Journal de physique iv vol:11 issue:PR8 pages:217-222
This paper aims to give further insights on the changes that are brought on bainite formation by prior hot-deformation. To this end, a thermomechanical treatment was performed on blocks of a 0.4C-1.5Si-1.4Mn steel, The chemistry of this alloy allowed hot-rolling in the full austenitic range up to large reductions without any significant recrystallisation, The deformed plates were then partially transformed to bainite and the resulting microstructures were subjected to investigation. The laths of bainitic ferrite appeared to be grouped in packets in which they exhibit the same crystallographic orientation. When no prior hot-deformation is applied, the bainite packets originating from the same austenite parent grain were randomly distributed. However, severely deformed austenite grains were found to give rise to typical orientations of the bainitic ferrite laths. These results were interpreted in terms of dislocation arrays interacting with a displacive transformation.