An article, such as a turbine engine component, formed from a nickel-base superalloy, the nickel-base superalloy containing a .gamma.'' tetragonal phase and comprising aluminum, titanium, tantalum, niobium, chromium, molybdenum, and the balance nickel, wherein the article has a time dependent crack propagation resistance of at least about 20 hours to failure at about 1100.degree. F. in the presence of steam. The invention also includes a nickel-base superalloy for forming such and article and methods of forming the article and making the nickel-base superalloy.