Abstract
Statistical analysis of fatigue strength distribution of sintered smooth specimens prepared from electrolytic iron (Fe) powder, Fe-l mass% graphite (Fe-1 mass%C) and Fe-5 mass%Cu compacts was investigated by the Probit method. The results were summarized as follows:
P-S-N curves for Fe compacts with different density levels, and Fe-1 mass%C and -5 mass%Cu compacts were obtained. Variation coefficients of fatigue strength for Fe compacts and two alloy compacts were within 4.5 to 9.9% and 5.6 to 8.7%, respectively. The scatter in fatigue strength of Fe compacts increased as the sintered density became lower. The inclined parts of S-N curves for Fe-C and -Cu compacts in the stress amplitude range from 196.1 to 274.6 MPa were no significant difference and therefore S-N curves for both the compacts were estimated to be the same.
It was found that the variation coefficients of fatigue strength for smooth specimens of sintered Fe and alloy compacts were smaller than those of cast steel and larger than those of carbon and alloy steels for machine structural use.
