Sliding wear behavior of a ferritic–pearlitic ductile cast iron with different nodule count

Abstract

The effect of graphite nodule characteristics (nodule count, nodule size and nodularity) on the wear behavior of ductile iron has been the subject of many researches to date to optimize its wear performance. The present work aims to illustrate the effect of nodule count on the sliding wear behavior of a ferritic–pearlitic ductile iron. Different ductile cast iron test samples, from 10 to 50mm in thickness, with the nodule counts varying between 150 and 450nod/mm2, were used. The samples for wear tests were heat treated in order to adjust the matrices to a ferritic–pearlitic microstructure. Wear tests were carried out using a pin-on-disk type apparatus based on ASTM-G99 standard under dry sliding conditions. It was found that the oxidative wear is operative at the lower load while adhesive associated with delamination wear is predominant mechanism at the higher load. Furthermore, at the lower applied loads, the specimens with the high nodule count exhibit lower wear rate than those having the low nodule count, while at the higher loads wear resistance deteriorates with increasing nodule count. The obtained results were discussed based on the effect of nodule count on oxidative, adhesive and delamination wear.