Kawasaki Steel Corporation

Jfe Steel Corporation

Michiro Komatsubara

Yasuyuki Hayakawa

Mitsumasa Kurosawa

Kunihiro Senda

Toshito Takamiya

Katsuo Iwamoto

Hiroi Yamaguchi

Atsuhito Honda

Takahiro Kan

Yoshiaki Iida

Kazuaki Tamura

Masaki Kawano

Ujihiro Nishiike

Toshio Sadayori

Minoru Takashima

Mineo Muraki

Toshio Ichida

Makoto Watanabe

Isao Matoba

Ko Matsumura

Takafumi Suzuki

Tetsuo Toge

Hiroaki Toda

Hiroshi Shimanaka

Hirotake Ishitobi

Keiji Nishimura

Yuka Komori

Masataka Yamada

Kenichi Sadahiro

Seiji Okabe

Shigehiro Takajo

Hirotaka Inoue

Bunjiro Fukuda

Fumihiko Takeuchi

Keiji Sakai

Masayoshi Ishida

Toshiro Fujiyama

Toshio Sandayori

Masako Hisata

Humihiko Takeuchi

Chizuko Goto

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.

Grain-oriented electrical steel sheet and method for manufacturing same

Grain-oriented magnetic steel sheet made by the method-including hot rolling and final finish annealing, wherein

Method of making grain-oriented magnetic steel sheet having low iron loss

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.

Grain-oriented electromagnetic steel sheet

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 (Po ) 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.

Grain oriented electromagnetic steel sheet exhibiting extremely small watt loss and method for producing the same

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.

Method of manufacturing grain-oriented electrical steel sheet

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&deg; 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.

Non-oriented magnetic steel sheet having low iron loss and high magnetic flux density and manufacturing method therefor

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.

Method of manufacturing a grain-oriented electromagnetic steel sheet

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.

Electromagnetic steel sheet and process for producing the same

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&deg; 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.

Method for manufacturing magnetic steel sheet having superior workability and magnetic properties

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.

Grain oriented electrical steel sheet having very low iron loss and production process for same

A grain-oriented electromagnetic steel sheet is provided which has a low ratio of iron loss in a weaker magnetic field to that in a stronger magnetic field and has special advantage in EI cores and the like. Also provided is a process for producing that steel sheet. The grain-oriented electromagnetic steel sheet is characterized in that its crystal grains of important components are specified in terms of their proportions in number, and the contents of Al, Ti and B, with a forsterite film formed on a surface of the steel sheet. In the process a low-Al silicon slab is heated at below 1,250&deg; C. before hot rolling and the hot-rolled sheet is annealed with a temperature rise in the range of from 5 to 25&deg; C./sec and at a temperature of from about 800 to 1,000 for a period of time of shorter than about 100 seconds.

Process for producing grain-oriented electromagnetic steel sheet

Growing community of inventors

Okayama, Japan

Michiro Komatsubara