| 摘要 |
A process for manufacturing very large nickel-base alloy rotor forgings which generally exceed 5000 pounds(about 2,300 kg) using powder metallurgy techniques, and the very large nickel-base alloy rotor forgings manufactured by the process are provided. A process of manufacturing a component from a gamma prime or gamma double prime precipitation-strengthened nickel-based superalloy comprises the steps of: forming a powder of the superalloy; filling the powder in a can and exhausting and sealing the can in a controlled environment; solidifying the can and the powder at a temperature, time, and pressure for producing a solidified material; heat-treating the solidified material at a high temperature to produce a billet of a size sufficient to form a forging of 2,300 kg or more; and forging the billet at a temperature and strain rate for producing a forging with a uniform fine grain of ASTM 10 or finer in whole. The nickel-based superalloy has a composition comprising, by weight percent, about 19 to 23% of chromium, about 7 to 8% of molybdenum, about 3 to 4% of niobium, about 4 to 6% of iron, about 0.3 to 0.6% of aluminum, about 1 to 1.8% of titanium, about 0.002 to 0.004% of boron, maximum about 0.35% of manganese, maximum about 0.2% of silicon, maximum about 0.03% of carbon, the balance of nickel and incidental impurities.
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