Observation of bainite surface reliefs in Fe-C alloy by atomic force microscopy

Atomic force microscopy was employed to study the reliefs (undulations) at the pre-polished surface resulting from the transformation of austenite to bainite in an Fe-0.33C-3.0Mn-2.15Si-1.25Ni (wt.%) alloy. All the surface re liefs observed were shown to be tent-shaped, which was confirmed by the obs ervation of corresponding microstructure of surface relief region after etc hing. The widths of surface reliefs are close to those of the bainite plate s, indicating no significant plastic deformation of adjacent matrix. The me asured surface relief angles agree well with the prediction of diffusion co ntrolled ledgewise growth theory. (C) 2001 Elsevier Science B.V. All rights reserved.