US5403547A — Oxidation resistant low expansion superalloys

Claim 1

Independent Claim 141 words

An oxidation resistant alloy having a relatively low coefficient of thermal expansion of less than about 13×10 -6 per ° C. at 427° C., characterized by resistance to oxygen embrittlement and further characterized by notch ductility at about 650° C. in the annealed and aged condition consisting essentially of, in percent by weight, about 25 to 50% nickel, about 5 to 50% cobalt, about 45 to 75% nickel plus cobalt, about 4 to 10% aluminum, about 0 to 2% titanium, 0 to about 0.2% carbon, 0 to about 6% chromium, 0 to about 2% total manganese, silicon and copper, 0 to about 0.5% silicon, 0 to about 5% molybdenum plus tungsten, about 0 to about 6% niobium, 0 to about 0.1% zirconium, 0 to about 0.02% boron, balance essentially iron in the range of 20% to 50% along with incidental impurities.

Claim 2

Dependent Claim 141 words

An oxidation resistant alloy having a relatively low coefficient of thermal expansion of less than about 13×10 -6 per ° C. at 427° C., characterized by resistance to oxygen embrittlement and further characterized by notch ductility at about 650° C. in the annealed and aged condition consisting essentially of, in percent by weight, about 25 to 50% nickel, about 5 to 50% cobalt, about 45 to 75% nickel plus cobalt, about 4 to 10% aluminum, about 0 to 2% titanium, 0 to about 0.2% carbon, 0 to about 6% chromium, 0 to about 2% total manganese, silicon and copper, 0 to about 0.5% silicon, 0 to about 5% molybdenum plus tungsten, about 0 to about 6% niobium, 0 to about 0.1% zirconium, 0 to about 0.02% boron, balance essentially iron in the range of 20% to 50% along with incidental impurities.

Claim 3

Dependent Claim 13 words

An alloy as in claim 1 which contains at least about 2% niobium.

Claim 4

Dependent Claim 15 words

An alloy as in claim 1 wherein the nickel content is about 30% to 45%.

Claim 5

Dependent Claim 15 words

An alloy as in claim 2 wherein the aluminum content is about 4.8 to 6%.

Claim 6

Dependent Claim 181 words

An oxidation resistant alloy consisting essentially of, in weight percent, about 25 to 50% nickel, about 5 to 50% cobalt, about 45 to 75% nickel plus cobalt, about 4 to 10% aluminum, 0 to 3% titanium, 0 to 10% niobium, 0 to 10% tantalum, 0 to 10% molybdenum, 0 to 10% tungsten, 0 to 3% vanadium, 0 to 2% silicon, 0 to 1% manganese, 0 to 1% copper, 0 to 6% chromium, 0 to 2% hafnium, 0 to 2% rhenium, 0 to 0.3% boron, 0 to 0.3% zirconium, 0 to 0.1% total magnesium, calcium, yttrium and rare earths, 0 to 0.5% nitrogen, 0 to 0.3% carbon, the balance of the alloy being iron in the range of 20 to 50% and incidental impurities, said alloy having a duplex structure, one crystalline component of which is a gamma phase, having a gamma prime precipitate therein, and another component have a bcc B2 structure enriched in aluminum compared to said crystalline component and said alloy having a coefficient of thermal expansion of less than about 13×10 -4 per ° C. at 427° C.

Claim 7

Dependent Claim 181 words

An oxidation resistant alloy consisting essentially of, in weight percent, about 25 to 50% nickel, about 5 to 50% cobalt, about 45 to 75% nickel plus cobalt, about 4 to 10% aluminum, 0 to 3% titanium, 0 to 10% niobium, 0 to 10% tantalum, 0 to 10% molybdenum, 0 to 10% tungsten, 0 to 3% vanadium, 0 to 2% silicon, 0 to 1% manganese, 0 to 1% copper, 0 to 6% chromium, 0 to 2% hafnium, 0 to 2% rhenium, 0 to 0.3% boron, 0 to 0.3% zirconium, 0 to 0.1% total magnesium, calcium, yttrium and rare earths, 0 to 0.5% nitrogen, 0 to 0.3% carbon, the balance of the alloy being iron in the range of 20 to 50% and incidental impurities, said alloy having a duplex structure, one crystalline component of which is a gamma phase, having a gamma prime precipitate therein, and another component have a bcc B2 structure enriched in aluminum compared to said crystalline component and said alloy having a coefficient of thermal expansion of less than about 13×10 -4 per ° C. at 427° C.

Claim 8

Dependent Claim 22 words

An oxidation resistant alloy as in claim 5 wherein cobalt is at least about 24% when iron is less than about 24%.

Claim 9

Dependent Claim 13 words

An oxidation resistant alloy as in claim 5 containing at least 1% niobium.

Claim 10

Dependent Claim 20 words

An oxidation resistant alloy as in claim 5 containing at least about 2.5% niobium and less than about 0.8% titanium.

Claim 11

Dependent Claim 14 words

An oxidation resistant alloy as in claim 5 containing about 4.8 to 6% aluminum.

Claim 12

Dependent Claim 21 words

An oxidation resistant alloy as in claim 5 containing about 1 to 2.5 % titanium and less than about 30% iron.

Claim 13

Dependent Claim 17 words

An oxidation resistant alloy as in claim 6 containing 0 to about 5% total molybdenum plus tungsten.

Claim 14

Dependent Claim 14 words

An oxidation resistant alloy as in claim 5 containing about 25 to 40% cobalt.

Claim 15

Dependent Claim 14 words

An oxidation resistant alloy as in claim 12 containing about 20 to 27.5% iron.

Claim 16

Dependent Claim 14 words

An oxidation resistant alloy as in claim 5 containing 0 to about 2% vanadium.

Claim 17

Dependent Claim 14 words

An oxidation resistant alloy as in claim 5 containing about 2 to 6% chromium.

Claim 18

Dependent Claim 14 words

An oxidation resistant alloy as in claim 5 containing about 2 to 6% molybdenum.

Claim 19

Dependent Claim 16 words

An oxidation resistant alloy as in claim 5 containing about 4 to 10% chromium plus molybdenum.

Claim 20

Dependent Claim 14 words

An oxidation resistant alloy as in claim 5 containing 0 to about 0.3% nitrogen.

Claim 21

Dependent Claim 72 words

An oxidation resistant alloy as in claim 5 containing about 25 to 45% nickel, about 25 to 35% cobalt, about 20 to 27.5% iron, about 4.8 to 5.8% aluminum, about 0 to 1.8% titanium, 0 to about 0.1% carbon, 0 to about 0.3% silicon, about 0.5 to 4% niobium, the sum of copper plus manganese being 0 to about 0.5% and the sum of molybdenum plus tungsten being 0 to about 5%.

Claim 22

Dependent Claim 59 words

An oxidation resistant alloy as in claim 5 containing about 25 to 40% nickel, about 25 to 35% cobalt, about 27.5 to 35% iron, about 4.8 to 5.8% aluminum, about 0 to 0.8% titanium, 0 to about 0.5 manganese, 0 to about 0.75% silicon, 0 to about 2% molybdenum, 0 to about 2% niobium and 0.001 to 0.01% boron.

Claim 23

Dependent Claim 16 words

An oxidation resistant alloy as in claim 5 which contains as said dispersoid an oxidic phase.

Claim 24

Dependent Claim 28 words

An oxidation resistant alloy as in claim 21 which contains about 0.2 to 2% oxidic phase selected from the group consisting of yttria and complex oxide of yttria.

Claim 25

Dependent Claim 24 words

The alloy of claim 5 wheien said alloy contains at least one additive selected from the group consisting of deoxidants, grain refiners and dispersoids.

Claim 26

Dependent Claim 155 words

An alloy consisting essentially of, in weight percent, about 20 to 50% nickel, about 5 to 50% cobalt, about 45 to 75% nickel plus cobalt, about 4 to 6% aluminum, about 0.5 to 6% niobium, about 0 to 0.5% titanium, about 0 to 0.1% carbon, about 0 to 2% silicon, about 0 to 0.3% boron, about 0 to 10% molybdenum, about 0 to 10% tungsten, about 0 to 10% tantalum, about 0to 3% vanadium, about 0 to 1% copper, about 0 to 1% manganese, about 0 to 6% chromium, about 0 to 2% rhenium, about 0 to 2% hafnium, about 0 to 0.3% zirconium, 0 to 0.1% total magnesium, calcium, yttrium and rare earths, about 0 to 0.5% nitrogen and balance iron in the range of about 20 to 50% along with incidental impurities and said alloy having a coefficient of thermal expansion of less than about 13×10 -6 per ° C. at 427° C.

Claim 27

Dependent Claim 155 words

An alloy consisting essentially of, in weight percent, about 20 to 50% nickel, about 5 to 50% cobalt, about 45 to 75% nickel plus cobalt, about 4 to 6% aluminum, about 0.5 to 6% niobium, about 0 to 0.5% titanium, about 0 to 0.1% carbon, about 0 to 2% silicon, about 0 to 0.3% boron, about 0 to 10% molybdenum, about 0 to 10% tungsten, about 0 to 10% tantalum, about 0to 3% vanadium, about 0 to 1% copper, about 0 to 1% manganese, about 0 to 6% chromium, about 0 to 2% rhenium, about 0 to 2% hafnium, about 0 to 0.3% zirconium, 0 to 0.1% total magnesium, calcium, yttrium and rare earths, about 0 to 0.5% nitrogen and balance iron in the range of about 20 to 50% along with incidental impurities and said alloy having a coefficient of thermal expansion of less than about 13×10 -6 per ° C. at 427° C.

Claim 28

Dependent Claim 14 words

The alloy of claim 24 wherein the iron content is less that about 30%.

Claim 29

Dependent Claim 14 words

The alloy of claim 25 wherein the bobalt content is about 25 to 40%.

Claim 30

Dependent Claim 14 words

The alloy of claim 24 wherein the chromium content is about 2 to 6%.

Claim 31

Dependent Claim 14 words

The alloy of claim 24 wherein the aluminum content is about 4.8 to 6%.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1998-04-03	1998-10-03	1999-04-04	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	2002-04-03	2002-10-03	2003-04-04	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2006-04-03	2006-10-03	2007-04-04	$7700.00	Window Closed / Lapsed

Oxidation resistant low expansion superalloys

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