15 - An Investigation of the Effects of Graphite Parameters on the Fracture Toughness of DI

Abstract:

This experimental program was divided into two phases. In Phase I, a systematic set of experiments were performed using dynamic tear specimens, modified Charpy specimens, and fracture mechanics specimens to try to obtain consistant indications of fracture toughness from these tests and determine the most economical approach to fracture toughness characterization of ductile iron. The second phase then utilized the approach selected from Phase I to study the effect of nodule size, shape, and volume fraction on the fracture toughness of ferritic ductile iron as well as the temperature used for ferritizing heat treatment.