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:
Nov. 13, 1990
Filed:
Feb. 09, 1989
Gunter Lehnert, Krefeld, DE;
Friedrich Behr, Krefeld, DE;
Manfred Heinritz, Remscheid, DE;
Dieter Gorres, Haan, DE;
Thyssen Edelstahlwerke AG, Krefeld, DE;
Abstract
A method for increasing the resistance to thermal shocks of the oxide layer of metallic heat conductive materials which contain 3% to 10% aluminum, 10% to 26% chromium, up to 3% zirconium and/or titanium and/or hafnium and/or niobium and/or silicon and/or 0.002% to 0.3% total of rare earths and/or yttrium in metallic form or as finely dispersed oxides, the remainder being iron and/or nickel and/or cobalt as well as the trace elements normally present in steels. The materials develop primarily aluminum oxide and/or chromium oxide on the surface when heated in a temperature range of 700.degree. C. to 1350.degree. C. in an oxygen-containing atmosphere. The materials are first heated in an oxygen-free atmosphere under conditions which cause recrystallization in their surface zone. They then are oxidized in an atmosphere which contains oxygen in chemically bound form.