Nippon Steel Corporation

Asahi-Dow Limited

Hironobu Kawasaki

Yuichi Sato

Saburo Ayusawa

Satoshi Kado

Takashi Watanabe

Tomohiko Hayashi

Teruo Ikeno

Isamu Iwami

Tsutomu Ozawa

Akimi Umezono

Atsuro Kodama

Akira Teramae

Koji Yamada

The present invention relates to a method for forming on a magnetic amorphous alloy a film which is extremely thin, insulating, and corrosion-resistant and, particularly, can prevent secular deterioration of magnetic properties due to changing of the surface properties of the magnetic amorphous alloy. The method of the present invention comprises the steps of: applying, on the surface of the magnetic amorphous alloy, a predetermined amount of an acidic solution containing chromic acid, phosphoric acid, and a fluorine compound; and drying and baking the acidic aqueous solution, thereby forming, on the magnetic amorphous alloy, a film substantially comprised of a chromium and a phosphoric compound.

Method for surface treatment of a magnetic amorphous alloy

The present invention relates to a magnetic amorphous alloy sheet having an improved insulating property and improved corrosion resistance. The present invention aims to provide a film which is used to cover the magnetic amorphous alloy sheet, thereby improving its corrosion resistance and increasing the layer insulation resistance, without impairing the magnetic properties. The film according to the present invention has a thickness of up to 1 .mu.m and comprises a chromium compound which comprises hydrated chromium oxide. The film may additionally comprises metallic chromium. The magnetic amorphous alloy according to the present invention is suitable for use as a transformer core achieving a high building factor.

Magnetic amorphous alloy sheet having a film thereon

A surface treated steel materials coated with manganese having a film of MmOOH (manganic hydroxide) formed thereon, which show excellent corrosion resistance, workability and weldability. The surface treated steel materials may be further coated with zinc as a base coating underlying the manganese coating or further coated with a coating of at least one selected from the group consisting of P, B, Si, Cu, Mn, Cr, Ni, Co, Fe, Zn, Al, Ca, Mg, Ti, Pb, Sn, inorganic carbon and their compounds and still further coated with an organic coating. The film of MmOOH (manganic hydroxide) is formed by a treatment in an aqueous solution containing Cr.sup.6+.

Surface treated steel materials

Manganese coated steel materials having a compact film of hydrated manganese oxide formed on the manganese coating by heating and drying. Manganese coated steel materials of the present invention show very excellent corrosion resistance in ordinary corrosive environments as well as special corrosive environments such as marine environments and young plant cultivation in mountaineous forests. For further improvement of corrosion resistance, organic coating and metal coatings are applied.

Manganese surface coated steel materials

A polyamide composition comprising 50 to 95 parts by weight of a polyamide and 50 to 5 parts by weight of an ethylenic copolymer of ethylene, an alkyl ester of unsaturated carboxylic acid, an unsaturated carboxylic acid and a metal salt of unsaturated carboxylic acid has excellent processability such as fluidity at melting and remarkably improved impact strength when molded. The polyamide composition may further contain one or more inorganic materials such as glass fiber without lowering physical properties.

Polyamide compositions

A bolt, nut and washer is first coated with an under-coating consisting of metal phosphate, and is then coated with a second or top coating consisting of a chromium compound and one or more of a metal salt of higher fatty acid, polyolefin and polyethylene tetrafluoride dissolved or dispersed in a vehicle. The composite coating improves the corrosion resisting and lubricating properties of bolts, nuts and washers coated therewith, and also serves as an excellent base for paints.

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Kawasaki, Japan

Hironobu Kawasaki