for a 31. (5 poisbs) Consider the TTT diagram and phase diagram shown below for

Question

for a 31. (5 poisbs) Consider the TTT diagram and phase diagram shown below for the phase diagram and TIT diagram are aligacd The temperature axes Fete (o) You are in charge of heat treating this steel. Your solution annealing furnace is set at a temperature of 800 C. Which of the following heat treatment sequences will produce Bainite? (a) Rapidly cool from 800°C to 650°C (in less than 0.5 seconds) and hold at 650PC for 10,000 seconds followed by water quenching. (b) Rapidly cool tom 800°C to 500°C (in less than 0.3 seconds) and hold at 500 for 10,000 seconds followed by water quenching (e) Rapidly cool from 800 C to 100°C (in less than 0.3 seconds) and hold at 100°C for d) Rapidly cool from 800°C to 100°C (in less than 0.5 seconds), re-heat to 350°C and hold (e) Rapidly cool from 800°C to 300°C (in less tham 0.5 seconds) and hold at 300 C for 10,000 seconds followed by water quenching. at 350 °C for 10,000 seconds followed by water quenching 10,000 scconds followed by water quenching. 13

Explanation / Answer

Correct option is e)

As can be seen from TTT graph. During Instant cooling from 800 to 300 degree C, Y will come to 300 degree celcius. Upon slow cooling for 10^4 seconds at 300 degree celcius, Phase transformation will occur in the horizontal line towards right at 300 degree C in TTT graph. As can be seen from graph, phase at that time will be of Baisite

Related Questions

Navigate

• Browse (All)
• Browse F
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.