Creep-resistant, rhenium-free nickel base superalloy

摘要

Disclosed is a nickel base alloy which is substantially free of rhenium and has a solidus temperature of more than 1320° C. Precipitates of a γ′-phase are present in a γ-matrix with a fraction of 40 to 50 vol % at 1050° C. to 1100° C., and a γ/γ′ mismatch at 1050° C. to 1100° C. is from −0.15% to −0.25%. The alloy comprises 11 to 13 at % aluminum, 4 to 14 at % cobalt, 6 to 12 at % chromium, 0.1 to 2 at % molybdenum, 0.1 to 3.5 at % tantalum, 0.1 to 3.5 at % titanium, 0.1 to 3 at % tungsten. The tungsten content of the γ-matrix is greater than that in the precipitated γ′-phases.

主权项

1. A nickel base alloy, wherein the alloy is substantially free of rhenium and has a solidus temperature of more than 1320° C., wherein precipitates of a γ′-phase are present in a γ-matrix with a fraction of from 40 to 50 vol % at temperatures of from 1050° C. to 1100° C., and a γ/γ′ mismatch at temperatures of from 1050° C. to 1100° C. is from −0.15% to −0.25%, and wherein the alloy comprises:
aluminum from 11 to 12 at %, cobalt from 8 to 10 at %, chromium from 6 to 8 at %, molybdenum from 0.5 to 1.5 at %, tantalum from 2 to 3.5 at %, titanium from 1 to 2 at %, tungsten from 2 to 3 at %, hafnium from 0.05 to 0.3 wt % or absent, remainder nickel and unavoidable impurities,a tungsten content of the γ-matrix being greater than a tungsten content of the precipitates of the γ′-phase.