Dear Spyridon Chaskis,

As you have mentioned that lower bainite contains two different types of carbides; one forms between the platelets of bainitic ferrite and the other forms as parallel arrays at about 60° to the axis of the bainite plate. This peculiar mode of precipitation in lower bainitic ferrite may arise because the carbides nucleate at the ferrite/austenite interface, and hence attempt to adopt a unique variant of the orientation relationship, one which gives an optimum match to both the austenite and ferrite with which they are in contact. Another reason is that the carbide precipitation within ferrite laths is influenced by the stresses associated with the displacive growth of lower bainite. Anyway, the carbides within bainitic ferrite laths follow Bagaryatski orientation relationship with the ferrite phase, such as

[0 0 1]Fe3C || [-1 0 1]alpha

[1 0 0]Fe3C || [1 1 1]alpha

[0 1 0]Fe3C || [-1 2 -1]alpha

Dear Spyridon Chaskis,

As you have mentioned that lower bainite contains two different types of carbides; one forms between the platelets of bainitic ferrite and the other forms as parallel arrays at about 60° to the axis of the bainite plate. This peculiar mode of precipitation in lower bainitic ferrite may arise because the carbides nucleate at the ferrite/austenite interface, and hence attempt to adopt a unique variant of the orientation relationship, one which gives an optimum match to both the austenite and ferrite with which they are in contact. Another reason is that the carbide precipitation within ferrite laths is influenced by the stresses associated with the displacive growth of lower bainite. Anyway, the carbides within bainitic ferrite laths follow Bagaryatski orientation relationship with the ferrite phase, such as

[0 0 1]Fe3C || [-1 0 1]alpha

[1 0 0]Fe3C || [1 1 1]alpha

[0 1 0]Fe3C || [-1 2 -1]alpha

I am agree with Arka Manda answer.