Corrosion of a fittings in a stainless steel vessel

[DustinMechEng]

I am testing a structure inside a stainless steel vessel filled with sea water. The structure has a brass fitting and several titanium fasteners. Neither the fitting nor fasteners come in contact with the vessel or each other but will be aprroximately 1 foot away from the vessel walls and each other.

Will the brass fitting or titanium fasteners corrode? If so, can I use a sacrificial anode such as zinc to prevent corrosion? Is their any other way to prevent corrosion or isolate the fittings and/or fasteners?

Thanks for the help!

 

[DustinMechEng]

Additional Note:

-The structure is plastic (non-conductive)
-There are no direct metal-to-metal contacts or any other electically conductive paths betweeen dissimilar metals aside from the salt water

My main question is whether dissimilar metals will produce a galvanic pair when immersed in salt water but not in direct contact.

 

[strider6]

if they are no connected, there is no an electrical path that close the circuit you'll not have corrosion.

regards

Strider

http://www.corrosionist.com

 

[EdStainless]

Make sure that your brass parts are mad of an alloy suitable for seawater. A NiBronze, NiAlBronze, or a CuNi would work. If you use standard brass you will get selective dezincification.

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[chief]

It would be advisable to install a sacrificial anode in the tank. Two dissimilar metals in a salt solution constitutes a battery and the inferior metal will deplete. I sometimes used to put a piece of junk metal in a tank to feed the negative ion monster. Crude , but it works and ok if it does not contaminate your processs.

Offshore Engineering&Design

 

[mshimko]

I disagree with Chief. If the dissimilar metals are not in electrical contact, there is no galvanic couple and no battery.

 

[EdStainless]

If you have multiple pieces of metal it is possible that there will be enough difference in potential between them that you will see some corrosion.
I am more concerned with the brass simply corroding on its own.

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