Here are some threads related to the heat treatment of 321 ss;
thread330-119356
thread367-119691
Yes. Inadvertent nitrogen pick-up in the 321 ss during solution treatment or during a stabilization heat treatment can result in the formation of unwanted precipitates. Nitrogen can combine with titanium (stabilizer), chromium and carbon to form CrN,Ti(CN) precipitates that adversely effect both corrosion resistance and loss of creep strength.