sigma phase detection in super duplex tubes

Present ultrasonic technology has probably no sufficient resolution to identify phases by their different acoustic impedance.

Ferrite meters such as Diverse MF300F, Feritscope MP30, can be calibrated (with a lot of effort) to coarsely quantify sigma phase and other intermetallics. Calibration involves replicas and sectioning. Unfortunately, the meters will only assess to around 3 mm depth.

Steve Jones
Materials & Corrosion Engineer

Cut out a section and perform the A923 tests.
If it is a real concern you can sacrifice a tube.

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Corrosion, every where, all the time.
Manage it or it will manage you.