The development of ultrastrong maraging stainless steels(MSSs)is always in high demand.However,traditional high-strength MSSs generally exhibit early plastic instability with a low uniform strain since the precipitate...The development of ultrastrong maraging stainless steels(MSSs)is always in high demand.However,traditional high-strength MSSs generally exhibit early plastic instability with a low uniform strain since the precipitated nanoparticles are non-coherent with the body-centered-cubic(BCC)lath martensitic matrix.Here,we design a novel ultrahigh strength MSS(Fe-5.30 Cr-13.47 Ni-3.10 Al-1.22 Mo-0.50 W-0.23 Nb-0.03 C-0.005 B,wt.%)using a cluster formula approach.A fabulous microstructure consisting of a uniform distribution of high-density coherent B2-Ni Al nanoprecipitates(3-5 nm)in BCC martensitic matrix was successfully obtained.This alloy has not only an exceedingly high ultimate tensile strength of 2.0 GPa,but also a decent uniform elongation of 4.2%-5.1%,which is almost triple of the value observed in existing MSSs.We present an in-depth discussion on the origins of ultrahigh strength and uniform plastic strain in the new alloy to validate our design strategy and further offer a new pathway to exploit highperformance MSSs.展开更多
基金supported by the National Natural Science Foundation of China[grant numbers 91860108,U1867201]Natural Science Foundation of Liaoning Province of China[grant number 2019-KF-05-01]the Fundamental Research Funds for the Central Universities[grant number DUT19LAB01]。
文摘The development of ultrastrong maraging stainless steels(MSSs)is always in high demand.However,traditional high-strength MSSs generally exhibit early plastic instability with a low uniform strain since the precipitated nanoparticles are non-coherent with the body-centered-cubic(BCC)lath martensitic matrix.Here,we design a novel ultrahigh strength MSS(Fe-5.30 Cr-13.47 Ni-3.10 Al-1.22 Mo-0.50 W-0.23 Nb-0.03 C-0.005 B,wt.%)using a cluster formula approach.A fabulous microstructure consisting of a uniform distribution of high-density coherent B2-Ni Al nanoprecipitates(3-5 nm)in BCC martensitic matrix was successfully obtained.This alloy has not only an exceedingly high ultimate tensile strength of 2.0 GPa,but also a decent uniform elongation of 4.2%-5.1%,which is almost triple of the value observed in existing MSSs.We present an in-depth discussion on the origins of ultrahigh strength and uniform plastic strain in the new alloy to validate our design strategy and further offer a new pathway to exploit highperformance MSSs.
