What can be the most likely process causes of shot peen rollover with high strength alloy single crystal castings on edges with radii of .005" to .015"?
Excessive rollover is generally caused by the intensity being too high. However, it may be that the bulk of the part requires an intensity high enough to cause rollover on the edges. Either way, you should definitely discuss this matter further with someone from Metal Improvement. Contact them via their website:
If you need to avoid it, I would machine a well-mated part (or have it fabbed out of ceramic)and place it tightly at the edge that rolls over, prior to peening.
If this is single crystal and does not chip at the edge, I am guessing that this is a superalloy??
