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. 10, 1977
Filed:
Mar. 26, 1975
Harry Tanczyn, Baltimore, MD (US);
Armco Steel Corporation, Middletown, OH (US);
Abstract
A method of cold-working and stress-relieving iron-chromium ferritic stainless steels of non-heat hardenable type in the AISI 400 series, thereby increasing the ultimate tensile strength while maintaining good tensile ductility. Cold-working is effected by peripherally contacting the steel, i.e., extruding and/or die drawing, to produce a 'cellular structure' not attainable in cold rolling. Repetitive cold-working and stress-relief anneals between about 750.degree. and 1200.degree. F increase the ultimate tensile strength in increments and restore the tensile ductility substantially to that of the hot rolled and annealed material, while maintaining the tensile to yield ratio substantially constant. Ultimate tensile strength up to about 400 ksi in small diameter wire is attainable.