Official Answer
Answer
Piki peening entwodui yon kouch estrès rezidyèl konpresiv sou sifas sezon prentan an. Nan aplikasyon pou wo-frekans, fant fatig prèske toujou kòmanse nan sifas la akòz pik estrès tansyon. Pwofondè kouch konpresiv la anjeneral $0.005$ a $0.015$ pous. Estrès total $\sigma_{net}$ vin $\sigma_{aplike} - \sigma_{konpresyon}$. Lè w kenbe estrès sifas nèt la anba papòt fatig, piki peening ka ogmante lavi sèvis la nan yon lòd nan grandè. For stainless steels, it also induces a slight work-hardening effect, though care must be taken to avoid 'over-peening' which can cause surface micro-tears in thin cross-section wire ($t < 0.010$ inches).
