You are in luck. We have several people here who are Very Good at forging S.S. Search for Guiseppe here on Art Metal and find some lovely stuff, indeed.

SmokyRick
Rick Crawford at Smoky Forge

Chris,

Sorry I didn't get to this earlier, but I was busy having fun at the QuadStates blacksmithing conference this weekend. Too much going on.

When forging stainless steel, it is important to do a "solution annealing" at the end of the forging. Bring the stainless up to about 1950 degrees Fahrenheit and hold it there for several minutes to get all the carbides back into solution. Then quench it to anneal and fix the new grain structure in place. This is a fairly sloppy description of the process, but it should work for you.

If you want the piece to have a shiny stainless finish, I recommend getting it electropolished if you have access to such a facility where you are. If you don't, then pickle it in a 20% solution of citric acid in water at 140 degrees F for an hour or more to passivate the surface. This passivation should be done after any grinding/sanding, and such grinding should be done with wheels, discs and brushes that are dedicated for stainless only and are never used on regular steel which will contaminate them.

hello,
i have forged a lot of stainless, often for outdoors. while harder to deform than mild steel, stainless is definately forgeable, it just has a narrower forging temperature range (yellow to full red, say). there is no problem with rapidly cooling it in water, either. if it is exposed to the environment after completion, all scale should be removed by either sand blasting, bead blasting, acid or electro-polishing. it will look kind of lifeless them so it has to be hand-polished with a succession of scotch-brite pads, preferably on a pneumatic high-speed tool, to bring the texture out again. if the object is something like an indoor sculpture or railing, it can be wire-brushed with a stainless brush to knock off the scale, then polished to bring out some highlights. a major pain in the fundament, but well worth it.
hope this helps.
arnon