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:
Sep. 13, 1977
Filed:
Jun. 30, 1976
Jerry L Arnold, Franklin, OH (US);
Joseph A Douthett, Monroe, OH (US);
Armco Steel Corporation, Middletown, OH (US);
Abstract
Internally nitrided ferritic stainless steel cold reduced strip and sheet and products fabricated therefrom having an elevated temperature creep strength and oxidation resistance superior to AISI Type 316 austenitic stainless steel, and good room temperature formability. A non-hardenble AISI Type 400 series ferritic stainless steel containing a nitride former (titanium, zirconium, hafnium, columbium, vanadium, tantalum or rare earth metals) in excess of the amount required to react completely with residual nitrogen and carbon in the steel is reacted with nitrogen internally by heat treatment in a nitrogen-hydrogen atmosphere at a temperature of at least about 800.degree. C but below that at which austenite will form under conditions precluding formation of chromium nitrides, chromium oxides, and austenite.