Shigeru Doi

Comparative evaluation of high-cycle fatigue strength and wear resistance for PDI material processed by heat treatment and gas carburizing furnace and ADI material

With a gas carburizing treatment processed to a pearlitic spherical graphite cast iron, investigations were carried out about its high cycle fatigue characteristics and wear resistance. The high cycle fatigue characteristics were evaluated by its rotary bending fatigue test, and fatigue strength was improved about 20 MPa greater than in test pieces before they are carburized. The starting point of fracture is from graphites in the vicinity of surface or from microdefects in casting, and a fracture mechanism of which starting point is in its internal part was not found. Furthermore, a better result was obtained in the wear resistance test than in that of austempered spherical graphite cast iron. Those were expressed by the difference of matrix structures.