Austempered ductile iron or AID casting is known as the great achievements in recent thirty years in the field of metallurgical casting. It is a kind of engineering material with excellent comprehensive properties, high strength, high wear resistance and good toughness; good self hardening in strong extrusion friction under dry friction under the action of friction is good. It can be widely used in automobile, railway equipment, mining machinery, general machinery, construction of the heavy load, wear parts. Such as: grinding ball and lining board; heavy automobile spring support, crankshaft, gear rack; damping system of the railway vehicle steering wedge, wear plate and wear pin sleeve; general machinery, engineering machinery, gear and other parts of the track plate. It can be widely used to replace steel castings, steel forging, compared with a reduction of both process and save time, and better than the performance of steel castings, forgings.
Austempered Ductile Iron is also referred to as ADI. This material has been developed to offer enhanced strength and wear resistant properties. Impact resistance of Ductile Iron is retained. This material also offers enhanced fatigue properties.
Post casting austempering is an isothermal heat treatment applied to SG Iron materials. The chemical analysis of the SG Iron has to be controlled very carefully to ensure that the maximum mechanical properties resulting from the post casting solution treatment are achieved.
Additions of copper, nickel and molybdenum are made to improve hardenability. Austempered Ductile Iron (ADI casting) is being used for demanding applications and is replacing carbon steel castings and forged components due to the following benefits:
Cost
When compared to carbon steel castings and steel forgings and fabrications ADI – Austempered Ductile iron has a lower manufacturing cost.
Cast ability
ADI has a lower casting temperature than steel and this allows for a superior surface finish and the ability to cast complex shapes incorporating changes of section.
Tensile Strength
1600 N/mm2 can be achieved with certain grades of Austempering Ductile Iron.
Weight Saving
ADI has a lower density than steel. Casting designs incorporate near net shape offering significant weight savings over steel castings.
Improved Noise Damping
The presence of graphite in the Austempering Ductile Iron improves noise damping.
Superior Wear and Abrasion Resistance
The wear characteristics of ADI improve in service. Hardening occurs during normal operational use. Therefore ADI is a perfect choice high abrasion application.
Machining
The ability to
cast to near net shape reduces the machining costs of ADI castings when
compared to steel products.
