Marshall, O'Toole, Gerstein, Murray & Bicknell
Method for treating the surface of stainless steel by high temperature oxidation
 This disclosure is concerned with a method for treating a stainless steel surface by high temperature oxidation. The surface of a stainless steel article is cleaned, TiO.sub.2 and SiO.sub.2 are mixed in microparticles to form a coating agent, and water is added to the mixture to make a slip. The slip is coated on the steel surface to form a coating having a uniform thickness. The coating is dried and the article is subjected to a heat-treatment to form an oxide film. This treatment is performed in an oxidizing atmosphere for a time and a temperature suitable for the color tone to be produced. A desirable temperature for the heat-treatment is between 350.degree. C. to 700.degree. C. When a coating agent is used, it is later removed by washing, etc. after cooling the article. Further, when less dissolution of iron from the stainless steel surface is required, a decolorization treatment is applied; that is, the colored oxide film is removed from the surface by dissolution using an acid or an electrolytic treatment. 
Shinko-Pfaudler Company, Ltd.
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inventional inventional
Mitsuaki Haruji Shigeo Tomihira Syuichi
Shibata Takahashi Goto Hata Takata