Spring material in 96% sulfuric

[magusinp]

What type of spring material would be recommended for 96% sulfuric, ambient temperature. This is a pipeline application so it probably has no entrained air.

We currently stock Inconel X750 springs. But I am afraid that these will not last very long. Is that true in your experience?

 

[TVP]

Inconel X-750 has only fair resistance to strongly oxidizing acids. Austenitic stainless steels are frequently used for environments that contain sulfuric acid, so perhaps Type 302 or Type 316 (spring temper, not annealed) would be appropriate. I have no experience designing springs for concentrated acid environments, so I would definitely discuss this with a metallurgist at an appropriate spring vendor or spring material supplier.

 

[jackpot]

The corrosion rate on sulfuric acid peaks at 12N or 31.4%. Adding inhibitors to the acid will help, but the main consideration, metallurgically speaking is, the amount of carbon in the steel that you select with lower being better.
There are grades oof SS like 302L and 316L that have very low amount of carbon, you may want to try these.
X750 has 0.08 max %C as does 302 and 316. The "L" versions have 0.03% max carbon, the 316L will perform better than the 302L. You may also consider using HASTELLOY® D-205TM alloy, which is designed specifically for high sulfuric acid concentrations and does come in wire.

Sincerely, Jackpot