Alloys or metallic compositions – Nickel base – Chromium containing
Reexamination Certificate
1998-09-04
2004-07-13
Ip, Sikyin (Department: 1742)
Alloys or metallic compositions
Nickel base
Chromium containing
C420S441000
Reexamination Certificate
active
06761854
ABSTRACT:
FIELD OF THE INVENTION
This invention relates to the field of nickel-base alloys possessing resistance to high temperature corrosive environments.
BACKGROUND OF THE INVENTION
Nickel-base high temperature alloys serve in numerous applications, such as, regenerators, recuperators, combustors and other gas turbine components, muffles and furnace internals, retorts and other chemical process equipment and transfer piping, boiler tubing, piping and waterwall aprons and waste incineration hardware. Alloys for these applications must possess outstanding corrosion resistance to meet the long life requirements becoming critical in new facility design and operation. While virtually all major industrial equipment is exposed to air on one surface or at one part of the unit, the internal surfaces can be exposed to very aggressive carburizing, oxidizing, sulfidizing, nitriding, or combinations of these corrodents. Consequently, maximum corrosion resistance to the broadest possible range of aggressive high temperature environments, is a long-sought aim of the metallurgical industry.
Traditionally, these alloys rely on precipitation hardening from a combination of &ggr;′ [Ni
3
(Al, Ti)], &ggr;″ [Ni
3
(Nb, Al, Ti)], carbide precipitation and solid solution strengthening to give the alloy strength. The &ggr;′ and &ggr;″ phases precipitate as stable intermetallics that are essentially coherent with the austenitic-fcc matrix. This combination of precipitates significantly enhances the high temperature mechanical properties of the alloy.
It is an object of this invention to provide an alloy that possesses resistance to carburizing, oxidizing, nitriding and sulfidizing environments.
It is a further object of this invention to provide an alloy with sufficient phase stability and mechanical integrity for demanding, high temperature applications.
SUMMARY OF THE INVENTION
A nickel-base alloy consisting of, in weight percent, 42 to 58 nickel, 21 to 28 chromium, 12 to 18 cobalt, 4 to 9.5 molybdenum, 2 to 3.5 aluminum, 0.05 to 2 titanium, at least one microalloying agent selected from the group consisting of 0.005 to 0.1 yttrium for carburization resistance and 0.01 to 0.6 zirconium for sulfidation resistance, 0.01 to 0.15 carbon, 0 to 0.01 boron, 0 to 4 iron, 0 to 1 manganese, 0 to 1 silicon, 0 to 1 hafnium, 0 to 0.4 niobium, 0 to 0.1 nitrogen, incidental impurities and deoxidizers.
REFERENCES:
patent: 2712498 (1955-07-01), Gresham et al.
patent: 3015558 (1962-01-01), Grant et al.
patent: 3151981 (1964-10-01), Smith et al.
patent: 3479157 (1969-11-01), Richards et al.
patent: 3681059 (1972-08-01), Shaw et al.
patent: 3723107 (1973-03-01), Richards et al.
patent: 3723108 (1973-03-01), Twigg et al.
patent: 3859060 (1975-01-01), Einstein et al.
patent: 4039330 (1977-08-01), Shaw
patent: 4474733 (1984-10-01), Susukida et al.
patent: 4727740 (1988-03-01), Yabuki et al.
patent: 4764225 (1988-08-01), Shankar et al.
patent: 4810467 (1989-03-01), Wood et al.
patent: 4981644 (1991-01-01), Chang
patent: 5370497 (1994-12-01), Doi et al.
patent: 5372662 (1994-12-01), Ganesan et al.
patent: 5556594 (1996-09-01), Frank et al.
patent: 5780116 (1998-07-01), Sileo et al.
patent: 5900078 (1999-05-01), Yakuwa et al.
patent: 5939204 (1999-08-01), Czech
patent: 6258317 (2001-07-01), Smith et al.
patent: 0260600 (1988-03-01), None
patent: 0790324 (1997-08-01), None
patent: 880805 (1961-10-01), None
patent: 61-147838 (1986-07-01), None
patent: WO9967436 (1999-12-01), None
Smith Gaylord Darrell
Tassen Curtis Steven
Bond Schoeneck & King , PLLC
Huntington Alloys Corporation
Ip Sikyin
LandOfFree
Advanced high temperature corrosion resistant alloy does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Advanced high temperature corrosion resistant alloy, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Advanced high temperature corrosion resistant alloy will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3250415