R. Kennedy, I. Dempster, W. D. Cao, B. Bond, R. Kenne, J. Aurrecoechea, ATI Allvac, Monroe, NC
Allvac® 718Plus® Alloy is a new Ni-base superalloy with advantages over the widely used commercial alloys 718 and Waspaloy. The alloy has been shown to respond readily to direct age (DA) processing, that is currently used with conventional alloy 718.
This paper will report on the results of a study of DA processing conditions for 718Plus alloy to optimize mechanical properties. Pancake forgings were produced with variations in forging temperature and starting billet microstructure. One half of each 718Plus forging was given the standard solution treat and age heat treatment, the second half being direct aged only.
Forging evaluation includes macro and microstructure, static mechanical properties (room and elevated temperature tensile, stress rupture and creep) and dynamic properties (low cycle fatigue). Results for direct aged forgings are compared to those of sub-solvus forged Waspaloy and to solution treated and aged alloy 718Plus.
