Strain Hardened 316 SST for Hydrogen Service 1

[Sullivan4874]

A lot of studies recommend 316 SST for hydrogen service. However, the condition of the material is seldom mentioned so I assume it is annealed.

My question is whether or not strain hardened 316 SST is suitable for hydrogen service. Does the stress state (e.g. pressure retaining component versus internal valve trim component) make a difference?

Thanks!

 

[EdStainless]

It depends on the amount of stain hardening. A little bit is fine, but more can be disaster. It depends on the strength level and the applied stresses.
Remember that the 316 is meta-stable and on cold work it forms maternsite.

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P.E. Metallurgy, consulting work welcomed

 

[Sullivan4874]

The material is ASTM A276 S31600 Condition B.

 

[EdStainless]

What is your service, pressure, temp, and so on?
What do the various specs say about this?
I want to recall reading (Sandia docs?) a caution against using cold worked 316L for rupture disks in H2 service.
If this for items such as valve trim I might look at Nitronic 40 or 50 for higher strength and good resistance.

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P.E. Metallurgy, consulting work welcomed

 

[MJCronin]

These people recommend the use of 316/316L (fully annealed condition) as superior to 304/304L AND type 321 in high pressure hydrogen service.

Notice how ASME B31.12 Hydrogen Piping and Pipelines - 2019 is repeatedly referenced for permitted materials...

http://www.asiaiga.org/uploaded_doc... Hydrogen Piping Systems at User Location.pdf

Let the games begin !!!!

Tell us much more about your system, piping, valves vessels etc...

Will you have any large pressure vessels or tanks ???

MJCronin
Sr. Process Engineer

 

Notice how ASME B31.12 Hydrogen Piping and Pipelines - 2019 is repeatedly referenced for permitted materials...

That would seem to make sense...

"Everyone is entitled to their own opinions, but they are not entitled to their own facts."

 

[EdStainless]

Both Sandia and NASA have published extensive material compatibility documents.
I can recall working with some 316ELI (ESR remelted) for a high pressure hydrogen application.
We have also supplied tubing that was cold worked in 21-6-9 (Nitronic 40) that was ESR remelted for high pressure hydrogen service (this is actually standard aircraft hydraulic tubing).
With austenitic SS there are a number of issues that impact H2 compatibility. Chemistry (higher Ni is better) which also interacts with the amount of residual delta ferrite (less is good) and the amount of transformation that you get on cold work (less is good). The cleanliness (cleaner is good) of the alloy (non-metallic inclusions)are also a factor. Anything that can trap H2 within the structure is detrimental.


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P.E. Metallurgy, consulting work welcomed

 

EdS,
Nickel is normally a little insufficient in routine austenitic SSs because of cost. It helps formability, especially in extreme processes like metal spinning, while suppressing martensite formation during cold work, and it can ensure zero ferrite.
Before I got halfway through your post I was already wondering about the sulphur question, in the same vein as the weldability problem that afflicts BPE tubing. Because we know that H is attracted to MnS inclusions.



"Everyone is entitled to their own opinions, but they are not entitled to their own facts."