Making ultra-high-yield-strength and high-ductility austenitic stainless steel by grain refinement and regularly arranging Cu-nanoprecipitates

This study achieves an unprecedented combination of ultra-high yield strength (1300 MPa) and high ductility (25%) in austenitic stainless steel (ASS) through grain refinement and innovative Cu microalloying. Unlike conventional random dispersion, nano-scale Cu precipitates form in ordered rows during recrystallization, enabling coherent strengthening (∼300 MPa) without sacrificing ductility. This unique microstructure overcomes the strength-ductility trade-off, outperforming grain-refined ASSs in the literature. The findings reveal a new precipitation mechanism involving periodic nucleation at the moving grain boundary during recrystallization via discontinuous precipitation, offering a scalable strategy for designing high-performance ASS.