Strange discontinuity near SS pipe surface
Strange discontinuity near SS pipe surface
(OP)
Hello,
We have examined SS pipe surface condition. There are some stress corrosion cracks on OD surface. But this subsurface discontinuity (please see attached file) is very strange. What is your opinion? I see the shape of defects like this in the first time in my practice.
Thank you in advance for any idea.





RE: Strange discontinuity near SS pipe surface
Does the part of the pattern follow forming flow lines?
I would suppose that it is SCC connecting with inclusions.
Can you take the piece that was adjacent to this and section it longitudinally?
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P.E. Metallurgy, Plymouth Tube
RE: Strange discontinuity near SS pipe surface
RE: Strange discontinuity near SS pipe surface
I have attached other photo (with deformation lines, notching and cracks like SCC).
RE: Strange discontinuity near SS pipe surface
Corrosion started as crevice corrosion in the lap, and then progressed as SCC.
That would be my call.
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P.E. Metallurgy, Plymouth Tube
RE: Strange discontinuity near SS pipe surface