Oxidation resistant superalloy
A nickel-based superalloy that forms a chromia scale in an oxidizing environment is disclosed. The alloy provides good oxidation resistance at temperatures below 900° C. in a dry or moist atmosphere. The superalloy is well-suited for components of gas or steam turbine engines including blades and vanes.
1 . A nickel-based superalloy expressed in weight percentages consisting essentially of:
15.5 to 18.5 Cr;
14.0 to 15.5 Co;
2.5 to 3.5 Mo;
2.0 to 3.5 Al;
4.0 to 5.5 Ti;
0.5 to 2.0 W;
0 to 1.5 Hf;
0 to 2.0 Fe;
0 to 1.0 Si;
0.01 to 0.1 B;
0 to 0.1 Zr;
0.03 to 0.20 C;
0 to 0.5 at least one rare earth elements selected from the group of Y, La, Ce, Nb, Dy, Pr, Sm, and Gd;
less than 0.1 S; and
balance formed from Ni.
2 . The superalloy of claim 1 , wherein the superalloy expressed in weight percentages consisting essentially of:
15.5 to 16.5 Cr;
14.0 to 15.5 Co;
2.75 to 3.25 Mo;
2.25 to 2.75 Al;
4.75 to 5.25 Ti;
1.0 to 1.5 W;
0 to 1.0 Hf;
0 to 0.5 Fe;
0 to 0.5 Si;
0.01 to 0.02 B;
0.025 to 0.08 Zr;
0.03 to 0.10 C;
0 to 0.2 at least one rare earth elements selected from the group of Y, La, Ce, Nb, Dy, Pr, Sm, and Gd;
less than 10 ppm S; and
the balance formed from Ni.
3 . The superalloy of claim 1 , wherein the superalloy expressed in weight percentages consisting essentially of:
15.5 to 16.5 Cr;
14.25 to 14.75 Co;
2.80 to 3.20 Mo;
2.30 to 2.60 Al;
4.80 to 5.20 Ti;
1.2 to 1.5 W;
0.10 to 0.15 Hf;
O to 0.2 Fe;
0.10 to 0.15 Si;
0.01 to 0.02 B;
0.025 to 0.050 Zr;
0.03 to 0.04 C;
250 to 750 ppm at least one rare earth elements selected from the group of Y, La, Ce, Nb, Dy, Pr, Sm, and Gd;
less than 2 ppm S; and
the balance formed from Ni.