Ultrastrong steel strengthened by multiple shearable nanostructures  

作　　者：L.J.Wang S.H.Jiang B.Peng B.H.Bai X.C.Liu C.R.Li X.J.Liu X.Y.Yuan H.H.Zhu Y.Wu H.Wang X.B.Zhang Z.P.Lu 

机构地区：[1]Beijing Advanced Innovation Center for Materials Genome Engineering,State Key Laboratory for Advanced Metals and Materials,University of Science and Technology Beijing,Beijing 100083,China [2]Institute of Metals,College of Materials Science and Engineering,Changsha University of Science and Technology,Changsha 410114,China [3]School of Materials Science and Engineering,University of Science and Technology Beijing,Beijing 100083,China

出　　处：《Journal of Materials Science & Technology》2023年第30期245-257,共13页材料科学技术（英文版）

基　　金：This research was supported by the National Key Research and Development Program of China(nos.2022YFB3705201 and 2022YFB4602101);National Natural Science Foundation of China(nos.51971018,U20B2025,11790293,52225103,51871016,51971017,52071024,52271003);the Funds for Creative Research Groups of NSFC(51921001);Projects of International Cooperation and Exchanges of NSFC(nos.51961160729,52061135207);111 Project(no.BP0719004);Program for Changjiang Scholars and In-novative Research Team in University of China(no.IRT_14R05),and the Fundamental Research Funds for the Central Universities of China:FRF-MP-20-43Z(JSH),FRF-TP-22-130A1(ZXB),FRF-TP-22-001C2(WY).

摘　　要：Precipitation of multiple strong nanoprecipitates is crucial for the development of ultrahigh-strength structural materials with a strength of 2.5 GPa or above.Nevertheless,the ductility usually loses rapidly with strength due to limited dislocation mobility and high cracking tendency if coarse non-deformable precipitates are employed.Herein,we report a 2.5 GPa maraging steel strengthened by an ultrahigh den-sity of intermeshed shearable nanostructures consisting of Ni(Al,Fe)nanoprecipitates and Mo-rich(∼30 at.%)disordered clusters,both of which assume coherent interfaces.The fully coherent B2-Ni(Al,Fe)par-ticles precipitate in an extremely fast fashion,effectively accelerating local aggregation of low-diffusivity Mo atoms and promoting the formation of Mo-rich clusters surrounding them.This elemental partition was found to be further enhanced by Co addition via depleting both residual Al and Mo within the ma-trix,leading to the formation of copious yet fine intermeshed nanostructures.During plastic deformation,the interlocked nanostructures not only enhance local cutting stress by combining long-range elastic and short-range chemically ordering effects but also improve dislocation activity and resist shear-induced plastic instability.The multiple shearable nanostructures endow decent ductility(>6%)of the 2.5 GPa steel,suggesting a new paradigm for designing ultrastrong steels.

关 键 词：Ultrahigh strength steel CO-PRECIPITATION Deformable nanostructures Mechanical properties Nanoprecipitates 

分 类 号：TG1[金属学及工艺—金属学]