The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 12, 1981
Filed:
Apr. 25, 1977
Chih-Chung Wang, Lexington, MA (US);
Kennecott Copper Corporation, New York, NY (US);
Abstract
Disclosed is a technique for providing a protective oxide layer on an alloy. The technique involves the preliminary cleaning of the alloy's surfaces to remove as much unwanted oxide as possible and the subsequent exposure of the alloy surface to an environment which produces an acid resistant oxide by selective oxidation of one of the constituents of the alloy and which acts as a reducing environment for other constituents of the alloy. For the production of a chromium oxide layer on a stainless steel comprising chromium, iron, and nickel, a suitable environment includes a 600.degree.-1200.degree. C. mixture of H.sub.2 and H.sub.2 O. If a major portion of the mixture is H.sub.2, the chromium is oxidized whereas the iron and nickel are not.