Kawasaki Steel Corporation

Jfe Steel Corporation

Mitsumasa Kurosawa

Michiro Komatsubara

Yasuyuki Hayakawa

Kunihiro Senda

Takeshi Imamura

Seiji Okabe

Masaki Kawano

Kazuaki Tamura

Toshito Takamiya

Minoru Takashima

Hiroaki Toda

Makoto Watanabe

Takahiro Kan

Toshio Sadayori

Susumu Sato

Takashi Obara

Atsuhito Honda

Katsuo Iwamoto

Hiroi Yamaguchi

Mineo Muraki

Yoshiaki Iida

Kozo Tsunoyama

Hideo Suzuki

Yuka Komori

Masayuki Sakaguchi

Tadashi Nakanishi

Ujihiro Nishiike

Hirotake Ishitobi

Takafumi Suzuki

Tetsuo Toge

Yoshinori Kobayashi

Keiji Sakai

Toshiro Fujiyama

Keisuke Kotani

Chizuko Goto

Hideo Yamagami

Toshio Sandayori

A grain oriented electromagnetic steel sheet is free from an undercoating mainly composed of forsterite (MgSiO), excellent in processability and magnetic properties and useful to production cost, and has a composition containing, by % by mass, 2.0 to 8.0% of Si, wherein secondary recrystallized grains contains fine crystal grains having a grain diameter of 0.15 mm to 0.50 mm at a rate of 2 grains/cmor more. In the process of producing the steel sheet, inhibitors are not utilized, and the fine crystal grains are achieved by high purification and low temperature final annealing.

Grain-oriented magnetic steel sheet having no undercoat film comprising forsterite as primary component and having good magnetic characteristics

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 method of manufacturing a grain-oriented steel sheet including hot-rolling a slab prepared using molten steel containing, by mass %, C of not more than about 0.08%, Si of about 2.0 to about 8.0% and Mn of about 0.005 to about 3.0%; optionally annealing the hot-rolled steel sheet; performing cold rolling once, or twice or more with intermediate annealing therebetween; performing primary recrystallization annealing in a low- or non-oxidizative atmosphere and adjusting the C content in the steel sheet after primary recrystallization annealing to be held in the range of about 0.005 to about 0.025 mass %; performing secondary recrystallization annealing; decarburization annealing; and, preferably, performing additional high-temperature continuous or batch annealing. A grain-oriented electrical steel sheet having a sufficiently high magnetic flux density and a low iron loss can be advantageously obtained even when it is manufactured without using an inhibitor.

Method of manufacturing grain-oriented electrical steel sheets

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

A grain oriented electrical steel sheet comprises metal part containing Si: about 2.5 to about 5.0 mass % and Cr: about 0.05 to about 1.0 mass %, and an insulation coating formed on a surface of the metal part. A tension imparted to the metal part in the rolling direction by the insulation coating is not smaller than about 3.0 MPa. Magnetic flux density B satisfies a specific relation formula. A plurality of linear strains or grooves are formed in a surface of the steel sheet and linearly extended at an angle of not larger than about 45&deg; (in each direction) relative to a direction perpendicular to a rolling direction such that an interval D of the linear strains or grooves satisfies a specific relation formula depending on the Cr content. A grain oriented electrical steel sheet is thereby obtained which has lower iron loss after domain refining treatment than conventional values. In the production process for the steel sheet of the invention, parameters such as annealing temperature in annealing before final cold rolling are controlled.

Grain oriented electrical steel sheet with low iron loss and production method for same

Electrical steel sheets having superior magnetic properties, anti-noise properties, and workability, are ideal for use a compact iron core material in electric apparatuses, such as compact transformers, motors, and electric generators. A totally new electrical steel sheet and a manufacturing method therefor are proposed, in which the electrical steel sheet is not only most advantageous in magnetic properties but also advantageous from economic point of view. That is, the electrical steel sheet of the present invention is composed of from about 2.0 to 8.0 wt % Si, from about 0.005 to 3.0 wt % Mn, from about 0.0010 to 0.020 wt % Al, balance essentially iron. The magnetic flux density B (L) in a rolling direction and the magnetic flux density B (C) in the direction perpendicular thereto are 1.70 T or more, and the B (L)/B (C) is 1.005 to 1.100. In addition, the secondary recrystallized grains inclined by 20&prime; or less with respect to the &lcub;100&rcub;<001> orientation are present in the steel sheet at an areal ratio of 50 to 80%, and secondary recrystallized grains inclined by 20&deg; or less with respect to the &lcub;110&rcub;<001> orientation are present in the steel sheet at an areal ratio of 6 to 20%.

Electrical steel sheet suitable for compact iron core and manufacturing method therefor

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

Grain-oriented silicon steel sheet with Bi as an auxiliary inhibitor and a forsterite coating film having a Cr spinel oxide subscale of FeCr O or Fe Mn Cr O (0.6&lE;x&lE;1), made from a steel slab containing 0.005-0.20 wt % of Bi and 0.1-1.0 wt % of Cr.

Grain-oriented silicon steel sheet and process for production thereof

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

Growing community of inventors

Okayama, Japan

Mitsumasa Kurosawa