Patent ID: 8879683

Claim:
A jet pump beam made of improved heat-treated nickel base alloy, produced by preparing a precipitation-strengthened nickel base alloy material having a component composition containing by mass %, Ni: 50.0% to 55.0%, Cr: 17.0% to 21.0%, Nb+Ta: 4.75% to 5.50%, Mo: 2.8% to 3.3%, Ti: 0.65% to 1.15%, Al: 0.2% to 0.8%, C: 0.08% or less, Mn: 0.35% or less, Si: 0.35% or less, S: 0.015% or less, P: 0.03% or less, Cu: 0.30% or less, B: 0.001% or less, and Co: 0.05% or less, and Fe and inevitable impurities constituting a remaining part, the nickel base alloy material having been subjected to solution heat treatment at a temperature of 1010° C. to 1090° C., and the nickel base alloy material having a γ″ phase (Ni 3 Nb) precipitate formed by subjecting the nickel base alloy material to age-hardening heat treatment at a temperature of 694° C. to 714° C. for 5 to 7 hours after the solution heat treatment.