Jack,
Does Arc height always accurately indicate compressive residual stress levels at a specific depth in the Almen strip. If yes, then can we correlate that to residual compressive stress in our parts consistently? What are the variables that would make that a poor measure for process control?
Name and Company Withheld

The answer is a "qualified" yes, the Almen strip is curving as a result of the compressive stresses induced and IF the key process parameters are unchanged then yes, the stress in your part will be consistent. However, media size and hardness may influence the (compressive) residual stress at a given intensity. It is therefore very important that you maintain the media quality and shot projection (velocity and flow rate).

Jack

But,what is the correlation between the Almen arc height and the level of residual stress. is there a simple formula or algorithm for the relation between the two?

Also, can we have a similar relationship between increase of hardness due to'cold work' by peening and the residual stress level?

Shankar
India

A simple chart is shown at our web site "Learning on Line":

http://www.shotpeener.com/learning/multi%20depth%20vs%20intensity.pdf