A ustempered ductile iron (ADI) is a specific type of spheroidal graphite cast iron (SGCI) grade which has attractive mechanical properties such as high tensile, fatigue strength, toughness and relatively good ductility. The grey cast iron, which is a widelyused engineering material, can have maximum 400 MPa ultimate tensile strength (UTS) values due to flake type of graphite. The flakes promote notcheffect and reduce ductility as well [1]. However if the graphite shape can be changed to a spheroidal or nodular form with some special casting techniques the UTS may reach to 800 MPa [2]. Further improvement of mechanical properties is possible by applying heat treatments, such as austempering, that change the matrix microstructure. The excellent mechanical properties of ADI, in particular the favorable combination of high tensile strength, wear resistance and ductility, predestine this material to act as a substitute for forged or case-hardened materials and Ductile Iron (DI) [2].