Abstract: Provided is a method of manufacturing a grain-oriented electrical steel sheet, with which a grain-oriented electrical steel sheet with low iron loss and little variation in iron loss can be stably manufactured by a tandem mill. The method includes subjecting a steel material to hot rolling to obtain a hot-rolled sheet, subjecting the hot-rolled sheet to cold rolling once or twice or more with intermediate annealing performed therebetween to obtain a cold-rolled sheet with a final sheet thickness, and then subjecting the cold-rolled sheet to decarburization annealing and then to secondary recrystallization annealing, wherein final cold rolling is performed by a tandem mill, and in the final cold rolling, the hot-rolled sheet is heated to a temperature range of 70° C. or higher and 200° C. or lower, then cooled to 60° C. or lower, and then introduced into a first pass of the tandem mill.

Abstract: A nitriding apparatus for manufacturing a grain-oriented electrical steel sheet is provided. The nitriding apparatus includes: a nitriding gas supply pipe for introducing gas including at least ammonia or nitrogen; and a nitriding treatment portion for successively performing high-temperature nitriding and low-temperature nitriding in nitriding treatment. The nitriding treatment portion includes a high-temperature treatment portion for performing the high-temperature nitriding and a low-temperature treatment portion for performing the low-temperature nitriding, and the nitriding gas supply pipe to the high-temperature treatment portion includes a cooling device.

Abstract: Provided is a surface treatment facility in which both surfaces of a material are subjected to continuous film deposition by PVD as the material is conveyed in the longitudinal direction, wherein flutter of the material subjected to coating can be suppressed. This surface treatment facility comprises a chamber configured to continuously deposit a film by PVD on both surfaces of a material as the material is conveyed in the longitudinal direction through the chamber; a conveyance mechanism for conveying the material subjected to coating; a blowing mechanism for blowing film-forming gas in the longitudinal direction on both sides of the material present in the chamber; and has an X/Y ratio within a range of 0.4 to 3.0 where X is the film-forming gas blowing speed, and Y is the conveyance speed of the material subjected to coating, and where the unit of measurement of X and Y is m/min.

Abstract: Provided is a method of manufacturing a grain-oriented electrical steel sheet that has a uniform texture all along the longitudinal direction and has small fluctuations in magnetic properties. The method includes subjecting a predetermined hot-rolled and annealed sheet to cold rolling, where at least one time of cold rolling has a total rolling reduction of 80 % or more and is performed by a tandem mill, rolling performed in at least one stand of the tandem mill is performed under conditions of a rolling reduction of 30 % or more and a biting temperature To °C of a work roll of the stand, and a temperature at which either or both of a leading end and a tail end of the hot-rolled and annealed sheet are bitten by the work roll is 70° C. or higher and at least 10° C. higher than the temperature To °C.

Abstract: Provided is a method of manufacturing a grain-oriented electrical steel sheet with which a grain-oriented electrical steel sheet with excellent magnetic properties and little variation in iron loss in the longitudinal direction of a coil can be stably manufactured. The method includes subjecting a steel slab to hot-rolling and optionally to annealing, then performing cold rolling once or twice or more to obtain a cold-rolled sheet with a final sheet thickness, and then subjecting the cold-rolled sheet to decarburization annealing and then secondary recrystallization annealing, where immediately before final cold rolling, a steel sheet is heated at a heating rate of 100° C./s or more to a heating temperature of 100° C. or higher and 350° C. or lower, and a time from when the steel sheet reaches the heating temperature to when it is bitten in a first pass of final cold rolling is set to within 5 seconds.

Abstract: Provided is a production method for a grain-oriented electrical steel sheet with which stable magnetic properties are obtained in the same coil. The method comprises: hot rolling a steel slab having a predetermined chemical composition, followed by annealing to obtain a hot-rolled and annealed sheet; cold rolling the hot-rolled and annealed sheet one time, or two times or more with intermediate annealing being performed therebetween, to obtain a cold-rolled sheet, followed by subjecting to primary and secondary recrystallization annealing, wherein in the cold rolling, a rolling reduction ratio is 80% or more at least one time out of the one time or two times or more, and a steel sheet temperature T0 (° C.) while a rolling rate is a set value R0 (mpm) and a steel sheet temperature T1 (° C.) while the rolling rate is less than or equal to 0.5×R0 (mpm) satisfy a formula (1).

Abstract: Disclosed is a grain-oriented electrical steel sheet capable of obtaining excellent magnetic properties stably over the entire coil length. A grain-oriented electrical steel sheet includes: a chemical composition containing, in mass %, C: 0.005% or less, Si: 2.0% to 4.5%, and Mn: 0.01% to 0.5%, and, in mass ppm, N: 20 ppm or less, each of Se, Te, and O: less than 50 ppm, S: less than 30 ppm, and acid-soluble Al: less than 40 ppm, and Ti: less than 30 ppm, of which 5 ppm or more and 25 ppm or less is acid-soluble Ti, with the balance being Fe and inevitable impurities; and precipitates containing Ti and N with a grain size of 200 nm or more at a frequency of 0.05 grains/mm2 or more.

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: When a grain-oriented electrical steel sheet is produced by heating a steel slab containing, by mass %, C: 0.020 to 0.10%, Si: 2.0 to 4.0%, Mn: 0.005 to 0.50%, Al: less than 0.010%, N, S and Se: less than 0.0050% each to a temperature of not higher than 1280° C., subjecting slab to hot rolling, hot-band annealing, single cold rolling or two or more cold rollings having intermediate annealing between each cold rolling and a primary recrystallization annealing combined with decarburization annealing, applying annealing separator onto steel sheet surface, and subjecting steel sheet to finish annealing and a flattening annealing, a rapid cooling is conducted at an average cooling rate of not less than 200° C./s from 800° C. to 300° C. in cooling process from maximum achieving temperature in at least one of hot band annealing and intermediate annealing, whereby grain-oriented electrical steel sheet having excellent magnetic properties is stably produced.

Abstract: In a method of producing a grain-oriented electrical steel sheet comprising subjecting a steel slab containing no inhibitor-forming components to hot rolling, cold rolling, primary recrystallization annealing working also as decarburization and to final annealing causing secondary recrystallization after applying an annealing separator on the surface, the final cold rolling for cold rolling the steel sheet to the final thickness uses a warm rolling with a tandem rolling mill at a total rolling reduction of not less than 80% at 150 to 280° C. and is performed by extending a pass line length of the steel sheet between the stands so that T satisfies T?1.3×L/V, where an distance between the stands is defined as L(m), a speed of the steel sheet passing between the stands is defined as V (mpm), and a pass time during which the steel sheet passes between the stands is defined as T(min).

Abstract: Provided is a method for nitriding a grain-oriented electrical steel sheet which is very useful in obtaining excellent magnetic properties with no variation, that enables generating glow discharge between positive electrodes and negative electrodes disposed in a nitriding zone and irradiating the generated plasma to a strip to perform appropriate nitriding.

Abstract: A grain-oriented electrical steel sheet that includes a base coating with a high TiN ratio advantageous for the application of tension to the steel sheet and has excellent magnetic property is provided. The grain-oriented electrical steel sheet includes: a base coating having a peak value PTiN of TiN in the form of osbornite, observed in a range of 42°<2?<43° and a peak value PSiO2 of SiO2 in the form of cristobalite, observed in a range of 23°<2?<25° of both more than 0 and satisfying a relationship PTiN?PSiO2, in thin-film X-ray diffraction analysis; and an iron loss W17/50 of 1.0 W/kg or less.

Abstract: A nitriding apparatus for manufacturing a grain-oriented electrical steel sheet is provided. The nitriding apparatus includes: a nitriding gas supply pipe for introducing gas including at least ammonia or nitrogen; and a nitriding treatment portion for successively performing high-temperature nitriding and low-temperature nitriding in nitriding treatment. The nitriding treatment portion includes a high-temperature treatment portion for performing the high-temperature nitriding and a low-temperature treatment portion for performing the low-temperature nitriding, and the nitriding gas supply pipe to the high-temperature treatment portion includes a cooling device.

Abstract: Provided is a method for producing a grain-oriented electrical steel sheet with which it is possible to obtain a grain-oriented electrical steel sheet exhibiting excellent magnetic properties. This method for prod producing a grain-oriented electrical steel sheet involves subjecting a surface of a grain-oriented electrical steel sheet which does not have a forsterite film thereon to a film formation treatment, and performing the film formation treatment while imparting tension to the grain-oriented electrical steel sheet which does not have a forsterite film thereon.

Abstract: A target replacement apparatus for use in replacement of a sputtering target, the sputtering target being used to carry out surface treatment by a physical vapor deposition method on a material to be surface-treated that is situated in a reduced pressure space of a chamber, the target replacement apparatus includes a target retaining portion retaining the sputtering target; an attachment and detachment mechanism used to detachably attach the target retaining portion to the chamber at a position where the sputtering target faces the material to be surface-treated that is situated in the reduced pressure space; and an isolating mechanism operable to isolate the target retaining portion attached to the chamber from the reduced pressure space in an openable and closable manner.

Abstract: In a grain-oriented electrical steel sheet manufacturing process of processing a steel slab having a predetermined composition to a final sheet thickness and then performing primary recrystallization annealing and nitriding treatment, the nitriding treatment is performed in at least two stages of temperatures including high-temperature nitriding and low-temperature nitriding, and a residence time in the high-temperature nitriding is 3 seconds or more and 600 seconds or less. In this way, nitrogen is efficiently diffused into the steel of the steel sheet before secondary recrystallization to precipitate AlN. Such a method can manufacture a grain-oriented electrical steel sheet having excellent magnetic property.

Abstract: Provided is a surface treatment facility in which both surfaces of a material subjected to coating are subjected to continuous film deposition by PVD as the material is conveyed in the longitudinal direction, wherein flutter of the material subjected to coating can be suppressed. This surface treatment facility: has a chamber and continuously deposits a film by PVD on both surfaces of a material subjected to coating as the material is conveyed in the longitudinal direction through the chamber; is further provided with a conveyance mechanism for conveying the material subjected to coating and a blowing mechanism for blowing film-forming gas in the longitudinal direction on both sides of the material subjected to coating present in the chamber; and has an X/Y ratio within a range of 0.4 to 3.0 where X is the film-forming gas blowing speed, where the unit of measurement is m/min, and Y is the conveyance speed of the material subjected to coating, where the unit of measurement is m/min.

Abstract: The disclosure contains, in mass % or mass ppm: C: 0.005% or less, Si: 2.0% to 5.0%, Mn: 0.01% to 0.5%, sol.Al: 10 ppm or less, N: 15 ppm or less, S and Se: each 10 ppm or less, and three or more selected from Sn, Sb, Cr, P, Mo and B whose contents satisfy a relational expression of 0.16?[% Sn]+[% Sb]+[% Cr]+2×[% P]+[% Mo]+[% B]?0.50, the balance being Fe and inevitable impurities, where a number of times of repeated bending in a bend test is 10 or more.

Abstract: A grain-oriented electrical steel sheet that includes a base coating with a high TiN ratio advantageous for the application of tension to the steel sheet and has excellent magnetic property is provided. The grain-oriented electrical steel sheet includes: a base coating having a peak value PTiN of TiN in the form of osbornite, observed in a range of 42°<2?<43° and a peak value PMg2SiO4 of Mg2SiO4 in the form of forsterite, observed in a range of 35°<2?<36° of both more than 0 and satisfying a relationship PTiN?PMg2SiO4, in thin-film X-ray diffraction analysis; and an iron loss W17/50 of 1.0 W/kg or less.

Abstract: When a steel sheet containing Si: 2-5 mass % after cold rolling is subjected to a primary recrystallization annealing and a finishing annealing for secondary recrystallization to form a grain-oriented electrical steel sheet, the primary recrystallization annealing is performed by rapid heating in the heating process and temperature keeping treatment at a certain temperature in the course of the heating to thereby obtain a grain-oriented electrical steel sheet having plural peaks in a distribution of misorientation angle between crystal orientation of secondary recrystallized grains and Goss orientation, wherein misorientation angle of the second smallest peak among the plural peaks is preferably not less than 5° and a grain size of secondary recrystallized grains is not more than 15 mm.