Ni-based superalloy

Abstract

The present invention relates to an Ni-based superalloy having a composition containing, in terms of % by mass, C: from 0.1 to 0.3%, Cr: from 8.0 to 12.0%, Mo: from 1.0 to 5.0%, Co: from 10.0 to 20.0%, Ta: from 0.01 to 1.50%, Ti: from 2.0 to 4.2%, Al: from 5.0 to 8.0%, V: from 0 to 1.5%, B: from 0.005 to 0.030%, and Zr: from 0.05 to 0.15%, with the balance being Ni and unavoidable impurities, and satisfying, in terms of atom %, Ti+Al being from 16.0 to 20.3% and Ti/Al being 0.3 or less.

What is claimed is: 
     
       1. A turbine wheel, comprising:
 a Ni-based superalloy having a composition comprising, in terms of % by mass:
 C: from 0.1% to 0.3%; 
 Cr: from 8.0% to 12.0%; 
 Mo: from 1.0% to 5.0%; 
 Co: from 10.0% to 20.0%; 
 Ta: from 0.01% to 1.50%; 
 Ti: from 2.0% to 4.2%; 
 Al: from 5.0% to 8.0%; 
 V: from 0% to 1.5%; 
 B: from 0.005% to 0.030%; and 
 Zr: from 0.05% to 0.15%, 
 
 with a balance being Ni and unavoidable impurities, and 
 satisfying, in terms of atom %:
 Ti+Al being from 16.0% to 20.3%; and 
 Ti/Al being 0.3 or less. 
 
 
     
     
       2. The turbine wheel according to  claim 1 , wherein, in terms of % by mass, the Ni-based superalloy consists of:
 C: from 0.1% to 0.3%; 
 Cr: from 8.0% to 12.0%; 
 Mo: from 1.0% to 5.0%; 
 Co: from 10.0% to 20.0%; 
 Ta: from 0.01% to 1.50%; 
 Ti: from 2.0% to 4.7%; 
 Al: from 5.0% to 8.0%; 
 V: from 0% to 1.5%; 
 B: from 0.005% to 0.030%; and 
 Zr: from 0.05% to 0.15%, 
 with the balance being Ni and the unavoidable impurities. 
 
     
     
       3. The turbine wheel according to  claim 1 , wherein Al is in a range from 6.8% to 8%. 
     
     
       4. The turbine wheel according to  claim 1 , wherein Al is in a range from 6.8% to 7.5%. 
     
     
       5. The turbine wheel according to  claim 1 , wherein Ta is in a range from 0.3% to 0.8%. 
     
     
       6. The turbine wheel according to  claim 1 , wherein the Ni-based superalloy has a specific gravity of 7.9 g/cm 3  or less.