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 having such a low Al concentration so that it is excellent in terms of the recycling efficiency of scrap iron and having a high magnetic flux density and low iron loss. The non-oriented electrical steel sheet according to the present invention has a chemical composition containing C; 0.0050 mass % or less, Si; 1.5 mass % to 5.0 mass %, Mn; 0.2 mass % to 3.0 mass %, sol.Al; 0.0030 mass % or less, P; 0.2 mass % or less, S; 0.0050 mass % or less, N; 0.0040 mass % or less, T.Ca; 0.0010 mass % to 0.0080 mass %, T.O; 0.0100 mass % or less, REM; 0.0001 mass % to 0.0050 mass %, and a balance of Fe and inevitable impurities, in which a value of a mass-related fractional expression ((T.Ca+REM)/(T.O+S)), which is a relational expression for the masses of the four constituents described above, that is, T.Ca, REM, T.O, and S, is 0.4 or more.

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 manufacturing a laminated iron core includes: inserting a plurality of electrical steel strips in a superposed state to feed rolls including a pair of upper and lower feed rolls that are driven by a drive device to feed the electrical steel strips in a superposed state into a die having a plurality of punching processes in sequence; joining a part or all of the superposed electrical steel strips together before entering the die or at an upstream stage portion of the die after feeding out the electrical steel strips from the pair of upper and lower feed rolls; and punching simultaneously the plurality of electrical steel strips in a superposed state in the die.

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: A steel containing C: not more than 0.0050%, Si: 0.1-5.0%, Mn: 0.02-3.0%, sol. Al: not more than 0.0050%, P: not more than 0.2%, S: not more than 0.0050%, N: not more than 0.0040%, T. Ca: 0.0010-0.0080%, T. O: not more than 0.0100% and having (T. Ca/T. O) of not less than 0.50 but not more than 2.0 by decarburizing to a C content of not more than 0.0050%, adding Si, decreasing Al as much as possible, and adding Ca is melted to form a slab. The slab is subjected to a hot rolling at a coiling temperature of not lower than 550° C., a cold rolling and a finish annealing, or the slab is subjected to a hot rolling, a hot band annealing at a temperature of 900-1150° C., a cold rolling and a finish annealing to thereby produce a non-oriented electrical steel sheet.

Abstract: A punch processing method for electrical steel sheets to manufacture core segments includes: stacking a plurality of electrical steel sheets; and punching out the plurality of electrical steel sheets in a stacked state simultaneously to manufacture the core segments, wherein in a case where the core segments are applied to a stator core in which a maximum magnetic flux density at a tooth portion is to be higher than a maximum magnetic flux density at a back yoke portion, degrees of Vickers hardness of an electrical steel sheet located second from a bottom side and above in the stacked state are set to 180 HV or higher, and 10 HV or higher than a value of degree of Vickers hardness of an electrical steel sheet located on the bottom side in the stacked state.

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: Methods for producing non-oriented electrical steel sheets comprising steps including hot rolling a slab having a chemical composition comprising C: not more than 0.01 mass %, Si: not more than 6 mass %, Mn: 0.05-3 mass %, P: not more than 0.2 mass %, Al: not more than 2 mass %, N: not more than 0.005 mass %, S: not more than 0.01 mass %, Ga: not more than 0.0005 mass %, and the remainder being Fe and inevitable impurities, pickling without conducting hot band annealing or after conducting hot band annealing or self-annealing, subjecting to one or more cold rollings including an intermediate annealing therebetween and a finish annealing, and forming an insulation coating, an average heating rate from 500 to 800° C. in the heating process of the finish annealing is not less than 50° C./s, whereby a non-oriented electrical steel sheet having excellent magnetic properties is obtained even if hot band annealing is omitted.