Hello, I'm new to Shot Peening. In developing the Sieve Analysis procedure, I created an excel to calculate the percent pass. However my question is (rather 2):
1) Other than a visual - how does graphing the results help? To me it is either passing the percentage or not.
2) Per AMS2430U It seems I only need 2 sieves per table 1 pg 4, One that allows .5% to be retained on sieve and on that allows 20% to pass through, thus 80% retention in sieve.
So my question is :Is my interpretation correct and why in all my searches everyone is using 5 or more sieves?
Rich,
First one must understand that there are different requirements for NEW Peening Media and In-Process Peening Media.
New Media is tested per AMS2431 5 SCREENS
In-process media is tested per AMS2430 2 SCREENS
There are different requirements for each. However, if you chose to always test your media to the as New Media, you would always pass the In-process test. Not necessarily a bad way to go but you are wasting a bit of time and wear and tear on your test sieves.
I'm not sure exactly what you mean by "graphing" in your first question, can you elaborate?
Personally, I use the two screen method but I changed the requirement to be 10% passing / 90% retained in my internal procedures. I track the data in Excel, this way I can see if a trend is developing and change the screen(s) in the peening machine before it becomes a specification violation. If you do this, make sure you word your procedure in a way that explains this is a preventive action and not a hard requirement trumping AMS2430.
Thanks for the response.
I've looked through AMS2431 and have found nor reference to sieve analysis. though what you say makes since - I still would like to know where that info came from.
as for graphing - in my searches on how to do sieve analysis - all examples given not only show the breakdown for percentages passing but also have it in a graph. (A Scatter Chart showing the curve in comparison to the exposure time)
You need to look at the particular slash document such as AMS2431/1, /2