Problem 8 A 0.50% C carbon steel is heated to 1000 C and equilibrated; then it is slowly cooled to 600 C, where it is held until an equilibrium structure develops, and then it is cooled to room temperature. (a) After this procedure, what phases are present, and what are their weight fractions? (b) After this procedure, approximately what weight fraction of the alloy is in the proeutectoid a phase, and what weight fraction is in the pearlite phase? (1539 C) 2802 F 2554 F Liquid Temperature, "F 1666 F (908 C) L+ Austenite L+ Cementite Austenite 2065 F (1130 C) Eutectic (Ledeburite) Aus. + Ferrite Austenite + Cementite H 1333 F (723 C) Eutectoid (pearlite) Ferrite Ferrite + Cementite 0 0.8 - eutectoid Hyper- eutectoid Steels K 2.0 4.3 Percent carbon by weight 6.67 Fe,C -Hypoeutectic- Hypereutectic. Castirons The iron-iron carbide equilibrium diagram labeled with common names