THIN WALL AUSTEMPERED DUCTILE IRON: A BEST REPLACEABLE MATERIAL TO STEEL AND ALUMINUM

In this paper the analysis of thin walled castings made of ductile iron is considered. It is shown that thin wall austempered ductile iron can be obtained by means of short-term heat treatment of thin wall castings without addition of alloying elements. Production of Thin Wall Austempered Ductile Iron (TWADI) components can have strength-to-density and elastic-to-density ratios that approach those of cast aluminum, making it theoretically possible to apply ADI in high strength light weight parts. Therefore, development of thin wall ADI technology is essential to permit designers for energy consuming equipment to choose the most appropriate material based on material properties, and not solely on weight or density. In the present work, ductile iron castings with different thicknesses were cast with an appreciate casting design to assure good mold filling. There are shown that thin wall ductile iron is an excellent base material for austempering heat treatments. Tensile strength and hardness increased with decreasing casting wall thickness due to the structure refinement effect and decreasing the volume fraction of retained structure in matrix. As a result high mechanical properties received in thin wall plates made of austempered ductile iron