NiCrMoNb age hardenable alloy for creep-resistant high temperature applications, and methods of making

Abstract

Nickel alloys, methods of making nickel alloys, articles including the nickel alloys, uses of the alloys, and methods of treating nickel alloys are described. The inventive heat resistant structural materials are suitable for applications requiring high yield stress at room temperature and good creep strength at high temperatures, such as in gas turbines, steam turbines, fossil energy boilers, aero engines, power generation systems using fluids such as supercritical carbon dioxide (e.g., advanced ultra-supercritical power plants), concentrated solar power plants, nuclear power plants, molten salt reactors: turbine blades, casings, valves, heat exchangers and recuperators.

1 - 32 . (canceled) 
     
     
         33 . A solid nickel alloy comprising Cr; Al; Ti; Nb; Ta; Mo, comprising a chemical inhomogeneity of Cr; Al; Ti; Nb; Ta; and Mo that is less than 10%; and wherein chemical inhomogeneity is characterizable by a measurement using wavelength dispersive x-ray fluorescence on a polished cross-section the alloy and wherein any selected 10 μm diameter area within a 10 mm 2  area of the polished surface has an elemental composition of each of Cr; Al; Ti; Nb; Ta; Mo that is within 10% of each element in the 10 mm 2  area. 
     
     
         34 . The alloy of  claim 33  wherein the nickel alloy is characterizable by a level of chemical homogeneity of less than ±5%. 
     
     
         35 . The alloy of  claim 33  comprising at least 15% Cr; at least 0.1% Al; at least 1.0% Ti; at least 2.0% Nb; at least 0.1% Ta; and at least 5.0% Mo. 
     
     
         36 . The alloy of  claim 33  wherein the nickel alloy comprises 19.0 to 22.5% Cr; 0.1 to 1.0% Al; 1.0 to 2.0% Ti; 3.0 to 5.0% Nb; 0.1 to 4.0% Ta; 4.0 to 7.0% Nb+Ta; 2.0 to 4.0% Fe; 0 to 0.06% C; 0 to 0.35% Mn; 7.0 to 9.5% Mo; 0 to 5.0% W; 0 to 0.20% Si; 0 to 0.05% V; 0 to 0.15% P; 0 to 0.010% S; and 0 to 0.010% B, wherein all % are wt %. 
     
     
         37 . An article comprising the alloy of  claim 33 . 
     
     
         38 . The article of  claim 37  comprising a components in: a steam turbine, coal fired boiler, gas turbine, combustion can, boiler tube, boiler pipe, power generation system, valve, heat exchanger or recuperator. 
     
     
         39 . The article of  claim 37  wherein the nickel alloy comprises 19.0 to 22.5% Cr; 0.1 to 1.0% Al; 1.0 to 2.0% Ti; 3.0 to 5.0% Nb; 0.1 to 4.0% Ta; 4.0 to 7.0% Nb+Ta; 2.0 to 4.0% Fe; 0 to 0.06% C; 0 to 0.35% Mn; 7.0 to 9.5% Mo; 0 to 5.0% W; 0 to 0.20% Si; 0 to 0.05% V; 0 to 0.15% P; 0 to 0.010% S; and 0 to 0.010% B, wherein all % are wt %. 
     
     
         40 . The alloy of  claim 33  wherein the nickel alloy is characterizable by a level of chemical homogeneity of less than ±1%. 
     
     
         41 . The alloy of  claim 40  comprising at least 15% Cr; at least 0.1% Al; at least 1.0% Ti; at least 2.0% Nb; at least 0.1% Ta; and at least 5.0% Mo. 
     
     
         42 . The alloy of  claim 33  wherein the nickel alloy is characterizable by a level of chemical homogeneity of less than ±2%.