Effect of Location in Y Block on Low Cycle Fatigue of Ferritic Ductile Cast Iron

To determine some of the microstructural parameters governing the low cycle fatigue strength and the crack propagation behavior of ferritic ductile cast irons, an experimental analysis of fatigue damage has been undertaken using four materials with different spheroidal graphite morphologies. It is shown that the frequency of the large graphite grain in the specimen surface layer strongly controlled the fatigue strength and the crack propagation behavior. In detail, the fatigue strength is mainly affected by the volumetric distribution of the spheroidal graphite, while the spheroidal graphite distribution in the surface layer played an important role during the microcrack propagation stage