. Using the isothermal transformation diagram for an iron-carbon alloy of eutectoid composition (Shown below), specify the nature of the final micro structure (in terms of micro constituents present and

approximate percentages of each) of a small specimen that has been subjected to the following time-temperature treatments. In each case assume that the specimen begins at 760°C (1400°F) and that it has been held at this temperature long enough to have achieved a complete and homogeneous austenitic structure. Cool rapidly to 700°C (1290°F), hold for 1ơʻ s, then quench to room temperature. (1.5 pt) Reheat the specimen in part (a) to 700°C (1290°F) for 20 h. Rapidly cool to 600°C (1110°F), hold for 4 s, rapidly cool to 450°C (840°F), hold for 10 s, then quench to room temperature. (1.5pt) Cool rapidly to 400°C (750°F), hold for 2 s, then quench to room temperature.