High strength ni-based superalloy

Abstract

The present invention provides a Ni-based alloy having a high strength and excellent hot workability. The present invention relates to a high strength Ni-based superalloy having a composition including, in terms of % by mass: C: 0.005 to 0.05%; Fe: 0.1 to 2.0%; Cr: 10 to 20%; Co: 10 to 20%; Mo: 1.0 to 8.0%; W: 1.0 to 8.0%; Ti: 0.1 to 2.0%; Al: 2.0 to 4.5%; and Nb: 0.1 to 2.0%, with the balance being Ni and unavoidable impurities.

1 . A high strength Ni-based superalloy having a composition comprising, in terms of % by mass:
 C: 0.005 to 0.05%;   Fe: 0.1 to 2.0%;   Cr: 10 to 20%:   Co: 10 to 20%;   Mo: 1.0 to 8.0%;   W: 1.0 to 8.0%;   Ti: 0.1 to 2.0%;   Al: 2.0 to 4.5%; and   Nb: 0.1 to 2.0%,   
       with the balance being Ni and unavoidable impurities. 
     
     
         2 . The high strength Ni-based superalloy according to  claim 1 , wherein the composition further comprises, in terms of ppm by mass, at least one of:
 P: 30 to 100 ppm; and   B: 50 to 250 ppm.   
     
     
         3 . The high strength Ni-based superalloy according to  claim 1 , wherein the composition further comprises, in terms of % by mass, at least one of:
 Mg: 0.01% or less; and   Zr: 0.01 to 0.50%.   
     
     
         4 . The high strength Ni-based superalloy according to  claim 1 , having a γ′ phase amount at 700° C. of 40 to 43% in terms of volume fraction. 
     
     
         5 . The high strength Ni-based superalloy according to  claim 1 , having a γ′ phase solution temperature of 1100° C. or lower. 
     
     
         6 . The high strength Ni-based superalloy according to  claim 1 , wherein a temperature range within which a reduction of area of the superalloy evaluated in a tensile test is 50% or more, is 120° C. or higher. 
     
     
         7 . The high strength Ni-based superalloy according to  claim 1 , which is used at a temperature of 600° C. or higher.