Heat-Resistant Superalloy

Abstract

Disclosed is a novel heat-resistant superalloy for turbine disks having a chemical composition consisting of, in mass %, 19.5-55% of cobalt, 2-25% of chromium, 0.2-7% of aluminum, 3-15% of titanium and the balance of nickel and inevitable impurities.

1 - 16 . (canceled) 
     
     
         17 . A heat-resistant superalloy characterized by containing in its composition  2  to 25% by mass of chromium, 0.2 to 7% by mass of aluminum, 19.5 to 55% by mass of cobalt and from {0.17×(mass % of cobalt−23)+3} to {0.17×(mass % of cobalt−20)+7} % by mass and 5.1% or more by mass of titanium, the balance of its composition being nickel and inevitable impurities. 
     
     
         18 . A heat-resistant superalloy as set forth in  claim 17 , characterized in that its cobalt content is from 23.1 to 55% by mass. 
     
     
         19 . A heat-resistant superalloy as set forth in  claim 17 , characterized in that its titanium content is from 6.1 to 15% by mass. 
     
     
         20 . A heat-resistant superalloy as set forth in  claim 17 , characterized by containing at least either 10% or less by mass of molybdenum or 10% or less by mass of tungsten. 
     
     
         21 . A heat-resistant superalloy as set forth in  claim 20 , characterized in that the molybdenum is less than 4% by mass. 
     
     
         22 . A heat-resistant superalloy as set forth in  claim 20 , characterized in that the tungsten is less than 3% by mass. 
     
     
         23 . A heat-resistant superalloy as set forth in  claim 17 , characterized by containing at least either 5% or less by mass of niobium or 10% or less by mass of tantalum. 
     
     
         24 . A heat-resistant superalloy as set forth in  claim 17 , characterized by containing at least any of 2% or less by mass of vanadium, 5% or less by mass of rhenium, 2% or less by mass of hafnium, 0.5% or less by mass of zirconium, 5% or less by mass of iron, 0.1% or less by mass of magnesium, 0.5% or less by mass of carbon and 0.1% or less by mass of boron. 
     
     
         25 . A heat-resistant superalloy as set forth in  claim 17 , characterized by containing 0.05% or less by mass of zirconium, 0.05% or less by mass of carbon and 0.05% or less by mass of boron. 
     
     
         26 . A heat-resistant superalloy as set forth in  claim 17 , characterized by containing 12 to 14.9% by mass of chromium, 2.0 to 3.0% by mass of aluminum, 20 to 24% by mass of cobalt, 6.1 to 6.5% by mass of titanium, 0.8 to 1.5% by mass of tungsten, 2.5 to 3.0% by mass of molybdenum, 0.01 to 0.10% by mass of zirconium, 0.01 to 0.05% by mass of carbon and 0.01 to 0.05% by mass of boron, the balance being nickel and inevitable impurities. 
     
     
         27 . A heat-resistant superalloy as set forth in  claim 26 , characterized by containing 0.05% or less by mass of zirconium, 0.05% or less by mass of carbon and 0.05% or less by mass of boron. 
     
     
         28 . A heat-resistant superalloy characterized by being obtained by adding a Co+Co 3 Ti alloy to a heat-resistant superalloy as set forth in  claim 26 . 
     
     
         29 . A heat-resistant superalloy characterized by being obtained by adding a Co+20 at % Ti alloy to a heat-resistant superalloy as set forth in  claim 26 . 
     
     
         30 . A heat-resistant superalloy member manufactured by one or more methods of casting, forging and powder metallurgy from a heat-resistant superalloy as set forth in  claim 17 .