Work on this problem in the provided answer sheet and submit through Gradescope. Composition (at%C) 10 15 5 20 25 1600 1538C 1493C L 1400 2500 1394C YL 1200 1147C 2.14 4.30 7. Austenite 2000 Temperature (C) 1000 Temperature (F) 912C y + Fezc 800 +R 1500 + 727C 0.76 600 0.022 a, Ferrite a + Fec Cementite (Fez) 1000 400 0 (Fe) 2 6 6.70 Composition (wt%C) Adapted from Binary Alloy Phase Diagrams, Vol. 1. 2nd edition, T. B. Massalski (Editor-in-Chief), 1990. Reprinted by permission of ASM International, Materials Park, OH. Phase diagram Fe-Fe3C Phase diagram Fe-Fe3C Percent Fe3c 6 9 3 12 15 Percent Fezc 6 9 3 12 15 HRC 80 320 35 Spheroidite 70 30 280 60 25 HRB 100 240 Fine pearlite 20 50 Coarse pearlite Coarse pearlite Brinell hardness number Ductility (% RA) 200 40 Rockwell hardness 160 30 Spheroidite 80 20 Fine pearlite 120 70 60 10 80 0 0.2 0.4 0.6 0.8 1.0 0.2 0.4 0.6 0.8 1.0 Composition (wt%C) Composition (wt% C) (b) (a) Figure 10.31 (a) & (b) 800 -Eutectoid temperature 1400 700 A 1200 P 600 1000 500 B Temperature (C) 800 400 Temperature (F) 300 600 M(start) 200 50% M + A 400 M(50%) M(90%) 100 200 0 10-1 10 102 103 104 105 Time (s) Figure 10.23 b. (1 point) What is the composition (wt% C) for this eutectoid steel? (don't forget the unit!) (1 point) Also, how do you determine this? If referring to a figure, be specific which figure. c. (2 points) What is the ductility (% RA) of this steel? (1 point) Also, how do you determine this? If referring to a figure, be specific which figure. d. (7 points) Describe an isothermal heat treatment process step-by-step to obtain this condition (microstructure & ductility) at room temperature, if the microstructure of the as received material is unknown. (Where to start, how to cool, where to hold for how long, what is the tempering condition, etc.) If referring to a figure, be specific which figure