Effect of grain boundary characteristics on the mechanical properties of ultrafine grained steel bar processed by multi-pass warm caliber rolling

摘要

Low angle boundaries developed at low strains due to the interaction of dislocations introduced during the deformation contribute to work hardening. The ultrafine grains that are formed at high strains and surrounded by high angle boundaries contribute to grain size strengthening. While high angle grain boundaries contribute to both strength and toughness, low angle boundaries are harmful to impact properties while they contribute to increase in strength.