EVALUATION OF FATIGUE BEHAVIOR ON ENGINE COMPONENT MADE OF AUSTEMPERED DUCTILE IRON

Austempered Ductile Iron (ADI) is a nodular cast iron, thermally treated by the austempering process, which results in superior mechanical properties such as tenacity, ductility, wear and fatigue resistance, broadening the application field of cast irons and becoming a high competitive engineering material. In this paper, some concepts about fatigue limits on ADI parts and their experimental validation through fatigue experiments are presented. These experiments were performed on two different connecting rods with the same geometric characteristics but obtained by two different processes. The conclusion was that microstructure characteristics of the matrix and graphite nodules and also the porosity are great influences on the fatigue behavior of this material applied to connecting rods