Effect of tempering conditions on the mechanical properties of ductile cast iron with dual matrix structure (DMS)

In this work, the effects of tempering time and temperature on the mechanical properties of a new class of ductile cast iron is investigated. The results show that for a tempering temperature range of 450–500°C, there is a sudden rise in the impact strength and ductility. By increasing the tempering temperature, the ultimate tensile strength drops initially, and within the range of 400–500°C, remains almost constant and is then followed by a decrease. With increasing the tempering time, the ultimate tensile strength and yield stress decrease for tempering periods up to 120 min, the impact strength increases for periods up to 90 min and ductility increases for periods up to 120 min