I have a similar looking NGVout of one of my motors but nothing forceful happened (thumped) to it for me to think that these cracks were caused by anything but overheating. I had similar cracks and erosion that were not as bad and I managed to resurface the NGV to use again. My point is that I think that overheating can cause the cracks that cause the erosion. I assume this is the course of events that took place here versus erosion causing cracks. I also assume somethign else happened to this motor that caused the overheat in the first place.
While everyone was focussed on looking at the damaged/corroded turbine vane, did anyone else happen to notice the rather ovbvious crack on the rim around from the corrosion?
The flattened area around the crack and distored vane (second picture) indicates to me that this thing was thumped, and rather hard.
Maybe that has something to do with the problems of this engine?