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Plating that withstands hydrogen chloride acid

Q. Hi, I am looking for a steel fastener to be plated to be able to withstand hydrogen chloride acid test. We do not require submersion of the parts in the acid but rather let it be exposed to the evaporation of the chemicals and see how long will it take to strip off the coating.

I've brought in some samples (zinc plated with JS500 sealer, Dacromet) yet have not had positive results yet.

I am wondering if someone can share some insight as of what type of plating is the best for this type of application?

Thanks!
Jade

Jade Goard
- Sheboygan Falls, Wisconsin
March 29, 2017

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Q. Hi Ted, thanks for your response.

Unfortunately we do not use ASTM or Mil to specify the plating. We came up with this Hydrogen Chloride acid vapor test as it simulates what the part will be put up to the test in the real life.

We put salt spray 1000 hours on the print but it is treated more like a benchmark. And there seems to be no clear correlation between the salt spray test result and our in house Hydrogen Chloride acid vapor test.

Not sure if my reply helps clarify the situation or it is still as clear as mud...

Jade Goard [returning]
- Sheboygan Falls, Wisconsin
March 30, 2017