Spring wire material for use in high pressure hydrogen gas? 1

[YetAgain]

Hello,
I am looking for a coil spring material suitable for use in high pressure hydrogen gas up to 6000 psi. Currently we use a 17-7 pH stainless spring and would like to have a substitute for use in hydrogen gas service. We are concerned that the 17-7 would be susceptible to hydrogen embrittlement when used in hydrogen gas service.

Based upon what I have researched the common austenitic stainless steels such as 304 and 316 have good resistance to hydrogen embrittlement but their yield strength is too low.

There is some research showing that nitrogen strengthened austenitic stainless steels might be a good choice for such a spring. XM-28 (Nitronic 32) stainless seems to be available as spring wire and has strengths high enough to meet our requirements. However, I have not found any data on XM-28's susceptibility to hydrogen embrittlement.

Does anyone have an insight as to whether XM-28 stainless would be an acceptable spring wire material in high pressure hydrogen gas?

Does anyone have some suggestions for other available spring materials for this application?

Thank You

 

[moltenmetal]

Elgiloy?

A PH grade of SS?

 

[EdStainless]

No, don't use PH SS grades.
An alloy that is fully austenitic will be resistant to hydrogen. Does the N-32 get magnetic when drawn? I know that you could do it with 21-6-9.

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Plymouth Tube

 

[TVP]

Are you looking at spring quality versions of Type 304 and 316? Spring quality Type 304 (ASTM A 313 or equivalent) will have ~ 10% lower strength than Type 631 (17-7 PH) for a given wire size, which is similar to XM-28 (UNS S24100). SEI published an excellent article on this subject a few years ago, and developed a new alloy that contains more Mn & N for austenite stabilization, similar to the Nitronic series grades, but I am not sure if they ever commercialized it. Use the following link for more information:

Development of Highly Hydrogen-resistant Stainless
Steel Spring Wire

http://www.sei.co.jp/tr_e/pdf/industrial/61-09.pdf

 

[swall]

Excellent article.