Abstract: One aspect of the present disclosure relates to a method for manufacturing a spun yarn made of carbon nanotubes. The method includes: a spun yarn precursor ? production step of producing a spun yarn precursor ? by pulling a plurality of carbon nanotubes from a carbon nanotube forest and spinning the carbon nanotubes while applying a tension of 6 mN or less per centimeter of a width of the carbon nanotube forest to the carbon nanotubes; a spun yarn precursor ? production step of producing a spun yarn precursor ? by applying a higher tension than in the spun yarn precursor ? production step to the spun yarn precursor ? to densify the spun yarn precursor ?; and a spun yarn production step of producing the spun yarn by electrically heating the spun yarn precursor ? while applying a tension to the spun yarn precursor ?.

Abstract: Provided is a method for producing a sliding member formed by impregnating a porous base member made of a bronze-based alloy with a resin material, the sliding member including a sliding surface where both the porous base member and the resin material are exposed, the method including: a step of preparing a back metal layer; a porous base member formation step of forming the porous base member by depositing particles of the bronze-based alloy on a surface of the back metal layer and sintering the particles; an impregnation step of impregnating the porous base member with the resin material; a deformation step of deforming an end edge of the back metal layer in a direction away from the sliding surface; and a cutting step of cutting the porous base member impregnated with the resin material to form the sliding surface.

Abstract: The linear groove formation method includes a resist forming process of forming a coated resist on a surface of a steel sheet, a laser irradiating process of irradiating laser beams onto the steel sheet while repeating a laser scanning in a direction intersecting a rolling direction of the steel sheet cyclically in the rolling direction of the steel sheet to remove the coated resist in portions irradiated with the laser beams, and an etching process of forming linear grooves by etching portions of the steel sheet from which the coated resist is removed. In the laser irradiating process, the coated resist is removed by using two or more laser irradiating devices, with a certain irradiation energy, a certain beam diameter in a direction perpendicular to a laser scanning direction, and a certain incidence angle with respect to the surface of the steel sheet.

Abstract: A grain-oriented electrical steel sheet having linear grooves formed cyclically in a rolling direction of the grain-oriented electrical steel sheet such that a longitudinal direction of the linear grooves intersects the rolling direction, in which each of the linear grooves has a discontinuous portion of center lines where center lines of the groove are shifted in a groove width direction, and when a width of the linear groove is defined as a and a distance in the groove width direction between the center lines in the discontinuous portion of center lines is defined as b, a and b satisfy relational expression (1) below. 0.05?b/a?0.

Abstract: Iron core vibration and transformer noise can be reduced by using, as a transformer iron core, an iron core formed by a stack of at least two types of grain-oriented electrical steel sheets that differ in magnetostriction by 2×10?7 or more when excited from 0 T to 1.7 T.

Abstract: A linear groove formation method including forming a coated resist on a surface of a steel sheet, irradiating two or more laser beams onto the surface of the steel sheet while scanning the laser beams in a direction intersecting the rolling direction of the steel sheet cyclically in a rolling direction of the steel sheet, and forming linear grooves by etching portions of the steel sheet. In the laser irradiating process, the coated resist is removed continuously in a sheet transverse direction of the steel sheet by using the laser beams irradiated from respective ones of two or more laser irradiation devices arranged in the sheet transverse direction, and the laser beams are irradiated by shifting centers of two of the laser beams irradiated from two of the laser two of the laser irradiation devices adjacent to each other in the sheet transverse direction.

Abstract: Disclosed is a grain-oriented electrical steel sheet including: closure domains, each containing a discontinuous region at a part thereof and extending at an angle within 30° with respect to a transverse direction of the steel sheet, wherein a closure domain overlapping portion in the discontinuous region on one surface of the steel sheet has a length ? in the transverse direction that is longer than a length ? in the transverse direction of the closure domain overlapping portion on the other surface of the steel sheet, and the length ? satisfies 0.5???5.0 and the length ? satisfies 0.2????0.8?. Consequently, the iron loss and the deterioration of magnetostrictive properties are suppressed in discontinuous regions, which would be inevitably formed when magnetic domain refining treatment is performed using a plurality of irradiation devices.

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: Provided is a method for manufacturing a grain-oriented electrical steel sheet. The method comprises: hot rolling a slab to obtain a hot rolled sheet; subjecting the hot rolled sheet to hot band annealing as necessary; subjecting the hot rolled sheet to cold rolling; subjecting the cold rolled sheet to decarburization annealing; applying an annealing separator having MgO as a main component onto a surface of the decarburization annealed sheet and subjecting the decarburization annealed sheet to final annealing to form the forsterite film; and applying an insulating coating treatment liquid onto the final annealed sheet and subjecting the final annealed sheet to flattening annealing to form a tension-applying insulating coating. A difference in total tensions between one and opposite surfaces of the sheet is less than 0.5 MPa. A difference in tensions between the forsterite films in one and opposite surfaces of the sheet is 0.5 MPa or more.

Abstract: An excellent low noise property and excellent low iron loss property are obtained. A grain-oriented electrical steel sheet includes refined magnetic domains formed by electron beam irradiation. When the maximum magnetic flux density is 1.7 T, the grain-oriented electrical steel sheet has a residual magnetic flux density of 0.1 to 0.7 times the residual magnetic flux density before the electron beam irradiation and a maximum magnetizing force of 1.1 to 2.0 times the maximum magnetizing force before the electron beam irradiation.

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: A grain-oriented electrical steel sheet for a wound transformer core. The steel sheet having a sheet thickness t, where t and an iron loss deterioration ratio obtained by subjecting the steel sheet under elliptic magnetization satisfy the following relations: (i) when t?0.20 mm, the iron loss deterioration ratio is 60% or less; (ii) when 0.20 mm<t<0.27 mm, the iron loss deterioration ratio is 55% or less; and (iii) when 0.27 mm?t, the iron loss deterioration ratio is 50% or less. The iron loss deterioration ratio is calculated from ((WA?WB)/WB)×100, where WA is iron loss under 50 Hz elliptic magnetization of 1.7 T in a rolling direction and 0.6 T in a direction orthogonal to the rolling direction, and WB is iron loss under 50 Hz alternating magnetization of 1.7 T in the rolling direction.

Abstract: Vibration of an iron core is reduced to reduce transformer noise. An iron core for a transformer comprises a plurality of grain-oriented electrical steel sheets stacked together, wherein at least one of the plurality of grain-oriented electrical steel sheets: (1) has a region in which closure domains are formed in a direction crossing a rolling direction and a region in which no closure domains are formed; and (2) has an area ratio R of 0.10% to 30%, the area ratio R being an area ratio, to the whole grain-oriented electrical steel sheet, of a region in which a shrinkage amount at a maximum displacement point when excited in the rolling direction at a maximum magnetic flux density of 1.7 T and a frequency of 50 Hz is at least 2×10?7 less than a shrinkage amount in the region in which no closure domains are formed.

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: Vibration of an iron core is reduced to reduce transformer noise. An iron core for a transformer comprises a plurality of grain-oriented electrical steel sheets stacked together, wherein at least one of the plurality of grain-oriented electrical steel sheets: (1) has a region in which closure domains are formed in a direction crossing a rolling direction and a region in which no closure domains are formed; (2) has an area ratio R0 of 0.10% to 3.0%, the area ratio R0 being defined as a ratio of S0 to S; and (3) has an area ratio R1a of 50% or more, the area ratio R1a being defined as a ratio of S1a to S1.

Abstract: A grain-oriented electrical steel sheet for a stacked transformer core. The steel sheet having a sheet thickness t, where t and an iron loss deterioration ratio obtained by subjecting the steel sheet under elliptic magnetization satisfy the following relations: (i) when t 0.20 mm, the iron loss deterioration ratio is 85% or less; (ii) when 0.20 mm<t<0.27 mm, the iron loss deterioration ratio is 80% or less; and (iii) when 0.27 mm?t, the iron loss deterioration ratio is 75% or less. The iron loss deterioration ratio is calculated from ((WA?WB)/WB)×100, where WA is iron loss under 50 Hz elliptic magnetization of 1.7 T in a rolling direction and 1.0 T in a direction orthogonal to the rolling direction, and WB is iron loss under 50 Hz alternating magnetization of 1.7 T in the rolling direction.

Abstract: A magnetic domain refining treatment is performed by dividing a surface of a steel sheet into a plurality of regions in a widthwise direction, disposing a laser irradiation apparatus or an electron beam irradiation apparatus in each of the regions, and forming beam-irradiated regions through beam irradiation, wherein beams are irradiated so that a nature of a juncture between beam-irradiated regions satisfies 0???0.3×a and ?1.2×a+0.02×w?0.5×??6.5????0.13×a?200×(1/w)+5.4 when TD spacing ? at the juncture between the beam-irradiated regions is ?3 to 0 mm, whereby a grain oriented electrical steel sheet having an excellent iron loss property is produced in a good productivity.

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: 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: A method of manufacturing a grain oriented electrical steel sheet includes subjecting a steel slab to a rolling process including cold rolling to obtain a steel sheet with a final sheet thickness, the steel slab containing by mass % C: 0.01% to 0.20%, Si: 2.0% to 5.0%, Mn: 0.03% to 0.20%, sol. Al: 0.010% to 0.05%, N: 0.0010% to 0.020%, at least one element selected from S and Se in a total of 0.005% to 0.040%, and the balance including Fe and incidental impurities; forming, by a chemical process, 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; subjecting the steel sheet to decarburization annealing; applying an annealing separator thereon mainly composed of MgO; and subjecting the steel sheet to final annealing to manufacture a grain oriented electrical steel sheet.