Ni-Cr-Co alloy for advanced gas turbine engines
A wrought age-hardenable nickel-chromium-cobalt based alloy suitable for use in high temperature gas turbine transition ducts possessing a combination of three specific key properties, namely resistance to strain age cracking, good thermal stability, and good creep-rupture strength contains in weight percent 17 to 22 chromium, 8 to 15 cobalt, 4.0 to 9.1 molybdenum, up to 7 tungsten, 1.39 to 1.65 aluminum, 1.50 to 2.30 titanium, up to 0.80 niobium, 0.01 to 0.2 carbon, up to 0.01 boron, up to 3 iron, up to 1.5 tantalum and less than 0.02 zirconium, with a balance of nickel and impurities. Certain alloying elements must be present in amounts according to two equations here disclosed.
1. A nickel-chromium-cobalt based alloy having a composition comprised in weight percent of:
17 to 22
chromium
8 to 15
cobalt
4.0 to 9.1
molybdenum
up to 7.0
tungsten
1.39 to 1.65
aluminum
1.50 to 2.30
titanium
up to 0.80
niobium
0.01 to 0.2
carbon
up to 0.015
boron
up to 1.5
tantalum
less than 0.02
zirconium
with a balance of nickel and impurities, the alloy further satisfying the following compositional relationships defined with elemental quantities being in terms of weight percent:
2.2<Al+0.56Ti+0.29Nb<2.9
6.5<Mo+0.52W≦9.1.
2. The nickel-chromium-cobalt based alloy of claim 1 , also containing iron up to 3 weight percent.
3. The nickel-chromium-cobalt based alloy of claim 1 , also containing in weight percent at least one of tantalum, up to 1.5%, manganese, up to 1.5%, silicon, up to 0.5%, and copper, up to 0.5%.
4. The nickel-chromium-cobalt based alloy of claim 1 , also containing at least one element selected from the group consisting of magnesium, calcium, hafnium, yttrium, cerium, and lanthanum, wherein each said element present comprises up to 0.05 weight percent of the alloy.
5. The nickel-chromium-cobalt based alloy of claim 1 wherein the alloy is in a form selected from the group consisting of wrought form, cast form, spray-formed and powder metallurgy form.
6. The nickel-chromium-cobalt based alloy of claim 5 , wherein the wrought form is selected from the group consisting of sheets, plates, bars, wires, tubes, pipes, and forgings.
7. The nickel-chromium-cobalt based alloy of claim 1 wherein the alloy is formed as a component for a gas turbine engine.
8. The nickel-chromium-cobalt alloy of claim 1 wherein the alloy contains in weight percent 1.40 to 1.65 aluminum, and
8.0≦Mo+0.52W≦9.0
Nb≦0.5.
9. A nickel-chromium-cobalt based alloy, suitable for use in gas turbine transition ducts, having a composition comprised in weight percent of:
17.5 to 21.3
chromium
8.3 to 14.2
cobalt
4.3 to 9.1
molybdenum
up to 7.0
tungsten
1.39 to 1.65
aluminum
1.59 to 2.28
titanium
up to 0.79
niobium
0.034 to 0.097
carbon
0.002 to 0.007
boron
up to 2.6
iron
up to 1.5
tantalum
less than 0.02
zirconium
with a balance of nickel and impurities, the alloy further satisfying the following compositional relationships defined with elemental quantities being in terms of weight percent:
2.35<Al+0.56Ti+0.29Nb<2.84
7.1<Mo+0.52W≦9.1.
10. The nickel-chromium-cobalt based alloy of claim 9 , also containing in weight percent at least one of tantalum, up to 1.5%, manganese, up to 1.5%, silicon, up to 0.5%, and copper, up to 0.5%.
11. The nickel-chromium-cobalt based alloy of claim 9 , also containing up to at least one element selected from the group consisting of magnesium, calcium, hafnium, yttrium, cerium, and lanthanum, wherein each said element present comprises up to 0.05 weight percent of the alloy.
12. The nickel-chromium-cobalt based alloy of claim 9 wherein the alloy is in a form selected from the group consisting of wrought form, cast form, spray-formed and powder metallurgy form.
13. The nickel-chromium-cobalt based alloy of claim 12 , wherein the wrought form is selected from the group consisting of sheets, plates, bars, wires, tubes, pipes, and forgings.
14. The nickel-chromium-cobalt based alloy of claim 9 wherein the alloy is formed as a component for a gas turbine engine.
15. The nickel-chromium-cobalt alloy of claim 9 wherein the alloy contains in weight percent 1.40 to 1.65 aluminum, and
8.0≦Mo+0.52W≦9.0
Nb≦0.5.
16. An improved gas turbine engine having a plurality of metal components wherein the improvement comprises at least one of the metal components in weight percent consisting essentially of:
17 to 22
chromium
8 to 15
cobalt
4.0 to 9.1
molybdenum
up to 7.0
tungsten
1.39 to 1.65
aluminum
1.50 to 2.30
titanium
up to 0.80
niobium
0.01 to 0.2
carbon
up to 0.015
boron
up to 1.5
tantalum
less than 0.02
zirconium
with a balance of nickel and impurities, the alloy further satisfying the following compositional relationships defined with elemental quantities being in terms of weight percent:
2.2<Al+0.56Ti+0.29Nb<2.9
6.5<Mo+0.52W≦9.1.
17. The improved gas turbine engine of claim 16 wherein the at least one of the metal components is a transition duct.
18. The improved gas turbine engine of claim 16 where the at least one of the metal components in weight percent consists essentially of:
17.5 to 21.3
chromium
8.3 to 14.2
cobalt
4.3 to 9.1
molybdenum
up to 7.0
tungsten
1.39 to 1.65
aluminum
1.59 to 2.28
titanium
up to 0.79
niobium
0.034 to 0.097
carbon
0.002 to 0.007
boron
up to 2.6
iron
up to 1.5
tantalum
less than 0.02
zirconium
with a balance of nickel and impurities, the alloy further satisfying the following compositional relationships defined with elemental quantities being in terms of weight percent:
2.35<Al+0.56Ti+0.29Nb<2.84
7.1<Mo+0.52W≦9.1.
19. The improved gas turbine engine of claim 16 wherein the alloy consisting essentially of in weight percent 1.40 to 1.65 aluminum and
8.0≦Mo+0.52W≦9.0
2.45≦Al+0.56Ti+0.29Nb≦2.9.
20. A nickel-chromium-cobalt based alloy having a composition comprised in weight percent of:
17 to 22
chromium
8 to 15
cobalt
7.9 to 9.1
molybdenum
up to 0.5
tungsten
1.39 to 1.65
aluminum
1.50 to 2.30
titanium
up to 0/5
niobium
0.01 to 0.2
carbon
up to 0.015
boron
up to 1.5
tantalum
less than 0.02
zirconium
with the balance of nickel and impurities, the alloy further satisfying the following compositional relationships defined with elemental quantities being in terms of weight percent:
2.2<Al+0.56Ti+0.29Nb<2.9
8.0<Mo+0.52W≦9.0.
21. The nickel-chromium-cobalt based alloy of claim 20 , also comprising iron up to 3 weight percent.
22. The nickel-chromium-cobalt based alloy of claim 20 , also containing in weight percent at least one of tantalum, up to 1.5%, manganese, up to 1.5%, silicon, up to 0.5%, and copper, up to 0.5%.
23. The nickel-chromium-cobalt based alloy of claim 20 , also containing at least one element selected from the group consisting of magnesium, calcium, hafnium, yttrium, cerium, and lanthanum, wherein each said element present comprises up to 0.05 weight percent of the alloy.
24. The nickel-chromium-cobalt based alloy of claim 20 wherein the alloy is in a form selected from the group consisting of wrought form, cast form, spray-formed and powder metallurgy form.
25. The nickel-chromium-cobalt based alloy of claim 24 , wherein the wrought form is selected from the group consisting of sheets, plates, bars, wires, tubes, pipes, and forgings.
26. A nickel-chromium-cobalt based alloys, suitable for use in gas turbine transition ducts, having a composition comprised in weight percent of:
17.5 to 21.3
chromium
8.3 to 14.2
cobalt
7.9 to 9.1
molybdenum
less than 0.1
tungsten
1.39 to 1.63
aluminum
1.59 to 2.28
titanium
up to 0.5
niobium
0.034 to 0.097
carbon
0.002 to 0.007
boron
up to 2.6
iron
up to 1.5
tantalum
with a balance of nickel and impurities, the alloy further satisfying the following compositional relationships defined with elemental quantities being in terms of weight percent:
2.35<Al+0.56Ti+0.29Nb<2.84
8.0<Mo+0.25W≦9.0.
27. The nickel-chromium-cobalt based alloy of claim 26 also comprising zirconium present in an amount less than 0.02 weight percent.
28. The nickel-chromium-cobalt based alloy of claim 26 , also containing in weight percent at least one of tantalum, up to 1.5%, manganese, up to 1.5%, silicon, up to 0.5%, and copper, up to 0.5%.
29. The nickel-chromium-cobalt based alloy of claim 26 , also containing at least one element selected from the group consisting of magnesium, calcium, hafnium, yttrium, cerium, and lanthanum, wherein each said element present comprises up to 0.05 weight percent of the alloy.
30. The nickel-chromium-cobalt based alloy of claim 26 wherein the alloy is in a form selected from the group consisting of wrought form, cast form, spray-formed and powder metallurgy form.
31. The nickel-chromium-cobalt based alloy of claim 30 , wherein the wrought form is selected from the group consisting of sheets, plates, bars, wires, tubes, pipes, and forgings.
32. The nickel-chromium-cobalt based alloy of claim 26 wherein the alloy contains less than 0.05 weight percent niobium.
33. The nickel-chromium-cobalt based alloy of claim 32 also comprising zirconium present in an amount less than 0.02 weight percent.