Production of low expansion superalloy products

Claim 1

A process for preparing a precipitation-hardened wrought product comprising establishing a melt of an alloy consisting essentially of 30% to 57% nickel, 1.7% to 8.3% chromium, 1% to 2% titanium, metal from the group columbium, tantalum and mixtures thereof in proportions providing the total percentage of columbium plus one-half the percentage of tantalum is 1.5% to 5%, up to 31% cobalt, up to 1.5% aluminum, up to 0.2% carbon, up to about 2% manganese, up to about 1% silicon, up to 0.03% boron and balance essentially iron in an amount of at least 34% of the alloy and having the composition proportioned in accordance with the following four relationships A, B, C' and D' whereby: (A) %Ni+0.88(%Co)-1.70(%Al)-2.01(%Ti)+0.26(%Mn+Cr) equal up to 51.8 (B) %Ni+1.13(%Co)-2.69(%Al)-1.47(%Ti)-1.93(%Mn)-2.51(%Cr)+1.87(%Cr) at least 40.8 (C') %Al+1.3(%Ti)+1.44(%Cb+1/2Ta)-0.12(%Cb+1/2Ta) 2 -0.37(%Cr)+0.03(%Cr) 2 at least 3.81 (D') %Al+1.3(%Ti)+0.25(%Cb+1/2Ta)-0)125(%Cr) up to 3.18 solidifying the alloy in a mold, separating the alloy and the mold, hot working the solidified alloy at temperature of about 2100° F. and below, and thereafter age-hardening the alloy with a heat treatment of at least 8 hours in the temperature range of 1350° F. to 1150° F.