Method for heat treating iron-nickel-chromium alloy

A method for heat treating an age-hardenable iron-nickelchromium 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 10250 C to 10750 C for 2-5 minutes, cold-worked about 20% to 60%, aged at a temperatur of about 7750 C for 8 hours followed by an air-cool, and then heated to a temperature in the range of 6500 C to 7000 C for 2 hours followed by an air-cool