The top is the edge of the barrel segment blown out at the time of a burst and the fracture is clearly ACROSS the crolle pattern; steel is grey-black, iron silver-white (3% Nitrol etched). The crack appears to be in the iron alternee.
The straight lines in the lower right are evidence of shear deformation at the time of the high pressure burst.
Additional metallurgical studies, including scanning electron microscopy, showed no corrosion and no low cycle fatigue.



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