Cast nickel-base alloys including iron
A cast nickel-base superalloy that includes iron added substitutionally for nickel. The cast nickel base superalloy comprises, in weight percent about 1-6% iron, about 7.5-19.1% cobalt, about 7-22.5% chromium, about 1.2-6.2% aluminum, optionally up to about 5% titanium, optionally up to about 6.5% tantalum, optionally up to about 1% Nb, about 2-6% W, optionally up to about 3% Re, optionally up to about 4% Mo, about 0.05-0.18% C, optionally up to about 0.15% Hf, about 0.004-0.015 B, optionally up to about 0.1% Zr, and the balance Ni and incidental impurities. The superalloy is characterized by a γ′ solvus temperature that is within 5% of the γ′ solvus temperature of the superalloy that does not include 1-6% Fe and a mole fraction of γ′ that is within 15% of the mole fraction of the superalloy that does not include 1-6% Fe.
1. A cast nickel-base superalloy comprising, in weight percent:
about 5% Fe,
16-19.1% Co,
20-22.5% Cr,
0.8-2.5% Al,
1.2-4% Ti,
0.75-1.5% Ta,
0.5-1% Nb,
2-3% W,
0.08-0.15% C,
0.004-0.01 B,
up to 0.02% Zr, and
the balance Ni and incidental impurities,
wherein the superalloy is a low γ′ alloy and the superalloy is characterized by a γ′ mole fraction that is no more than 15% less than a comparative γ′ mole fraction of a comparable superalloy that does not include 1-6% Fe.
2. The superalloy of claim 1 wherein the superalloy has a nominal composition comprising, in weight percent:
about 5% Fe,
19.1% Co,
22.5% Cr,
1.2% Al,
2.3% Ti,
0.94% Ta,
0.8% Nb,
2% W,
0.08% C,
0.004% B,
0.02% Zr, and
the balance Ni and incidental impurities.
3. The superalloy of claim 1 wherein the superalloy has a nominal composition comprising, in weight percent:
about 5% Fe,
19% Co,
22.5% Cr,
1.9% Al,
3.7% Ti,
1.4% Ta,
1% Nb,
2% W,
0.15% C,
0.01% B,
0.1% Zr, and
the balance Ni and incidental impurities.
4. The superalloy of claim 1 wherein the superalloy is characterized by a γ′ solvus temperature that is no more than 5% less than a comparative γ′ solvus temperature of the comparable superalloy that does not include 1-6% Fe.
5. The superalloy of claim 1 wherein the cast nickel-base superalloy includes, in weight percent, 5% iron.