Abstract: Strength at elevated temperatures and thermal shock resistance of austempered ductile irons at high temperatures has been less intentioned, because of instability of ausferrite phase. In this research the tensile properties of this iron and pearlitic ductile cast iron have been investigated by short time high temperature tensile tests. Also thermal shock tests were done at the molten lead bath at 1000 􀁱C . In these experiments, at first samples were immersed partially in the molten lead bath for 25 seconds and then either cooled in air or quenched in water. Results of short time high temperature tensile and thermal shock tests showed that ADI samples have higher strength and shock resistance than the pearlitic ductile samples.

Keywords: austempered ductile iron, thermal shock, strength.