Back to Basics: Coverage

Author:  Prof. Dr. David Kirk, Coventry University, U.K.
Source:  The Shot Peener magazine, Vol 35, Issue 3, Summer 2021
Doc ID:  2021028
Year of Publication:  2021
Abstract:  
INTRODUCTION Coverage and peening intensity are the two major properties for peened components that have to be both measured and controlled. As with all definitions “The Devil is in the Detail.” SAE’s J2277 does not help clarity of understanding and is somewhat misleading as the following extract indicates: “Coverage is defined as the percentage of a surface that has been impacted by the peening media. The minimum peening time required to obtain 100% coverage is determined by gradually increasing total peening time until the entire surface being peened exhibits overlapping dimpling. Coverages above 100% are multiples of the exposure time required to achieve 100% coverage.” Only the first sentence is accurate!