Structure of Widmanstatten crystals of ferrite and cementite

Structural analysis of Widmanstatten crystals in ?8, 10, and 5cyrillic letter El carbon steel shows that Widmanstatten ferrite is first deposited at the austenite grain boundaries in cast 50cyrillic letter El steel. The intervals are filled with polyhedral ferrite. The plates of Widmanstatten ferrite and cementite are laminar in structure. The layer thickness is ̃10 3 nm or less. Analysis of the fine structure of the Widmanstatten plates confirms that the layers of plate crystals grow by diffusional migration of steps along their broad boundaries. The laminar structure of the crystals of Widmanstatten ferrite and cementite explains their behavior in plastic deformation of the steel. © 2008 Allerton Press, Inc.