Abstract: The present invention provides a non-oriented silicon steel with excellent magnetic properties and a manufacturing process therefor. During the manufacturing process of the present invention, the temperature T of the molten steel of steel tapped from a converter during steelmaking and the carbon content [C] and the free oxygen content [O] comply with the following formula: 7.27×103?[O][C]e(?5000/T)?2.99×104, and the final annealing step uses tension annealing at a low temperature for a short time. A non-oriented silicon steel with a low iron loss, and excellent anisotropy of iron loss can be obtained by means of the manufacturing process of the present invention.

Abstract: Provided is a method for manufacturing a high silicon steel sheet having excellent producibility and magnetic properties. The method includes: casting a molten metal as a strip having a thickness of 5 mm or less, the molten metal comprising, by weight %, C: 0.05% or less (excluding 0%), N: 0.05% or less (excluding 0%), Si: 4% to 7%, Al: 0.5% to 3%, Si+Al: 4.5% to 8%, and the balance of Fe and inevitable impurities; hot-rolling the cast strip at a temperature of 800° C. or higher; annealing the hot-rolled strip at a temperature within a range of 900° C. to 1200° C.; cooling the annealed strip; warm-rolling the quenched strip at a temperature within a range of 300° C. to 700° C.; and finally annealing the warm-rolled strip at a temperature within a range of 800° C. to 1200° C.

Abstract: The present invention provides a steel for nitrocarburizing having excellent mechanical workability before nitrocarburizing, and showing excellent fatigue properties after nitrocarburizing, which is suitable for applying in mechanical structural components for automobiles etc. prepared by adjusting the composition so that it contains in mass %, C: 0.01% or more and less than 0.10%, Si: 1.0% or less, Mn: 0.5% to 3.0%, P: 0.02% or less, S: 0.06% or less, Cr: 0.3% to 3.0%, Mo: 0.005% to 0.4%, V: 0.02% to 0.5%, Nb: 0.003% to 0.15%, Al: 0.005% to 0.2%, and Sb: 0.0005% to 0.02%, and the balance including Fe and incidental impurities, and setting the area ratio of bainite phase to the whole microstructure to more than 50%.

Abstract: Disclosed are a non-oriented electrical steel sheet and a method of manufacturing the same. The non-oriented electrical steel sheet of the present invention includes 0.005 wt % or less of C, 1.0-4.0 wt % of Si, 0.1-0.8 wt % of Al, 0.01-0.1 wt % of Mn, 0.02-0.3 wt % of P, 0.005 wt % or less of N, 0.001-0.005 wt % of S, 0.005 wt % or less of Ti, 0.01-0.2 wt % of at least one of Sn and Sb, and the remainder including Fe and other impurities unavoidably added thereto, wherein Mn, Al, P, and S may respectively fulfill the empirical formula 0.8?{[Mn]/(100*[S])+[Al]}[P]?40, wherein [Mn], [Al], [P], and [S] respectively refer to weight percentages of Mn, Al, P, and S.

Abstract: A grain oriented electrical steel sheet reduces local exfoliation of insulating coating films and thus has excellent corrosion resistance and insulation properties. The grain oriented electrical steel sheet may be obtained by, assuming that a1 (?m) is a film thickness of the insulating coating at the floors of linear grooves and a2 (?m) is a film thickness of the insulating coating on a surface of the steel sheet at portions other than the linear grooves, controlling a1 and a2 to satisfy the following formulas (1) and (2): 0.3 ?m?a2?3.5 ?m??(1), and a1/a2?2.5??(2).

Abstract: Provided is a grain-oriented electric steel sheet having superior magnetic property and to a grain-oriented electric steel sheet including 2.0 to 4.5 weight % of Si, 0.001 to 0.10 weight % of C, 0.010 weight % or lower of Al, 0.08 weight % or lower of Mn, 0.005 weight % or lower of N, 0.002 to 0.050 weight % of S, the remainder being Fe and other unavoidable impurities. The steel sheet having been subjected to secondary recrystallization using at least any one of grain boundary-segregated elementary S and an FeS precipitate as a grain growth inhibitor.

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 method for producing grain-oriented electrical steel sheets includes subjecting a steel slab to hot rolling to obtain a hot rolled sheet, the steel slab having a composition consisting of, by mass % or mass ppm, C: 0.08% or less, Si: 2.0% to 4.5% and Mn: 0.5% or less, S, Se, and O: less than 50 ppm each, sol.Al: less than 100 ppm, N: 80 ppm or less, and the balance being Fe and incidental impurities, and satisfying the relation of sol.Al (ppm)?N (ppm)×(26.98/14.00)?30 ppm; then subjecting the hot rolled sheet to annealing and rolling to obtain a cold rolled sheet; then subjecting the cold rolled sheet to nitriding treatment, under specific condition, before, during or after primary recrystallization annealing; then applying an annealing separator on the cold rolled sheet; and subjecting the cold rolled sheet to secondary recrystallization 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: The location where forsterite is present is checked in a region from which light excited by an electron beam is emitted when a material containing forsterite is irradiated with an electron beam. The material is preferably a grain oriented electrical steel sheet having a forsterite layer. In addition, it is preferable that the accelerating voltage be 10 kV or more when an electron beam is radiated when the material is a grain oriented electrical steel sheet having a tension coating layer on the forsterite layer.

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: A method for producing a grain-oriented electrical steel sheets includes subjecting a steel slab to hot rolling to obtain a hot rolled sheet, the steel slab having a specific composition; then subjecting the hot rolled sheet to annealing and rolling to obtain a cold rolled sheet; then subjecting the cold rolled sheet to nitriding treatment with a nitrogen increase of 50 to 1000 ppm, during or after primary recrystallization annealing; then applying an annealing separator on the cold rolled sheet; and setting the staying time in a temperature range of 300 to 800° C. in the secondary recrystallization annealing to 5 to 150 hours.

Abstract: A grain oriented electrical steel sheet has a magnetic domain structure modified by strain introduction without a trace of treatment, in which noise generated when the grain oriented electrical steel sheet is used laminated on an iron core of a transformer is effectively reduced by: setting a magnetic flux density B8 to 1.92 T or higher; then setting a ratio of average magnetic domain width of treated surface after strain-introducing treatment Wa to average magnetic domain width before strain-introducing treatment W0 as Wa/W0<0.4; and setting a ratio of Wa to average magnetic domain width of untreated surface Wb as Wa/Wb>0.7; and further setting a ratio of average width of magnetic domain discontinuous portion Wd in the untreated surface to average width of magnetic domain discontinuous portion in treated surface resulting from strain-introducing treatment Wc as Wd/Wc>0.8; and setting Wc<0.35 mm.

Abstract: A method of manufacturing a grain oriented electrical steel sheet uses austenite (?)-ferrite (?) transformation which develops excellent magnetic properties, uses T? calculated from equation (1) and performs the first pass of rough hot rolling at a temperature of (T??100)° C. or higher with a rolling reduction of 30% or more, and further uses T?max calculated from equation (2) and performs any one pass of finish hot rolling in a temperature range of (T?max±50)° C. with a rolling reduction of 40% or more: T?[° C.]=1383.98?73.29[% Si]+2426.33[% C]+271.68[% Ni]??(1) T?max[° C.]=1276.47?59.24[% Si]+919.22[% C]+149.03[% Ni]??(2) where [% A] represents content of element “A” in steel (mass %).

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: In a method of producing a grain-oriented electrical steel sheet by hot rolling a steel slab having a chemical composition comprising C: 0.001 to 0.10 mass %, Si: 1.0 to 5.0 mass %, Mn: 0.01 to 0.5 mass %, S and/or Se: 0.005 to 0.040 mass %, sol. Al: 0.003˜0.050 mass % and N: 0.0010 to 0.020 mass %, subjecting to single cold rolling or two or more cold rollings including an intermediate annealing therebetween to a final thickness, performing primary recrystallization annealing, and thereafter applying an annealing separator to perform final annealing, a temperature range of 550° C. to 700° C. in a heating process of the primary recrystallization annealing is rapidly heated at an average heating rate of 40 to 200° C./s, while any temperature zone of from 250° C. to 550° C. is kept at a heating rate of not more than 10° C./s for 1 to 10 seconds, whereby the refining of secondary recrystallized grains is attained and grain-oriented electrical steel sheets are stably obtained with a low iron loss.

Abstract: A wire rod and steel wire having superior magnetic characteristics and a method for manufacturing same, wherein the wire rod and the steel wire can be used in transformers, vehicles, electric or electronic products, or the like which require low iron loss and high permeability. Provided are a wire rod and steel wire having superior magnetic characteristics and a method for manufacturing same, wherein the wire rod or the steel wire comprises, by wt %, 0.03 to 0.05% of C, 3.0 to 5.0% of Si, 0.1 to 2.0% of Mn, 0.02 to 0.08% of Al, 0.0015 to 0.0030% of N, and the remainder being Fe and unavoidable impurities. The wire rod and steel wire having directional properties may be provided by a general manufacturing process without using expensive alloying elements and without having to add a manufacturing facility.

Abstract: An austenitic antibacterial stainless steel formulation provides a high strength, highly corrosion resistant, antimicrobial product at a relatively low cost wherein antimicrobial performance is dramatic and greater mechanical properties and corrosion resistance are achieved as well. The alloy may comprise key constituents of Fe, Cr, Ni, and C plus a mischmetal having Ce and La components.

Abstract: Grain-oriented electrical steel sheets with good magnetic properties are industrially stably produced, by using as the material, a steel slab having a predetermined composition, wherein after cold rolling and before the start of secondary recrystallization annealing, the cold rolled sheet is subjected to nitriding treatment with nitrogen content of 50 mass ppm or more and 1000 mass ppm or less, and a total content of 0.2 mass % to 15 mass % of a sulfide and/or sulfate is contained in an annealing separator, and a staying time in the temperature range of 300° C. to 800° C. in the heating stage of secondary recrystallization annealing of 5 hours or more is secured to precipitate silicon nitride (Si3N4) and MnS, and using the silicon nitride in combination with MnS as inhibiting force for normal grain growth to significantly reduce variation of magnetic properties.

Abstract: Provided is a method for manufacturing a grain-oriented electrical steel sheet, the method comprising: heating a grain-oriented electrical steel sheet slab; hot-rolling the heated slab; optionally annealing the hot-rolled steel sheet; subjecting the resulting steel sheet to one cold rolling or two or more cold rollings with intermediate annealing therebetween; subjecting the cold-rolled steel sheet to primary recrystallization annealing; and subjecting the annealed steel sheet to secondary recrystallization annealing, wherein the primary recrystallization annealing sequentially comprises an ultra-rapid heating process of heating the steel sheet at an average heating rate of 300° C./sec or higher, a rapid heating process of heating the steel sheet at a lower average heating rate than the average heating rate of the ultra-rapid heating process, but not lower than 100° C.

Abstract: A vibration layer is formed by the AD method on a cavity plate before forming pressure chambers, a common electrode is formed on the vibration layer, and a piezoelectric layer is formed on the common electrode by the AD method. Subsequently, the pressure chambers are formed in the cavity plate by the etching. After that, individual electrodes are formed on the piezoelectric layer. Subsequently, the stack of the cavity plate, the vibration layer, the common electrode, the piezoelectric layer, and the individual electrodes is heated at about 850° C. to simultaneously perform the annealing of the piezoelectric layer and the sintering of the individual electrodes and the common electrode. Accordingly, the atoms of the cavity plate are suppressed from being diffused into the driving portions of the piezoelectric layer.

Abstract: In a method for producing a grain-oriented electrical steel sheet by comprising a series of steps of hot rolling a raw steel material containing C: 0.002-0.10 mass %, Si: 2.0-8.0 mass % and Mn: 0.005-1.0 mass % to obtain a hot rolled sheet, subjecting the hot rolled steel sheet after or without hot band annealing to one stage cold rolling or two or more stage cold rollings including an intermediate annealing therebetween to obtain a cold rolled sheet having a final sheet thickness, subjecting the cold rolled sheet to decarburization annealing combined with primary recrystallization annealing, applying an annealing separator to the steel sheet surface and then subjecting to a final annealing, when rapid heating is performed at a rate of not less than 50° C./s in a range of 200-700° C. of the decarburization annealing, the cold rolled sheet is subjected to holding at any temperature of 250-600° C.

Abstract: A laser processing apparatus includes a laser irradiation unit has a structure providing an intensity distribution of the laser beam focused on the grain-oriented electrical steel sheet on a cross-section in a direction perpendicular to the scanning direction on the grain-oriented electrical steel sheet so as to satisfy Ib/Ia?2, where Ra1 and Ra2 are distances between the centroid of the intensity distribution and positions at which the intensity integration value from the centroid of the intensity distribution is 43% of the total intensity integration value, beam intensities Ia1 and Ia2 are intensities of the laser beam corresponding to Ra1 and Ra2, respectively, Ia is the average value of Ia1 and Ia2 and Ib is the beam intensity at the centroid of the intensity distribution.

Abstract: A fast-speed laser scoring method is provided, in which a set of related laser scoring device is used to simultaneously score lines on the upper surface and the lower surface of an oriented silicon steel strip, which is being fed and traveling forwards on a production line, with high-focalized continuous wave laser beam; the lines scored on the upper surface and the lines scored on the lower surface have the same space between every two adjacent scored lines but are staggered each other in order to reduce iron loss evenly. The space between every two adjacent scored lines on the same surface is 6-12 mm, laser power is 1000-3000 W and scanning speed is 100-400 m/min. The machining rate of the scoring method and device attains 1.5-2 times the one of conventional scoring methods which can not simultaneously score the upper and lower surfaces of a steel strip at a time. The lines scored on a steel strip by the method can reduce iron loss of the strip by 10-16%.

Abstract: A method includes preparing a steel slab in which contents of inhibitor components have been reduced, i.e. content of Al: 100 ppm or less, and contents of N, S and Se: 50 ppm, respectively; subjecting the steel slab to hot rolling and then either a single cold rolling process or two or more cold rolling processes interposing intermediate annealing(s) therebetween to obtain a steel sheet having the final sheet thickness; and subjecting the steel sheet to primary recrystallization annealing and then secondary recrystallization annealing. The primary recrystallization annealing includes heating the steel sheet to temperature equal to or higher than 700° C. at a heating rate of at least 150° C./s, cooling the steel sheet to a temperature range of 700° C. or lower, and then heating the steel sheet to soaking temperature at the average heating rate not exceeding 40° C./s in a subsequent heating zone.

Abstract: A grain oriented electrical steel sheet that is subjected to magnetic domain refining treatment by electron beam irradiation and exhibits excellent low-noise properties when assembled as an actual transformer in which tension exerted on the steel sheet by the forsterite film is 2.0 MPa or higher both in a rolling direction and a direction transverse (perpendicular) to the rolling direction, and a ratio of an irradiation pitch in a thermal strain introduced region (B) to a spot diameter (A) on an electron beam irradiation surface satisfies 0.5?B/A?5.0.

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 1.91T, 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 is subjected to magnetic domain refinement by laser irradiation or electron irradiation and exhibits excellent low noise properties and low iron-loss properties when assembled into a real transformer device, by setting: the total tension (A) in rolling direction imparted to the steel sheet by the forsterite coating and the tension coating to be equal to or higher than 10.0 MPa; setting the total tension (B) in a direction orthogonal to the rolling direction imparted to the steel sheet by the forsterite coating and the tension coating to be equal to or higher than 5.0 MPa; and setting the total tension (A) and the total tension (B) to satisfy a formula shown below. 1.0?A/B?5.

Abstract: A hot rolled silicon steel producing method comprises: silicon steel slab heating process, rough rolling process and finish rolling process. The heating process comprises a pre-heating stage, a heating stage and a soaking stage. The pre-heating stage satisfies the following formula (1). In the formula, VTp is a temperature increasing rate, in the pre-heating stage, whose unit is ° C./min; t is a total heating time of the slab in the heating furnace, and t=180-240 min; and Tc is an initial temperature when the slab is put into the furnace, whose unit is ° C. By using the foregoing formula, the heating process and the rough rolling process are changed, an occurrence rate of edge defects during the production of the hot rolled silicon steel can be reduced, and the hot rolled silicon steel with good surface quality can be produced. V Tp > 220 ? ? min t × 100 ? ° ? ? C . T C + 200 ? ° ? ? C . × 25 ? ° ? ? C .

Abstract: An asymmetric rolling method for rolling a rolling material by using at least one pair of working rolls comprises rolls rotating at the same linear velocity and having different diameters. An asymmetric rolling apparatus may comprise a first roll contacting a first surface of a rolling material, a second roll having a diameter different from that of the first roll and contacting a second surface of the rolling material opposite to the first surface, and a power providing unit for providing power to each of the first and second rolls to adjust a ratio between angular velocities of the first and second rolls.

Abstract: A grain oriented electrical steel sheet has thickness of forsterite film at bottom portions of grooves formed on a surface of the steel sheet is ?0.3 ?m, groove frequency is ?20%, abundance ratio of grooves crystal grains directly beneath themselves, each crystal grain having orientation deviating from Goss orientation by ?10° and grain size ?5 ?m, total tension exerted on the steel sheet in the rolling direction by the forsterite film and tension coating is ?10.0 MPa, total tension exerted on the steel sheet in a direction perpendicular to the rolling direction by the forsterite film and tension coating is ?5.0 MPa and total tension satisfies 1.0?A/B?5.0, where A is total tension exerted in rolling direction by forsterite film and tension coating, and B is total tension exerted in direction perpendicular to rolling direction by forsterite film and tension coating.

Abstract: A machine for the surface treatment of a cylinder includes a first operative station for supporting the cylinder and for bringing it into rotation around its longitudinal axis, and at least a second operative station cooperating with the first station for generating and emitting, by means of an optical fiber apparatus, pulsed laser radiations randomly striking the surface of the cylinder and defining a desired roughness on the same surface; the second station being adjustably coupled with the first station in a first direction parallel with respect to the axis of the cylinder and carrying one or more pulsed laser radiation emitting heads, and slidingly assembled with respect to the cylinder in a second direction perpendicular to the axis of the cylinder.

Abstract: A grain oriented electrical steel sheet may reduce iron loss of material with linear grooves formed thereon for magnetic domain refinement and offer excellent low iron loss properties when assembled as an actual transformer, where the steel sheet has sheet thickness of 0.30 mm or less, linear grooves are formed at intervals of 2-10 mm in the rolling direction, the depth of each of the linear grooves is 10 ?m or more, the thickness of the forsterite film at bottom portions of the linear grooves is 0.3 ?m or more, total tension applied to the steel sheet by the forsterite film and tension coating is 10.0 MPa or higher in rolling direction, and the proportion of eddy current loss in iron loss W17/50 of the steel sheet is 65% or less when alternating magnetic field of 1.7 T and 50 Hz is applied to the steel sheet in the rolling direction.

Abstract: Methods and systems for estimating the residual static terms for multi-component land datasets are described. A one-pass estimation simultaneously using P-P pre-stack data and P-S pre-stack data for generating common source residual statics for the P-P data and the P-S data and separate receiver residual statics for the P-P data and the P-S data. A series of iterations are performed using either a linear or a non-linear simulation to converge on acceptable residual statics.

Abstract: The present invention has as objective a procedure for the oriented-grain magnetic sheet that provides particular operative hot rolling mill conditions of silicon steel slabs, by means which it is possible to highly contain the heterogeneities of hot rolled sheet re-crystallization. The use of these operative conditions permits to reduce the growing tendency of the crystallized grain during the annealing of the sheets at a final thickness that precedes the secondary oriented re-crystallization. Contemporarily, the particular operational conditions of hot rolling mill according to the invention permit a fine precipitation of secondary phases useful to the control of the grain growing, starting from a quantity of sulphur (S) and nitrogen (N) in matrix lower than corresponding provided by the conventional technologies and consequently disposable in metallic solid solution before the rolling after the heating of the slabs at temperature values lower than 1300° C.

Abstract: In a method of producing a grain-oriented electrical steel sheet by hot-rolling a steel slab of a chemical composition containing C: 0.001˜0.10%, Si: 1.0˜5.0%, Mn: 0.01˜1.0%, at least one of S and Se: 0.01˜0.05% in total, sol. Al: 0.003˜0.050%, N: 0.001˜0.020% by mass, subjecting to cold rolling, a primary recrystallization annealing, application of an annealing separator mainly composed of MgO and a finish annealing, a temperature rising rate S1 between 500˜600° C. in the primary recrystallization annealing is made to not less than 100° C./s and a temperature rising rate S2 between 600˜700° C. is made to 30° C./s˜0.6×S1° C./s, while a total content W (mol %) of an element having an ionic radius of 0.6˜1.3 ? and an attracting force between the ion and oxygen of not more than 0.7 ??2 included in the annealing separator to MgO is adjusted to satisfy 0.01S2?5.5?Ln (W)?0.01S2?4.3 to produce a grain-oriented electrical steel sheet having excellent iron loss properties and coating properties.

Abstract: A high-strength steel sheet comprises, by weight, not less than 0.25% and not more than 0.5% of C, not less than 4% and not more than 14% of Mn, not less than 6.5% and not more than 9.5% of Cr, and not less than 0.3% and not more than 3% of Si. The high-strength steel sheet satisfies formulas 1 and 2, formula (1) being 12?2.0Si+5.5Al+Cr+1.5Mo?25 and formula (2) being 13?30C+0.5Mn+0.3Cu+Ni+25N?17, and mainly consists of austenite, and the high-strength steel sheet has yield strength of not less than 1000 MPa and total elongation of not less than 20%. In formulas 1 and 2, each element in the above formulas indicates the content, in weight %, of the element.

Abstract: Hot rolling is performed on a steel with a predetermined composition containing Ti: 0.0020 mass % to 0.010 mass % and/or Cu: 0.010 mass % to 0.50 mass % to obtain a hot-rolled steel sheet. Annealing is performed on the hot-rolled steel sheet to obtain an annealed steel sheet. Cold rolling is performed on the annealed steel sheet to obtain a cold-rolled steel sheet. Decarburization annealing and nitridation annealing are performed on the cold-rolled steel sheet to obtain a decarburized nitrided steel sheet. Then, finish annealing is performed on the decarburized nitrided steel sheet. When obtaining the decarburized nitrided steel sheet, heating on the cold-rolled steel sheet is started in a decarburizing and nitriding atmosphere, then first annealing is performed at a first temperature within a predetermined range, and then second annealing is performed at a second temperature within a predetermined range.

Abstract: In a method for producing a grain-oriented electrical steel sheet, grooves each having a given length and extending in a direction including a direction perpendicular to a transportation direction of the grain-oriented electrical steel sheet are formed at given intervals in the transportation direction by irradiating the surface of the grain-oriented electrical steel sheet with a laser beam while scanning the surface of the grain-oriented electrical steel sheet with the laser beam. Further, in the method for manufacturing a grain-oriented electrical steel sheet, the laser beam is a continuous-wave laser beam having a laser wavelength ? of 1.0 ?m to 2.1 ?m, power density Pd [W/mm2] which is obtained by dividing laser beam intensity P by a focused beam area S is 5×105 W/mm2 or more, and the power density Pd [W/mm2] and scanning speed V [mm/s] of a focused spot of the laser beam on the surface of the grain-oriented electrical steel sheet satisfy a relationship of 0.005×Pd+3000?V?0.005×Pd+40000.

Abstract: Provided is an asymmetric rolling method including: entering a to-be-rolled material having a first surface and a second surface between a first roll and a second roll that has a greater diameter than that of the first roll and a rotary angular speed that is different from that of the first roll while the first surface and the second surface respectively contact the first roll and the second roll, followed by rolling, and entering the rolled to-be-rolled material between a third roll and a fourth roll that has a greater diameter than that of the third roll and a rotary angular speed that is different from that of the third roll while the first surface and the second surface respectively contact the fourth roll and the third roll, followed by rolling, wherein different shear stresses are applied to the first and second surfaces of the to-be-rolled material.

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 grain-oriented electrical steel sheet has low iron loss properties obtained though magnetic domain refining treatment by a chemical means. The steel sheet has a linear groove extending in a direction forming an angle of 45° or less with a direction orthogonal to a rolling direction of the steel sheet, in which presence frequency of fine grains with a length in the rolling direction of 1 mm or less in a floor portion of the groove is 10% or less, including 0% indicative of the absence of fine grains, the groove is provided with a forsterite film in an amount of 0.6 g/m2 or more in terms of Mg coating amount per one surface of the steel sheet, and an average of angles (3 angles) formed by <100> axes of secondary recrystallized grains facing the rolling direction and a rolling plane of the steel sheet is 3° or less.

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: The present invention manufactures a steel sheet for a rotor core for an IPM motor, wherein the steel sheet has a magnetic flux density B8000 of 1.65 T or more as measured when magnetic field strength is 8000 A/m, and a residual magnetic flux density Br of 0.5 T or more as measured at that time, and optionally, a coercivity Hc of 100 A/m or more as measured after magnetization reaches 8000 A/m. By using the steel sheet manufactured according to the present invention for a rotor core of an IPM motor, it is possible to increase further an output torque in a high-speed rotational range and raise further the maximum rotational speed.

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: In a method for manufacturing grain oriented electrical steel sheets from a slab, controlling the steel sheet temperature so as to satisfy T (t)<FDT?(FDT?700)×t/6 (wherein T (t): steel sheet temperature (° C.), FDT: finishing temperature (° C.) and t: time (sec) after the completion of finish rolling) throughout the entire length of a coil during cooling after the completion of finish rolling in hot rolling, and controlling the steel sheet temperature of a tip portion of the coil representing 10% of the length of the coil to be not less than 650° C. at a lapse of 3 seconds from the completion of hot rolling, thus manufacturing a grain oriented electrical steel sheet exhibiting excellent magnetic properties throughout the entire coil length.

Abstract: A hot strip for producing an electric steel sheet has the following alloy composition in weight %: C: 0.001 to 0.08 Al: 4.8 to 20 Si: 0.05 to 10 B: up to 0.1 Zr: up to 0.1 Cr: 0.1 to 4, remainder iron and melting related impurities.

Abstract: A method for producing a silicon steel normalizing substrate comprises: steelmaking, hot rolling and normalizing steps. The normalizing step uses a normalizing furnace having a nonoxidizing heating furnace section. The nonoxidizing heating furnace section comprises more than 3 furnace zones. An energy investment ratio of the furnace zones used in the nonoxidizing heating furnace section is adjusted, so as to control an excess coefficient ? of the nonoxidizing heating furnace section to be within a range of 0.8??<1.0.

Abstract: A method for producing a silicon steel normalizing substrate comprises steelmaking, hot rolling and normalizing steps. A normalizing furnace is used in the normalizing step, and along a moving direction of strip steel, the normalizing furnace sequentially comprises: a preheating section, a nonoxidizing heating section, a furnace throat, furnace sections for subsequent normalizing processing, and a delivery seal chamber. Furnace pressures of the normalizing furnace are distributed as follows: the furnace pressure of a downstream furnace section adjacent to the furnace throat along the moving direction of the strip steel is the highest, the furnace pressure decreases gradually from the furnace section with the highest furnace pressure to a furnace section in an inlet direction of the normalizing furnace, and the furnace pressure decreases gradually from the furnace section with the highest furnace pressure to a furnace section in an outlet direction of the normalizing furnace.