HIC & PWHT FOR S316/S316L MATERIALS
HIC & PWHT FOR S316/S316L MATERIALS
(OP)
one of our client asking to carry HIC testing as well as PWHT on weldment of 316 material. is it possible to carry the test or we can deviate the requirement by any technical reason.





RE: HIC & PWHT FOR S316/S316L MATERIALS
For PWHT, this is really unnecessary for 316 stainless steel, and will lower the corrosion resistance in certain environments. I would try to avoid exposure to PWHT.
RE: HIC & PWHT FOR S316/S316L MATERIALS
Steve Jones
Corrosion Management Consultant
http://www.linkedin.com/pub/8/83b/b04
All answers are personal opinions only and are in no way connected with any employer.
RE: HIC & PWHT FOR S316/S316L MATERIALS
The gentlemen above have quoted you chapter and verse on why neither PWHT or HIC apply to an austenitic stainless.
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P.E. Metallurgy, Plymouth Tube
RE: HIC & PWHT FOR S316/S316L MATERIALS
Also if it is applicable then which cases or scenario?
RE: HIC & PWHT FOR S316/S316L MATERIALS
If it is a small fabrication you could solution anneal after weld to get better corrosion resistance in the welds, but that is the only choice.
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P.E. Metallurgy, Plymouth Tube
RE: HIC & PWHT FOR S316/S316L MATERIALS
PWHT is not recommanded for austenitic Stainless Ssteel SS material, unless the manufacturer can certify that the properties will be as initial material. solution annealing is probably the only accepted PWHT, also for brittle phase transformation.
as per ASME I think it is not applicable
PWHT (around 600-620°C) usually refers to TTH of Carbon Steel CS welds to relax internal stress for reducing risks of SSC and SOHIC of CS materials. welded austenitic SS materials usually already have low harness and low internal stress levels after welding.
SS material shall be used in accordance with NACE MR0175 part3
I never heard about HIC damage on austenitic SS material, maybe because low corrosion rates on SS induce low hydrogen generation and low HIC risks, and maybe also because the cfc austenitic matrix can accept more hydrogen before saturation than a cc ferritic or martensitic matrix. Level of inclusions is also probably lower in SS than in CS material.
RE: HIC & PWHT FOR S316/S316L MATERIALS
RE: HIC & PWHT FOR S316/S316L MATERIALS
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P.E. Metallurgy, Plymouth Tube
RE: HIC & PWHT FOR S316/S316L MATERIALS