Zecor and SX (both proprietary) are versions of A610/A611 high silicon austenitic stainless steels. I wouldn't use any of these at 80%, that is way too low for them.
The problem with almost all of these alloys that have been batted about is that their useful concentration range is limited. They will either go to hell at 70%, or at 90%. The exception is B-3, but the cost is steep.
I guess that the question that comes to mind is why do you have 80% acid (sounds odd), and can it ever be more concentrated, or less concentrated?
Look at FRP.
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P.E. Metallurgy, Plymouth Tube