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:
Mar. 08, 1977
Filed:
Aug. 25, 1975
Rollin E Hook, Dayton, OH (US);
Armco Steel Corporation, Middletown, OH (US);
Abstract
Deep drawing quality, low carbon steel is strengthened by alloy-nitrogen precipitation strengthening. A deoxidized, low carbon steel sheet or strip stock, or article formed therefrom, containing from about 0.02% to 0.2% titanium in solution, from about 0.025% to 0.3% columbium in solution, from about 0.025% to 0.3% zirconium in solution, singly or in admixture, is heat treated at 1100.degree. to 1300.degree. F (593.degree. to 705.degree. C) in an atmosphere containing 1% to 20% by volume ammonia for a time sufficient to produce an iron nitride surface layer, and then denitrided in a hydrogen-nitrogen atmosphere containing 6% to 50% hydrogen by volume at 1200.degree. to 1400.degree. F (649.degree. to 760.degree. C) for a time sufficient to remove the iron nitride surface layer and to reduce nitrogen in solid solution to less than 0.03% by weight.