Abstract: A grain-oriented electrical steel sheet exhibits reduced iron loss and reduced noise. The electrical steel sheet has magnetic domains refined by regions with a high lattice defect density being locally formed on the surface of or within the steel sheet, in which the regions with a high lattice defect density has a hardness, as measured by a micro Vickers hardness meter, equal to or lower than that of other regions.

Abstract: A grain-oriented electrical steel sheet is subjected to magnetic domain refining treatment by irradiating a steel sheet surface with an electron beam having a beam diameter d of 0.40 mm or less, wherein a modulated irradiation line region is formed with repeating units connected to each other in the line region direction, a periodic distance of the repeating units in the modulated irradiation line region is ?×d mm to 2.5×d mm, a repeating interval of the modulated irradiation line region in the rolling direction is 4.0 mm to 12.5 mm, and intensity of the electron beam is not lower than an intensity with which long and narrow divided magnetic domains extending in the modulated irradiation line region direction are formed at least on an irradiated side, and not higher than an intensity with which coating damage does not occur and a plastic strain region is not formed on the irradiated side.

Abstract: A grain-oriented electrical steel sheet exhibits reduced iron loss and reduced noise. The electrical steel sheet has magnetic domains refined by regions with a high lattice defect density being locally formed on the surface of or within the steel sheet, in which the regions with a high lattice defect density has a hardness, as measured by a micro Vickers hardness meter, equal to or lower than that of other regions.

Abstract: A grain-oriented electromagnetic steel sheet having a multiplicity of fine grains having a diameter of about 3 mm or less on the surface of the steel sheet, in a numerical ratio of about 65% or more and of about 98% or less relative to the constituting grains that penetrate the sheet along the direction parallel to its thickness, and a method for producing the same. The fine grains are artificially created and regularly disposed with a random orientation in the steel sheet, and contribute to decreasing the strain susceptibility of the steel. More preferably, a treatment for finely dividing magnetic domains is applied on the surface of the steel sheet. Transformers based upon the steel sheet have excellent magnetic characteristics (iron loss and magnetic flux density) together with strain resistance, and the steel sheet has good practical device characteristics (building factor) after being assembled into a transformer.

Abstract: The invention is a grain-oriented magnetic steel sheet having extremely low iron loss, suitable for use as an iron core material for transformers and power generators, and a method for producing the same. The method includes forming a coating layer on a surface of a steel sheet having a thickness of 0.27 mm or less by vapor deposition in a low oxidizing atmosphere with an oxygen partial pressure (Po2) of less than 0.1 atm and a total pressure of 0.1 atm or more. The steel sheet has extremely low iron loss with a thickness of 0.27 mm or less and includes a coating layer formed by vapor deposition on a matrix surface.

Abstract: Manufacturing a grain-oriented electrical steel sheet, a secondary recrystallization step and a forsterite coating forming step are separated into first batch annealing for developing secondary recrystallization and second batch annealing for forming a forsterite coating, with continuous annealing performed between these two steps of batch annealing, to produce a grain-oriented electrical steel sheet that is superior in both magnetic characteristics and coating characteristics.

Abstract: The present invention relates to a grain-oriented magnetic steel sheet having extremely low iron loss, which is suitable for use as an iron core material for transformers and power generators, and to a method for producing the same. That is, in accordance with the present invention, a method for producing a grain-oriented magnetic steel sheet includes the step of forming a coating layer on a surface of the matrix of a steel sheet having a thickness of 0.27 mm or less by vapor deposition in a low oxidizing atmosphere with an oxygen partial pressure (Po2) of less than 0.1 atm and a total pressure of 0.1 atm or more. A grain-oriented magnetic steel sheet of the present invention having extremely low iron loss with a thickness of 0.27 mm or less includes a coating layer formed by vapor deposition on a matrix surface.

Abstract: A grain-oriented electromagnetic steel sheet having a multiplicity of fine grains having a diameter of about 3 mm or less on the surface of the steel sheet, in a numerical ratio of about 65% or more and of about 98% or less relative to the constituting grains that penetrate the sheet along the direction parallel to its thickness, and a method for producing the same. The fine grains are artificially created and regularly disposed with a random orientation in the steel sheet, and contribute to decreasing the strain susceptibility of the steel. More preferably, a treatment for finely dividing magnetic domains is applied on the surface of the steel sheet.

Abstract: Non-oriented magnetic steel sheets, which are mainly used as materials for iron cores for use in electric apparatuses, have a low iron loss and a high magnetic flux density at the same time. The non-oriented magnetic steel sheet comprises from about 1.5 to about 8.0 weight % Si, from about 0.005 to about 2.50 weight % Mn, and not more than about 50 ppm each of C, S, N, O, and B, in which a crystal orientation parameter <&Ggr;> is 0.200 or less. In addition, the average crystal grain diameter is preferably from about 50 to about 500 &mgr;m, and an areal ratio of crystal grains on a surface of the steel sheet is preferably 20% and less, in which crystal plane orientations of the crystal grains are within 15° from the <111> axis. In addition, the non-oriented magnetic steel sheet preferably contains small amounts of elements such as Al, Sb, Ni, Sn, Cu, P, and Cr. The manufacturing method for the non-oriented magnetic steel is also described.

Abstract: Manufacturing a grain-oriented electrical steel sheet, a secondary recrystallization step and a forsterite coating forming step are separated into first batch annealing for developing secondary recrystallization and second batch annealing for forming a forsterite coating, with continuous annealing performed between these two steps of batch annealing, to produce a grain-oriented electrical steel sheet that is superior in both magnetic characteristics and coating characteristics.

Abstract: Non-oriented magnetic steel sheets, which are mainly used as materials for iron cores for use in electric apparatuses, have a low iron loss and a high magnetic flux density at the same time. The non-oriented magnetic steel sheet comprises from about 1.5 to about 8.0 weight % Si, from about 0.005 to about 2.50 weight % Mn, and not more than about 50 ppm each of C, S, N, O, and B, in which a crystal orientation parameter <&Ggr;> is 0.200 or less. In addition, the average crystal grain diameter is preferably from about 50 to about 500 &mgr;m, and an areal ratio of crystal grains on a surface of the steel sheet is preferably 20% and less, in which crystal plane orientations of the crystal grains are within 15° from the <111> axis. In addition, the non-oriented magnetic steel sheet preferably contains small amounts of elements such as Al, Sb, Ni, Sn, Cu, P, and Cr. The manufacturing method for the non-oriented magnetic steel is also described.

Abstract: A grain-oriented electromagnetic steel sheet having a multiplicity of fine grains having a diameter of about 3 mm or less on the surface of the steel sheet, in a numerical ratio of about 65% or more and of about 98% or less relative to the constituting grains that penetrate the sheet along the direction parallel to its thickness, and a method for producing the same. The fine grains are artificially created and regularly disposed with a random orientation in the steel sheet, and contribute to decreasing the strain susceptibility of the steel. More preferably, a treatment for finely dividing magnetic domains is applied on the surface of the steel sheet. Transformers based upon the steel sheet have excellent magnetic characteristics (iron loss and magnetic flux density) together with strain resistance, and the steel sheet has good practical device characteristics (building factor) after being assembled into a transformer.

Abstract: A method of making a grain-oriented electromagnetic steel sheet having a low iron loss and a high magnetic flux density, from a steel slab with 0.03 to 0.095 wt % carbon, about 1.5 to 7.0 wt % Si, about 0.03 to 2.50 wt % manganese, about 0.003 to 0.040 wt % sulfur and/or selenium, about 0.0010 to 0.0070 wt % borbon, about 30 to 120 wtppm nitrogen, about 0.015 wt % or less aluminum, and about 0.010 wt % or less vanadium by subjecting the steel slab to reheating, hot rolling, rapid cooling, cold rolling, primary recrystallization annealing, coating with an annealing separator, final annealing, secondary recrystallization, and coiling.

Abstract: Non-oriented magnetic steel sheets, which are mainly used as materials for iron cores for use in electric apparatuses, have a low iron loss and a high magnetic flux density at the same time. The non-oriented magnetic steel sheet comprises from about 1.5 to about 8.0 weight % Si, from about 0.005 to about 2.50 weight % Mn, and not more than about 50 ppm each of C, S, N, O, and B, in which a crystal orientation parameter <&Ggr;> is 0.200 or less. In addition, the average crystal grain diameter is preferably from about 50 to about 500 &mgr;m, and an areal ratio of crystal grains on a surface of the steel sheet is preferably 20% and less, in which crystal plane orientations of the crystal grains are within 15° from the <111> axis. In addition, the non-oriented magnetic steel sheet preferably contains small amounts of elements such as Al, Sb, Ni, Sn, Cu, P, and Cr. The manufacturing method for the non-oriented magnetic steel is also described.

Abstract: Electromagnetic steel sheet from a high-purity steel slab, composed essentially of Si 2.0 to 8.0 wt %, Mn 0.005 to 3.0 wt % and Al 0.0010 to 0.012 wt % with each of Se, S, N and O each not more than 30 ppm.

Abstract: Grain-oriented magnetic steel sheet made by the method comprising of hot rolling and final finish annealing, wherein (1) the O content in the steel slab is limited to up to about 30 wtppm; (2) for the entire steel sheet including an oxide film before final finish annealing, from among impurities, the Al content is limited to up to about 100 wtppm, and the contents of B, V, Nb, Se, S, and N, to up to about 50 wtppm; and (3) during final finish annealing, the N content in the steel is, at least in the temperature region of from about 850 to 950° C., limited within the range of from about 6 to 80 wtppm.

Abstract: Manufacturing semiprocessed non-oriented magnetic steel sheets, which has superior workability in steps of assembling cores for motors or the like, in which improvement in productivity and higher accuracy of the products can be realized, by hot rolling a steel slab containing about 0.001 to 0.03 wt % C, about 0.1 to 1.0 wt % Si, about 0.01 to 1.0 wt % Al, about 0.05 to 1.0 wt % Mn, and about 0.001 to 0.15 wt % P, cold rolling the hot rolled sheet, continuous annealing the cold rolled sheet, and skin pass rolling the annealed sheet, wherein the average cooling rate in the continuous annealing process is about 10° C./second or more and skin pass rolling is performed at a reduction rate of about 0.5 to 5% within about 20 hours after continuous annealing.

Abstract: Electromagnetic steel sheet from a high-purity steel slab, composed essentially of Si 2.0 to 8.0 wt %, Mn 0.005 to 3.0 wt % and Al 0.0010 to 0.012 wt % with each of Se, S, N and O each not more than 30 ppm.

Abstract: In a grain oriented electrical steel sheet used for cores of transformers and generators, a high alignment degree of grain orientations reduces iron loss, by precipitating very fine AlN or/and BN and providing strong inhibiting effect against the growth of the primary recrystallized grains, providing radically improved texture and grain structure in the steel.

Abstract: Grain-oriented magnetic steel sheet made by the method-including hot rolling and final finish annealing, wherein (1) the O content in the steel slab is limited to up to about 30 ppm; (2) for the entire steel sheet having final thickness including an oxide film before final finish annealing, from among impurities, the Al content is limited to up to about 100 wtppm, and the respective contents of B, V, Nb, Se, S, P, and N, to up to about 50 wtppm each; and (3) during final finish annealing, the N content in the steel is, at least in the temperature region of from about 850 to 950° C., limited within the range of from about 6 to 80 wtppm.