Abstract
In order to investigate the effect of shot-peening on the fatigue characteristics of metals, preliminary fatigue tests by the rotary bending method were carried out on polished and shot-peened materials of pure iron, Si-Mn steel, 17S Al alloy and 4/6 brass, and the results obtained were as follows: (1) The endurance life was prolonged by several times in all the materials and the fatigue strength at 107 cycles was increased by 3∼13% by shot-peening. (2) The fatigue limit was not varied or only slightly increased by repolishing in order to remove the surface roughness after shot-peening. (3) The fatigue limit was reduced by high temperature annealing in order to soften the hardened surface layer after shot-peening and this tendency was the stronger the higher the tensile strength was increased.
