Iron carbide phase diagrams

austenite (gamma iron)

Can allow up to 2% carbon into structure, denser than ferrite, has bigger holes than ferrite therefore can dissolve more carbon, dense structure has more slip planes so easily flattened

Ferrite (alpha iron)

Smaller holes can only dissolve <0.03% carbon, very soft and ductile, softest structure and has low tensile strength

Cementite (Fe3C)

Compound iron carbide contains up to 6.67% carbon very hard and Brittle low tensile strength but high compressive strength hardest structure

Pearlite

Eutectoid composing w 0.83% carbon consists of alternating Bands of ferrite and cementite, contains 87% ferrite