Low-alloy Steels in Wet H2S Service
Low-alloy Steels in Wet H2S Service
(OP)
I've been unable to find material discussing the performance of low-alloy steels in wet H2S service with respect to blistering, HIC/SOHIC, etc. I understand that carbon steel is the "go-to" , but if the benefits to low-alloy steels are marginal or non-existent I'm interested in seeing documentation and hearing from experience. The reason this comes up is not for design, but rather in the case where a low-alloy vessel changes service. Is there any reason to believe that the low-alloy will see any benefit over carbon steel at all?
Thanks in advance.
Thanks in advance.





RE: Low-alloy Steels in Wet H2S Service
RE: Low-alloy Steels in Wet H2S Service
RE: Low-alloy Steels in Wet H2S Service
http://www.icorr.net/wp-content/uploads/2011/01/H2...
RE: Low-alloy Steels in Wet H2S Service
Petrotrim Services, LLC
www.petrotrim.com
RE: Low-alloy Steels in Wet H2S Service
Sounds like a risky project. Can I guess that an existing C steel vessel has failed and you are looking for a handy replacement?
(1) Composition is an issue - do you have actual MTRs for ALL materials?
(2) I strongly recommend you do a 100% survey with phased-array UT (that is a fairly expensive proposition all by itself).
(3) While you can possibly* measure weld HAZ hardness at the surface, the risk also exists below the surface.
(4) Can you measure hardness along 100% of all welds? It's an all-day task for me to go inside a tank and properly evaluate maybe 8-10 spots on representative welds.
Monatomic hydrogen in iron is a happy wanderer, and it walks a crooked path.
* I say 'possibly' because field hardness testing has <20% probability of giving accurate results.
"If you don't have time to do the job right the first time, when are you going to find time to repair it?"