Home Forums General Discussion Shot Peening Process, Intensity, Coverage intensity independent of time

Hi all;
As we know intensity is independent of time,but coverage not.
Recently,i'm reading a process sepc(ABP1-2028) in which it is written as "The peening time, or part feed rate, shall be selected such that the required intensity in each location is achieved and the coverage requirements of 4.3.2.4 are met."
It looks like peening time affect intensity? what do you think about the sentence?

The sentence is capable of being misinterpreted. Peening intensity is independent of time but peening intensity measurement depends on time - arc height which increases by 10% when the peening time is doubled. The specification may have intended to refer to intensity measurement at each location.

I agree with Socrates comments and want to offer a recommendation:

Known: Intensity is calculated using 4 different times (min), achieving 4 arc heights (min) that we use to generate a saturation curve. Subsequent verification of intensity is often done by creating 1 arc height with the T1 time of the accepted/established saturation curve. The arc height in this case is conveniently equal to the intensity value.

Having multiple strip locations on one fixture can make verification difficult if the various T1 values from each location's saturation curve must be used as a peening time. J443 comes to the rescue by allowing all the strip locations be peened at the same/single amount of time with verification of the expected (target) arc height for that time as it corresponds to its saturation curve. Essentially, the same is done when a peening time of a part can only be a whole number, such as a number of passes.

With this in mind, you should be able to determine an expected/target arc height for your process at the given feed rate and number of passes that are needed to obtain proper coverage of the part. Of course make sure the actual arc heights are within the specs tolerances to the target arc heights.

This should satisfy the spec where the peening time of a part can also be used to verify proper intensity.

Appreciate your comments.
Happy New Year.