Use the TTT diagram below and assume that the initial temperature is 760 ˚C What is the nature of the microstructure, in terms of 1) microconstituents present and 2) approximate percentages of the microconstituents when the specimen is rapidly cooled to 450°C, held for 10 seconds, and then quenched to room temperature?

What is the composition of an iron–carbon alloy for which the fraction of total cementite is 0.10?

Which microstructure is spheroidite?

Compute the rate of a reaction that obeys Avrami kinetics, assuming that the constants n and k have values of 3.385 and 1.162 × 10–9, respectively, for time expressed in seconds.

What is the approximate Brinell Hardness Number for a specimen of a eutectoid iron-carbon alloy (0.76 wt% C) that is first completely transformed to austenite, then cooled to room temperature at 160 oC/s cooling rate (see the attached figures)?

Rank the following iron-carbon alloys and associated microstructures from the hardest to the softest:I. 0.25 wt% C with coarse pearliteII. 0.80 wt% C with coarse pearliteIII. 0.25 wt% C with spheroiditeIV. 0.80 wt% C with fine pearlite

Consider a hypothetical eutectic phase diagram for metals A and B that is similar to that for the lead–tin system (see figure below). Determine the composition of the alloy that consists of the primary beta phase and the eutectic microconstituent (the fraction of the primary beta phase is 0.367).

For cooling of an alloy that is 70wt% Sn-30wt% Pb from 400 C to room temperature, what is the order of phases that you would expect to see?    

What is the nature of the microstructure, in terms of microconstituents present in a specimen with 1.12 wt% C when the specimen is rapidly cooled from 920°C to 600°C, held for 1 second, then cooled to 300°C, held for 10 seconds and quenched to room temperature?

Rank the following iron-carbon alloys and associated microstructures from the softest to the hardest:I. 0.25 wt% C with coarse pearliteII. 0.80 wt% C with BainiteIII. 0.25 wt% C with spheroiditeIV. 0.80 wt% C with fine pearlite