Our company has a WPS written to Sec IX with 2 pqr's supporting it for GTAW.  One is for 304L to 304L using ER308L filler and the other is for 316L to 316L using ER316L.  I would like to know if I am interperting the code correctly when I think I can use this procedure to weld 304L to 316L either using ER308L or ER316L because they are the same P-numbers and F-numbers.  Would I also be correct in saying that  I'm pulling this out of QW424 (Base materials used for procedure qualification) and base materials qualified.