Definition - What does Shot Peening mean?
Shot peening is a finishing process performed on a metal part that protects it from fatigue and stress corrosion failures, thereby enhancing product life. It is a cold working process performed on the metals and composites during the manufacturing stage to enhance their mechanical properties and produce a compressive residual stress layer on the material so it can withstand stresses acting on it during the operational state.
Corrosionpedia explains Shot Peening
The shot peening process is performed at the end of the metal product's manufacturing process to provide a higher resistance to fatigue and stress corrosion. In the shot peening process, very small spherical shot (usually steel, ceramic or glass) are bombarded on the product's surface at great speed like a peen hammer. When the shot strikes the surface, they cause a dimpling effect on the surface and create compression stresses under the dimples. With continuous shot bombardment, multiple layers of overlapping dimples are created on the entire surface of the product and provide the strength to withstand compression stresses when the product goes into an operational state. This method reduces the finished product's susceptibility to fatigue failure, cracking, galling, corrosion failure, erosion and cavitation.
The shot peening method is considered to be the most effective and economical way to induce residual compressive stresses in the finished product.