There may be more to your question than meets the eye.  You probably need some high level engineering support here.

Inco 718 is a precipitation hardenable superalloy and this leads to a number of steps and questions when doing repair work on castings or wrought components.

Typically 718 castings when repaired are in an annealed state, and after the repairs are accomplished, further stress relief or thermal conditioning take place.

Many of the more modern 718 castings are also HIP'ed (Hot Isostatic Pressing) which increases the sensitivity of the base metal and usually requires modified welding procedures to limit heat input dramatically.

There are certainly differences between wrought and cast Inco 718, grain refinement and solidification phases being most notable.