Galvanic Corrosion

[amar4]

My question is: Which will experience more galvanic corrosion, 316SS and carbon steel or Ni-resist and carbon steel? This application will be in brackish water. I am considering going from Ni-Resist to 316 and I'm concerned about the interaction between the new Ni-resist part and an existing carbon steel part. The parts are bolted without a gasket and are the same size. Thanks.

 

[bimr]

I don't think there is a conclusive answer.

The intensity of galvanic corrosion is determined by the conductivity, oxygen content and effective anode to cathode area ratio which you have not mentioned.

The factors that influence stainless steel corrosion are oxygen, chloride ion, conductivity crevices, sediment, scales and deposits, biological activity, chlorination, surface condition, low pH, and temperature in order of importance.

The Ni-resists are typically specified for handling salt solutions and sea water.

Would think that you would have better results with a Ni-resist than 316SS which has more of a corrosion risk in brackish water.

 

[EdStainless]

I agree, 316 would be a poor choice for brackish water.
I would suspect that the CS would be attacked worse coupled to 316 than to NiResist.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, Plymouth Tube