Bearfoil and DERG
In the photograph of the fractured stub pipe in the area of the fracture, I think the surface having swirl marks on it is the result of subsequent forensic examination. That is to say, the swirls come from a radial cutting wheel under coolant spray (may account for the brownish color). The examiners were probably trying to get a better view of the fracture itself, and cut away an unaffected area to enable this. I am sure there are other unreleased photographs that show this component in its original state as found before analysis.
Turbine D