Method for heat treating iron-nickel-chromium alloy
AssigneeThe United States of America as represented by the United States Department of Energy
InventorsHoward F. Merrick, Michael K. Korenko
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Abstract
A method for heat treating an age-hardenable iron-nickel-chromium alloy to obtain a bimodal distribution of gamma prime phase within a network of dislocations, the alloy consisting essentially of about 25% to 45% nickel, 10% to 16% chromium, 1.5% to 3% of an element selected from the group consisting of molybdenum and niobium, about 2% titanium, about 3% aluminum, and the remainder substantially all iron. To obtain optimum results, the alloy is heated to a temperature of 1025.degree. C. to 1075.degree. C. for 2-5 minutes, cold-worked about 20% to 60%, aged at a temperature of about 775.degree. C. for 8 hours followed by an air-cool, and then heated to a temperature in the range of 650.degree. C. to 700.degree. C. for 2 hours followed by an air-cool.
Claims11
A method for heat treating an iron-nickel-chromium alloy consisting essentially of about 25% to 45% nickel, 10% to 16% chromium, 1.5% to 3% of an element selected from the group consisting of molybdenum and niobium, about 1% to 3% titanium, about 0.5% to 3.0% aluminum and the remainder substantially all iron;
- which method comprises the steps of heating the alloy to a temperature in the range of 1000.degree. C. to 1100.degree. C. for 30 seconds to 1 hour followed by a furnace-cool, cold-working the alloy 10% to 80%, heating the alloy to a temperature of about 750.degree. C. to 800.degree. C. for 4-15 hours followed by an air-cool, and then heating the alloy to a temperature in the range of 650.degree. C. to 700.degree. C. for 2-20 hours followed by an air-cool.
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