CONTROLLED SHOT PEENING TO PREVENT FATIGUE AND STRESS-CORROSION CRACKING

Controlled Shot-Peening is a pre-stressing technique conducted to impart a residual compressive stress of known magnitude and depth to metallic materials. The technique is used by aerospace, automotive, agricultural, marine, offshore, medical, chemical and mining industries to prevent surface failures. Nearly all component failures in any industry are surface related whether they be fatigue, stress corrosion, fretting, galling, spalling or intergranular corrosion, and can be influenced beneficially by surface cold work. This paper describes how the process is conducted, with details of the compressive stress, hardness and surface roughness induced; how the process has developed and where the future lies with the latest computer monitored techniques. These latest control techniques enable Shot-Peening to be used as a design tool as well as a remedial treatment.