4) Figure 3 shows the Fe-C phase diagram. We equilibrate an Fe-0.6 wt% C specimen at 1000 °C and subsequently slowly cool it to 722 °C and hold it there for some time. Its microstructure consists of proeutectoid ferrite (F)) and pearlite (P): (a) Sketch the microstructure and calculate the wt% of F and P present; (b) calculate the total wt% Cm and F present in the specimen; (c) What will happen to the microstructure if we hold the specimen at 722 °C for a very long time? Explain why. (20)