Shot peening technology was first developed during the 1920s and 1930s. The process involves projecting a high-velocity stream of shots onto a metal surface, generating a layer of localized plastic deformation. This treatment leads to positive changes in the microstructure of the surface layer and introduces a residual compressive stress field. Both the modified microstructure and the residual compressive stress field serve as critical strengthening mechanisms, considerably improving the component's resistance to fatigue failure and stress corrosion cracking.

Wear, corrosion, and fracture are the three primary failure modes of engineering metal components. Among them, fracture is the most critical in terms of consequences. Within fracture failures, fatigue fracture accounts for the largest proportion (between 40% and 50%) in civilian machinery components and up to 90% in military and aerospace components.

Shot peening offers significant advantages: it is applicable to a wide range of material types and strength levels, and can be used on components of varied geometry and size. Its strengthening effect is highly competitive with other surface enhancement processes for many applications. Since its introduction, shot peening has attracted considerable attention from the machinery manufacturing industries all around the world and has been widely adopted. Its application continues to expand to this day.