Pearlitic ductile cast iron: fatigue crack paths and damaging micromechanisms

Abstract

The influence of the graphite nodules morphology (shape, dimension and distribution) on ductile cast irons (DCIs) mechanical properties is experimentally confirmed both in static, quasi static and cyclic loading conditions. According to the most recent results, these graphite elements cannot be merely considered as “microvoids embedded in a metal matrix”, but their presence implies a modification of the damaging micromechanisms and this modification I s influenced by the metal matrix microstructure.In this works, the different damaging mechanisms that are active in the graphite nodules in a pearlitic DCI are semi-quantitatively analyzed using light optical microscope observations of the fracture surface profiles.