Ductile Iron:
Ductile Iron castings are produced for applications requiring strength, toughness, good machinability, and low cost. Ductile Iron contains spheroidal (nodular) shaped graphite, is higher strength than Gray Iron, responds well to Induction Hardening, and weighs about 10% less than steel for the same section size. Dotson Iron Castings produces Ductile Iron grades D60, D65, D80, and D100.Gray Iron:
Gray Iron contains flake shaped graphite which provides excellent machinability and sound dampening capabilities. Gray iron exhibits excellent castability due to its fluidity during pouring, and is often used in applications requiring pressure tightness. Dotson Iron Castings produces Gray Iron grades G30, G35, and G40.Compacted Graphite Iron:
Compacted Graphite Iron (CGI) contains vermicular graphite, a stunted graphite flake which is intermediate to Gray Iron Flakes or Ductile Iron Nodules. As a result, the properties of CGI are typically intermediate to that of Gray and Ductile Irons. Generally, CGI is suitable to most applications where Gray Iron is desirable but higher strengths are required.Austempered Ductile Iron:
Austempering is a specialized heat treatment which transforms Ductile Iron into a high strength, wear resistant material. The material contains graphite nodules like normal Ductile Iron but also contains an engineered matrix of Ferrite and carbon rich Austenite, referred to as Ausferrite. ADI is also useful in high fatigue-strength and high impact-strength applications. Austempered ductile iron is produced in grade 1 through grade 5.Carbidic Austempered Ductile Iron:
Carbidic Austempered Ductile Iron (CADI) is produced by austempering ductile iron that has a controlled volume of carbides present for an even greater abrasion resistant material. The resulting microstructure consists of carbides within an ADI matrix (ausferrite). CADI is utilized where abrasion (wear) resistance is of primary concern. It is more wear resistant than Grade 1600 (GR 5) ADI, less expensive and tougher than many abrasion resistant irons and can replace Mn steel at an equal or lower cost.*Information from Applied Process, Inc.