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, ...

Changing the carbon content of the alloy changes the microstructure of the pearlite and hence the mechanical properties of the alloy. The vertical alloy composition line on the partial phase diagram ...