Back to Basics - Shot Peening in a Nutshell

Author:  Dr. David Kirk
Source:  The Shot Peener magazine, Vol 36, Issue 1, Winter 2022
Doc ID:  2022007
Year of Publication:  2022
INTRODUCTION This article aims to cover just the basic features of shot peening. Other articles can be referred to for extended accounts. Shot peening is, essentially, a surface workhardening process. Impacting, high-velocity particles plastically deform the component’s surface. This plastic deformation induces changes in the component’s properties. The most desirable of these changes is normally the increase in the fatigue strength of the component. Fatigue strength increase is caused by two factors: work-hardening and the compressively stressed surface layer. Shot peening can also be employed to correct small, unwanted component distortion. Shot-peened surfaces necessarily have tiny dents that may or may not be advantageous. Control of shot peening centers on coverage and intensity. Coverage being the percentage of the surface that is dented and intensity being proportional to the thickness of the plastically deformed surface layer. The plastically deformed surface layer is equivalent to what can be regarded as a “magic skin”.

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