Corrosion rate of SS 316L 1

[tsasi2]

Dear,

we are using SS 316L pipe line for sulphuric acid 98.5% concentration at 85 deg. C. now we are facing problem of Cr & Ni content is high. what is the alternate pipe material for sulphuric acid 98.5% con. at 85 deg. C. what is the corrosion rate of SS 316L (in mils / year).

 

[EdStainless]

I presume that this is high purity, absolutely no Cl.
What is the flow velocity? That is important.

Look at alloy 20 to start with.
60C is about the max with 316L, at any real flow velocity.
The other option would be one of the high Si alloys, but they are harder to find and work with.

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P.E. Metallurgy, Plymouth Tube

 

[georgeverghese]

Before you move on to more expensive alloys, presume you have taken precautions to exclude oxygen in the vapor space / prevent O2 from dissolving into oleum in the storage tank / all other upstream equipment?

 

[tsasi2]

The velocity of the acid pipe line is 1 M/s.
10" dia pipe flow rate is 180 M3/h.