Shot blasting and shot peening are both processes that involve propelling abrasive particles at a surface for various purposes, but they serve different functions and have distinct applications.
Shot Blasting:
Purpose: Shot blasting is primarily used for cleaning, preparing, or roughening a surface. It is a method of surface preparation before coating, painting, or bonding processes.
Process: During shot blasting, small metallic or abrasive particles (shots) are forcefully propelled at a surface using compressed air, centrifugal wheels, or blast turbines. The impact of the shots removes contaminants, old coatings, rust, or scale, leaving a clean and textured surface.
Applications: Common applications include preparing metal surfaces for painting, cleaning industrial equipment, removing corrosion, and enhancing the adhesion of coatings.
Shot Peening:
Purpose: Shot peening is a process designed to improve the fatigue strength and durability of metal components. It induces compressive stresses in the surface layer, enhancing the material's resistance to fatigue, stress corrosion cracking, and other forms of material degradation.
Process: In shot peening, small metallic shots are directed at a metal surface with enough force to cause plastic deformation. This deformation introduces residual compressive stresses in the material, which counteracts tensile stresses that can lead to fatigue failure.
Applications: Shot peening is commonly used in the aerospace, automotive, and manufacturing industries to enhance the fatigue life of components such as aircraft engine parts, automotive springs, gears, and other critical metal parts.
In summary, shot blasting is primarily a cleaning and preparation process for surfaces, while shot peening is a controlled deformation process that imparts beneficial compressive stresses to improve the mechanical properties of metal components. Both processes use the impact of small particles, but their objectives and applications differ significantly.