Quantification of Shot Peening Coverage

Author:  Prof. Dr. David Kirk, Coventry University, U.K.
Source:  The Shot Peener magazine, Vol 28, Issue 4, Fall 2014
Doc ID:  2014036
Year of Publication:  2014
Abstract:  
Shot peening is essentially a surface metalworking process. A stream of high-energy shot particles does work on the surface of components. The work done manifests itself in the form of dents. Coverage with dents increases with peening time. The progress of coverage is illustrated in fig.1. The rate of increase in coverage slows down with increase in the amount of peening – following the “Law of Diminishing Returns.” An important practical requirement is that the applied shot stream must achieve a required degree of coverage in an economical time. As coverage increases a surface layer of work-hardened, compressively-stressed component material is generated. It is this “magic skin” that promotes improvement in service performance.