Properties Of ADI Compared To The Steel

The ductile iron is an iron based alloy which contain a carbon content that is enough to exceed it's solubility in the iron, resulting in the presence of pure carbon or graphite dispersed within an iron Matrix. The selection of ADI as a material for design consideration has been driven by the ductile iron foundries and austempering suppliers and not by the mechanical design community. The properties of Austempered Ductile Iron are depend on the relative amounts of pearlite and ferrite present within the Matrix micro structure.

Ferrite is a low strength and soft phase so the strength of iron decreases as the volume of ferrite alloys increase. The shape and number of graphite nodule is important when producing the ductile iron. The Austempered Ductile Iron castings range are from a few grams to 200 tonnes in size can be produced using different molding methods. To produce Austempered Ductile Iron, the ductile iron may undergo a heat treating process. The steps for ADI are the same as for the steel, the resulted micro-structure is different.

A qualified heat treater can work with a designer to choose proper chemistry of Ductile Iron to be Austempered. In order to be successful at ADI, harden-ability or the chemistry of the iron is important. The ADI is a heat treating process that is applied to improve the properties of ductile iron. The base iron must be of high quality for the success of process of ductile iron. ADI has some unique properties related to the fatigue strength.