Work-hardening of ferrite and microstructure-based modelling of its mechanical behaviour under tension

Current work-hardening theories have mainly focused on centred cubic structures, e.g. copper and aluminium, and no particular attention has been paid to body-centred cubic materials such as ferrite. This research investigates the work-hardening at room temperature of a set of extra-low and ultra-low carbon steels deformed under tension. Within the homogeneous deformation range, from the end of yield point elongation to the onset of necking, the work-hardening rate of ferrite decreases with stress (strain). A one-parameter microstructure-based model has been applied to predict the mechanical behaviour of ferrite. This model provides a simple tool capable of prediction with only simple input parameters: steel composition and ferrite grain size.