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Hydrogen Embrittlement and Stainless Steel

February 21, 2008

I manufacture compressed gas hoses. We have an application that provides hydrogen gas to a Hydrogen fuel cell, through a six cylinder manifold. At one time, we experienced a few hose failures (cracking, then breaking). Upon further investigation, we discovered that the hose was type 304 stainless. We were told by a metallurgical consultant also that (due to H₂ embrittlement) 304 is incompatible with hydrogen gas. We were then instructed to change out all 304 hoses with 316 stainless steel hoses.

Is there a chart or some kind of simple guideline regarding compatibility of metals with gases? Do you know if my previous statement is accurate?

Thanks,

Patrick Kirk
- Portland, Oregon

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September 7, 2009

Is there any movement in your application and at what temperature / pressure you are operating? We have published metal hose charts for all applications. But not sure if that is your issue.
Let me know if you have a movement, pressure and temperature questions. And we will advice from there.

Mike O'Neill
- Downingtown, Pennsylvania

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Hi, Patrick. As a non-metallurgist, I'd be very reluctant to -- based on a snap impression from an internet posting -- challenge the opinion of a metallurgical consultant you retained to study the situation in depth. Still, atomic hydrogen is the usual cause for embrittlement, not hydrogen gas; and embrittlement is more a function of the strength/hardness of the steel than the type of stainless steel employed.

Regards,

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
September 8, 2009