| 摘要 |
A method of producing a nickel base alloy includes casting the alloy within a casting mold and subsequently annealing and overaging the ingot at least 1200 ~F (649 ~C) for at least 10 hours. The ingot is electroslag remelted at a melt rate of at least 8 Ibs/min. (3.63 kg/min.), and the ESR ingot is then transferred to a heating furnace within 4 hours of complete solidification and is subjected to a novel post-ESR heat treatment. A suitable VAR electrode is provided form The ESR ingot, and the electrode is vacuum arc remelted at a melt rate of 8 to 11 lbs/minute (3.63 to 5.00 kg/minute) to provide a VAR ingot. The method allows premium quality VAR ingots having diameters greater than 30 inches (762 mm) to be prepared from Alloy 718 and other nickel base superalloys subject to significant segregation on casting.
|
