What is Austempered Ductile Iron (ADI)?

ADI is a material produced through a unique heat treatment process. This process involves high temperature homogenisation of components followed by isothermal quenching into molten salt baths at elevated temperatures.

Key Benefits of ADI

• ADI offers dimensional predictability.
• Components can be cast near nett shape.
• ADI offers a low relative cost per unit of yield strength.

As an alternative to steel castings, forgings, fabrications and even light alloys including aluminium, ADI offers worth while cost savings.

• ADI is approx 10% lighter than steel.

What Properties does ADI give?

Austemper treated irons combine strength, ductility, toughness and wear resistance. ADI offers such a combination of superior properties because it can be cast like any other member of the Ductile Iron family. The Austemper process produces mechanical properties that are superior to conventional ductile irons, cast and forged aluminium and many cast and forged steels.

• ADI offers twice the strength of conventional ductile irons which can be achieved with similar levels of ductility.
• At a given hardness level, ADI can achieve equivalent tensile strength to that of steel.
• ADI offers excellent damping capacity, up to five times that of steel.
• ADI offers toughness and fatigue strengths that are equal to or better than cast or forged steels.

Unlike carburized steels that lose wear resistance as the carburized case is worn away, the wear resistance of austempered materials improves in service due to unique work hardening characteristics.

Base Material Options

To maximise the unique combination of properties, it is important that a nodular iron of good commercial quality is used.