How to avoid crevice corrosion? 1

[ChFa]

Hello, everyone, I have a question on how to avoid crevice corrosion. I wanted to measure the pitting potential of stainless steel with welding seam. The exposure area (1 cm2)is fixed by the cell. However, crevice corrosion always occured near the seam. Do you have any good advices to avoid the crevice corrosion?

 

[EdStainless]

There are a couple of ways to do this. The best is to flush the seal with clean water. Do a search for the "Avesta cell".
The other way that sort of works is to use square o-rings and synthetic grease. This should eliminate the crevice.

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P.E. Metallurgy, Plymouth Tube

 

[ChFa]

@EdStainless
Thank you very much for your kind reply. I have a O-ring made by Polytetrafluoroethylene, but I did not work well. What you mean in your reply is the O-ring made by rubber？ And could you introduce some kinds of synthetic grease for avoiding crevice corrosion to me? Thank you very much!

 

[EdStainless]

Any elastomer (Buna will work) in a true square cross section.
We used either silicone grease (vacuum grease) or Krytox. You have to use very little grease and be careful, there is no solvent for these and if you get any on the sample it is ruined.

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P.E. Metallurgy, Plymouth Tube