Using the isothermal transformation diagram for a $1\mathrm{.}13$ wt$.\%$ C steel alloy $($given below$),$ determine the final microstructure $($in terms of just the microconstituents present$)$ of a small specimen that has been subjected to the following time$$temperature treatments. In each case assume that the specimen begins at $920$C and that it has been held at this temperature long enough to have achieved a complete and homogeneous austenitic structure. $(8$ points$)($a$)$ Rapidly cool to $250$C$,$ hold for $103$ s$,$ then quench to room temperature. $($b$)$ Rapidly cool to $775$C$,$ hold for $500$ s$,$ then quench to room temperature. $($c$)$ Rapidly cool to $400$C$,$ hold for $500$ s$,$ then quench to room temperature. $($d$)$ Rapidly cool to $700$C$,$ hold at this temperature for $105$ s$,$ then quench to room temperature.$($e$)$ Rapidly cool to $650$C$,$ hold at this temperature for $3$ s$,$ rapidly cool to $400$C$,$ hold for $25$ s$,$ then quench to room temperature. $($f$)$ Rapidly cool to $350$C$,$ hold for $300$ s$,$ then quench to room temperature. $($g$)$ Rapidly cool to $675$C$,$ hold for $7$ s$,$ then quench to room temperature. $($h$)$ Rapidly cool to $600$C$,$ hold at this temperature for $7$ s$,$ rapidly cool to $450$C$,$ hold at this temperature for $4$ s$,$ then quench to room temperature.