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, ...
The properties of steel can be improved in terms of fatigue, weldability, hardness, wear and corrosion resistance, ductility, and tensile strength by either alloy addition or heat treatment processes.