Charles,
AWS D1.1:2006 has ASTM A992 listed in Table 3.1 Group II as a prequalified base material(it was added in AWS D1.1:2000).
As far as UT or RT requirements...that would be up to the customer's specs as to whether or not it is required.
John Wright
edit: as far as the preheat, if using AWS D1.1 Table 3.2, it goes by the thickness to decide the preheat/interpass requirements.