Nippon Steel Corporation

Hideyuki Kobayashi

Satoshi Arai

Kazutoshi Takeda

Hiroyasu Fujii

Kenichi Murakami

Hideyuki Hamamura

Tatsuhiko Sakai

Shuichi Yamazaki

Yuji Kubo

Norikazu Fujii

Masato Mizokami

Hotaka Honma

Eiichi Nanba

Kaoru Sato

A grain-oriented electrical steel sheet includes: a base steel sheet; a primary film formed on a surface of the base steel sheet; and a tension insulation coating formed on a surface of the primary film, in which a magnetic domain control is performed by irradiating the tension insulation coating with a laser from above. When a strip-like sample having a length of 300 mm in a direction parallel to a rolling direction of the grain-oriented electrical steel sheet and a length of 60 mm in a direction parallel to a transverse direction is extracted from the grain-oriented electrical steel sheet, a range from a surface of the tension insulation coating to a depth position of 5 &#x3bc;m toward the base steel sheet side from an interface between the base steel sheet and the primary film is removed by pickling at least one surface of the sample, and a warpage amount of the sample is thereafter measured, the warpage amount satisfies predetermined conditions.

Grain-oriented electrical steel sheet causing low core loss and low magnetostriction

An object of the present invention is to provide a grain-oriented electrical steel sheet with low core loss and low magnetostriction and a method for producing the same. The grain-oriented electrical steel sheet is excellent in reduced core loss and magnetostriction while under a high flux density of 1.9 T, comprises a refined magnetic domain comprising a laser irradiated portion which has melted and resolidified to form a solidified layer, wherein the thickness of the solidified layer is 4 &#x3bc;m or less. The grain-oriented electrical steel sheet may further comprise a laser irradiated portion where a surface roughness Rz is small and a cross section viewed from a transverse direction has a concave portion having a width of 200 &#x3bc;m or less and a depth of 10 &#x3bc;m or less for further improvement.

Low core loss grain-oriented electrical steel sheet and method for 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

A high permeability grain-oriented electromagnetic steel sheet with a higher tension-imparting effect and more excellent cohesion and magnetic properties compared to the prior art, which also maintains sufficient corrosion resistance to withstand practical use; the grain-oriented electromagnetic steel sheet has on its surface an insulation coating comprising a first layer composed mainly of a divalent or trivalent metal hydrogen phosphate salt and silica, and a second layer composed mainly of aluminum borate and leaving a surface roughness of 0.1 &mgr;m-0.35 &mgr;m in terms of Ra (center like average roughness).

Grain-oriented electromagnetic steel sheet with excellent coating properties and process for its manufacture

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Himeji, Japan

Hideyuki Kobayashi