hydrogen disbonding 1

[deckie1026]

We have a vessel with shell material SA 765 Gr II clad with inconel alloy 625. Design temperature is 104 C. We will fit a non load bearing internal( alloy 825 ) to the shell. We plan to fillet weld (ESW process) the internal directly to the cladding. Vessel is in sour gas service.

Is hydrogen disbonding a potential problem at this temperature ?

 

[deckie1026]

Clarification. The cladding is ESW process.

 

[metengr]

Ah, I was wondering about using that. Also, please do not cross post. What is the cladding thickness (.062")? I presume you intend to fillet weld the attachment to the cladding surface. What type of welding process are you thinking of using to join the non-load bearing attachment?

 

[deckie1026]

cladding is 6 mm.

 

[stanweld]

What is your operating pressure? We have had similarly constructed vessels in similar service operating at over 1000 psi with no disbondment of the cladding at the nonpressure attachments. I doubt that you will experience any disbondment.

 

[deckie1026]

Operating pressure is 150 bar. My concern is the design temperature although 104 C is not high temperature. Does anyone have experience with disbondment in this temperature range ?

 

[ijzer]

See fig.1 in ASTM G 146. No disbonding below 350 Deg. C