Patent · US Expired

Method for increasing the resistance to thermal shocks in heating conductor materials

US4969960A · kind A · utility

6Cited by

2References

10Claims

0Family size

Assignee

Thyssen Edelstahlwarke AG · DE

Inventors

Gunter Lehnert · Krefeld, DE
Friedrich Behr
Manfred Heinritz · Remscheid, DE
Dieter Gorres · Haan, DE

Key dates

Filing date	Feb 9, 1989
Grant date	Nov 13, 1990
Priority date	—
Expiry date	Feb 9, 2009

Classification

Technology area (CPC C)Chemistry; Metallurgy
CPC primaryC23C8/02
WIPO fieldSurface technology, coating
WIPO sectorChemistry

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.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.