抄録
The surface nanocrystallization of various steels by air blast shot peening was investigated. It was found that nanocrystalline layers can be produced when higher shot speed and longer process period than those of conventional shot peening were applied. The produced nanocrystalline layers are several μm thick and show extremely high hardness. The layers have clear boundaries with the adjacent work-hardened regions. By annealing, slow grain growth without recrystallization is observed in the layers. Those characteristics are similar to those observed in the nanocrystalline layers produced by other techniques, such as ball milling, ball drop and particle impact deformations.
