An ultra-high-strength 12Mn maraging steel realized via nanoscale heterostructure engineering

摘要

A 12Mn maraging steel Fe-12Mn-5Co-1Ti-1Mo-1Si, strengthened by the Heusler Fe2TiSi phase, was designed with nanoscale heterostructures. When aged at 450 & DEG;C, fine Fe2TiSi particles uniformly precipitate within the martensite lath, contributing as the main strengthening phase. At the same time, a nanoscale austenite layer was observed to grow at the lath interface, significantly toughening the martensite lath matrix. With this hierarchical nano-structure, the super-high tensile strength of -1700 MPa with good elongation of -7 % at break was achieved. Our case uncovers that hierarchical nanoscale heterogeneous microstructure could pave a new path to achieve synergistic improvement of strength and ductility..

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