HCL Corrosion, High Temp

[prmmel]

We manufacture thermal oxidizers and we are getting into more diverse, "createive" applications. We have an electric unit that will oxidizer chlorinated compounds, thus generating HCL in the 0-500ppm range (typically 50ppm or less). The process elevates the temp to 1000F. We are looking at 2205 and 904SS vs going to Hastelloy due to cost. Can anyone advise on the 2205 and 904SS.
Thanks,
Mel

 

[metengr]

I would not recommend 2205 Duplex for exposure to service temperatures at or above 600 deg F. This material will develop precipitates that result in loss of toughness and corrosion resistance.

Regarding 904 material, my sources indicate this would not be suitable for your stated service conditions above 250 deg F. You would be better off with Hastelloy comparable material.

 

[moltenmetal]

Dry or wet makes a big difference. Are you taking the exhaust below the condensation point?

FWIW, consider inconel 600 or 625 instead of Hastelloys if the service is hot and dry.