INTEGRITY OF CAST IRON MATERIALS CONTAINING DEFECTS

摘要

In this paper, illustrations of the fatigue behaviour of a spheroidal graphite cast iron containing microshrinkages are presented in order to point out some of the factors that must be taken into account to evaluate accurately the integrity of components under fatigue sollicitations. The data reported concerns fatigue lifetime, short and long crack growth behaviour and environmental effects. The accuracy of the different calculations of fatigue resistance and fatigue limit based on long crack data are analysed in comparison with experimental results. In particular it is shown that the idealisation of casting defects by pre-existent cracks and the use of △K effective values for long cracks are very conservative.