NiCrMoNb age hardenable alloy for creep-resistant high temperature applications, and methods of making

The alloy of any of the preceding claims comprising at least 0.1% Ta, or at least 0.2% Ta, or at least 1.0% Ta, or 0.1 to 4.0% Ta;

• or none or consisting essentially of none of Co.

The alloy of any of the above claims comprising at least 3.5% Nb, or at least 4.0% Nb.

(canceled)

The alloy of any of the above claims comprising δ (and/or η) phase precipitates at the grain boundaries and, optionally, further comprising γ′ (or γ″ or γ′/γ″) precipitates distributed within a γ matrix grain interior.

The alloy of any of the above claims characterizable by a time to failure at 700° C. and 483 MPa of at least 230 h, or at least 270 h, or at least 300 h, or at least 400 h, or in the range of 230 to 750 h or in the range of 230 to 700 h.

The alloy of any of the above claims characterizable by a time to failure at 790° C. and 207 MPa of at least 320 h, or at least 400 h, or at least 500 h, or in the range of 230 to 650 h or in the range of 230 to 550 h.

The alloy of any of the above claims characterizable by a time to failure at 750° C. and 345 MPa of at least 180 h, or at least 200 h, or at least 250 h, or at least 300 h, or in the range of 180 to 500 h or in the range of 180 to 450 h.

10-12. (canceled)

The alloy of any of the above claims characterizable by ultimate tensile strength at 750° C. of at least 800 MPa, or at least 850 MPa, or at least 900 MPa, or in the range of 800 to 1050 MPa or 800 to 950 MPa.

The alloy of any of the above claims characterizable by ultimate tensile strength at 800° C. of at least 600 MPa, or at least 650 MPa, or at least 700 MPa, or in the range of 650 to 900 MPa or 650 to 800 MPa.

The alloy of any of the above claims characterizable by 0.2% yield stress at room temperature of at least 850 MPa, or at least 900 MPa, or at least 1000 MPa, or in the range of 800 to 1150 MPa or 800 to 1100 MPa.

The alloy of any of the above claims characterizable by 0.2% yield stress at 600° C. of at least 750 MPa, or at least 850 MPa, or at least 900 MPa, or in the range of 750 to 1050 MPa or 750 to 1000 MPa.

The alloy of any of the above claims characterizable by 0.2% yield stress at 700° C. of at least 700 MPa, or at least 800 MPa, or at least 850 MPa, or in the range of 700 to 1000 MPa or 700 to 950 MPa.

The alloy of any of the above claims characterizable by 0.2% yield stress at 750° C. of at least 700 MPa, or at least 750 MPa, or at least 800 MPa, or in the range of 700 to 850 MPa or 700 to 800 MPa.

The alloy of any of the above claims characterizable by 0.2% yield stress at 800° C. of at least 500 MPa, or at least 550 MPa, or at least 600 MPa, or in the range of 500 to 800 MPa or 500 to 700 MPa.

20-26. (canceled)

A method of heat treating a nickel alloy comprising Cr and Nb, comprising the sequential steps of treating the nickel alloy:

• 820±30° C. for 5 to 100 h followed by cooling to
• 750±15° C. at a rate of 1 to 5° C./min, and then
• holding at 750±15° C. for 2 to 15 h.

29-32. (canceled)

34-35. (canceled)

An article comprising the alloy of the any of the above claims.

(canceled)