While the basic pitting performance and mechanism
are similar to those for other aluminum
alloys, the IG corrosion, exfoliation, and stresscorrosion
cracking (SCC) susceptibility of this
class of alloys is far more complex. The specific
metallurgical features controlling the corrosion
performance are equally complex. Metallurgical
effects on corrosion behavior of these alloys have
been studied for decades (Ref 11, 15–17) and continue
to be areas of active research (Ref 19–22).
Much of the work is particularly focused on
SCC. However, in many cases the exfoliation
and IG corrosion performance will trend similarly
with SCC. This is not a universal rule; there are
some exceptions for commercial alloys and tempers.
Here, however, the general assumption will
apply unless specifically stated otherwise.