look in the ABS rules:
http://www.eagle.org/absdownloads/index.cfm

Look at Inconel steel, I’ve seen a number of turbine exhaust constructed of it, and it seems to weather heat and weather. Good Luck!
http://en.wikipedia.org/wiki/Inconel

Inconel is not steel.  It's a family of nickel alloys that contain little iron.  All are hideously expensive, and very difficult to work.  Only governments can afford to use Inconel for Diesel exhausts, in which application they last for decades.  The few marine gas turbine exhausts made of Inconel that I've seen didn't last decades.

Special Metals also makes Incoloy, a family of alloys comprisinng 30..40 pct nickel and 20..40 pct iron, which are slightly more workable and slightly more affordable than Inconel, but still probably uneconomical for large engine exhausts.

http://www.painc.com/chemical_composition.htm

Mike Halloran
Pembroke Pines, FL, USA

I've had relatively good success with Corten steel in Tanker applications.
As it is a more expensive material, good cost benefit is achieved by limiting its use to the area of highest corrosion, the 2-3 meters of exhaust piping above the funnel, that is constantly exposed to weather.
This is also typically a more "expensive" area to do repairs due to elevation and the requirement or large crane support and scaffolding, so you will want to maximize time between repairs.
Whereas mild steel piping wold be severely corroded in 3-5 years, Corten double/triple the interval. If your working on a newbuilding spec, try to get it included initially, and it will save your company  tens of thousands down the road.
Rgds,
RKK
www.rkkimmons.com
Rgds,

Thanks for the reply MASE81.  Can you say a bit more about it. I would appreciate if you can share some study or report.

Regards,