For a $99\mathrm{.}6$ wt$\%$ Fe$-0\mathrm{.}40$ wt$\%$ C steel at a temperature just below the eutectoid, determine the following:

a$)$ The compositions of $F{e}_{3}C$ and ferrite $().$

b$)$ The amount of cementite $($in grams$)$ that forms in $100g$ of steel.

c$)$ The amounts of pearlite and proeutectoid ferrite $()$ in the $100g.$

d$)$ The fraction of eutectoid ferrite

$($e$)$ Microstructure

$C_L,c_0,c_{}$

$C_{},c_0,c_L$

$L=\frac{S}{S+R},S=6\mathrm{.}3$

$=\frac{R}{R+S},\frac{0\mathrm{.}4}{6\mathrm{.}7}$

$($:$C$