1. The Fe-C system
Pearlite

2. Pearlite forms by diffusion - takes time
The Fe-C system
Pearlite is two phases
FE + CM
Pearlite forms by diffusion - takes time
See time-temperature-transformation (TTT) curves -
this one for 0.8 w/o C
diffusion rate high,
Grxn low
diffusion rate low,
Grxn high

3. The Fe-C system
Hypoeutectoid steels - cooling from AUS range
Proeutectoid FE
starts to form

4. The Fe-C system
Hypoeutectoid steels - cooling from AUS range
Eutectoid (P) forms

5. Hypoeutectoid steels - cooling from AUS range
The Fe-C system
Hypoeutectoid steels - cooling from AUS range
Proeutectoid FE + P P FE

6. Hypoeutectoid steels - where does C go?
The Fe-C system

7. Hypoeutectoid steels - strength vs P content
The Fe-C system