NDE method for stress corrosion cracking 1

[metengr]

bhart192;
Proper cleaing is necessary for surface nondestructive testing. I would recommend wet fluorescent magnetic particle testing (WFMT). This nondestructive examination method is one of the most sensitive to surface inspection, and this is what you need for cracking which typically initiates along an exposed surface.

 

[gtaw]

My vote would be to use ultra sensitive fluorescent penetrant testing.

SCC often consists of numerous small tight cracks along the grain boundaries that require extended dwell time and development time to be visible when examined under ultraviolet light.

Wet fluorescent magnetic particle testing is fine for fatigue cracks, but typically isn't sensitive enough for detecting SCC in the early stages of initiation.


Best regards - Al

 

[Duwe6]

Concur with GTAW, wet Fluorescent MT, using an AC yoke.

For non-magnetic metals, use "Level III" [high sensitivity] Dye Penetrant -- my favorite is Ardrox P-133. For PT, surface cleaning is critical. I would use a "Hotsey" hydroblast; about 3-5000 psig, hot water, and a little soap [organic surfectant]. Vapor degreasing is best for anything you can fit into the degreaser enclosure.

 

[SectionIX]

White contrast MPI is a reasonable alternative to wet fluorescent, plus you can document the indications with relative ease as compared to wet fluorescent.

 

[metengr]

Wet fluorescent magnetic particle testing is fine for fatigue cracks, but typically isn't sensitive enough for detecting SCC in the early stages of initiation.

Disagree with the above statement. SCC can begin as small pits, which can be seen via proper WFMT. SCC can begin as small branched cracks, which can also be seen by proper WFMT.