2 shows the optical micrographs of the steel at differently
tempered conditions. All the heat-treated steel samples
show tempered martensitic structure. Scanning electron micrographs
are taken to further examine the microstructural changes
at different tempered conditions, Fig. 3. From SEM micrographs
it is observed that in all the tempered cases the martensitic lath
size and grain size are more or less similar.