Novel method for the fatigue strength assessment of heavy sections made by ductile cast iron in presence of solidification defects

The fatigue strength of ferritic, pearlitic, and solution strengthened ferritic ductile irons taken from heavy sections and characterized by long solidification times has been assessed. Starting from the idea of Murakami and co-workers, a new model for the prediction of the fatigue strength is proposed. It allows a sound fatigue assessment of the fatigue strength of as-cast ductile irons containing solidification defects, such as low nodule count, exploded, chunky and spiky graphite, or microshrinkage porosities. The newly developed equation validated by means of an extensive benchmarking with data taken from the literature has shown a very high potential for applications to thick-walled components.