Method for heat treating iron-nickel-chromium alloy
AssigneeThe United States of America as represented by the United States Department of Energy
InventorMichael K. Korenko
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Abstract
A method for heat treating an age-hardenable iron-nickel-chromium alloy to obtain a morphology of the gamma-double prime phase enveloping the gamma-prime phase, the alloy consisting essentially of about 40 to 50% nickel, 7.5 to 14% chromium, 1.5 to 4% niobium, 0.3 to 0.75% silicon, 1 to 3% titanium, 0.1 to 0.5% aluminum, 0.02 to 1% carbon, 0.002 to 0.0015% boron and the remain substantially all iron. To obtain optimal results, the alloy is cold-worked 20 to 60% followed by heating at 1050.degree. C. for 1/2 hour with an air-cool plus heating at 800.degree. C. for 2 hours with a furnace cool to 625.degree. C. The alloy is then held at 625.degree. C. for 12 hours, followed by an air-cool.
Claims5
A method for heat treating an age-hardenable iron-nickel-chromium alloy consisting essentially of about 40 to 50% nickel, 7.5 to 14% chromium, 1.5 to 4% niobium, 0.3 to 0.75% silicon, 1 to 3% titanium, 0.1 to 0.5% aluminum, 0.02 to 1% carbon, 0.002 to 0.0015% boron and the remainder substantially all iron, which method comprises the steps of cold-working the alloy 20 to 60% followed by heating in the range of 1000.degree. C. to 1100.degree. C. for up to 1 hour with an air-cool, and thereafter heating the alloy in the range of 750.degree. C. to 850.degree. C. for 1.5 to 2.5 hours.
A method for heat treating an age-hardenable iron-nickel-chromium alloy consisting essentially of about 40 to 50% nickel, 7.5 to 14% chromium, 1.5 to 4% niboium, 0.3 to 0.75% silicon, 1 to 3% titanium, 0.1 to 0.5% aluminum, 0.02 to 1% carbon, 0.002 to 0.0015% boron and the remainder substantially all iron, which method comprises the steps of cold-working the alloy 20 to 60%, thereafter solution annealing the alloy at a temperature of about 1050.degree. C., thereafter aging the alloy at about 800.degree. C. for about 2 hours with a furnace cool to about 625.degree. C., and finally holding the alloy at about 625.degree. C. for about 12 hours, followed by an air-cool.
A method for heat treating an age-hardenable iron-nickel-chromium alloy consisting essentially of about 45% nickel, about 12% chromium, about 3.6% niobium, about 0.35% silicon, about 1.7% titanium, about 0.3% aluminum, about 0.03% carbon and the remainder iron, which method comprises the steps of solution annealing said alloy in the range of about 1000.degree. C. to 1100.degree. C. after cold-working, heating the alloy at 800.degree. C. for 2 hours with a furnace cool to 625.degree. C., and thereafter holding the alloy at 625.degree. C. for 12 hours, followed by an air-cool.
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