(57) An Ni-based wrought superalloy in accordance with the present invention includes:
(a) from 0.005 to 0.2 mass% of C; (b) from 0 to 1 mass% of Si; (c) from 0 to 1 mass%
of Mn; (d) from 10 to 24 mass% of Cr; (e) at least one of Mo and W, the total content
expressed by "[Mo content] + 0.5×[W content]" being from 5 to 17 mass%; (f) from 1
to 2 mass% of Al; (g) from 0.5 to 3.5 mass% of Ti; (h) from 0 to 10 mass% of Fe; (i)
at least one of from 0.002 to 0.02 mass% of B and from 0.01 to 0.2 mass% of Zr; and
(j) the balance being Ni and inevitable impurities, the Ni content being from 48 to
80 mass%. Furthermore, the Ni-based wrought superalloy has a polycrystalline body
including a plurality of grains, and an average size of the grains after a heat treatment
is from 72 to 289 µm. Moreover, a plurality of granular precipitations precipitate
along the grain boundaries of the Ni-based wrought superalloy after the heat treatment,
and an average length of the granular precipitations along the grain boundary is from
0.5 to 2.5 µm in an arbitrary cross-sectional view of the polycrystalline body.
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