  The present study evidences the role of ferrite grain size distributions on
the occurrence of void initiation in a low carbon steel. Various
thermomechanical treatments were done to create ultrafine, bimodal and coarse
range of ferrite grain distributions. A two parameter characterization of
probable void initiation sites is proposed; elastic modulus difference and
difference in Schmid factor of the grains surrounding the void. All
microstructures were categorized based on the ability to ease or resist void
nucleation. For coarse grains, elastic modulus difference as well as the Schmid
factor difference is highest, intermediate for ultrafine and lowest for bimodal
microstructure.
