Improvement of the work hardening rate of ultrafine grained steels through second phase particles

Ultrafine grained steels show little room temperature tensile ductility compared with coarse grained samples of the same compositions. In order to increase the ductility, the work hardening rate of various ultrafine grained steels with different carbon contents was studied. The increase in the amount of finely dispersed cementite particles leads to an improved work hardening rate, which is sufficiently large to balance the negative effect of grain refinement on ductility.