Nickel-based heat-resistant superalloy

Abstract

Disclosed herein is a nickel-based heat-resistant superalloy produced by a casting and forging method, the nickel-based heat-resistant superalloy comprising 2.0 mass % or more but 25 mass % or less of chromium, 0.2 mass % or more but 7.0 mass % or less of aluminum, 19.5 mass % or more but 55.0 mass % or less of cobalt, [0.17×(mass % of cobalt content−23)+3] mass % or more but [0.17×(mass % of cobalt content−20)+7] mass % or less and 5.1 mass % or more of titanium, and the balance being nickel and inevitable impurities, and being subjected to solution heat treatment at 93% or more but less than 100% of a γ′ solvus temperature.

1 . A nickel-based heat-resistant superalloy produced by a casting and forging method, the nickel-based heat-resistant superalloy comprising 2.0 mass % or more but 25.0 mass % or less of chromium, 0.2 mass % or more but 7.0 mass % of less of aluminum, 19.5 mass % or more but 55.0 mass % or less of cobalt, [0.17×(mass % of cobalt content−23)+3] mass % or more but [0.17×(mass % of cobalt content−20)+7] mass % or less and 5.1 mass % or more of titanium, and the balance being nickel and inevitable impurities, and being subjected to solution heat treatment at 93% or more but less than 100% of a γ′ solvus temperature. 
     
     
         2 . The nickel-based heat-resistant superalloy according to  claim 1 , wherein the cobalt is contained in an amount of 21.8 mass % or more but 55.0 mass % or less. 
     
     
         3 . The nickel-based heat-resistant superalloy according to  claim 1 , wherein the titanium is contained in an amount of 5.5 mass % or more but 12.44 mass % or less. 
     
     
         4 . The nickel-based heat-resistant superalloy according to  claim 3 , wherein the titanium is contained in an amount of 6.1 mass % or more but 12.44 mass % or less. 
     
     
         5 . The nickel-based heat-resistant superalloy according to  claim 1 , which is subjected to solution heat treatment at 94% or more but less than 100% of the γ′ solvus temperature. 
     
     
         6 . The nickel-based heat-resistant superalloy according to  claim 1 , which contains one or both of 10 mass % or less of molybdenum and 10 mass % or less of tungsten. 
     
     
         7 . The nickel-based heat-resistant superalloy according to  claim 6 , wherein the molybdenum is contained in an amount of less than 4 mass %. 
     
     
         8 . The nickel-based heat-resistant superalloy according to  claim 6 , wherein the tungsten is contained in an amount of less than 3 mass %. 
     
     
         9 . The nickel-based heat-resistant superalloy according to  claim 1 , which contains one or both of 10 mass % or less of tantalum and 5.0 mass % or less of niobium. 
     
     
         10 . The nickel-based heat-resistant superalloy according to  claim 1 , which contains at least one of 2 mass % or less of vanadium, 5 mass % or less of rhenium, 0.1 mass % or less of magnesium, 2 mass % or less of hafnium, and 3 mass % or less of ruthenium. 
     
     
         11 . The nickel-based heat-resistant superalloy according to  claim 1 , which comprises 12 mass % or more but 14.9 mass % or less of chromium, 2.0 mass % or more but 3.0 mass % or less of aluminum, 20.0 mass % or more but 27.0 mass % or less of cobalt, 5.5 mass % or more but 6.5 mass % or less of titanium, 0.8 mass % or more but 1.5 mass % or less of tungsten, 2.5 mass % or more but 3.0 mass % or less of molybdenum, at least one of 0.01 mass % or more but 0.2 mass % or less of zirconium, 0.01 mass % or more but 0.15 mass % or less of carbon, and 0.005 mass % or more but 0.1 mass % or less of boron, and the balance being nickel and inevitable impurities.