Fatigue loading of a ferritic ductile cast iron: damaging characterization

Ductile cast irons offer and interesting combination of overall mechanical properties and technological peculiarities, allowing to obtain a high castability (peculiar of cast irons) with good tensile strength and toughness values (peculiar of steels). This result is due to their chemical composition that allows to obtain graphite elements in nodular shape directly from the melt. Ductile cast iron mechanical properties are strongly influenced both by the matrix microstructure and by the graphite nodules. The role of these elements cannot be merely ascribed to a simple matrixgraphite “debonding” damaging mechanism, but, according to previously published results, this role is more complex. In this work, customized image processing procedures were optimized to analyze the evolution of the damaging micromechanisms in a fatigue loaded ferritic ductile cast iron, focusing the graphite elements.