IFRs, normally when a material is not listed in in Sec II, Part D, it means it is not recognized by ASME and is therefore not permitted, unless perhaps by Code case. However, these materials are normally used as pressure retaining rather than structural. You may be able to use your I-beam off the pressure boundary, however you will have to determine allowables some other way.
BTW, I am looking at ASTM A-992-04a and only see a single grade.
Regards,
Mike