When generating a saturation curve a 10% maximum increase in arc height between T1 & T2 is the norm. I have a problem that calls for low intensity peening. The drawing calls for .004-.006N, the specification allows for the flatness of the almen strip to be +/-.0015. As you can see if we target the nominal .005N, there is potential for us to be out of the range not only for the intensity range but the 10% range as well (.0005). Shouldn't the 10% rule be somewhat more for low intensity peening? Also shouldn't the intensity callout have a wider range than the flatness requirement?

You might try to measure the pre-peen bow of the strip and subtract it from the post-peen bow. This technique is also called "compensation" and is used at General Electric and other critical peening shops. This should only be applied to strips that have less than .0005" pre-bow.

Jack,

Pete sent me an e-mail regarding saturation. In it he stated that T2 while having to be less than 10% increase from T1 maybe outside the specified intensity range. I agree but where is this clearly defined other than in GEAE specifications? None of our other customers allow this. Is this something that will be addressed in next revision of AMS-2430?

-Walt