Simultaneous improvement of strength and plasticity: Additional work-hardening from gradient microstructure

A gradient structure (GS) in grain size along the radial direction was introduced into Fe-Mn-C twinning induced plasticity (TWIP) steel by the original torsion & annealing treatment. Comparing with the homogeneous structures (HS), GS shows a better mechanical property, evading the strength-ductility trade-off dilemma.286