I have the following question regarding material grade F6NM

We have found the material as forged bar under SA-182 F6NM (UNS S41500) but we also want to use rolled material which normally should comply with SA-479. Within SA-479 you will only find the UNS no S41500 with nearly the same mechanical and chemical properties.
However for design and calculation we have to follow ASME II -D. This part only shows grade F6NM.
How can we qualify rolled material UNS S41500 for use in accordance with ASME II D? We need bar material from 25 - 300, but you will not find forged material with diameter less than 100mm.