Measured Rockwell hardness data $($C scale$),$ impact energy data, and micrographs will be provided on D$2$L$.$

$(20$ points$)$ For plain carbon steels $1018(0\mathrm{.}18wt\%C),1045(0\mathrm{.}45wt\%C),$ and $1095(0\mathrm{.}95wt\%C),$ that are slowly cooled from $920C$ to $726C.$

Which equilibrium phases are present, what are their compositions, and what is the relative amount of each phase?

Which microconstituents are present in each steel and what is the relative amount of each microconstituent?