316 on flowing water, submerged

[purpletoes]

Hello,
I am using a 316SS that is starting to show early signs of corrosion after exposure of 4-6 months. Does anyone have any recommendation for a replacement metal or coating? The metal goes on a water vehicle. The O-ring is also wshowing some MgCl2 and organic Carbon-Oxygen..
Thanks

 

[unclesyd]

Could you rewrite your last sentence concerning the O-ring as it is now it doesn't make senses?

 

[gr2vessels]

Easy, use Super Duplex Stainless Steel, Super Austenitic Stainless Steel or better still, use Titanium, which is also lighter. Coating, yes;- aluminium thermal spraying, if the surface finish is acceptable. Perhaps pickling, every 3 month, before the corrosion shows up.
Other solutions, remove from water the MgCl2, the Carbon and the Oxygen prior to use. Or remove the water all together, it is the culprit of carrying the MgCl2, Carbon and Oxygen. Ignore the O-ring, it is showing to much anyway.
Howzat,
gr2vessels

 

[EdStainless]

Fresh water or seawater?
If fresh then you should look at using a weld overlay in the seal area (say a 6% Mo super-austenitic grade) and better o-rings.
If seawater, then you need a different alloy. The super-duplex and super-austenitic being my first suggestions.

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