Will 25% ammonia vapor balance water vapor between 350°C - 550°C corrode 304 SS? If you know the answer how did you find it what was your source or equation or book? Will it cause pitting or stress corrosion cracking as it moves through a 304SS pipe?
Following Paper gives Corrosion rate for 304 SS in Ammonia + Water Vapor environment:-
Louis Caruso, Harold Mitchels,"Resistance of copper-nickel alloys to ammonia corrosion in simulated steam condenser environments" in Proceedings of American Power, vol. 4, 1980, pp. 319-323.
Although this literature does not consider corrosion at high temperature.
Normally SS wont corrode at Room temperature. So you may have to look for reference that considers both high temp and ammonia. Following might help:
(I have not read it completely but it discusses stainless steels from process equipment in ammonia production plants.)
Following references should help too (though you have to go through them to check their usefulness and these references won't be available freely ):-
- MTI, Materials Selector for for Hazardous Chemicals, MS-6: Ammonia and Caustic Soda
- NACE Conference Paper 03523 Stress Corrosion Cracking of Austenitic Stainless Steel in Fertilizer Plants
- NACE Conference Paper 02439 External SCC Phenomena of Austenitic Stainless Steel in Urea Plants
Hope this helps,