NICKEL-BASED HEAT-RESISTANT ALLOY

PROBLEM TO BE SOLVED: To provide an Ni-based heat-resistant alloy excellent in creep strength and creep ductility after being used at high temperature for a long time.SOLUTION: An Ni-based heat-resistant alloy contains, by mass, 0.1% or less C, 1% or less Si, 1% or less Mn, 15.0% to below 28.0% Cr, 3-18% of Mo+0.5W, 0.5% to 2.5% Al, over 0.5% to 2.0% Ti, 0.1-2.0% Nb, and 0.0005-0.01% B, with the balance comprising 50% or more Ni and impurities, and satisfies formula (1) and formula (2), with the proviso that the strain in lattice matching between the precipitated phase and the matrix phase is 0.4% or less, and the volume fraction of a gammer prime phase at 750°C is 25 mol% or less, wherein formula (1): Al-Ti≥-0.1 and formula (2): Al-(Ti+Nb) ≤0.1 are satisfied. In formulae (1) and (2), the element symbols are substituted by the contents (mass%) of the corresponding elements.