Enhanced local deformability in ultra-high strength stainless steel via a short-time annealing

Cold-deformed austenitic stainless steels usually sacrifice deformability for high strength. A short-time annealing at 600 °C for 2 min was conducted on cold-rolled 301 stainless steel, which dramatically improved its local deformability by 270% (from 7.61% to 28%) while maintaining the ultra-high strength level of 2 GPa. Microstructural observation revealed 11.7% reversed austenite formation and a reduction in martensite dislocation density (1.31 × 10¹⁶ to 5.5 × 10¹⁵ m^-2) without recrystallization. The enhanced local deformability is attributed to the synergistic interplay of two key mechanisms: (1) enhanced work-hardening capability due to the formation of martensite produced by cold rolling tempering and (2) the transformation-induced plasticity effect of the reversed austenite, which effectively coordinates localized deformation and suppresses crack nucleation.