Using the isothermal transformation diagram for an iron-carbon alloy of eutectoid composition (Figure 10.23), specify the nature of the final microstructure (in terms of microconstituents 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 760C and that it has been held at this temperature long enough to have achieved a complete and homogeneous austenitic structure. 8. Cool rapidly to 350C, hold for 103s, then quench to room temperature. (b) Rapidly cool to 600C, hold for 4s, rapidly cool to 450C, hold for 10s, then quench to room temperature. (6) Reheat the specimen in part (b) to 700C for 20h. (W) Rapidly cool to 575C, hold for 20s, rapidly cool to 350C, hold for 100s, then quench to room temperature