1. Using the isothermal transformation diagram below, describe the microstructure present in a eutectoid carbon steel, after each of the following heat treatments. From 800 C: (a) Cool to 450 C and hold for 10 s, cool to 375 C hold for 100 s, quench to 25 C. (b) Cool to 650 C and hold for 300 s, and quench to 25 C. (c) Cool to 720 C and hold for 100 s, quench to 400 C and hold for 200s, and quench to 25 C.

Of the following alloys, pick the one(s) thatmay be strengthened by heat treatment,cold work, or both: R50250 titanium, AZ31Bmagnesium, 6061 aluminum, C51000 phos-phor bronze, lead, 6150 steel, 304 stainlesssteel, and C17200 beryllium copper.

please draw each question on the TTT diagram

The Iron-Carbon system: Phase Diagram 1. You heat treated a 1045 steel plate by heating it to 900°C and slowly cooling it to 725 °C, which is below the eutectoid temperature. What phases are present at 725°C? What are the compositions of each phase at 725°C?  What are the weight fractions of each phase at 725°C?  What microconstituents are present at 725°C? What are the compositions of each microconstituent at 725°C? What are the weight fractions of each microconstituent at 725°C?

Do not give answer in image and hand writing

7. Consider 1.5 kg of a 99.6 wt% Fe-0.4 wt% C steel that is cooled to a temperature just below the eutectoid. (a) How many kilograms of ferrite (a) form? (b) How many kilograms of cementite (Fe;C) form? Include your tie line in the solution. 1600| L 1400 T(°C) 1200 (austenite) y+L 1148°C L+Fe;C 1000 Y + Fe;C 800 727°C 600 a + Fe;C 400 1 2 4 6 6.7 C, wt% C Fe;C (cementite)

a: Quench to from 800oC to 350oC and hold for 102 seconds:b: Quench the alloy to room temperaturec: Reheat the alloy to 700oC and hold for 105 seconds

Using the time-temperature-transformation diagram, what steel phases would you generate by cooling from 900ºC A. quenching in cold water to 520ºC in 0.5 second, holding the sample temperature constant for 1000 seconds at 520ºC, and then quenching to room temperature B. cooling down to room temperature over a period of 2 weeks?

A.2 (i) (ii) Explain how an understanding of the creep failure mechanisms of high temperature nickel alloys has led to alloy and manufacturing developments which have resulted in an increase in the maximum operating temperature of a jet engine turbine blade. If we quench a plain carbon steel we can produce a very strong/hard and yet brittle material. Why does the quench lead to this change in properties, and what subsequent heat treatment would enable us to mostly retain the high strength whilst improving the ductility? Explain the effects of your proposed heat treatments in terms of the phase changes and microstructural features developed at each stage.

Look up the standard aluminum alloy heat treatment temper designations. Use the designations to justify the yield strength behavior of the following aluminum alloys listed in Table 1.2: 2024-T3 vs. 2024-T6 and 7075-T6 vs. 7075-T73.