Austempered Ductile Iron (ADI) Casting

Austempering has been a process applied to steel since the 1930s. This is a heat treatment that is often applied to ferrous metals to give them greater strength and toughness. Unlike traditional tempering techniques, austempering involves keeping the metal at the quenching temperature for an extended period of time. After the metal is heated beyond 1500 degrees Fahrenheit, it is quenched in a molten salt bath typically between 400 and 750 degrees Fahrenheit. Holding the part in the bath transforms the part’s microstructure from austenite to bainite, which gives it more durability, wear resistance, and fatigue strength compared to as-cast ductile iron.

Austempered ductile iron (ASTM A897) offers a number of advantages when compared to traditional ductile iron and gray iron. Its tensile strength, ductility, toughness, and fatigue resistance are all higher than those other materials, but there are other reasons why many industries depend on ADI castings.

For example, it also provides superior vibration dampening and heat transfer compared to other metals. Its strength-to-weight ratio also makes it a better choice in many contexts than steel or aluminum.

The superior mechanical properties of austempered ductile iron make it a common material for a variety of components typically exposed to heavy-duty use and extreme conditions. These include:

• Automotive wheel hubs, timing gears, and suspension brackets
• Railroad switches, gears, and braking systems
• Agricultural hitches, digger teeth, and ploughs
• Mining sprockets, rollers, and wear plates

Since 1946, we’ve been the shell mold process leaders in the casting industry. We’ve earned a reputation for innovation thanks to our early adoption of shell mold casting, and our numerous certifications show our persistence & dedication to improve our services. Our clients know they can trust us to provide them with the highest standards of quality as well as exceptional customer service.

To learn more about our work with austempered ductile iron and how it can work for your needs, reach out and speak with a knowledgeable member of our staff today.