Ductile iron discovery in 1948 gave a new lease on life to the cast iron family. In fact these cast irons are characterised both by a high castability and by high toughness values, combining cast irons and steel good properties. Ductile cast irons are also characterised by high fatigue crack propagation resistance, although this property is still not widely investigated. In the present work we considered three different ferritic-pearlitic ductile cast irons, characterised by different ferrite/pearlite volume fractions, and an austempered ductile cast iron. Their fatigue crack propagation resistance was investigated in air by means of fatigue crack propagation tests according to ASTM E647 standard, considering three different stress ratios (R = Kmin/Kmax = 0.1; 0.5; 0.75). Crack surfaces were extensively analysed by means of a scanning electron microscope both considering a traditional procedure and performing a quantitative analysis of 3D reconstructed surfaces, mainly focusing graphite nodules debonding mechanisms and considering the microstructure influence.

Fatigue Damaging Micromechanisms in Ductile Cast Irons

CAVALLINI, Mauro;
2006

Abstract

Ductile iron discovery in 1948 gave a new lease on life to the cast iron family. In fact these cast irons are characterised both by a high castability and by high toughness values, combining cast irons and steel good properties. Ductile cast irons are also characterised by high fatigue crack propagation resistance, although this property is still not widely investigated. In the present work we considered three different ferritic-pearlitic ductile cast irons, characterised by different ferrite/pearlite volume fractions, and an austempered ductile cast iron. Their fatigue crack propagation resistance was investigated in air by means of fatigue crack propagation tests according to ASTM E647 standard, considering three different stress ratios (R = Kmin/Kmax = 0.1; 0.5; 0.75). Crack surfaces were extensively analysed by means of a scanning electron microscope both considering a traditional procedure and performing a quantitative analysis of 3D reconstructed surfaces, mainly focusing graphite nodules debonding mechanisms and considering the microstructure influence.
File allegati a questo prodotto
Non ci sono file associati a questo prodotto.

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/11573/189480
 Attenzione

Attenzione! I dati visualizzati non sono stati sottoposti a validazione da parte dell'ateneo

Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus ND
  • ???jsp.display-item.citation.isi??? ND
social impact