Since this is a storage tank I would guess that this is exposed to air, and in that case SS would be very expensive to move to a high enough alloy to resist corrosion at 80C.
Lined CS is the most common. There are high temp multi-layer epoxy lining systems used for this type of application.
Thank you SJones and EdStainless for your reply. Anyway I am curious about the corrosion resistance of stainless steel 304 and 316L against 12% brine solution at 80degC. May any of you assist?
When you say "brine", what do you mean? 12% NaCl in water and nothing else? Or is there dissolved gasses? Will the headspace be exposed to air? Whats the pH? Etc. Etc. Etc.
Mind, there really aren't many answers to the above that would make a 300 series acceptable in a concentrated brine solution at 80 c. ClSCC is a very real possibility at that temperature.
I'd go one step further and say that there are NO conditions which would make 300 series stainless steels acceptable under these conditions, other than operation 1 day per year with a total disassembly and clean-out between operations perhaps.
The only applications where a 3xx stainless would be in a reducing environment (No oxygen) and pH >10.
At pH=8, T80=C 316L will have a limit of about 200ppm Cl open to air.
A 6%Mo superaustenitic would not handle 12% NaCl at 80C.
You would have to go to a Cr-Mo-Ni alloy such as C22, 686, or 59.
