Patent ID: 8545643

Claim:
A nickel-molybdenum-chromium-tungsten based alloy which becomes harder after a 48-hour heat treatment at 1400° F. and then has a Rockwell C hardness of at least 23, the alloy having a composition comprised in weight percent of: 7 to 9 chromium 21 to 24 molybdenum greater than 5 tungsten up to 3 iron up to 0.8 copper with a balance of nickel and impurities, the alloy further satisfying the following compositional relationship: 31.95 <R< 33.45 where the R value is defined by the equation: R= 2.66Al+0.19Co+0.84Cr−0.16Cu+0.39Fe+0.60Mn+Mo+0.69Nb+2.16Si+0.47Ta+1.36Ti+1.07V+0.40W.