THIS IS A MATERIALS AND MANUFACTURING QUESTION

7. (2 points) Which of the following heat treatment recipes would result in 100% B? Hint: only one answer is correct, make sure that only B is formed... 800 A 1400 Eutectoid temperature 700 1200 600 *** 1000 500 B 1 800 Temperature (C) Temperature (F) 400 600 300 Mstart) 50% 400 200 MA M(50%) A(90%) 100 200 0 10- 104 10 10-1 10 1 102 Time (s) (A) Heat to 800C; Quench to 600C; Hold for 10 seconds; Quench to room temperature (B) Heat to 800C; Quench to 400C; Hold for 1 second; Quench to room temperature () Heat to 800C; Hold for 10 seconds; Quench to 300C; Hold for 104 seconds; Quench to room temperature (D) Heat to 800C; Quench to 600C; Hold for 5 seconds; Quench to 300C; Hold for 10 seconds; Quench to room temperature (E) Heat to 800C; Quench to 600C; Hold for 50 seconds: Quench to 400C; Quench to room temperature