Abstract: A non-oriented electrical steel sheet having: low high-frequency iron loss and high magnetic flux density; an inner layer and surface layers provided on both sides of the inner layer, the surface layers and the inner layer having specific chemical compositions; the thickness t of 0.01 mm to 0.35 mm; a multilayer ratio of ti to t of 0.10 to 0.70, t1 denoting a total thickness of the surface layers; a difference between [Si]1 and [Si]0 of 1.0 mass % to 4.5 mass % or less, [Si]1 denoting a Si content in each of the surface layers and [Si]0 denoting a Si content in the inner layer; and a difference between [Mn]0 and [Mn]1 of 0.01 mass % to 0.40 mass %, [Mn]0 denoting a Mn content at a mid-thickness position t/2 and [Mn]1 denoting an average Mn content in a region from a surface to a position at a depth of ( 1/10)t.

Abstract: 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 ? of not less than 0.030 and a rolling reduction of not less than 15%.

Abstract: Provided is a multilayer electrical steel sheet having both low high-frequency iron loss and high magnetic flux density. The multilayer electrical steel sheet has an inner layer and surface layers provided on both sides of the inner layer, in which each of the surface layers has a Si content of 2.5 mass % to 6.0 mass %, the inner layer has a Si content of 1.5 mass % to 5.0 mass %, and the multilayer electrical steel sheet has: ?Si of 0.5 mass % or more; ?Al of 0.05 mass % or less; ??1.0/400 of 1.0×10?6 or less; a sheet thickness t of 0.03 mm to 0.3 mm; and a ratio of a total thickness of the surface layers ti to t of from 0.10 to 0.70.

Abstract: Provided is a multilayer electrical steel sheet having low high-frequency iron loss and high magnetic flux density. The multilayer electrical steel sheet has an inner layer and surface layers provided on both sides of the inner layer, in which the surface layers and inner layer have predetermined chemical compositions, the multilayer electrical steel sheet having: ?Si of 0.5 mass % or more, ?Si being defined as a difference between a Si content in the surface layer [Si]1 and a Si content in the inner layer [Si]0 represented by [Si]1?[Si]0; ??1.0/400 of 1.0×10?6 or less, ??1.0/400 being defined as an absolute value of the difference between a magnetostriction of the surface layer ?1.0/400,1 and a magnetostriction of the inner layer ?1.0/400,0; a sheet thickness t of 0.03 mm to 0.3 mm, and a ratio of a total thickness of the surface layers t1 to t of from 0.10 to 0.70.

Abstract: According to the disclosure, it is possible to increase the magnetic flux density and reduce iron loss by setting a chemical composition containing, by mass %, C: 0.0050% or less, Si: 1.50% or more and 4.00% or less, Al: 0.500% or less, Mn: 0.10% or more and 5.00% or less, S: 0.0200% or less, P: 0.200% or less, N: 0.0050% or less, O: 0.0200% or less, and at least one of Sb: 0.0010% or more and 0.10% or less, and Sn: 0.0010% or more and 0.10% or less, with the balance being Fe and inevitable impurities, an Ar3 transformation temperature of 700° C. or higher, a grain size of 80 ?m or more and 200 ?m or less, and a Vickers hardness of 140 HV or more and 230 HV or less.

Abstract: In a production of a non-oriented electrical steel sheet comprising subjecting a slab containing a particular composition to a hot rolling, a hot-band annealing, a cold rolling to form a cold-rolled sheet and a finish annealing, a rolling reduction of a final finish rolling pass in the hot rolling is not less than 10%, and a coiling temperature is not higher than 620° C., and a soaking temperature in the finish annealing is 600 to 800° C. to achieve such properties that a recrystallization ratio is less than 100% as an area ratio, a strength C is not less than 2.0 and a strength difference C-D is not more than 2.0, where C is a strength at ?=0° and ?1=0° and D is a strength at ?=20° and ?1=0° in a section of ?2=45° of ODF obtained in a central layer of a sheet thickness.

Abstract: A non-oriented electrical steel sheet having high magnetic flux density and a low iron loss at a high frequency is produced by subjecting a slab containing, in mass %, C: not more than 0.0050%, Si: 2.8 to 6.5%, Mn: 0.05 to 2.0%, P: not more than 0.10%, S: not more than 0.0050%, Al: 0.3 to 2.0%, N: not more than 0.0050% and Zn: 0.0005 to 0.0050% to a hot rolling, a hot-band annealing, a cold rolling and a finish annealing, a dew point in the hot-band annealing is set to 0 to 70 ° C. and an atmosphere of the finish annealing has a nitrogen content of not more than 30 vol % and a dew point of not higher than ?20° C., and a ratio of the amount of nitrogen present as AlN in an entire sheet thickness to the amount of nitrogen present as AlN in a layer from one-side surface of steel sheet to a depth of 1/20 of sheet thickness is made to not less than 5.0.

Abstract: Proposed is a non-oriented electrical steel sheet being low in iron loss and excellent in tensile strength and fatigue strength, which has a chemical composition comprising C: not more than 0.005 mass %, Si: 3 to 5 mass %, Mn: not more than 5 mass %, P: not more than 0.1 mass %, S: not more than 0.01 mass %, Al: not more than 3 mass %, N: not more than 0.005 mass %, Zn: 0.0005 mass % to 0.003 mass %, and the remainder being Fe and inevitable impurities, an average crystal grain size being not more than 40 ?m, the number of the inclusions having a diameter of not less than 5 ?m being not more than 5/mm2, a tensile strength being not less than 600 MPa, and the fatigue strength being not less than 450 MPa.

Abstract: A method for producing a non-oriented electrical steel sheet by hot rolling a steel slab having a chemical composition including C: not more than 0.0050 mass %, Si: not more than 4.0 mass %, Mn: 0.03-3.0 mass %, P: not more than 0.1 mass %, Se: not more than 0.0010 mass %, Al: not more than 3.0 mass %, Ni: not more than 3.0 mass %, Cr: not more than 5.0 mass %, Ti: not more than 0.003 mass %, and Nb: not more than 0.003 mass % and subjecting the sheet to hot band annealing if necessary, a cold rolling, and further a finish annealing, wherein the heating in the finish annealing is conducted in two stages of performing induction heating and subsequently a radiation heating and a zone from 600° C. to 740° C. in the induction heating is heated at an average heating rate of not less than 50° C./sec, whereby a high magnetic flux density can be obtained stably.

Abstract: To stably improve the magnetic flux density by utilizing induction heating and radiant heating during final annealing of a non-oriented electrical steel sheet. A method of manufacturing a non-oriented electrical steel sheet, including subjecting a slab having a predetermined chemical composition to hot rolling with or without performing hot-rolled sheet annealing, and then to cold rolling either once, or twice or more with intermediate annealing performed therebetween, and then to final annealing, where a material before final cold rolling has a recrystallization ratio of less than 80% and a {100}<011> intensity of 8 or less in a ¼ layer, and in the final annealing, an average heating rate from 600° C. to 720° C. is 50° C./s or higher, and an average heating rate from 720° C. to 760° C. is 5° C./s or higher.

Abstract: 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): ( 8 ? 0 ? 0 ? 0 + 400 × Si ? ( mass ? ? % ) ) { ( - log ? ( Al ? ( mass ? ? % ) × N ? ( mass ? ? % ) ) + 1.7 + 0.2 × Si ? ( mass ? ? % ) } - 2 ? 7 ? 3 . 1 ? 5 ? T ? 1200 , ( 1 ) 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.

Abstract: A non-oriented electrical steel sheet with an average magnetostriction ?p-p at 400 Hz and 1.0 T of not more than 4.5×10?6, and area ratio of recrystallized grains at a section in rolling direction of steel sheet of 40 to 95% and an average grain size of 10 to 40 ?m is obtained by subjecting a steel slab containing, in mass %, C: not more than 0.005%, Si: 2.8 to 6.5%, Mn: 0.05 to 2.0%, Al: not more than 3.0%, P: not more than 0.20%, S: not more than 0.005%, N: not more than 0.005%, Ti: not more than 0.003%, V: not more than 0.005% and Nb: not more than 0.005% and satisfying Si-2Al-Mn?0 to hot rolling, hot-band annealing, cold rolling and finish annealing under adequate cold rolling and finish annealing conditions, and a motor core is manufactured by such a steel sheet.

Abstract: Provided is a non-oriented electrical steel sheet that contains substantially no Al and contains large amounts of Si and Mn and has low iron loss, comprising a chemical composition containing C: 0.0050% or less, Si: 2.0% or more and 6.0% or less, Mn: 1.0% or more and 3.0% or less, P: 0.20% or less, S: 0.0050% or less, N: 0.0050% or less, Al: 0.0050% or less, and one or more selected from B: 0.0001% or more and 0.0050% or less, Nb: 0.0001% or more and 0.0050% or less, and V: 0.0005% or more and 0.0500% or less, with a balance consisting of Fe and inevitable impurities, wherein a number density of Si—Mn nitrides with an average diameter of 50 nm or more and 500 nm or less is 1 or less per ?m3.

Abstract: Disclosed is a non-oriented electrical steel sheet low in iron loss that is substantially free of Al and contains large amounts of Si and Mn. The disclosed non-oriented electrical steel sheet has a chemical composition containing C: 0.0050% or less, Si: 2.0% to 6.0%, Mn: 1.0% to 3.0%, P: 0.20% or less, S: 0.0050% or less, N: 0.0050% or less, and Al: 0.0050 % or less, with the balance being Fe and inevitable impurities, in which Si—Mn nitrides having an average diameter of 50 nm to 500 nm has a number density of 1/?m3 or less.

Abstract: There are provided a method for producing a non-oriented electrical steel sheet, a method for manufacturing a motor core from such a steel sheet, and a motor core. In the production of a non-oriented electrical steel sheet by subjecting a steel slab containing given amounts of C, Si, Mn, P, S, Al, N, Ti, Nb and V, provided that Si, Al and Mn satisfy Si-2Al—Mn?0, to hot rolling, cold rolling, finish annealing and stress relief annealing, whereby a high-strength rotor core and a stator core having excellent magnetic properties after stress relief annealing can be obtained from the same steel material.

Abstract: A method of producing a non-oriented electrical steel sheet by hot rolling and cold rolling a steel slab comprising by mass % C: not more than 0.0050%, Si: 2-7%, Mn: 0.05-2.0%, P: not more than 0.2%, S: not more than 0.005%, Al: not more than 3%, N: not more than 0.005%, Ti: not more than 0.003%, Nb: not more than 0.005% and V: not more than 0.005% and then subjecting to a finish annealing and a stress-relief annealing, conditions of the finish annealing and stress-relief annealing are adjusted so that a yield stress of the steel sheet after the finish annealing is not less than 400 MPa and a ratio of a magnetic flux density B50S of the steel sheet after the stress-relief annealing to a magnetic flux density B50H after the finish annealing is not less than 0.99.

Abstract: Iron loss is reduced by increasing magnetic flux density. Disclosed is a non-oriented electrical steel sheet has a chemical composition containing, by mass %, C: 0.0050% or less, Si: 1.50% or more and 4.00% or less, Al: 0.500% or less, Mn: 0.10% or more and 5.00% or less, S: 0.0200% or less, P: 0.200% or less, N: 0.0050% or less, O: 0.0200% or less, and Ca: 0.0010% or more and 0.0050% or less, with the balance being Fe and inevitable impurities, in which the non-oriented electrical steel sheet has an Ar3 transformation temperature of 700° C. or higher, a grain size of 80 ?m or more and 200 ?m or less, and a Vickers hardness of 140 HV or more and 230 HV or less.

Abstract: A non-oriented electrical steel sheet produced by hot rolling a steel slab containing, by mass %, C: not more than 0.0050, Si: 3.2 to 4.5%, Mn: 0.1 to 2.0%, P: not more than 0.020%, As: not more than 0.0030%, Sn+Sb: 0.005 to 0.10%, and one or two elements selected from Mo and W by a content ranging from 0.0020 to 0.10% in total, subjecting the resultant steel sheet to one cold rolling or two or more cold rollings including an intermediate annealing therebetween to achieve a final sheet thickness, and then subjecting the cold rolled sheet to finish annealing, a N2 content in an atmosphere in the finish annealing is set to not more than 20 vol %, and average strain rate in the first pass is set to not more than 4/sec, allowing the cold rolling property to improve with no degradation in magnetic property and no decrease in productivity.

Abstract: Provided is a multilayer electrical steel sheet having both low high-frequency iron loss and high magnetic flux density. The multilayer electrical steel sheet has an inner layer and surface layers provided on both sides of the inner layer, in which each of the surface layers has a Si content of 2.5 mass % to 6.0 mass %, the inner layer has a Si content of 1.5 mass % to 5.0 mass %, and the multilayer electrical steel sheet has: ?Si of 0.5 mass % or more; ?Al of 0.05 mass % or less; ??1.0/400 of 1.0×10?6 or less; a sheet thickness t of 0.03 mm to 0.3 mm; and a ratio of a total thickness of the surface layers ti tot of from 0.10 to 0.70.

Abstract: Provided is a multilayer electrical steel sheet having low high-frequency iron loss and high magnetic flux density. The multilayer electrical steel sheet has an inner layer and surface layers provided on both sides of the inner layer, in which the surface layers and inner layer have predetermined chemical compositions, the multilayer electrical steel sheet having: ?Si of 0.5 mass % or more, ?Si being defined as a difference between a Si content in the surface layer [Si]1 and a Si content in the inner layer [Si]0 represented by [Si]1?[Si]0; ??1.0/400 of 1.0×10?6 or less, ??1.0/400 being defined as an absolute value of the difference between a magnetostriction of the surface layer ?1.0/400,1 and a magnetostriction of the inner layer ?1.0/400,0; a sheet thickness t of 0.03 mm to 0.3 mm, and a ratio of a total thickness of the surface layers t1 to t of from 0.10 to 0.70.