Mag. Particle indications in 17-4SS Part 1

[cwiese]

Our vendor for pressure vessel component made from 17-4 H1025 SS (per AMS5643)has reported that during the MP exam there are several bright and scattered indications. The indications extend through the ID feature of the component, not just the outer suface. The indications do NOT show with dye pen. My first guess is that it could be delta ferrite?
1) What other potential sources of the indications do you you suggest I look for?
2) If it is delta ferrite, what are some negative effects of this condition?

 

[EdStainless]

Could you use UT? Could these be related to inclusions?
Either way I would be concerned about the localized nature of the indications. I am not sure what the implications on toughness would be.

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Plymouth Tube

 

[cwiese]

We do not have UT here, but I will radiograph it look for inclusions. The MP indications are certainly large enough to show up on the x-ray.
As far as toughness, we have no specific impact strength requirement. We are considering pressurizing to rupture one of "worst" of the questionable parts.

 

[metengr]

cwiese;
I think pressurizing to rapture is a little overkill, don't you? First off, I agree with the RT. Second, you might have delta ferrite stringers that are producing the wet fluorescent MT indications. If this is the case, all might not be lost. You need to still disposition the item, but attempting to pressurize and fail is a bit drastic. If anything, I would scrutinize the material chemistry and test reports for clues.