On dislocation accumulation and work hardening in Hadfield steel

Density measurements have been made on specimens of Hadfield steel deformed to various strains in tension and compression to determine values of the dislocation density. The rate of dislocation accumulation is considerably higher than for other face-centred cubic metals reported in the literature. However, the high work hardening rate at true strains above about 0.15 is attributed mainly to mechanical twinning, which contributes about twice the effect of that from dislocation accumulation.