"PTFE causing corrosion"
Question:
"We have extrusion dies that are made from 304 ss. We see corrosion pits on the interior surface of the dies. The material that is extruded through the dies is PTFE. What interaction between the PTFE and the 304 ss could be causing the corrosion pitting?"
Answer:
First, you should verify that the pitting is caused by corrosion and not by some other mechanism. This is a guess; however, assuming that you are correct, you might investigate whether residual hydrofluoric acid from processing is contributing to the corrosion.