Jfe Steel Corporation

Kawasaki Steel Corporation

Shin-etsu Chemical Co., Ltd.

Hiroaki Toda

Yoshihiko Oda

Tadashi Nakanishi

Yoshiaki Zaizen

Kunihiro Senda

Hiroi Yamaguchi

Mitsumasa Kurosawa

Makoto Watanabe

Shinji Koseki

Seiji Okabe

Michiro Komatsubara

Takeshi Omura

Atsuhito Honda

Takafumi Suzuki

Yuji Kimura

Toshito Takamiya

Shigehiro Takajo

Tomoyuki Okubo

Mineo Muraki

Tatsuhiko Hiratani

Kazuhiro Hanazawa

Norifumi Yoshida

Masaaki Kohno

Ken-ichiro Suzuki

Koji Nishikawa

Tadashi Nakanish

Disclosed is a grain-oriented electrical steel sheet that exhibits excellent iron loss properties and a good building factor, in which damage to a tension coating is suppressed. In a grain-oriented electrical steel sheet having a tension coating, an interlaminar current is 0.15 A or less, a plurality of linear strain regions extending in a direction transverse to the rolling direction are formed, the strain regions are formed at line intervals in the rolling direction of 15 mm or less, each of the strain regions has closure domains formed therein, and each of the closure domains has a length d along the sheet thickness direction of 65 &#x3bc;m or more and a length w along the rolling direction of 250 &#x3bc;m or less.

Grain-oriented electrical steel sheet and process for producing same

A non-oriented electrical steel sheet having a chemical composition comprising C: not more than 0.010 mass %, Si: 1.0-7.0 mass %, Mn: 0.001-3.0 mass %, sol. Al: 0.0001-3.5 mass %, P: 0.01-0.2 mass %, S: not more than 0.010 mass %, N: not more than 0.010 mass % and the remainder being Fe and inevitable impurities, wherein a ratio (P/Fe) of a peak-peak height Pof P near to an electronic energy of 120 eV to a peak-peak height Feof Fe near to an electronic energy of 700 eV in an Auger differential spectrum obtained by analyzing a broken surface of a grain boundary through Auger electron spectroscopy is not less than 0.1 and a sheet thickness is 0.10-0.50 mm, and a motor using such a non-oriented electrical steel sheet as an iron core.

Non-oriented electrical steel sheet having high magnetic flux density and motor

According to the present invention, a high-strength electrical steel sheet that is suitable as rotor material for a high speed motor, steadily has high strength, and also has excellent magnetic properties can be obtained by setting the chemical composition thereof to include, by mass %, C: 0.005% or less, Si: more than 3.5% and 4.5% or less, Mn: 0.01% or more and 0.10% or less, Al: 0.005% or less, Ca: 0.0010% or more and 0.0050% or less, S: 0.0030% or less, and N: 0.0030% or less, Ca/S being 0.80 or more, the balance being Fe and incidental impurities, and by setting the sheet thickness to 0.40 mm or less, the non-recrystallized deformed microstructure to 10% or more and 70% or less, tensile strength (TS) to 600 MPa or more, and iron loss Wto 30 W/kg or less.

High-strength electrical steel sheet and method of producing the same

A non-oriented electrical steel sheet having a high magnetic flux density and a low anisotropy contains C: not more than 0.01 mass %, Si: 1-4 mass %, Mn: 0.05-3 mass %, P: 0.03-0.2 mass %, S: not more than 0.01 mass %, Al: not more than 0.004 mass %, N: not more than 0.005 mass %, As: not more than 0.003 mass %, and preferably further contains one or two of Sb: 0.001-0.1 mass % and Sn: 0.001-0.1 mass % or further contains one or two of Ca: 0.001-0.005 mass % and Mg: 0.001-0.005 mass %.

Non-oriented electrical steel sheet having excellent magnetic properties

By using a hot-rolled steel sheet of a predetermined chemical composition, and annealing the hot-rolled steel sheet in nitrogen atmosphere at 1000&#xb0; C. for 30 seconds, and then immersing in a solution of 7% HCl at 80&#xb0; C. for 60 seconds to obtain a hot-rolled steel sheet having a pickling weight loss of 10 g/mor more and 35 g/mor less, it is possible to obtain a hot-rolled steel sheet for producing a non-oriented electrical steel sheet that not only has excellent magnetic properties such as iron loss properties and magnetic flux density, but also has reduced steel sheet surface defects and an excellent manufacturing yield.

Hot-rolled steel sheet for producing non-oriented electrical steel sheet and method of producing same

A non-oriented electrical steel sheet having a high magnetic flux density and a low iron loss at not only a commercial frequency but also a high frequency zone, which has a chemical composition including C: not more than 0.0050 mass %, Si: more than 1.5 mass % but not more than 5.0 mass %, Mn: not more than 0.10 mass %, sol. Al: not more than 0.0050 mass, P: more than 0.040 mass % but not more than 0.2 mass %, S: not more than 0.0050 mass %, N: not more than 0.0040 mass % and Ca: 0.001-0.01 mass % and the remainder being Fe and inevitable impurities and a compositional ratio of CaO in oxide-based inclusions existing in a steel sheet of not less than 0.4 and/or a compositional ratio of AlOof not less than 0.3, and a hot rolled steel sheet used as a raw steel material thereof.

Non-oriented electrical steel sheet and hot rolled steel sheet thereof

A steel slab having a chemical composition including C: not more than 0.005 mass %, Si: not more than 4 mass %, Mn: 0.03-2 mass %, P: not more than 0.2 mass %, S: not more than 0.004 mass %, Al: not more than 2 mass %, N: not more than 0.004 mass %, Se: not more than 0.0010 mass % and the balance being Fe and inevitable impurities is subjected to hot rolling, cold rolling and recrystallization annealing up to 740&#xb0; C. at an average heating rate of not less than 100&#xb0; C./s to produce a semi-processed non-oriented electrical steel sheet being high in the magnetic flux density and low in the iron loss after stress relief annealing.

Method for producing semi-processed non-oriented electrical steel sheet having excellent magnetic properties

The pickling loss when a hot-rolled steel sheet having a predetermined chemical composition is annealed at 1000&#xb0; C. for 30 seconds in a nitrogen atmosphere and then immersed in a solution of 7% HCl at 80&#xb0; C. for 60 seconds is in a range of 40 g/mor more and 100 g/mor less. A hot-rolled steel sheet for production of a non-oriented electrical steel sheet with not only excellent magnetic properties such as iron loss and magnetic flux density but also excellent recyclability and steel sheet surface appearance can thus be obtained.

Hot-rolled steel sheet for production of non-oriented electrical steel sheet and method of manufacturing same

A non-oriented electrical steel sheet having a high magnetic flux density and a low iron loss is produced by hot rolling a steel slab comprising C: not more than 0.005 mass %, Si: not more than 4 mass %, Mn: 0.03-3 mass %, Al: not more than 3 mass %, P: 0.03-0.2 mass %, S: present at not more than 0.005 mass %, N: not more than 0.005 mass %, Ca: 0.0005-0.01 mass %, provided that an atom ratio of Ca to S ((Ca mass %/40)/(S mass %/32)) is within a range of 0.5-3.5, and the balance being Fe and incidental impurities, hot band annealing, cold rolling, and then conducting recrystallization annealing by heating at an average temperature rising rate of not less than 100&#xb0; C/s up to at least 740&#xb0; C.

Method of producing non-oriented electrical steel sheet

A non-oriented electrical steel sheet has a chemical composition having C: not more than 0.005 mass %, Si: 2-7 mass %, Mn: 0.033 mass %, Al: not more than 3 mass %, P: not more than 0.2 mass %, S: not more than 0.005 mass %, N: not more than 0.005 mass %, Se: 0.0001&#x2dc;0.0005 mass %, As: 0.0005&#x2dc;0.005 mass % and the remainder being Fe and inevitable impurities, and an iron loss Win excitation at 50 Hz and 1.5 T of not more than 3.5 W/kg and a ratio (x/t) of amount of shear drop x (mm) to thickness t (mm) in punching of steel sheet of not more than 0.15 and is excellent in the iron loss property before punching and less in the deterioration of the iron loss property by punching.

Non-oriented electrical steel sheet being less in deterioration of iron loss property by punching

A method produces a high strength electrical steel sheet in which a cumulative rolling reduction ratio in rough rolling is 73.0% or more, in which in a hot band annealing step, an annealing condition is selected that satisfies an area ratio of recrystallized grains after hot band annealing of 100%, and a recrystallized grain size of 80 &#x3bc;m to 300 &#x3bc;m, under a condition where annealing temperature is 850&#xb0; C. to 1000&#xb0; C., and annealing duration is 10 seconds to 10 minutes, and in which in a final annealing step, an annealing condition is selected that satisfies an area ratio of recrystallized grains after the final annealing of 30% to 95%, and a length in the rolling direction of a connected non-recrystallized grain group of 2.5 mm or less, under a condition where annealing temperature is 670&#xb0; C. to 800&#xb0; C., and annealing duration is 2 seconds to 1 minute.

Method of producing electrical steel sheet

Provided is a method for stably obtaining a non-oriented electrical steel sheet with high magnetic flux density and excellent productivity, at a low cost by casting in a continuous casting machine a slab having a chemical composition including by mass %, C&#x2266;0.0050%, 3.0%&#x3c;Si&#x2266;5.0%, Mn&#x2266;0.10%, Al&#x2266;0.0010%, 0.040%&#x3c;P&#x2266;0.2%, N&#x2266;0.0040%, 0.0003%&#x2266;S&#x2266;0.0050%, Ca&#x2266;0.0015%, and total of at least one element selected from Sn and Sb: 0.01% or more and 0.1% or less, balance including Fe and incidental impurities, subjecting the slab to heating, then subjecting the slab to hot rolling to obtain a hot rolled steel sheet, then subjecting the steel sheet to hot band annealing, pickling, subsequent single cold rolling to obtain a final sheet thickness, then subjecting the steel sheet to final annealing, wherein in the hot band annealing, soaking temperature is 900&#xb0; C. or higher and 1050&#xb0; C. or lower, and cooling rate after soaking is 5&#xb0; C/s or more.

Method for manufacturing non-oriented electromagnetic steel sheet

A grain oriented electrical steel sheet is subjected to magnetic domain refinement by laser irradiation and has magnetic flux density Bof at least 1.91T, wherein the nitrogen content in the forsterite coating is 3.0 mass % or less. The grain oriented electrical steel sheet satisfies recent demand for iron loss reduction.

Grain oriented electrical steel sheet and method for manufacturing the same

A non-oriented electrical steel sheet has a chemical composition including, in mass %, C: 0.005% or less, Si: 5% or less, Al: 3% or less, Mn: 5% or less, S: 0.005% or less, P: 0.2% or less, N: 0.005% or less, Mo: 0.001 to 0.04%, Ti: 0.0030% or less, Nb: 0.0050% or less, V: 0.0050% or less, Zr: 0.0020% or less, one or both of Sb and Sn: 0.001 to 0.1% in total, and the balance being iron and incidental impurities.

Non-oriented electrical steel sheet

A grain oriented electrical steel sheet (1) suppresses the content of Cr in the grain oriented electrical steel sheet to 0.1 mass % or less; (2) sets the coating weight of a forsterite coating, in terms of basis weight of oxygen therein, to at least 3.0 g/mand thickness of an anchor portion as a lower portion of forsterite coating to 1.5 &#x3bc;m or less; and (3) controls setting the magnitude of deflection of a test specimen having length: 280 mm to at least 10mm when the forsterite coating is provided on only one surface thereof and at least 20 mm when forsterite coating and the tension coating are provided on the surface.

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Kurashiki, Japan

Hiroaki Toda