Shot peening technology originated in the 1920s–1930s. It utilizes a high-velocity stream of shots impacting the metal surface, inducing a layer of cyclic plastic deformation. This process results in beneficial changes in the microstructure of the surface layer and introduces a residual compressive stress field. The modified microstructure and the residual compressive stress field are two key strengthening factors that enhance resistance to fatigue failure and stress corrosion cracking (including hydrogen embrittlement). As a result, the reliability and durability of metal components are significantly improved.

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—approximately 40%–50% in civilian machinery components and up to 90% in military and aerospace components.

Shot peening offers significant advantages: it is not restricted by material type, static strength, or component geometry and size. Moreover, its strengthening effect is unmatched by other surface enhancement processes. Since its introduction, shot peening has attracted considerable attention from the machinery manufacturing industries of developed countries and has been widely adopted. Its application continues to expand to this day.