Originally Posted by
Turbine D
Because the defect is contained in the billet. the billet is sliced into what will be multiple disks after forging. The forging process then moves the defect into a particular location of the forged disk. It is not a haphazard event. Fact is, if you were to locate the defect in the billet slice, a computer program can predict after forging where the defect will wind up. Something new in technology comes along everyday, eh?
But the defect wasn't detected in the billet, or at any subsequent manufacturing stage, so a theoretical ability to track it through the process doesn't help. Similar defects
might be in similar places in other discs from the same billet, but defects in other discs could be anywhere unless/until the prime defect cause in the billet is known.