Abstract
Rotating bending fatigue tests were carried out for three metals: low carbon steel (S15C) with four grain sizes, pure copper and austenitic stainless steel (SUS304). The distributions of crack initiation life Ni, growth life Np and failure life Nf defined in this study were expressed as a two-parameter Weibull distribution. The statistical scatter of Ni, Np and Nf distributions increased roughly with the increase of grain size, except the smallest one and with the decrease of stacking fault energy, and decreased with progress of fatigue. The SUS304 showed the highest value of the correlation coefficient between the coefficient of variation η of the Nf distribution and the slope of S-N curves a was expressed as η=c(a)-b, where b and c are constants.
