Hydrogen embrittlement of CS? 1

[lcmechengr]

Should there be any concern for Hydrogen embrittlement of Carbon Steel piping used in fuel gas service with high conectrations of Hydrogen? The system will be operating at temperatures less than 200 deg F. Is there a minimum temperature were Hydrogen will not migrate into the metal? Thanks for any advice.

 

[metengr]

No. The temperature you stated is too low. The ability for hydrogen to diffuse into/out of steel increases significantly at and above 400 deg F.

 

[NickelMet]

If you want to find out more about carbon steel in hydrogen service, I suggest you pick up a copy of API 941. It is a reference and guidelines for material selection of low alloy carbon steels in hydrogen service. This document contains the Nelson Curves which relate materials, partial pressure of hydrogen, and temperature.

~NiM