Nippon Steel Corporation

Nippon Steel Sumitomo Metal Corporation

Eiichi Nanba

Satoshi Arai

Nobuo Tachibana

Kazutoshi Takeda

Yuji Kubo

Hotaka Honma

Shuichi Yamazaki

Kenichi Murakami

Yousuke Kurosaki

Kazumi Mizukami

Kenji Kosuge

Kishio Mochinaga

Naoki Yagi

Shinya Ishii

Katsuyuki Yanagihara

Fumikazu Ando

Koki Tanaka

Nobusato Morishige

Hideyuki Kobayashi

A method according to the present invention has: isolating, by extraction, particles contained in a metal material to be analyzed in a solution using a particle isolator; dispersing the particles isolated by extraction into a solvent to prepare a dispersion, and fractionating the dispersion into a plurality of particle dispersions based on particle sizes, using a field flow fractionator; and irradiating laser light on each of the particle dispersions separated based on predetermined particle sizes, to thereby measure absolute values of the particle size based on angular dependence of reflection intensity, and also to thereby measure the number density based on magnitude of reflection intensity.

Method of analyzing particle size distribution of particles in metal material

The present invention is a grain-oriented electrical steel sheet characterized in that Bi is present at 0.01 to less than 1,000 ppm in terms of mass at the interface of the substrate steel and the primary film of the grain-oriented electrical steel sheet. The grain-oriented electrical steel sheet is produced by any of the processes of: before decarburization annealing, applying preliminary annealing for 1 to 20 sec. at 700&#xb0; C. or higher and controlling an atmosphere in the temperature range; controlling the maximum attaining temperature B (&#xb0; C.) before final cold rolling so that the maximum attaining temperature B may satisfy the expression, &#x2212;10&#xd7;ln(A)+1,100&#x2266;B&#x2266;10&#xd7;ln(A)+1,220, in accordance with a Bi content A (ppm) and at the same time heating the steel sheet cold rolled to the final thickness to 700&#xb0; C. or higher within 10 sec. or at a heating rate of 100&#xb0; C./sec. or more before decarburization annealing, or immediately thereafter applying preliminary annealing for 1 to 20 sec. at 700&#xb0; C. or higher; or controlling a TiOamount B added in relation to MgO of 100 as parts by weight and an MgO coating amount C (g/m) so that the expression, A&#x2266;B&#xd7;C&#x2266;400, may be satisfied in accordance with the Bi content A (ppm).

Ultra-high magnetic flux density grain-oriented electrical steel sheet excellent in iron loss at a high magnetic flux density and film properties and method for producing the same

Grain-oriented electrical steel sheet excellent in coating adhesion is provided. The steel sheet contains Si: 2 to 7% mass % and has a primary coating composed mainly of forsterite on its surface. A compound (A) containing one or more elements selected from among Ca, Sr and Ba, at least one rare earth metal, and sulfur is incorporated in the primary coating so as to reside in the interface layer between the primary coating and the steel sheet. As a result, occurrence of primary coating exfoliation at regions that are strongly worked during manufacture of a wound core transformer or the like is prevented.

Grain-oriented electrical steel sheet excellent in coating adhesion and method of producing the same

The present invention provides oriented magnetic steel plate with excellent coating adhesion, in particular coating edge peeling resistance, that is, oriented magnetic steel plate with excellent coating adhesion containing, by mass %, Si: 1.8 to 7% and having a primary coating having forsterite as its main ingredient on its surface, said oriented magnetic steel plate characterized in that said primary coating contains one or more of Ce, La, Pr, Nd, Sc, and Y in an areal weight per side of 0.001 to 1000 mg/m; characterized in that said primary coating contains Ti in an areal weight per side of 1 to 800 mg/m; and characterized in that said primary coating contains one or more of Sr, Ca, and Ba in an areal weight per side of 0.01 to 100 mg/m.

Oriented magnetic steel plate excellent in coating adhesion and method of production of same

Grain-oriented electrical steel sheet excellent in film characteristics and magnetic characteristics, process for producing same, and decarburization annealing facility used in same process

A process for producing a grain-oriented electrical steel sheet wherein during the decarburization annealing step, the steel sheet is first rapidly heated in a rapid heating chamber and the PH O/PH ratio in the rapid heating chamber is more than the PH O/PH ratio in the decarburization annealing furnace so as to provide improved oxide film adhesion.

Method of producing unidirectional electromagnetic steel sheet having excellent film characteristics and magnetic characteristics

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Himeji, Japan

Eiichi Nanba