Microstructural banding of a hot-rolled HY-100 steel plate was accentuated
by cooling slowly from the austenite region, which resulted in alternating
layers of soft, equiaxed ferrite, and hard "granular ferrite." The segregat
ion of substitutional alloying elements such as Ni and Cr was identified as
the main cause for the microstructural banding. Such banding induces aniso
tropic flow behavior at large strains, with deformation constrained by "pan
cake-shaped" bands of the hard granular ferrite. Tensile tests of circumfer
entially notched HY-100 specimens were performed in order to explore the st
ress dependence of failure in the slow-cooled as well as the quenched and t
empered conditions. The failure behavior of the slow-cooled, microstructura
lly banded material exhibited a pronounced susceptibility to a void-sheet m
ode of failure. However, the absence of carbides within the equiaxed ferrit
e delays void coalescence and material failure to higher strains than in a
quenched and tempered microstructure, despite the increased susceptibility
to shear localization.