The eutectoid phase transition in the iron carbon system takes place at 727 C. The three components in equilibrium at this temperature are Austenite, g, with the composition Fe - 0.77 wt % C, Ferrite, ...

When the alloy reaches the eutectoid temperature the untransformed austenite undergoes a transformation to pearlite and the already formed cementite remains unchanged. The microstructure is now a ...