Ni-base superalloy and gas turbine component using the same

Abstract

A Ni-base superalloy of the present invention essentially includes, by weight %, Co: 9 to 11%, Cr: 9 to 12%, Mo: up to 1%, W: 6 to 9%, Al: 4 to 5%, Ti: 4 to 5%, Nb: up to 1%, Ta: up to 3%, Hf: 0.5 to 2.5%, Re: up to 3%, C: 0.05 to 0.15%, B: 0.005 to 0.015%, Zr: up to 0.05%, and the balance of Ni and inevitable impurities. This alloy, as a component material of an industrial gas turbine, has an excellent resistance to corrosion at high temperatures to deal with low-quality fuel and a resistance to oxidation at high temperatures and high-temperature strength to deal with improvement in thermal efficiency due to high-temperature demands and can ensure a high yield at a casting process.

1 . A Ni-base superalloy consisting essentially of: by weight %, Co: 9 to 10%, Cr: 9 to 10%, Mo: 0.5 to 1%, W: 6 to 8%, Al: 4 to 5%, Ti: 4 to 5%, Ta: 2 to 3%, Hf: 0.5 to 2.5%, Re: 1 to 3%, C: 0.05 to 0.1%, B: 0.005 to 0.01%, Zr: up to 0.02%, and the balance of Ni and inevitable impurities. 
   
   
       2 . A Ni-base superalloy consisting essentially of: by weight %, Co: 10 to 11%, Cr: 10 to 12%, W: 8 to 9%, Al: 4 to 5%, Ti: 4 to 5%, Nb: up to 1%, Hf: 0.5 to 2.5%, C: 0.05 to 0.15%, B: 0.005 to 0.015%, Zr: 0.01 to 0.05%, and the balance of Ni and inevitable impurities. 
   
   
       3 . A Ni-base superalloy according to  claim 1 , wherein said weight % of Hf is 0.5 to 1%. 
   
   
       4 . A Ni-base superalloy according to  claim 2 , wherein said weight % of Hf is 0.5 to 1%. 
   
   
       5 . A gas turbine component wherein it is manufactured by using said Ni-base superalloy as defined in  claim 1 . 
   
   
       6 . A gas turbine component wherein it is manufactured by using said Ni-base superalloy as defined in  claim 2 . 
   
   
       7 . A gas turbine component wherein it is manufactured by using said Ni-base superalloy as defined in  claim 3 . 
   
   
       8 . A gas turbine component wherein it is manufactured by using said Ni-base superalloy as defined in  claim 4 . 
   
   
       9 . A gas turbine component according to  claim 5 , wherein said gas turbine component is manufactured by a directional solidification casting method. 
   
   
       10 . A gas turbine component according to  claim 6 , wherein said gas turbine component is manufactured by a directional solidification casting method. 
   
   
       11 . A gas turbine component according to  claim 7 , wherein said gas turbine component is manufactured by a directional solidification casting method. 
   
   
       12 . A gas turbine component according to  claim 8 , wherein said gas turbine component is manufactured by a directional solidification casting method.