Gray iron castings are almost universally applied in all major industrial sectors that demand high strength, plasticity, toughness, wear resistance, resistance to severe thermal and mechanical shocks, and tolerance for high or low temperatures, corrosion resistance, and dimensional stability. To meet the varying requirements of these conditions, there are numerous grades of ductile iron available, offering a wide range of mechanical and physical properties.

Most ductile iron castings, as stipulated by the International Standardization Organization ISO 1083, are produced in a non-alloyed state. Clearly, this category includes high-strength grades with tensile strength exceeding 800 Newtons/mm and elongation of 2%. At the other end of the spectrum are high-ductility grades with elongation greater than 17%, corresponding to lower strength (as low as 370 Newtons/mm). Tensile strength and elongation are not the sole criteria for material selection by designers; other critical properties include yield strength, modulus of elasticity, wear resistance, fatigue strength, hardness, and impact properties. Additionally, corrosion resistance, oxidation resistance, and electromagnetic properties may be crucial for designers. To meet these specific applications, a series of austenitic ductile irons, commonly referred to as Ni-Resis ductile irons, have been developed. These austenitic ductile irons are primarily alloyed with zinc, chromium, and manganese and are listed in international standards.