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:
Jan. 12, 1999
Filed:
Jul. 29, 1997
Zofia E Niemczura, Valparaiso, IN (US);
Kenneth E Blazek, Crown Point, IN (US);
Inland Steel Company, Chicago, IL (US);
Abstract
A method for producing strip cast, austenitic stainless steel strip comprises providing a strip cast strip having an initial microstructure including a detrimental amount of delta ferrite and a detrimental amount of dendritic structure is provided. The strip may have a composition comprising the following ingredients: 0.4 wt. % max. carbon, 5-38 wt. % nickel, and 15-28 wt. % chromium. The strip is subjected to a cold rolling step prior to any annealing step. Upon subsequent annealing, (a) the amount of delta ferrite in the strip is reduced to substantially below the detrimental amount of delta ferrite that was in the strip prior to cold rolling and (b) the amount of dendritic structure in the strip is reduced to below the detrimental amount of dendritic structure that was in the strip prior to cold rolling. By employing the method of the present invention, an austenitic stainless steel strip having a high quality surface is produced. After cold rolling and annealing, the microstructure of the strip may comprise austenitic and less than about 10% delta ferrite by volume.