Method for producing large diameter ingots of nickel base alloys

A method of producing a nickel base alloy that is substantially free of positive and negative segregation, the method comprising:

• casting a nickel base alloy in, a casting mold, wherein the nickel base superalloy is Alloy 718;
• annealing and averaging the alloy by heating the alloy at at least 1550° F. (843° C.) for at least 10 hours;
• electroslag remelting the alloy at a melt rate of at least 10 lbs/min. (4.54 kg/min.);
• transferring the alloy to a heating furnace within 4 hours of complete solidification after electroslag remelting;
• holding the alloy within the heating furnace at a first furnace temperature of 900° F. (482° C.) to 1800° F. (982° C.) for at least 10 hours;
• increasing the furnace temperature by no greater than 100° F./hour (55.6° C./hour) to an intermediate furnace temperature;
• and
• further increasing the furnace temperature by no greater than 200° F./hour (111° C./hour) from the intermediate furnace temperature to a second furnace temperature of at least 2125° F. (1163° C.), and holding at the second temperature for at least 10 hours;
• and
• vacuum arc remelting a VAR electrode of the alloy at a melt rate of 9 to 10.25 lbs/minute (4.09 to 4.66 kg/min) to provide a VAR ingot.