This structure makes the alloy more brittle than the eutectoid pearlite structure. The micrograph shows the microstructure for an Fe - 1.4 wt % C steel, the white regions being cementite.

The hypoeutectoid steel is the most ductile and the ductility has decreased by a factor of three for the eutectoid alloy. In hyper-eutectoid alloys the additional, brittle cementite on the pearlite ...