Abstract: A gamma-prime precipitation hardening nickel-base yttria particle-dispersion-strengthened superalloy having a composition consisting essentially, by weight %, of 3.5 to 6.0 % of Al, 7.0 to 10.0 % of Co, 8.0 to 10.5 % of Cr, 0.5 to 1.5 % of Ti, 4.0 to 6.5 % of Ta, 7.0 to 9.0 % of W, 1.5 to 2.5 % of Mo, 0.02 to 0.2 % of Zr, 0.001 to 0.1 % of C, 0.001 to 0.02 % of B, 0.5 to 1.7 % of Y.sub.2 O.sub.3 and the balance being Ni. It has an excellent high-temperature creep rupture strength and a good corrosion resistance at high temperatures.

Abstract: A gamma-prime precipitation hardening nickel-base yttria particle-dispersion-strengthened superalloy having a composition consisting essentially of, by weight, 3.0 to 6.0% of Al, 8.5 to 10.9% of Co, 3.9 to 7.5% of Cr, 0.5 to 1.2% of Ti, 3.6 to 6.3% of Ta, 11.4 to 13.3% of W, 0.02 to 0.2% of Zr, 1.3 to 2.6% of Mo, 0.001 to 0.1% of C, 0.001 to 0.02% of B, 0.5 to 1.7% of yttria (Y.sub.2 O.sub.3), not more than 0.8% of O and the balance being Ni and having a structure composed of coarse recrystallized grains with a GAR of at least 20 and a short axis diameter of at least 0.