Abstract
It is well-known that the strength of flake graphite cast iron is controlled by the morphology of the graphite. Studies on the strength of flake graphite cast iron have mainly been discussed in relation to the shape of graphite as a notch effect so far. However, the observation of the graphite shape with a microscope to evaluate only by the notch defect raises certain doubts. We therefore investigated the effect of the graphite tip radius on the mechanical properies of cast iron (Experiment-1). In Experiment-2, using pure Fe-C-Si cast iron (3.4 mass % Cand 1.8 mass % Si) as the parent material, we evaluated the influence of minor elements such as P and S on the microstructure, and tensile properties of as-cast and ferritized samples.
