U.S. patent application number 12/870873 was filed with the patent office on 2012-03-01 for nickel-iron-base alloy and process of forming a nickel-iron-base alloy.
This patent application is currently assigned to GENERAL ELECTRIC COMPANY. Invention is credited to Ganjiang FENG, George GOLLER, Matthew LAYLOCK, Joseph RAZUM.
Application Number | 20120051963 12/870873 |
Document ID | / |
Family ID | 44533958 |
Filed Date | 2012-03-01 |
United States Patent
Application |
20120051963 |
Kind Code |
A1 |
FENG; Ganjiang ; et
al. |
March 1, 2012 |
NICKEL-IRON-BASE ALLOY AND PROCESS OF FORMING A NICKEL-IRON-BASE
ALLOY
Abstract
A nickel-iron-base alloy has by weight about 0.06% to about
0.09% C, about 35% to about 37% Fe, about 12.0% to about 16.5% Cr,
about 1.0% to about 2.0% Al, about 1.0% to about 3.0% Ti, about
1.5% to about 3.0% W, up to about 5.0% Mo, up to about 0.75% Nb, up
to about 0.2% Mn, up to about 0.1% Si, up to about 0.006% B, and
balance essentially Ni. A method for making the nickel-iron-base
alloy is also disclosed.
Inventors: |
FENG; Ganjiang; (Greenville,
SC) ; GOLLER; George; (Greenville, SC) ;
RAZUM; Joseph; (Greenville, SC) ; LAYLOCK;
Matthew; (Greenville, SC) |
Assignee: |
GENERAL ELECTRIC COMPANY
Schenectady
NY
|
Family ID: |
44533958 |
Appl. No.: |
12/870873 |
Filed: |
August 30, 2010 |
Current U.S.
Class: |
420/586.1 ;
420/584.1 |
Current CPC
Class: |
C22C 30/00 20130101;
C22C 19/056 20130101 |
Class at
Publication: |
420/586.1 ;
420/584.1 |
International
Class: |
C22C 30/00 20060101
C22C030/00 |
Claims
1. A nickel-iron-base alloy comprising by weight about 0.06% to
about 0.09% C, about 35% to about 37% Fe, about 12.0% to about
16.5% Cr, about 1.0% to about 2.0% Al, about 1.0% to about 3.0% Ti,
about 1.5% to about 3.0% W, up to about 5.0% Mo, up to about 0.75%
Nb, up to about 0.2% Mn, up to about 0.1% Si, up to about 0.006% B,
and balance essentially Ni.
2. The alloy of claim 1, comprising about 0.07% to about 0.09% C,
about 2.0% to about 3.0% Ti, about 2.0% to about 3.0% W, about 3.0%
to about 5.0% Mo, and up to about 0.1% Nb.
3. The alloy of claim 1, comprising about 0.07% to about 0.09% C,
about 2.0% to about 3.0% Ti, about 1.5% to about 2.5 W, about 3.0%
to about 5.0 Mo, and up to about 0.1% Nb.
4. The alloy of claim 1, comprising about 0.07% to about 0.09% C,
about 2.0% to about 3.0% Ti, about 1.5% to about 2.5% W, about 0.5
to about 1.5% Mo, and up to about 0.1% Nb.
5. The alloy of claim 1, comprising about 0.06% to about 0.08% C,
about 1.0% to about 2.5 Ti, about 1.5% to about 2.5 W, up to about
0.25 Mo, and 0.25% to about 0.75 Nb.
6. The alloy of claim 1, comprising about 0.07% to about 0.09% C,
about 12.0% to about 13.0% Cr, about 1.35% to about 1.65% Al, about
2.25% to about 2.75 Ti, about 2.3% to about 2.7% W, about 3.4% to
about 3.6% Mo, up to about 0.1% Nb.
7. The alloy of claim 1, comprising about 0.07% to about 0.09% C,
about 13.5% to about 14.5% Cr, about 1.35% to about 1.65% Al, about
2.25% to about 2.75 Ti, about 1.8% to about 2.2% W, about 3.9% to
about 4.1% Mo, up to about 0.1% Nb.
8. The alloy of claim 1, comprising about 0.07% to about 0.09% C,
about 15.5% to about 16.5% Cr, about 1.35% to about 1.65% Al, about
2.25% to about 2.75 Ti, about 1.8% to about 2.2% W, about 0.9% to
about 1.1% Mo, up to about 0.1% Nb.
9. The alloy of claim 1, comprising about 0.06% to about 0.08% C,
about 15.5% to about 16.5% Cr, about 1.35% to about 1.65% Al, about
1.5% to about 1.8% Ti, about 1.8% to about 2.2% W, up to about
0.12% Mo, about 0.4% to about 0.6% Nb.
10. The alloy of claim 1, comprising about 0.08% C, about 36% Fe,
about 12.5% Cr, about 1.50% Al, about 2.50 Ti, about 2.50 W, about
3.50 Mo, up to about 0.1% Nb.
11. The alloy of claim 1, comprising about 0.08% C, about 36% Fe,
about 14.0% Cr, about 1.50% Al, about 2.50% Ti, about 2.00% W,
about 4.00% Mo, up to about 0.1% Nb.
12. The alloy of claim 1, comprising about 0.08% C, about 36% Fe,
about 16.0% Cr, about 1.50% Al, about 2.50% Ti, about 2.00% W,
about 1.00% Mo, up to about 0.1% Nb.
13. The alloy of claim 1, comprising about 0.07% C, about 37% Fe,
about 16.0% Cr, about 1.50% Al, about 1.75 Ti, about 2.00% W, up to
about 0.12% Mo, about 0.50% Nb.
14. The alloy of claim 1, wherein the alloy has a solidification
range of less than about 110.degree. F., a gamma prime solvus of
greater than about 1700.degree. F., substantially no eta phase, a
laves phase of less than about 5%, and a sigma phase of less than
about 5%.
15. The alloy of claim 1, wherein the composition is devoid of
Co.
16. The alloy of claim 1, wherein the modified alloy has a creep
rupture life of about 25 ksi to about 30 ksi at about 1400.degree.
F. per 1000 hr.
17. The alloy of claim 1, wherein the composition is a modification
of a base alloy composition, the base alloy composition comprising
about 0.05% C, about 0.20% Al, about 2.80% Ti, about 12.50% Cr,
about 5.70 Mo, about 36% Fe and a second composition including
about 16.00% Cr, about 37% Fe, about 2.90% Nb, about 1.75% Ti,
about 0.20% Al, and about 0.02% C.
18. A gas turbine component formed from the alloy of claim 1.
19. A alloy, wherein the alloy has a solidification range of less
than about 110.degree. F., a gamma prime solvus of greater than
about 1700.degree. F., substantially no eta phase, a laves phase of
less than about 5%, a sigma phase of less than about 5%, and is
devoid of Co.
20. A process of forming a modified alloy, the process comprising:
providing a base alloy composition; identifying a plurality of
predetermined properties; modifying the base alloy composition to
form a modified alloy composition having the plurality of
predetermined properties; wherein the plurality of predetermined
properties includes a solidification range of less than about
110.degree. F., a gamma prime solvus of greater than about
1700.degree. F., substantially no eta phase, a laves phase of less
than about 5%, and a sigma phase of less than about 5%; and wherein
the base alloy composition comprises one or more of a first
composition comprising about 0.05% C, about 36% Fe, about 12.50%
Cr, about 0.20% Al, about 2.80% Ti, up to about 0.12% W, about
5.70% Mo, up to about 0.1% Nb, up to about 0.2% Mn, up to about
0.1% Si, up to about 0.006% B, balance essentially Ni and a second
composition including about 0.02% C, about 37% Fe, 16.00% Cr, about
0.20% Al, about 1.75% Ti, up to about 0.12% W, up to about 0.12%
Mo, about 2.90% Nb, up to about 0.2% Mn, up to about 0.1% Si, up to
about 0.006% B, balance essentially Ni.
Description
FIELD OF THE INVENTION
[0001] The present invention is directed to alloys, articles
including alloys, and processes of forming alloys. More
specifically, the present invention is directed to a
nickel-iron-base alloy and a process of forming a nickel-iron-base
alloy.
BACKGROUND OF THE INVENTION
[0002] The operating temperature within a gas turbine engine is
both thermally and chemically hostile. Significant advances in high
temperature capabilities have been achieved through the development
of iron, nickel and cobalt-based superalloys and the use of
environmental coatings capable of protecting superalloys from
oxidation, hot corrosion, etc., but coating systems continue to be
developed to improve the performance of the materials.
[0003] In the compressor portion of a gas turbine engine,
atmospheric air is compressed to 10-25 times atmospheric pressure,
and adiabatically heated to 800.degree.-1250.degree. F.
(427.degree. C.-677.degree. C.) in the process. This heated and
compressed air is directed into a combustor, where it is mixed with
fuel. The fuel is ignited, and the combustion process heats the
gases to very high temperatures, in excess of 3000.degree. F.
(1650.degree. C.). These hot gases pass through the turbine, where
airfoils fixed to rotating turbine disks extract energy to drive
the fan and compressor of the engine, and the exhaust system, where
the gases provides sufficient thrust to propel the aircraft. To
improve the efficiency of operation of the engine, combustion
temperatures have been raised. Of course, as the combustion
temperature is raised, steps must be taken to prevent thermal
degradation of the materials forming the flow path for these hot
gases of combustion.
[0004] Demand for enhanced performance continues to increase. This
demand for enhanced performance applies for newer engines and
modifications of proven designs. Specifically, higher thrusts and
better fuel economy are among the performance demands. To improve
the performance of engines, the combustion temperatures have been
raised to very high temperatures. This can result in higher thrusts
and/or better fuel economy.
[0005] Stator components (nozzles and shrouds) are hot gas path
components for gas turbines. It is desirable for the stator
components to have oxidation resistance, thermal-mechanical fatigue
capability and high temperature creep strength. Traditionally, the
stator components are made of Ni-based or Co-based cast
superalloys. These superalloys suffer from the drawback that they
can have very high costs.
[0006] Known attempts to use different materials have been
unsuccessful. For example, advanced stainless steels (for example
Alumina-Forming Austenitic (AFA) alloys, developed by Oak Ridge
National Laboratory) contain nano-precipitates and oxide-forming
elements and demonstrate an outstanding heat-resistance. However,
these advanced stainless steels have undesirably low creep strength
for nozzles. Particularly, the creep strength of these advanced
stainless steels only reaches about one half of design requirement
for gas turbine nozzles.
[0007] Another group of low cost alternative materials,
nickel-iron-base superalloys including A286, INCOLOY.RTM. 901,
INCOLOY.RTM. 903 and IN706, have been regarded as suffering from
several drawbacks. "INCOLOY" is a federally registered trademark of
alloy produced by Inco Alloys International, Inc., Huntington, W.
Va. For example, INCOLOY.RTM. 901 has been regarded as lacking
gamma prime phases (resulting in low creep strength), containing
significant amounts of eta, sigma, and laves phases (resulting in
low ductility and/or poor long-term mechanical properties), and
having a wide solidification range and poor castability.
[0008] A nickel-iron-base alloy and a process of forming a
nickel-iron-base alloy that do not suffer from the above drawbacks
is desirable in the art.
SUMMARY OF THE INVENTION
[0009] According to an exemplary embodiment of the present
disclosure, a nickel-iron-base alloy having by weight about 0.06%
to about 0.09% C, about 35% to about 37% Fe, about 12.0% to about
16.5% Cr, about 1.0% to about 2.0% Al, about 1.0% to about 3.0% Ti,
about 1.5% to about 3.0% W, up to about 5.0% Mo, up to about 0.75%
Nb, up to about 0.2% Mn, up to about 0.1% Si, up to about 0.006% B,
and balance essentially Ni.
[0010] According to another exemplary embodiment of the present
disclosure, a nickel-iron-base alloy has a solidification range of
less than about 110.degree. F., a gamma prime solvus of greater
than about 1700.degree. F., substantially no eta phase, a laves
phase of less than about 5%, a sigma phase of less than about 5%,
and is devoid of Co.
[0011] According to another exemplary embodiment of the present
disclosure, a process of forming a modified alloy includes
providing a base alloy composition, identifying a plurality of
predetermined properties, and modifying the base alloy composition
to form a modified alloy composition having the plurality of
predetermined properties. The plurality of predetermined properties
includes having a solidification range of less than about
110.degree. F., having a gamma prime solvus of greater than about
1700.degree. F., having substantially no eta phase, having a laves
phase of less than about 5%, and having a sigma phase of less than
about 5%. The base alloy composition includes one or more of a
first composition comprising about 0.05% C, about 36% Fe, about
12.50% Cr, about 0.20% Al, about 2.80% Ti, up to about 0.12% W,
about 5.70% Mo, up to about 0.1% Nb, up to about 0.2% Mn, up to
about 0.1% Si, up to about 0.006% B, balance essentially Ni and a
second composition including about 0.02% C, about 37% Fe, 16.00%
Cr, about 0.20% Al, about 1.75% Ti, up to about 0.12% W, up to
about 0.12% Mo, about 2.90% Nb, up to about 0.2% Mn, up to about
0.1% Si, up to about 0.006% B, balance essentially Ni.
[0012] One advantage of an embodiment of the present disclosure
includes the modified alloy having a desirable creep strength
through the formation of sufficient amount of gamma prime phase and
reduced or eliminated Eta phase.
[0013] Another advantage of an embodiment of the present disclosure
includes the modified alloy having desirable ductility and/or
long-term mechanical properties.
[0014] Another advantage of an embodiment of the present disclosure
includes the modified alloy having desirable castability.
[0015] Other features and advantages of the present invention will
be apparent from the following more detailed description of the
preferred embodiment, taken in conjunction with the accompanying
drawings which illustrate, by way of example, the principles of the
invention.
DETAILED DESCRIPTION OF THE INVENTION
[0016] Provided is a nickel-iron-base alloy having a plurality of
predetermined properties and a process of forming a
nickel-iron-base alloy having a plurality of predetermined
properties.
[0017] Embodiments of the present disclosure involve a
nickel-iron-base alloy formed from one or more low cost alloys
previously regarded as unsuitable for hot gas path components such
as engine turbine stators. The nickel-iron-base alloy does not
contain Eta phaseresulting in a desirable creep strength. The
nickel-iron-base alloy has desirable ductility and/or long-term
mechanical properties. Also, the nickel-iron-base alloy has
desirable castability.
[0018] The nickel-iron-base alloy can be formed by any suitable
process. In one embodiment, the nickel-iron-base alloy has a creep
rupture life of about 1000 hours at about 1400.degree. F. and at
about 25 ksi to about 30 ksi of loading. In one embodiment, the
nickel-iron-base alloy is resistant to oxidation for 48,000 hours.
In one embodiment, low cycle fatigue of the modified alloy is
substantially the same as FSX414 alloy.
[0019] In one embodiment, the process includes providing a base
alloy. The base alloy is one or more alloys previously considered
undesirable for hot gas path components. For example, in one
embodiment, the base alloy is Base Alloy 1. As used herein, "Base
Alloy 1" refers to an alloy having a composition of about 0.05% C,
about 0.20% Al, about 2.80% Ti, about 12.50% Cr, about 5.70 Mo,
about 36% Fe, and other suitable elements (throughout the
disclosure, all percents are by weight unless otherwise specified).
In one embodiment, Base Alloy 1 further includes up to about 0.12%
W, up to about 0.1% Nb, up to about 0.2% Mn, up to about 0.1% Si.,
up to about 0.006 B, and a balance essentially Ni. In a further
embodiment, Base Alloy 1 does not include Co.
[0020] In another embodiment, the base alloy is Base Alloy 2. As
used herein, "Base Alloy 2" refers to an alloy having a composition
of about 16.00% Cr, about 37% Fe, about 2.90% Nb, about 1.75 Ti,
about 0.20% Al, about 0.02% C, and other suitable elements. In one
embodiment, Base Alloy 2 further includes up to about 0.12% W, up
to about 0.2% Mn, up to about 0.1% Si., up to about 0.006 B, and a
balance essentially Ni. In a further embodiment, Base Alloy 2 does
not include Co.
[0021] The process continues by identifying a plurality of
predetermined properties desired for the modified alloy. Data
corresponding to the plurality of predetermined properties can be
analyzed by a computer executed program such as a computational
thermodynamic modeling program. The computer executed program
correlates data regarding the base alloys and generates outputs of
properties corresponding to the modified alloy. The outputs
generated are based upon the modifications to composition of the
base alloy that form the modified alloy. Analysis of the generated
outputs permits identification of one or more compositions to be
further analyzed.
[0022] The properties include any suitable quantifiable properties.
The properties include a solidification range, a gamma prime
solvus, a lack of eta phase, a laves phase percent, a sigma phase
percent, a laves phase formation temperature, other suitable
properties, or any combination thereof In one embodiment, the
solidification range is less than about 110.degree. F. resulting in
good castability. In one embodiment, the gamma prime solvus is
greater than about 1700.degree. F. In one embodiment, the lack of
eta phase includes being devoid of eta phase. In one embodiment,
the laves sigma percent is less than about 5%. In one embodiment,
the formation temperature is less than about 1200.degree. F.
[0023] The correlation of data regarding the base alloys and
outputs of properties corresponding to the nickel-iron-base alloy
can involve any suitable relationship between compositional
modifications to the base alloy and properties affected. For
example, Al reduces eta phase. Including a concentration of greater
than about 1% Al eliminates eta phase. Thus, the correlation of
data can generate an output indicating an absence of eta phase upon
a concentration of Al exceeding about 1%. Other relationships that
can be correlated are that increasing the concentration of Mo
increases eta phase, increasing the concentration of W reduces eta
phase, increasing the concentration of Al reduces the
solidification range, and combinations thereof. Combined
correlations can also be utilized. For instance, when Al is at
about 0.8%, increasing the concentration of W increases
solidification. However, when Al is at about 1.5%, increasing the
concentration of W reduces solidification. Thus, the concentration
of Al and the concentration of W can be related in the
correlation.
[0024] The correlation can further include additional experimental
data based upon analysis of a component formed with the
nickel-iron-base alloy and comparisons of the predetermined
properties for different compositions of the nickel-iron-base
alloy. For example, the data can include any combination of
specific chemistries, scale-up heats, long-term microstructure
stability studies, long-term oxidation tests, creep tests (for
example 5,000 hour creep tests), and other mechanical property
tests.
[0025] Based upon the correlation, a selection (either manual or
automatic) of the base alloy(s) utilized and modified
nickel-iron-base alloy(s) to be formed into the component is made.
The component can be formed by any suitable technique (for example,
casting, forging, heat treating, repair welding, or any suitable
combination thereof).
[0026] In one embodiment, the nickel-iron-base alloy includes a
compositional range of about 0.07% to about 0.09% C, about 35% to
about 37% Fe, about 12.0% to about 16.5% Cr, about 1.0% to about
2.0% Al, about 2.0% to about 3.0% Ti, about 2.0% to about 3.0% W,
about 3.0% to about 5.0% Mo, up to about 0.1% Nb, up to about 0.2%
Mn, up to about 0.1% Si, up to about 0.006% B, and a balance
essentially Ni. In a further embodiment, the nickel-iron-base alloy
includes a compositional range of about 0.07% to about 0.09% C,
about 35% to about 37% Fe, about 12.0% to about 13.0% Cr, about
1.35% to about 1.65% Al, about 2.25% to about 2.75% Ti, about 2.3%
to about 2.7% W, about 3.4% to about 3.6% Mo, up to about 0.1% Nb,
up to about 0.2% Mn, up to about 0.1% Si, up to about 0.006% B, and
a balance essentially Ni. In a further embodiment, the
nickel-iron-base alloy is devoid of Co.
[0027] In another embodiment, the nickel-iron-base alloy includes a
compositional range of about 0.07% to about 0.09% C, about 35% to
about 37% Fe, about 12.0% to about 16.5% Cr, about 1.0% to about
2.0% Al, about 2.0% to about 3.0% Ti, about 1.5% to about 2.5% W,
about 3.0% to about 5.0% Mo, up to about 0.1% Nb, up to about 0.2%
Mn, up to about 0.1% Si, up to about 0.006% B, and a balance
essentially Ni. In a further embodiment, the nickel-iron-base alloy
includes a compositional range of about 0.07% to about 0.09% C,
about 35% to about 37% Fe, about 13.5% to about 14.5% Cr, about
1.35% to about 1.65% Al, about 2.25% to about 2.75 Ti, about 1.8%
to about 2.2% W, about 3.9% to about 4.1% Mo, up to about 0.1% Nb,
up to about 0.2% Mn, up to about 0.1% Si, up to about 0.006% B, and
a balance essentially Ni. In a further embodiment, the
nickel-iron-base alloy is devoid of Co.
[0028] In one embodiment, the nickel-iron-base alloy includes a
compositional range of about 0.07% to about 0.09% C, about 35% to
about 37% Fe, about 12.0% to about 16.5% Cr, about 1.0% to about
2.0% Al, about 2.0% to about 3.0% Ti, about 1.5% to about 2.5% W,
about 0.5% to about 1.5% Mo, up to about 0.1% Nb, up to about 0.2%
Mn, up to about 0.1% Si, up to about 0.006% B, and a balance
essentially Ni. In a further embodiment, the nickel-iron-base alloy
includes a compositional range of about 0.07% to about 0.09% C,
about 35% to about 37% Fe, about 15.5% to about 16.5% Cr, about
1.35% to about 1.65% Al, about 2.25% to about 2.75 Ti, about 1.8%
to about 2.2% W, about 0.9% to about 1.1% Mo, up to about 0.1% Nb,
up to about 0.2% Mn, up to about 0.1% Si, up to about 0.006% B, and
a balance essentially Ni. In a further embodiment, the
nickel-iron-base alloy is devoid of Co.
[0029] In one embodiment, the nickel-iron-base alloy includes a
compositional range of about 0.06% to about 0.08% C, about 35% to
about 37% Fe, about 12.0% to about 16.5% Cr, about 1.0% to about
2.0% Al, about 1.0% to about 2.5% Ti, about 1.5% to about 2.5% W,
up to about 0.25% Mo, about 0.25% to about 0.75% Nb, up to about
0.2% Mn, up to about 0.1% Si, up to about 0.006% B, and a balance
essentially Ni. In a further embodiment, the nickel-iron-base alloy
includes a compositional range of about 0.06% to about 0.08% C,
about 35% to about 37% Fe, about 15.5% to about 16.5% Cr, about
1.35% to about 1.65% Al, about 1.5% to about 1.8% Ti, about 1.8% to
about 2.2% W, up to about 0.12% Mo, about 0.4% to about 0.6% Nb, up
to about 0.2% Mn, up to about 0.1% Si, up to about 0.006% B, and a
balance essentially Ni. In a further embodiment, the
nickel-iron-base alloy is devoid of Co.
[0030] In one embodiment, the nickel-iron-base alloy can have a
composition originally based upon the composition of Base Alloy 1.
In one embodiment, the nickel-iron-base alloy includes a
composition of about 0.08% C, about 36% Fe, about 12.5% Cr, about
1.50% Al, about 2.50% Ti, about 2.50% W, about 3.50% Mo, up to
about 0.1% Nb, up to about 0.2% Mn, up to about 0.1% Si, up to
about 0.006% B, and a balance essentially Ni. In another
embodiment, the nickel-iron-base alloy includes a composition of
about 0.08% C, about 36% Fe, about 14.0% Cr, about 1.50% Al, about
2.50% Ti, about 2.50% W, about 4.00% Mo, up to about 0.1% Nb, up to
about 0.2% Mn, up to about 0.1% Si, up to about 0.006% B, and a
balance essentially Ni. In another embodiment, the nickel-iron-base
alloy includes a composition of about 0.08% C, about 36% Fe, about
16.0% Cr, about 1.50% Al, about 2.50% Ti, about 2.50% W, about
1.00% Mo, up to about 0.1% Nb, up to about 0.2% Mn, up to about
0.1% Si, up to about 0.006% B, and a balance essentially Ni.
[0031] In one embodiment, the nickel-iron-base alloy can have a
composition originally based upon the composition of Base Alloy 2.
In one embodiment, the nickel-iron-base alloy includes a
composition of about 0.07% C, about 37% Fe, about 16.0% Cr, about
1.50% Al, about 1.75% Ti, about 2.00% W, up to about 0.12% Mo,
about 0.50% Nb, up to about 0.2% Mn, up to about 0.1% Si, up to
about 0.006% B, and a balance essentially Ni.
[0032] In one embodiment, the composition of the alloy is used in
hot gas turbine components. For example, the alloy can be used in
stator components including, but not limited to, a nozzle, a
shroud, other suitable portions, or combinations thereof.
[0033] While the invention has been described with reference to a
preferred embodiment, it will be understood by those skilled in the
art that various changes may be made and equivalents may be
substituted for elements thereof without departing from the scope
of the invention. In addition, many modifications may be made to
adapt a particular situation or material to the teachings of the
invention without departing from the essential scope thereof.
Therefore, it is intended that the invention not be limited to the
particular embodiment disclosed as the best mode contemplated for
carrying out this invention, but that the invention will include
all embodiments falling within the scope of the appended
claims.
* * * * *