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.
Last edited by 54lg; 02/21/12 11:53 AM.