摘要 |
An article is formed from an ingot of a nickel-iron base alloy having a composition including from about 4.5 weight percent niobium to about 5.5 weight percent niobium and capable of forming delta-phase precipitates, and having fewer than about 1 grain per square inch at 100X magnification. An array of intragranular delta-phase precipitates (36) is precipitated within the ingot to provide grain nucleation sites. The ingot having the array of delta-phase precipitates (36) therein is deformed at a temperature below a delta-phase solvus temperature, thereby producing a fine-grained billet.
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