Nippon Steel Corporation

Idemitsu Kosan Company, Limited

Eisuke Minematsu

Takeshi Kubota

Fumiaki Takahashi

Shuichi Yamazaki

Osamu Tanaka

Norikazu Fujii

Masato Mizokami

Takahito Mizumura

Kikuji Hirose

Masao Yabumoto

Toshihiko Uemura

Keiji Noma

Naoki Nagase

Seikichi Kitabatake

Hideo Sugii

Isao Noguchi

Provided are: a metalworking oil composition having excellent workability and rust inhibiting performance, which is prepared by blending (A) at least one carboxylate selected from a polyhydric alcohol ester of a monocarboxylic acid and a monohydric alcohol ester of a polycarboxylic acid, (B) a phosphorus-containing compound, and (C) a rust inhibitor, wherein the monocarboxylic acid has 9 or more and 21 or less carbon atoms, and the content of the carboxylate is 0.6% by mass or more based on the total amount of the composition; and a metalworking method using the composition.

Metalworking oil composition and metalworking method

A wound core is formed by laminating a plurality of bent bodies formed from a grain-oriented electrical steel sheet having a coating containing phosphorus formed on a surface, in a sheet thickness direction of the grain-oriented electrical steel sheet, in which the bent body is formed in a rectangular shape by having four flat portions and four corner portions adjacent to the flat portions, the corner portion has a bent region having a total bending angle of approximately 90&#xb0; in a side view, the number of deformation twins present in the bent region in the side view is five or less per 1 mm of a length of a center line in the bent region in the sheet thickness direction, and the amount of phosphorus eluted from the corner portion in a case of being boiled in water for 30 minutes is 6.0 mg or less per 1 mof a surface area of the corner portion.

Wound core and manufacturing method thereof

A method for forming an insulating film on a grain-oriented silicon steel sheet by applying an insulating coating solution comprising 100 parts by weight (calculated as the solid component) of a mixture of colloidal substances, composed of 50 to 98 weight % (calculated as the solid component SiO.sub.2) of colloidal silica having a partical diameter not larger than 50 nano m, and 2 to 50 weight % (calculated as the solid component) of at least one colloidal substance having a particle diameter randing from 80 to 3000 nano m, selected from the group consisting of oxides, carbides, nitrides, sulfides, borides, hydroxides, silicates, carbonates, borates, sulfates, nitrates and chlorides of Fe, Ca, Ba, Zn, Al, Ni, Sn Cu, Cr, Cd, Nd, Mn, Mo, Si, Ti, W, Bi, Sr, and V, 130 to 250 parts by weight of at least one selected from the group consisting of phosphates of Al, Mg, Ca, and Zn, and 10 to 40 parts by weight of at least one selected from the group consisting of chromic anhydride, chromate, and dichromate. The insulating coating produces good surface film lubricity and good heat resistance and excellent workability when fabricating into a wound core as well as excellent iron loss properties.

Production of grain-oriented silicon steel sheets having an insulating

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Chiyoda-ku, Japan

Eisuke Minematsu