Question on Pearlite Structure

[processeng01]

Hi,

I would appreciate if anyone can clear up my confusion about the following subject:

We know that during the transformation of austenite to pearlite, nucleation and growth of alternate plates of cementite and ferrite occur within austenite grain boundaries. Are the cementite and ferrite plates actually separate grains? In other words, is there a grain boundary between each Fe3C and ferrite plates?

Thanks for the response in advance.

 

[metengr]

processeng01;
Ferrite and iron carbide (Fe₃C - cementite) are considered phases of steel, which exhibit a specific crystal structure and appear on a phase diagram for carbon steels.

If you review the definition of a grain boundary, the interface surrounding the ferrite grains - ferrite to ferrite or ferrite to cementite would be by definition grain boundaries.