By using the Iron-Carbon (Fe-C) phase diagram provided herein, answer the following questions: Sketch the microstructure of alloys A, B, and C in the following temperature ranges when they are cooled from 1000 oC very slowly (equilibrium cooling). Identify all phases in the microstructures. Comment on the mechanical properties of the resultant alloy as well its constituent phases. Please be concise. For alloy A: T=1000 oC, TA>T>727 oC and T=600 oC; for alloy B: T=728 oC, T= 727 oC and T= 600 oC; and for alloy C: T=1000 oC, TC>T>727 oC and T=600 oC. Would you choose steel with a carbon content greater or smaller than 0.77 wt% C if you needed moderate strength and good ductility? Justify your answer by taking microstructural considerations into account.

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T (C) 1600- The Fe-C Phase Diagram 1539 C 1400--1394C 1200 1000 A a+y 800- Q-TA I Y 0.77% a 600- 0.022 400- 0 0.42 11.15 L Y+L 1148 C Tc 2.11% 727C + a+FeC 4.3% y+FeC 2 3 4 er. 5 P=1 atm L+FeC + 6 6.67 T (C) 1600- The Fe-C Phase Diagram 1539 C 1400--1394C 1200 1000 A a+y 800- Q-TA I Y 0.77% a 600- 0.022 400- 0 0.42 11.15 L Y+L 1148 C Tc 2.11% 727C + a+FeC 4.3% y+FeC 2 3 4 er. 5 P=1 atm L+FeC + 6 6.67