Abstract: An electrical steel sheet includes a surface part in which a Si concentration in the steel sheet changes continuously from a high Si concentration to a low Si concentration in a thickness direction of the steel sheet from a surface of the steel sheet, as defined by a symmetry plane located at the center of the steel sheet in the thickness direction, a boundary part in which the Si concentration changes discontinuously, and an inner part in which the Si concentration does not change substantially in the thickness direction of the steel sheet, the inner part including the center of the steel sheet in the thickness direction, wherein the electrical steel sheet has a stress distribution such that an in-plane tensile stress is generated in the surface part and an in-plane compressive stress is generated in the inner part.

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: 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: Iron loss is reduced by increasing magnetic flux density. 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, and O: 0.0200% or less, with the balance consisting of Fe and inevitable impurities, in which the 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, a Vickers hardness of 140 HV or more and 230 HV or less.

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 method for producing a non-oriented electrical steel sheet by hot rolling a steel slab containing C: not more than 0.0050%, Si: not more than 5.0%, Mn: not more than 3.0%, P: not more than 0.2%, S: not more than 0.005%, Al: not more than 3.0%, N: not more than 0.005%, Ni: not more than 3.0%, Cr: not more than 5.0%, Ti: not more than 0.005%, and subjecting the sheet to a cold rolling and a finish annealing, wherein the heating in the finish annealing is conducted in two stages of performing an induction heating and subsequently a radiation heating and the induction heating is conducted up to not lower than 720° C. at an average heating rate of not less than 50° C./sec between 600° C. and 700° C. and a time from the end of the induction heating to the start of the radiation heating is not more than 8 seconds.

Abstract: A laminated core manufacturing device includes: an overlapping unit configured to overlap the plurality of laminated core materials conveyed along different conveyance routes; an edge position correction unit configured to align edge positions in a width direction of the plurality of laminated core materials between the plurality of laminated core materials and to correct shift of each edge position of the plurality of laminated core materials with respect to a standard edge position; an uplift prevention unit configured to prevent uplift of the plurality of laminated core materials; and a punching unit configured to punch out the plurality of laminated core materials which are overlapped by the overlapping unit and have been subjected to a process to align the edge positions and to correct shift of the edge positions performed by the edge position correction unit, and a process to prevent the uplift performed by the uplift prevention unit.

Abstract: A high-silicon steel sheet is excellent in terms of punching workability and magnetic property. The high-silicon steel sheet has a chemical composition containing, by mass %, C: 0.02% or less, P: 0.02% or less, Si: 4.5% or more and 7.0% or less, Mn: 0.01% or more and 1.0% or less, Al: 1.0% or less, O: 0.01% or less, N: 0.01% or less, and the balance being Fe and inevitable impurities, a grain-boundary oxygen concentration (oxygen concentration with respect to chemical elements segregated at grain boundaries) of 30 at % or less, and a microstructure in which a degree of integration P(211) of a {211}-plane of ?-Fe on a surface of the steel sheet is 15% or more P(211)=p(211)/S×100(%), wherein S=p(110)/100+p(200)/14.93+p(211)/25.88+p(310)/7.68+p(222)/1.59+p(321)/6.27+p(411)/1.55, and p(hkl): integrated intensity of a peak of X-ray diffraction of an {hkl}-plane.

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: 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: 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.

Abstract: Iron loss is reduced by increasing magnetic flux density. 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, and O: 0.0200% or less, with the balance consisting of Fe and inevitable impurities, in which the 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, a Vickers hardness of 140 HV or more and 230 HV or less.

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: A Laminated core manufacturing device includes: an overlapping unit configured to overlap the plurality of laminated core materials conveyed along different conveyance routes; an edge aligning unit configured to align edge positions in a width direction of the plurality of laminated core materials between the plurality of laminated core materials; an uplift prevention unit configured to prevent uplift of the plurality of laminated core materials; an edge position correction unit configured to correct the edge positions in the width direction of the plurality of laminated core materials; and a punching unit configured to punch out the plurality of laminated core materials which are overlapped by the overlapping unit and have been subjected to an edge position alignment process performed by the edge aligning unit, an uplift prevention process performed by the uplift prevention unit, and an edge position correction process performed by the edge position correction unit.

Abstract: A non-oriented electrical steel sheet having a high magnetic flux density and a low iron loss at not only a commercial frequency but also a high frequency zone, which has a chemical composition including C: not more than 0.0050 mass %, Si: more than 1.5 mass % but not more than 5.0 mass %, Mn: not more than 0.10 mass %, sol. Al: not more than 0.0050 mass, P: more than 0.040 mass % but not more than 0.2 mass %, S: not more than 0.0050 mass %, N: not more than 0.0040 mass % and Ca: 0.001-0.01 mass % and the remainder being Fe and inevitable impurities and a compositional ratio of CaO in oxide-based inclusions existing in a steel sheet of not less than 0.4 and/or a compositional ratio of Al2O3 of not less than 0.3, and a hot rolled steel sheet used as a raw steel material thereof.

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: 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% HCl 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: 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: 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 comprising 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: present at not more than 0.005 mass %, N: not more than 0.005 mass %, Ca: 0.0005-0.01 mass %, provided that an atom ratio of Ca 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/s up to at least 740° C.

Abstract: In the production of a non-oriented electrical stress sheet by hot rolling a slab having a chemical composition comprising, by mass %, C: not more than 0.005, Si: 1.5-6.0, Mn: 0.05-2.0 and P: 0.03-0.15, subjecting to a hot band annealing, if necessary, cold rolling, finish annealing, and forming an insulation coating, the cooling from 700° C. to 500° C. in the finish annealing is conducted in an oxidizing atmosphere with an oxygen potential PH2O/PH2of not less than 0.001 for 1-300 seconds, whereby P is segregated into the surface of the steel sheet after the finish annealing to obtain a non-oriented electrical steel sheet enhancing a crystal grain growth properties in the stress relief annealing.