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#863 - 02/21/12 06:52 AM Understanding of SAE J443-2010
54lg Offline
Member

Registered: 05/23/06
Posts: 7
Dear all,

this is Kevin, I have a question about SAE J443-2010:

1) para 6.1 states "Nozzle centerline positions or wheel cages should be set so that they produce an impact angle of impingement greater than 30 degrees". does it mean, actual impact peening angle shall be 30 degree or above? or other meaning?

2) para 7.2 states "The nearest practicable time to T should then be used. The arc heights obtained must repeat the value from the saturation curve 0.038 mm (0.0015 in) or other value acceptable to the customer." how to understand "nearst"? In our company, I develop the saturation curve based on passes/strokes growth, incremental-based.
Typical testing is 1x, 2x, 4x and 8x, and most of time 4x is first data point because it is less than 10% between 8x and 4x, and more than 10% between 4x and 2x. If I use saturation point solver (excel template download from shotpeener.com, then maybe 2.55x will be a ideal saturation point. Thus how to select nearest practicable time? 2x or 3x ?
If choose 2x, there maybe at a risk, some auditor may ask me to verify the arc height of 2x and 4x, the increment between 4x and 2x is more than 10% most of time.
If choose 3x, the increment between 6x and 3x should be less than 10% most of time. Can I use 4x instead of 3x, because programming is easy to realize 2x, 4x, 6x, even passes.

can anyone help me ? thanks in advance.


Edited by 54lg (02/21/12 06:53 AM)

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#865 - 02/21/12 01:37 PM Re: Understanding of SAE J443-2010 [Re: 54lg]
Socrates Offline


Registered: 02/20/06
Posts: 108
This question needs some clarification. Do you mean that "most of the time 4x is the first data point" or did you mean that "most of the time 4x is the data point that is the first one to be less than 10% lower than the next longer point"? This second interpretation is now outmoded. If you use a saturation point solver program then this gives you a unique value for peening intensity. For your example of the unique point on the curve at 2.55 then you have to decide which is the nearest PRACTICABLE time. Using integral passes then 3 passes is obviously the nearest to 2.55. You would have to persuade auditors that to use 3 passes was not practicable.

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#866 - 02/22/12 06:26 AM Re: Understanding of SAE J443-2010 [Re: Socrates]
54lg Offline
Member

Registered: 05/23/06
Posts: 7
Thanks for your answer. I mean, 4x is first one data point, so should be second interpretation.
maybe it is now outmode, but our shot peening machine program is performed based strokes/passes increment. so cannot realize 2.55 strokes.
2.55 strokes is just a example, if use saturation point solver program and got 2.43 strokes, then should choose 2 strokes?

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#867 - 02/22/12 07:39 AM Re: Understanding of SAE J443-2010 [Re: 54lg]
Socrates Offline


Registered: 02/20/06
Posts: 108
It is, of course, impossible to apply a fraction of a pass to a component, That is why the requirement is to apply the nearest practicable 'time'. If the Solver program indicates 2.43 as the 'time' for the unique intensity point then you should use 2 passes for verification purposes. Bear in mind that the intensity that you are trying to confirm is not that for 2.43 but the intensity value read from the curve at 2.00 passes.

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#868 - 02/22/12 08:40 AM Re: Understanding of SAE J443-2010 [Re: 54lg]
Dave Barkley Offline


Registered: 04/13/11
Posts: 43
Loc: USA
"Bear in mind that the intensity that you are trying to confirm is not that for 2.43 but the intensity value read from the curve at 2.00 passes."

I want to correct one thing in this statement as we see confusion on this regularly in our peening courses. When referring to any arc height that does not correspond directly to the T1 value it is just an arc height, not an intensity value. With that I offer a revised statement:

"Bear in mind that the intensity that you are trying to confirm is not that for 2.43 but the arc height value read from the curve at 2.00 passes."

One might say that you're actually verifying the previous saturation curve that gave you the intensity value.
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EI Shot Peening Training

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#870 - 02/22/12 10:20 AM Re: Understanding of SAE J443-2010 [Re: 54lg]
Socrates Offline


Registered: 02/20/06
Posts: 108
Agreed. It was a slip of the tongue to use the word "intensity" rather than "arc height".

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#872 - 02/23/12 06:10 AM Re: Understanding of SAE J443-2010 [Re: Socrates]
54lg Offline
Member

Registered: 05/23/06
Posts: 7
thanks everybody. it is clear.

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#875 - 02/29/12 10:51 AM Re: Understanding of SAE J443-2010 [Re: 54lg]
Dave Barkley Offline


Registered: 04/13/11
Posts: 43
Loc: USA
I'm going to revive this topic as I've just had an interesting question. posed to me...

The confirmation of the saturation curve can be done by using the nearest achievable data point when the exposure is done in passes/strokes. In the case above the operator would use the arc height value at 2 passes as a target value for confirmation.

When using the Curve Solver program by Dr Kirk the actual data points are often adjusted to generate a fitted curve. If the actual arc height at 2 passes was .0103 but the Curve Solver corrects the point to .0106, which should the operator use as the target: .0103 or .0106?

My answer is to use the adjusted value of .0106 as the target to be within +/- .0015. Do you agree Socrates?
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EI Shot Peening Training

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#877 - 02/29/12 02:44 PM Re: Understanding of SAE J443-2010 [Re: 54lg]
Socrates Offline


Registered: 02/20/06
Posts: 108
Yes.

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#1360 - 04/06/18 02:13 AM Re: Understanding of SAE J443-2010 [Re: 54lg]
Amanda Offline
Member

Registered: 04/02/18
Posts: 1
Thanks for the answer. I was having the same doubt.
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