For $Fe-\%0,35C$ alloy, determine;

a$)$ Initial transformation temperature of the austenit

b$)$ Primary microconstituent

c$)$ The amounts and compositions of each phase at $728C$

d$)$ The amounts and compositions of each phase at $726C$

e$)$ The amounts and compositions of microconstituents at $726C$

For $Fe-\%1,15C$ alloy, determine;

a$)$ Initial transformation temperature of the austenit

b$)$ Primary microconstituent

c$)$ The amounts and compositions of each phase at $728C$

d$)$ The amounts and compositions of each phase at $726C$

e$)$ The amounts and compositions of microconstituents at $726C$

Using the isothermal transformation diagram for an iron$-$carbon alloy of eutectoid composition, specify the nature of the final microstructure $($in terms of microconstituents present and approximate percentages$)$ of a small specimen that has been subjected to the following time$-$temperature treatments. In each case assume that the specimen begins at $760C$ and that it has been held at this temperature long enough to have achieved a complete and homogeneous austenitic structure.

a$)$ Rapidly cool to $350C,$ hold for ${10}^{4}s,$ and quench to room temperature.

b$)$ Rapidly cool to $250C,$ hold for $100s,$ and quench to room temperature.

c$)$ Rapidly cool to $650C,$ hold for $20s,$ rapidly cool to $400C,$ hold for ${10}^{3}s,$ and quench to room temperature.

Determine the carbon content of a steel which contain wt$.94\%$ pearlite and wt$.6\%$ cementite at room temperature.