[DIAGRAM] Fe C True Equilibrium Diagram

Review Fe-C phase diagram • 2 important points-Eutectoid (B): γ⇒α+Fe 3C-Eutectic (A): L ⇒γ+Fe 3C Fe 3 C (cementite) 1600 1400 1200 1000 800 600 400 0 12 3 4 5 66.7 L γ (austenite) γ+L γ+Fe 3C α+Fe 3C α + γ L+Fe 3C δ (Fe) C o, wt% C 1148°C T(°C) α 727°C = Teutectoid A R S 4.30 Result: Pearlite = alternating layers of αand Fe.. It increases with increase in carbon % as reflected in Fe-C Equilibrium diagram. It is extremely hard. The hardness and brittleness of cast iron is believed to be due to the presence of the cementite. It decreases tensile strength. This is formed when the carbon forms definite combinations with iron in form of iron carbides which are extremely.

Conventionally, the complete Fe - C diagram should extend from 100% Fe to 100 % carbon (graphite), but it is normally studied upto 6.67% carbon (Fe 3 C) because iron alloys of practical industrial importance contain not more than 5% carbon. Fe - Fe 3 C is not a true equilibrium diagram, since Fe 3 C.. In the first assumption, cast irons can be classified as white cast irons and grey cast irons according to the solidification. In this way, if the solidification followed the metastable equilibrium diagram (Fe-Fe 3 C), a white cast iron would be obtained. If the solidification followed the stable equilibrium diagram (Fe-graphite), a grey cast iron would be obtained.