Austenitic SS for Steam Application

[pingmi]

Hi,

Would it be a good idea to make a pipe fitting out of ASTM A182 Gr F316 material for an application where steam at high pressure / temperature (100+ Barg / 525°C) is present?

I'm not sure if plain austenitic steels like gr 316 would end up with Intergranualar Corrosion at temperature 525°C in presence of corrosive ambience. Has anyone experienced it?

OR Instead of F316, would it be better to use a stabilized grade like F347 for this application?

Thanks in advance.

 

[metengr]

pingmi;
No. During normal service conditions, you will not experience SCC. I would be more concerned with sigma phase formation and ID exfoliation in 316 ss over time that could result in creep failure.

My preference would be to use a stabilized grade of austenitic stainless steel - 347H or 321H, which is more suitable for high temperature and pressure steam service.

 

[strider6]

intergranular corrosion due to sensitization can be a problem for prolonged exposure to high temeperature 800 to 1500°F (427 to 816°C).
It all dependeds on the time of exposure and corrosivity of the service.
"Both Alloys 316 and 317L are susceptible to precipitation of chromium carbides in grain boundaries when exposed to temperatures in the 800 to 1500°F (427 to 816°C) range. Such "sensitized" steels are subject to intergranular corrosion when exposed to aggressive environments."

http://www.sandmeyersteel.com/316-316L.html#3

S.

Corrosion Protection & Corrosion Control