Question 1 Using the Animated Figure TTT 0.45C, the isothermal transformation di

Question

Question 1 Using the Animated Figure TTT 0.45C, the isothermal transformation diagram for a 0.45 wt% C steel alloy, specify the nature of the final microstructure in terms of the microconstituents present) of a small specimen that has been subjected to the following temperature treatments. In each case assume that the specimen begins at 845 °C and that it has been held at this temperature long enough to have achieved a complete and homogeneous austenitic structure References a) Rapidly cool to 700 degrees C, hold for 100,000 s, then quench to room temperature. Secure https://edugen wileyplus.com/edugen/player/references/index.uni?mode-help References Time # b) Rapidly cool to 625 degrees C, hold for 1 s, then quench to room temperature Temperature = 900 1600 800 Click if you would like to Show Work for this question: 1400 700 1200 By accessing this Question Assistance, you will learn while you earn points based on the Point 600 1000 500 A+B 800 400 M (start) M (50%) M (90% 600 300 200 400 100 10 102 103 104 10%

Explanation / Answer

a) Here the material is isothemally transformed at 700 o C for 100,000 s. By this time all austenite has been transformed to coarse pearlite microstructure. Then it is quenched (high rate of cooling), so it's toughness will be looking by increasing hardness. There us no phase change.

b) By rapidly cooling to 625 o C and holding for 1s, about 40% of austenite has transformed to coarse pearlite. It is then quenched to room temperature, passing through martensite region of formation, the remaining 60%if austenite transforms into martensite. So a 40%pearlite-60%martensite is formed

Related Questions

Navigate

• Browse (All)
• Browse Q
• Subjects

---

---

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