Analysis of shot peening residual stress distribution based on dislocation configuration

ABSTRACT

The distribution profile of residual stress on the surface layer of shot-peened materials is often in a hook shape. We analysed the distribution characteristics of residual stress by detecting dislocation configurations. The position of maximum compressive residual stress (MCRS) shifts inward with an increase in shot peening strength. It was found that long-term orderly dislocation pile-up groups frequently appeared in the MCRS region. The location of MCRS is not necessarily related to maximum dislocation density. At low strength, both the maximum dislocation density and the MCRS are on the surface region. At high strength, the surface region structures are composed of sub-grains and dislocation cells. The position of maximum dislocation density is between the surface region and the MCRS.

KEYWORDS:

• Residual stresses
• deformation microstructure
• dislocation structure
• surface modification

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the National Natural Science Foundation of China [grant number 51975084], [grant number 51405059]; the Aeronautical Science Foundation of China [grant number 20185425009], [grant number 201936025001]; and the Fundamental Research Funds for the Central Universities.