What shot peening actualy is
Shot peening is process used to produce residual stress layer which is compressive. This process also modifies mechanical properties of metals.
Basically shot peening is kinda branch of sandblasting, only difference is that shor peening operates by mechanism of plasticity while sandblating works on abrasion. Shot peening also produces a lot less dust since it removes less material.
The rest of process is almost similar to sandblasting. Popular method includes air blast systems and also centrifugal blast wheels. In air blast media is introduced by various methods. This is then put into the path of high pressure air which is then all accelerated through nozzle. Kinda same as sandblasting.
This process is used on many areas, from clutch springs, coil springs, gearwheels, gear aprts adn many more. It can also be used for decoring, sand removal, surface finishing and many more. Shot peening can also be used to give media cosmetic effect. Shot peening also produces larger surface features which results in effect being more pronounced.