Notes:
There are two classical forms upper and lower bainite, depending upon the transformation temperature. A plate of ferrite forms supersaturated in carbon, which can decarburise more or less, depending upon the temperature.
Macroscopically the plates are sub-units of a sheaf of bainite. The sub-unit mechanism was first introduced to explain how the transformation could occur slowly and still be a displacive reaction. Subsequently the sub-units were observed experimentally.