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:
Jun. 10, 2008
Filed:
Sep. 11, 2003
Jean-marc Raick, Liege, BE;
Jean-pierre Crutzen, Embourg, BE;
Edgard Dosogne, Ouffet, BE;
Michel Renard, Slins, BE;
Jean-Marc Raick, Liege, BE;
Jean-Pierre Crutzen, Embourg, BE;
Edgard Dosogne, Ouffet, BE;
Michel Renard, Slins, BE;
Drever International S.A., Liege (Angleur), BE;
Abstract
A method for heat treating metallic strips inside a heat treatment chamber at a pressure greater than atmospheric pressure including passing the strips through at least one heating zone of the chamber and moving the strip through at least one cooling zone of the chamber. A first protective gas atmosphere containing nitrogen and hydrogen and/or helium is established in all but at least one cooling zone. The at least one cooling zone has a second protective atmosphere containing nitrogen and a second amount of hydrogen, the second amount of hydrogen is greater than the first amount. Nitrogen is introduced into the chamber, and a protective gas containing a third hydrogen content greater than the second hydrogen content is injected into the cooling zone, producing a gas exchange between one zone of the chamber having the first protective atmosphere and the cooling zone, and controlling the flow of introduction and injection.