Back to Basics: The “Magic Skin”

Author:  Dr. David Kirk
Source:  The Shot Peener magazine, Vol 35, Issue 1, Winter 2021
Doc ID:  2021008
Year of Publication:  2021
Abstract:  
INTRODUCTION The whole point of shot peening is to improve the service life of industrial components. Peening achieves this aim by inducing a “magic skin” into the components. This skin is a thin surface layer that has two defining characteristics— work-hardening and compressive residual stress. For too long it was assumed that compressive surface residual stress was the only significant factor. Nowadays it is recognized that work-hardening is an equally important factor. As a simple equation we have that: WORK-HARDENING + COMPRESSIVE SURFACE RESIDUAL STRESS = INCREASED S E R V I C E P E R FORMANCE