A Ni-based alloy includes, as a chemical composition, C, Si, Mn, Cr, Mo, Co, Al, Ti, B, P, S, and a balance consisting of Ni and impurities. The average grain size d is 10 μm to 300 μm, when the average grain size d is an average grain size in unit of μm of a γ phase included in a metallographic structure of the Ni-based alloy. Precipitates with a major axis of 100 nm or more are absent in the metallographic structure. An area fraction ρ is f2 or more, when the area fraction ρ and the f2 are expressed by using the average grain size d and amounts in mass % of each element in the chemical composition.
1. A Ni-based alloy comprising, as a chemical composition, by mass %,
0.001% to 0.15% of C,
0.01% to 2% of Si,
0.01% to 3% of Mn,
15% to less than 28% of Cr,
3% to 15% of Mo,
more than 5% to 25% of Co,
0.2% to 2% of Al,
0.2% to 3% of Ti,
0.0005% to 0.01% of B,
0% to 3.0% of Nb,
0% to 15% of W,
0% to 0.2% of Zr,
0% to 8% of Ta,
0% to 8% of Re,
0% to 15% of Fe,
f1 expressed by a following Expression 1 or less of P,
0.01% or less of S,
at least one selected from
0.005% to 1% of Hf,
0.0005% to 0.05% of Mg,
0.0005% to 0.05% of Ca,
0.0005% to 0.5% of Y,
0.0005% to 0.5% of La,
0.0005% to 0.5% of Ce,
0.0005% to 0.5% of Nd, and
a balance consisting of Ni and impurities,
wherein, an average grain size d is an average grain size in unit of μm of a γ phase included in a metallographic structure of the Ni-based alloy, and the average grain size d is 10 μm to 300 μm,
wherein precipitates with a major axis of 100 nm or more are absent in the metallographic structure, and
wherein, an area fraction ρ is expressed by a following Expression 2 using the average grain size d and amounts in unit of mass % of each element in the chemical composition, and the area fraction ρ is f2 expressed by a following Expression 3 or more,
f 1=0.01−0.012/[1+exp{( B− 0.0015)/0.001}] (Expression 1)
ρ=21 ×d 0.15 +40×(500 ×B/ 10.81+50 ×C/ 12.01+Cr/52.00) 0.3 (Expression 2)
f 2=32 ×d 0.07 +115×(Al/26.98+Ti/47.88+Nb/92.91) 0.5 (Expression 3).
2. The Ni-based alloy according to claim 1 comprising, as the chemical composition, by mass %,
0.05% to 3.0% of Nb.
3. A Ni-based alloy tube comprising a Ni-based alloy according to claim 2 for a production thereof.
4. The Ni-based alloy according to claim 2 comprising, as the chemical composition, by mass %, at least one selected from
0.005% to 0.2% of Zr,
0.01% to 8% of Ta,
0.01% to 8% of Re, and
1.5% to 15% of Fe.
5. A Ni-based alloy tube comprising a Ni-based alloy according to claim 4 for a production thereof.
6. The Ni-based alloy according to claim 2 comprising, as the chemical composition, by mass %,
1% to 15% of W.
7. A Ni-based alloy tube comprising a Ni-based alloy according to claim 6 for a production thereof.
8. The Ni-based alloy according to claim 6 comprising, as the chemical composition, by mass %, at least one selected from
0.005% to 0.2% of Zr,
0.01% to 8% of Ta,
0.01% to 8% of Re, and
1.5% to 15% of Fe.
9. A Ni-based alloy tube comprising a Ni-based alloy according to claim 8 for a production thereof.
10. The Ni-based alloy according to claim 1 comprising, as the chemical composition, by mass %,
1% to 15% of W.
11. The Ni-based alloy according to claim 10 comprising, as the chemical composition, by mass %, at least one selected from
0.005% to 0.2% of Zr,
0.01% to 8% of Ta,
0.01% to 8% of Re, and
1.5% to 15% of Fe.
12. A Ni-based alloy tube comprising a Ni-based alloy according to claim 11 for a production thereof.
13. A Ni-based alloy tube comprising a Ni-based alloy according to claim 10 for a production thereof.
14. The Ni-based alloy according to claim 1 comprising, as the chemical composition, by mass %, at least one selected from
0.005% to 0.2% of Zr,
0.01% to 8% of Ta,
0.01% to 8% of Re, and
1.5% to 15% of Fe.
15. A Ni-based alloy tube comprising a Ni-based alloy according to claim 14 for a production thereof.
16. A Ni-based alloy tube comprising a Ni-based alloy according to claim 1 for a production thereof.