Please see AWS D1.1 :2004 C1.2 Limitations(2nd and 3rd sentence)
Basically it is left up to the EOR if the base material is outside of the scope of D1.1.
This gives some insight to the code writer's intentions.
Refer to 4.7.3 for steels not listed in Table 3.1 or Annex M.
Prequalified procedures can not be used because of paragraph 3.14 due to the material being over 50ksi min yield.
just a few thoughts,
John Wright