Other

Fujikin Inc.

Nippon Kinzoku Co., Ltd.

Tetsutaro Ogushi

Takehisa Konishi

Nobukazu Ikeda

Tadahiro Ohmi

Akihiro Morimoto

Yasuyuki Shirai

Eiji Ideta

Tomoge Hitomi

Kazuaki Hatakeyama

The object of the present invention is to form a chromium-oxide film, excellent in corrosion resistance, without containing an oxide film of other metal onto the metallic material. The chromium-oxide passivation film, excellent in corrosion resistance, without containing the oxide film of other metal can be formed inexpensively and in a short time, and a fluid supplying system for safely supplying fluid with hard corrosivity is able to be provided. One step of forming the passivation film consisting of a chromium oxide layer by giving heat treatment, in an oxidizing atmosphere, after coating chromium on the metallic material having a surface roughness (Ra) not more than 1.5 &#x3bc;m.

Metal material having formed thereon chromium oxide passive film and method for producing the same, and parts contacting with fluid and system for supplying fluid and exhausting gas

The object of the present invention is to form a chromium-oxide film excellent in corrosion resistance without containing an oxide film of other metal onto the optional metallic material. The chromium-oxide passivation film excellent in corrosion resistance without containing the oxide film of other metal can be formed inexpensively and in a short time, and a fluid supplying system for supplying fluid hard in corrosivity in safety is able to be provided. This invention comprises a step of forming the passivation film consisting of a chromium oxide by giving heat treatment in an oxidizing atmosphere after coating chromium on metallic material of which surface roughness (Ra) of a coat surface is not more than 1.5 &#x3bc;m

A process for surface treatment of stainless steel sheets for excellent corrosion resistance and gloss is provided according to which a BA film or a passive film is formed on the stainless steel sheet; the sheet is dipped in a treatment solution containing 0.1 to 50% by weight of phosphoric acid, 0.1 to 10.0% by weight of a molybdate, chromic acid or a mixture thereof, and 0.1 to 2.0% by weight of magnesium oxide, sodium silicate or a mixture thereof; and cathodic treatment is carried out under the conditions of 1 to 600 A.sec/dm.sup.2 integrated electric current density and 0.degree. to 90.degree. C. solution temperature.

Process for surface treatment of stainless steel sheet

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Tokyo, Japan

Tetsutaro Ogushi