Looking for some reading material on grooving errosion/corrosion in ERW seamed 316 pipe

[Arron_]

I've searched the forum and found this old post which describes what I am looking for almost perfectly, the problem is most of the links shared in that post are no longer working, hence my repost.

Just looking for some articles on grooving corrosion in stainless pipe seams with various acids and potential causes.

Not looking to solve a specific problem, just interested after seeing some samples of this onsite.

 

[EdStainless]

There are numerous articles about hydrogen grooving of carbon steel in sulfuric service.
If you are getting grooving or erosion in stainless steel then you need to look deeper.
If the material is under annealed you can get weld attack because of the residual delta ferrite.
Or you can get HAZ attack if there is sensitization though this is usually related to impurities in the acid.

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P.E. Metallurgy, Plymouth Tube

 

[Arron_]

Thanks ED, yes I've found the numerous articles for carbon steel which is why I'm asking this question, so I can look a bit deeper into this as the client commented they just swapped to seamless pipe and are now getting better life out of the spools.

I would like to understand the root cause a little better for my own interest.

 

[EdStainless]

The real solution is buy SS and require that it be well annealed.
There are many easy ways to do that.
Or if they want to be lazy and just spend money then go seamless.
And pray that it was annealed properly also.....

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P.E. Metallurgy, Plymouth Tube

 

[cap1a79]

Refer to the below link.

http://vgoinc.com/wp-content/uploads/2015/07/Case-Study-Sulfuric-Acid-Supply-Line.pdf

Quoted from "Case Study: Failure Analysis of Sulfuric Acid Supply Line, 2015 VGO, Inc. (503) 239-6000 | info@vgoinc.com |

http://www.vgoinc.com"

"The corrosion damage exhibited two distinct morphologies and was the result of two, related corrosion mechanisms. That is, the pipe exhibited both general thinning, caused by the corrosive attack of sulfuric acid due to excessive flow velocities and/or turbulence, and highly-directional, localized grooves, caused by “hydrogen-grooving”, a corrosion mechanism associated with intermittent flow.
In particular, in the area just beyond the leak, the pipe had been thinned to less than 0.020 inch. Elsewhere, the entire length of the submitted section of line had also been thinned, with minimum thicknesses ranging from 0.060 to 0.080 inch, compared to an original thickness of 0.133 inch (i.e., nominal wall thickness for 1-inch, Schedule 40 pipe). The general thinning was due to flow-induced destruction of the passive protective surface film which forms on carbon steel in concentrated sulfuric acid service and protects it from corrosion.
In addition to the general thinning, the line also exhibited numerous, fine, diagonal (helical) grooves, characteristic of hydrogen grooving, a corrosion mechanism caused by the alternate formation of hydrogen bubbles, which collect on the surface of the pipe during stagnant conditions, followed by flushing of the bubbles during periods of flow, resulting in localized destruction of the passive protective surface film."

Lee SiHyoung,
WorleyParsons Oman Engineering,