Metal finishing Q&As since 1989

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Hydrogen embrittlement?

2002

I have been specifying Teflon coated hi tensile bolts for sub sea use for some time and now need an alternative. Will cad plated studs/bolts cause hydrogen embrittlement if used in a sub sea environment @ about 50 centigrade? Sac anode CP is applied.

Thanks,

Gary Evans
- Perth, Australia

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It sounds like you need to perform some testing which simulates this environment. Typically, a notched tensile is prepared with the cad plate and are load tested. A certain percentage of the failure load( depending to what standard you are working to ) is applied (around 75% of the breaking load) statically to another notched tensile for a specified period i.e 8 days. If it breaks before the required duration then the conclusion is hydrogen embrittlement.

M Hogan
- Melbourne
2002

Why do not use titanium alloy bolts?

Andrey Igolkin
- St.Petersburg, Russia
2002