Abstract: A non-oriented electrical steel sheet has a chemical composition that includes C: not more than 0.005%, Si: 1.5-4%, Mn: 1.0-5%, P: not more than 0.1%, S: not more than 0.005%, Al: not more than 3 mass %, N: not more than 0.005 mass %, Bi: not more than 0.0030% as mass % and the remainder being Fe and inevitable impurities or a chemical composition containing C: not more than 0.005%, Si: 1.5-4%, Mn: 1.0-5%, P: not more than 0.1%, S: not more than 0.005%, Al: not more than 3 mass %, N: not more than 0.005 mass %, Bi: not more than 0.0030% and further one or two of Ca: 0.0005-0.005% and Mg: 0.0002-0.005%, and is stably excellent in the high-frequency iron loss property even if a great amount of Mn is included.

Abstract: A non-oriented electrical steel sheet having a high magnetic flux density and a low anisotropy contains C: not more than 0.01 mass %, Si: 1-4 mass %, Mn: 0.05-3 mass %, P: 0.03-0.2 mass %, S: not more than 0.01 mass %, Al: not more than 0.004 mass %, N: not more than 0.005 mass %, As: not more than 0.003 mass %, and preferably further contains one or two of Sb: 0.001-0.1 mass % and Sn: 0.001-0.1 mass % or further contains one or two of Ca: 0.001-0.005 mass % and Mg: 0.001-0.005 mass %.

Abstract: A non-oriented electrical steel sheet has a chemical composition including C: not more than 0.005 mass %, Si: 1.5-4 mass %, Mn: 1-5 mass %, P: not more than 0.1 mass %, S: not more than 0.005 mass %, Al: not more than 3 mass %, N: not more than 0.005 mass %, Pb: not more than 0.001 mass % and the remainder being Fe and inevitable impurities or a chemical composition including C: not more than 0.005 mass %, Si: 1.5-4 mass %, Mn: 1-5 mass %, P: not more than 0.1 mass %, S: not more than 0.005 mass %, Al: not more than 3 mass %, N: not more than 0.005 mass %, Pb: not more than 0.0020 mass % and further one or two of Ca: 0.0005-0.007 mass % and Mg: 0.0002-0.005 mass %, and has a stable and excellent high-frequency iron loss property even when Mn content is high.

Abstract: A steel slab having a chemical composition including C: not more than 0.005 mass %, Si: not more than 4 mass %, Mn: 0.03-2 mass %, P: not more than 0.2 mass %, S: not more than 0.004 mass %, Al: not more than 2 mass %, N: not more than 0.004 mass %, Se: not more than 0.0010 mass % and the balance being Fe and inevitable impurities is subjected to hot rolling, cold rolling and recrystallization annealing up to 740° C. at an average heating rate of not less than 100° C./s to produce a semi-processed non-oriented electrical steel sheet being high in the magnetic flux density and low in the iron loss after stress relief annealing.

Abstract: By using a hot-rolled steel sheet of a predetermined chemical composition, and annealing the hot-rolled steel sheet in nitrogen atmosphere at 1000° C. for 30 seconds, and then immersing in a solution of 7% HCl at 80° C. for 60 seconds to obtain a hot-rolled steel sheet having a pickling weight loss of 10 g/m2 or more and 35 g/m2 or less, it is possible to obtain a hot-rolled steel sheet for producing a non-oriented electrical steel sheet that not only has excellent magnetic properties such as iron loss properties and magnetic flux density, but also has reduced steel sheet surface defects and an excellent manufacturing yield.

Abstract: The pickling loss when a hot-rolled steel sheet having a predetermined chemical composition is annealed at 1000 ° C. for 30 seconds in a nitrogen atmosphere and then immersed in a solution of 7 % HCI at 80 ° C. for 60 seconds is in a range of 40 g/m2 or more and 100 g/m2 or less. A hot-rolled steel sheet for production of a non-oriented electrical steel sheet with not only excellent magnetic properties such as iron loss and magnetic flux density but also excellent recyclability and steel sheet surface appearance can thus be obtained.

Abstract: According to the present invention, a high-strength electrical steel sheet that is suitable as rotor material for a high speed motor, steadily has high strength, and also has excellent magnetic properties can be obtained by setting the chemical composition thereof to include, by mass %, C: 0.005% or less, Si: more than 3.5% and 4.5% or less, Mn: 0.01% or more and 0.10% or less, Al: 0.005% or less, Ca: 0.0010% or more and 0.0050% or less, S: 0.0030% or less, and N: 0.0030% or less, Ca/S being 0.80 or more, the balance being Fe and incidental impurities, and by setting the sheet thickness to 0.40 mm or less, the non-recrystallized deformed microstructure to 10% or more and 70% or less, tensile strength (TS) to 600 MPa or more, and iron loss W10/400 to 30 W/kg or less.

Abstract: A non-oriented electrical steel sheet has a chemical composition having C: not more than 0.005 mass %, Si: 2-7 mass %, Mn: 0.033 mass %, Al: not more than 3 mass %, P: not more than 0.2 mass %, S: not more than 0.005 mass %, N: not more than 0.005 mass %, Se: 0.0001˜0.0005 mass %, As: 0.0005˜0.005 mass % and the remainder being Fe and inevitable impurities, and an iron loss W15/50 in excitation at 50 Hz and 1.5 T of not more than 3.5 W/kg and a ratio (x/t) of amount of shear drop x (mm) to thickness t (mm) in punching of steel sheet of not more than 0.15 and is excellent in the iron loss property before punching and less in the deterioration of the iron loss property by punching.

Abstract: Provided is a method for stably obtaining a non-oriented electrical steel sheet with high magnetic flux density and excellent productivity, at a low cost by casting in a continuous casting machine a slab having a chemical composition including by mass %, C: 0.0050% or less, Si: more than 3.0% and 5.0% or less, Mn: 0.10% or less, Al: 0.0010% or less, P: more than 0.040% and 0.2% or less, N: 0.0040% or less, S: 0.0003% or more and 0.0050% or less, Ca: 0.0015% or more, and total of at least one element selected from Sn and Sb: 0.01% or more and 0.1% or less, balance including Fe and incidental impurities, subjecting the slab to heating, then subjecting the slab to hot rolling to obtain a hot rolled steel sheet, then subjecting the steel sheet to hot band annealing, pickling, subsequent single cold rolling to obtain a final sheet thickness, then subjecting the steel sheet to final annealing, wherein in the hot band annealing, soaking temperature is 900° C. or higher and 1050° C.

Abstract: A non-oriented electrical steel sheet having a high magnetic flux density and a low iron loss is produced by hot rolling a steel slab including C: not more than 0.005 mass %, Si: not more than 4 mass %, Mn: 0.03˜3 mass %, Al: not more than 3 mass %, P: 0.03˜0.2 mass %, S: not more than 0.005 mass %, N: not more than 0.005 mass %, Ca: 0.0005˜0.01 mass %, provided that an atom ratio to S (Ca (mass %)/40)/(S (mass %)/32) is within a range of 0.5˜3.5, and the balance being Fe and incidental impurities, hot band annealing, cold rolling and then conducting recrystallization annealing by heating at an average temperature rising rate of not less than 100° C./sec up to at least 740° C.

Abstract: A method produces a high strength electrical steel sheet in which a cumulative rolling reduction ratio in rough rolling is 73.0% or more, in which in a hot band annealing step, an annealing condition is selected that satisfies an area ratio of recrystallized grains after hot band annealing of 100%, and a recrystallized grain size of 80 ?m to 300 ?m, under a condition where annealing temperature is 850° C. to 1000° C., and annealing duration is 10 seconds to 10 minutes, and in which in a final annealing step, an annealing condition is selected that satisfies an area ratio of recrystallized grains after the final annealing of 30% to 95%, and a length in the rolling direction of a connected non-recrystallized grain group of 2.5 mm or less, under a condition where annealing temperature is 670° C. to 800° C., and annealing duration is 2 seconds to 1 minute.

Abstract: A non-oriented electrical steel sheet has a chemical composition including, in mass %, C: 0.005% or less, Si: 5% or less, Al: 3% or less, Mn: 5% or less, S: 0.005% or less, P: 0.2% or less, N: 0.005% or less, Mo: 0.001 to 0.04%, Ti: 0.0030% or less, Nb: 0.0050% or less, V: 0.0050% or less, Zr: 0.0020% or less, one or both of Sb and Sn: 0.001 to 0.1% in total, and the balance being iron and incidental impurities.

Abstract: A non-oriented electrical steel sheet having a high magnetic flux density in a rolling direction of the steel sheet is produced by hot rolling a raw steel material including C: not more than 0.03 mass %, Si: not more than 4 mass %, Mn: 0.03˜3 mass %, Al: not more than 3 mass %, S: not more than 0.005 mass %, N: not more than 0.005 mass % and the balance being Fe and inevitable impurities, and then cold rolling and finishing annealing to produce a non-oriented electrical steel sheet, characterized in that a crystal grain size before the cold rolling is rendered into not more than 100 ?M and the finishing annealing is conducted by rapidly heating up to a temperature exceeding recrystallization temperature at an average temperature rising rate of not less than 100° C./sec.

Abstract: A grain oriented electrical steel sheet is subjected to magnetic domain refinement by laser irradiation and has magnetic flux density B8 of at least 1.91 T, wherein the nitrogen content in the forsterite coating is 3.0 mass % or less. The grain oriented electrical steel sheet satisfies recent demand for iron loss reduction.

Abstract: A grain oriented electrical steel sheet (1) suppresses the content of Cr in the grain oriented electrical steel sheet to 0.1 mass % or less; (2) sets the coating weight of a forsterite coating, in terms of basis weight of oxygen therein, to at least 3.0 g/m2 and thickness of an anchor portion as a lower portion of forsterite coating to 1.5 ?m or less; and (3) controls setting the magnitude of deflection of a test specimen having length: 280 mm to at least 10 mm when the forsterite coating is provided on only one surface thereof and at least 20 mm when forsterite coating and the tension coating are provided on the surface.

Abstract: In a grain-oriented electrical steel sheet having phosphate-based coatings, which contain no chromium and which impart a tension, on the surfaces of a steel sheet with ceramic underlying films therebetween, the coating amount of oxygen in the underlying film is 2.0 g/m2 or more and 3.5 g/m2 or less relative to both surfaces of the steel sheet. Consequently, a grain-oriented electrical steel sheet with a chromium-less coating is provided. The resulting steel sheet has coating properties at the same level as those of a steel sheet with chromium-containing coatings and realizes high hygroscopicity resistance and a low iron loss without variations.

Abstract: In a grain-oriented electrical steel sheet having phosphate-based coatings, which contain no chromium and which impart a tension, on the surfaces of a steel sheet with ceramic underlying films therebetween, the coating amount of oxygen in the underlying film is 2.0 g/m2 or more and 3.5 g/m2 or less relative to both surfaces of the steel sheet. Consequently, a grain-oriented electrical steel sheet with a chromium-less coating is provided. The resulting steel sheet has coating properties at the same level as those of a steel sheet with chromium-containing coatings and realizes high hygroscopicity resistance and a low iron loss without variations.

Abstract: A grain oriented electrical steel sheet comprises metal part containing Si: about 2.5 to about 5.0 mass % and Cr: about 0.05 to about 1.0 mass %, and an insulation coating formed on a surface of the metal part. A tension imparted to the metal part in the rolling direction by the insulation coating is not smaller than about 3.0 MPa. Magnetic flux density B8 satisfies a specific relation formula. A plurality of linear strains or grooves are formed in a surface of the steel sheet and linearly extended at an angle of not larger than about 45° (in each direction) relative to a direction perpendicular to a rolling direction such that an interval D of the linear strains or grooves satisfies a specific relation formula depending on the Cr content. A grain oriented electrical steel sheet is thereby obtained which has lower iron loss after domain refining treatment than conventional values.

Abstract: Grain-oriented silicon steel sheet with Bi as an auxiliary inhibitor and a forsterite coating film having a Cr spinel oxide subscale of FeCr2O4 or FexMn1-xCr2O4 (0.6≦x≦1), made from a steel slab containing 0.005-0.20 wt % of Bi and 0.1-1.0 wt % of Cr.

Abstract: A grain oriented electrical steel sheet comprises metal part containing Si: about 2.5 to about 5.0 mass % and Cr: about 0.05 to about 1.0 mass %, and an insulation coating formed on a surface of the metal part. A tension imparted to the metal part in the rolling direction by the insulation coating is not smaller than about 3.0 MPa. Magnetic flux density B8 satisfies a specific relation formula. A plurality of linear strains or grooves are formed in a surface of the steel sheet and linearly extended at an angle of not larger than about 45° (in each direction) relative to a direction perpendicular to a rolling direction such that an interval D of the linear strains or grooves satisfies a specific relation formula depending on the Cr content. A grain oriented electrical steel sheet is thereby obtained which has lower iron loss after domain refining treatment than conventional values.