) in a transverse cross-section perpendicular to a rolling direction. Therefore, the grain-oriented electrical steel sheet has excellent stable magnetic properties throughout the length of a coil.

Abstract: When a non-oriented electrical steel sheet is manufactured, simultaneously having superior magnetic properties and high strengths, a composition containing 0.02% or less of C, 4.5% or less of Si, 5.0% or less (including 0) of Ni, and 0.2% to 4.0% of Cu is used, and a solute Cu is allowed to appropriately remain in finish annealing. In the steel sheet thus obtained, finely shaped Cu is precipitated by aging treatment, and while the magnetic properties are not degraded, the yield stress is increased to not less than CYS (MPa) represented by the following formula: note CYS=180+5,600[% C]+95[% Si]+50[% Mn]+37[% Al]+435[% P]+25[% Ni]+22d?1/2 where d is an average grain diameter (mm) of crystal grains.

Abstract: In a method for manufacturing a grain-oriented electrical steel sheet using steel containing less than 100 ppm of Al and 50 ppm or less each of N, S, and Se as a starting material, purification annealing is performed at 1050° C. or more, the partial pressure of hydrogen in the atmosphere being adjusted to 0.4 atm or less in a temperature range above 1170° C. for a purification annealing conducted at a temperature above 1170° C., or 0.8 atm or less in a temperature range of 1050° C. or more for a purification annealing conducted at a temperature of 1170° C. or less, to prevent deterioration of the bend properties due to the impurities.

Abstract: When a non-oriented electrical steel sheet is manufactured, simultaneously having superior magnetic properties and high strengths, a composition containing 0.02% or less of C, 4.5% or less of Si, 5.0% or less (including 0) of Ni, and 0.2% to 4.0% of Cu is used, and a solute Cu is allowed to appropriately remain in finish annealing. In the steel sheet thus obtained, finely shaped Cu is precipitated by aging treatment, and while the magnetic properties are not degraded, the yield stress is increased to not less than CYS (MPa) represented by the following formula: note CYS=180+5,600[% C]+95[% Si]+50[% Mn]+37[% Al]+435[% P]+25[% Ni]+22d?1/2 where d is an average grain diameter (mm) of crystal grains.

Abstract: In a method for manufacturing a grain-oriented electrical steel sheet using steel containing less than 100 ppm of Al and 50 ppm or less each of N, S, and Se as a starting material, purification annealing is performed at 1050° C. or more, the partial pressure of hydrogen in the atmosphere being adjusted to 0.4 atm or less in a temperature range above 1170° C. for a purification annealing conducted at a temperature above 1170° C., or 0.8 atm or less in a temperature range of 1050° C. or more for a purification annealing conducted at a temperature of 1170° C. or less, to prevent deterioration of the bend properties due to the impurities.

Abstract: A method of manufacturing a grain-oriented steel sheet including hot-rolling a slab prepared using molten steel containing, by mass %, C of not more than about 0.08%, Si of about 2.0 to about 8.0% and Mn of about 0.005 to about 3.0%; optionally annealing the hot-rolled steel sheet; performing cold rolling once, or twice or more with intermediate annealing therebetween; performing primary recrystallization annealing in a low- or non-oxidizative atmosphere and adjusting the C content in the steel sheet after primary recrystallization annealing to be held in the range of about 0.005 to about 0.025 mass %; performing secondary recrystallization annealing; decarburization annealing; and, preferably, performing additional high-temperature continuous or batch annealing. A grain-oriented electrical steel sheet having a sufficiently high magnetic flux density and a low iron loss can be advantageously obtained even when it is manufactured without using an inhibitor.

Abstract: The invention is a grain-oriented magnetic steel sheet having extremely low iron loss, suitable for use as an iron core material for transformers and power generators, and a method for producing the same. The method includes forming a coating layer on a surface of a steel sheet having a thickness of 0.27 mm or less by vapor deposition in a low oxidizing atmosphere with an oxygen partial pressure (Po2) of less than 0.1 atm and a total pressure of 0.1 atm or more. The steel sheet has extremely low iron loss with a thickness of 0.27 mm or less and includes a coating layer formed by vapor deposition on a matrix surface.