To answer your question about argon flow rate, it depends on the type of shielding cup you are using. I recommend using a gas lens to diffuse the gas flow. Then, depending on cup size, your shield gas flow should be 25-30 cfh (for larger cup sizes, you need slightly higher gas flow)...
Croy: I have to agree with metengr, I believe you will be fine with Inco 718 filler wire instead of 625. Are you planning to weld manually, or try to automate the process? There are orbital GTAW systems on the market with wire feed capability that could be used for your application, if the...
