Enhancing strength and ductility in heterolamellar medium-Mn steel through bamboo-like microstructure design

Abstract

Nature has long inspired technological innovations, fostering the rapidly developing field of bionics. Inspired by the microstructure of bamboo, we have developed a bamboo-like structure for steel. This novel steel achieves a tensile strength exceeding 1200 MPa and a uniform elongation nearing 68%, resulting in a product of strength and uniform elongation up to 83 GPa·%. The high strength of the steel is primarily attributed to its ultra-fine lamellar grains. Additionally, the graded occurrence of multiple deformation mechanisms collectively maintains its exceptional work-hardening capability. This study presents a new approach to enhancing the performance of medium-Mn steels.

Keywords

• Heterolamellar microstructure
• bamboo-like steel
• medium-Mn steel
• strength–ductility synergy
• ferrite + austenite