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:
Jul. 28, 1998
Filed:
Aug. 20, 1996
Applicant:
Inventor:
Peter Zylla, Krefeld, DE;
Assignee:
Messer Griesheim-GmbH, , DE;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C21D / ;
U.S. Cl.
CPC ...
148634 ; 148596 ; 148703 ;
Abstract
When cold strip is annealed, diffusion welds, so-called stickers, frequently form on the strip surface. In order to avoid these, the cold strip, above 600.degree. C. (holding time) is coated by oxidation with a thin surface film which prevents the sticking together. Below 600.degree. C., during the cooling phase, this surface film is removed again by reduction. In the case of a protective gas comprising a hydrogen content greater than 5%, remainder nitrogen, carbon dioxide is preferably added as oxidizing agent. The process is controlled via a defined oxygen partial pressure. The reduction is performed via the hydrogen.