Can stainless steel which has been work hardened by bending ever be annealed or softened again? Or has it been for ever compromised so as to prevent further bending? I know for sure there are metallurgists on this board who can answer.
nial

The short answer is yes.

The other part is knowing what type of stainless steel it is so you can employ the right process.

This link has some basic information.
http://www.azom.com/article.aspx?ArticleID=1141

Not a metallurgist, but I would assume it depends on the type of stainless.

A simple question really has a long answer.
Dislocations are responsible for the malleability of metals. Dislocations are imperfections in the lattice structure that allow movement of the material. As you work harden, more and more dislocations are produced but these intertwine with each other and 'pinning' point in the lattice such as interstitial atoms.
Annealing allows the materials to flow and the lattice to re-arrange itself so it will again flow at a lower stress.
The temperatures would be very high and for annealing are greater than 1/2Tm.-Dick

We used 301 because it work hardened allowing us to draw it deeper than a similar amount of 304. 304 is very common in the market. You might be smart to start with 304. By the way stainless becomes magnetic when it work hardens. We used a film thickness gauge to determine how far the transformation had proceded.
bill