Precipitation-strengthened nickel-iron-chromium alloy
AssigneeGeneral Electric Company
InventorsJianqiang Chen, Jon Conrad Schaeffer, Anjilivelil Kuruvilla
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Abstract
An Fe—Ni—Cr alloy formulated to contain a strengthening phase that is able to maintain a fine grain structure during forging and high temperature processing of the alloy. The alloy contains a sufficient amount of titanium, zirconium, carbon and nitrogen so that fine titanium and zirconium carbonitride precipitates formed thereby are near their solubility limit in the alloy when molten. In the production of an article from such an alloy by thermomechanical processing, a dispersion of the fine titanium and zirconium carbonitride precipitates form during solidification of the melt and remain present during subsequent elevated processing steps to prohibit austenitic grain growth.
Claims27
A nickel-iron-chromium alloy containing, by weight, less than 0.05 niobium, at least 0.05% zirconium, at least 0.05% carbon, at least 0.05% nitrogen, a carbon:nitrogen weight ratio of at least 1:2 to less than 1:1, sufficient titanium, zirconium, and/or aluminum to be free of chromium carbides, and titanium, zirconium, carbon, and nitrogen in amounts sufficient to form a uniform dispersion of fine titanium and zirconium carbonitride [(TixZr1−x)(CyN1−y)] precipitates in an amount near the solubility limit of the titanium and zirconium carbonitride precipitates in a molten state of the alloy.
A nickel-iron-chromium alloy consisting of, by weight, about 32% to about 38% iron, about 22% to about 28% chromium, about 0.10% to about 0.60% titanium, about 0.05% to about 0.30% zirconium, about 0.05% to about 0.30% carbon, about 0.05% to about 0.30% nitrogen, about 0.05% to about 0.5% aluminum, up to 0.99% molybdenum, up to about 0.01% boron, up to about 1% silicon, up to about 1% manganese, the balance nickel and incidental impurities, wherein carbon and nitrogen are present in a carbon:nitrogen weight ratio of at least 1:2 to less than 1:1.
A nickel-iron-chromium alloy consisting of, by weight, about 34% to about 40% nickel, about 32% to about 38% iron, about 22% to about 28% chromium, about 0.10% to about 0.60% titanium, about 0.05% to about 0.30% zirconium, about 0.05% to about 0.30% carbon, about 0.05% to about 0.30% nitrogen, about 0.05% to about 0.5% aluminum, up to 0.99% molybdenum, up to about 0.01% boron, up to about 1% silicon, up to about 1% manganese, less than 0.05 weight percent of each of niobium, tantalum and vanadium, and incidental impurities, the alloy having a carbon:nitrogen weight ratio of at least 1:2 to less than 1:1, the alloy containing a uniform dispersion of fine titanium and zirconium carbonitride precipitates in an amount near the solubility limit of the titanium and zirconium carbonitride precipitates in a molten state of the alloy.
Dependencies are inferred from the claim text.