Compute the volume percent of graphite, VGr, in a 2.5 wt% C cast iron, assuming that all the carbon exists as the graphite phase. Assume densities of 7.9 and 2.3 g/cm3 for ferrite and graphite, respectively.

The volume percent of graphite is 91.906 per cent.

Explanation:

The volume percent of graphite () is determined by the following expression:

Where:

- Volume occupied by the graphite phase, measured in cubic centimeters.

- Volume occupied by the ferrite phase, measured in cubic centimeters.

The volume of each phase can be calculated in terms of its density and mass. That is:

Where:

, - Masses of the graphite and ferrite phases, measured in grams.

, - Densities of the graphite and ferrite phases, measured in grams per cubic centimeter.

Let substitute each volume in the definition of the volume percent of graphite:

Let suppose that 100 grams of cast iron are available, masses of each phase are now determined:

If , , and , the volume percent of graphite is:

The volume percent of graphite is 91.906 per cent.

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