Fatigue Properties of Heavy Section GJS-600-10 Cast Iron Castings

This study investigated the fatigue properties of heavy section solution strengthened ferritic spheroidal cast iron (SSF-DI) EN-GJS-600-10 castings in three different section sizes. A silicon content of 4.0% was used. To estimate the influence of the size of solidification microshrinkage cavities, graphite nodules, and graphite nodule clusters on the fatigue strength of the investigated iron grade, scanning electron microscope inspections of the fracture surfaces and extreme value analysis of the crack initiating defect size, area, were made. The results show that the Murakami–Endo area - parameter model adequately predicts the fatigue limit of heavy section EN-GJS-600-10 castings. Moreover, surface defects with a size between 144 and 1599 µm behaved as a short crack, and no critical size for a long crack could be observed. Finally, microshrinkage cavities were the most detrimental defects on the fracture surfaces that influenced the fatigue limit.