Abstract
Stainless steels exhibit strength-ductility trade-off and insufficient elevated-temperature strength. Here, we report a novel low-cost, cobalt-free, Fe47Cr16Ni26Ti6Al5 medium-entropy stainless steel (MESS) strengthened by high-density coherent L12 nanoprecipitates (NPs) with a high ultimate tensile strength of 1.35 GPa and a total elongation of 36% at room temperature (RT). The ductile L12 NPs working together with the dynamic refinement of the deformation substructures cause an excellent work-hardening ability. Furthermore, the MESS maintains a high yield strength of ∼0.8 GPa at 700°C, which is not only better than many iron-based superalloys and stainless steels but also comparable to some nickel-based superalloys. The steady-state creep rates at 750°C are at least two orders of magnitude lower than those of some nickel-based superalloys and heat-resistant steels. The excellent creep resistance is achieved via the strong interactions between sliding dislocations and stable L12 NPs, which effectively impede the movement of dislocations.
Original language | English |
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Journal | Matter |
DOIs | |
State | Accepted/In press - 2024 |
Funding
The present work was financially supported by the National Natural Science Foundation of China (11935004 and 51971195), the Natural Science Foundation of Hebei Province (E2024203087 and B2024203054), the Youth Fund Project of Science and Technology Research of Hebei Province (QN2020210), and the Research Grants Council of Hong Kong (MHP/064/20). P.K.L. appreciates support from the National Science Foundation (DMR-1611180, 1809640, and 2226508) and the US Army Research Office (W911NF-13\u20131-0438, W911NF-19\u20132-0049, and FA9550-23-1-0503). R.F. thanks the Materials and Engineering Initiative at the Spallation Neutron Source (SNS), Oak Ridge National Laboratory (ORNL), for support. A portion of the current research used resources at SNS, a US Department of Energy (DOE) Office of Science User Facility operated by the ORNL. The authors would like to thank Dr. Dunji Yu for assistance with neutron diffraction experiments, Prof. Mingxin Huang for constructive comments on this paper, and Dr. Zuohua Wang and Dr. Tingting Yang for assistance with TEM characterization. This manuscript has been authored by UT-Battelle, LLC under contract DE-AC05-00OR22725 with the US Department of Energy. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes. The Department of Energy will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan (http://energy.gov/downloads/doe-public-access-plan). T.S. B.S. and S.X. designed the study. B.S. S.X. Z.B. and T.S. supervised K.W. F.M. C.D. and S.D. for the synthesis of specimens and the characterization of microstructures and mechanical properties. K.W. F.M. and Z.Y. conducted XRD, SEM, EBSD, and mechanical property tests. K.W. C.D. and S.D. performed TEM observations and analyses. H.Z. and Y.W. conducted correlative 3D ATP. K.W. X.C. T.S. and P.K.L. analyzed the data and discussed the results. R.F. and K.A. performed the in situ neutron diffraction experiments and analyzed the resultant data. K.W. X.C. R.F. P.K.L. and T.S. wrote the manuscript. All authors discussed the results and commented on the manuscript. The authors declare that they have European, American, Japanese, and Korean patent applications and Chinese patent registrations related to this work. The present work was financially supported by the National Natural Science Foundation of China ( 51971195 and 11935004 ), the Natural Science Foundation of Hebei Province ( B2020203037 ), the Youth Fund Project of Science and Technology Research of Hebei Province ( QN2020210 ), and the Research Grants Council of Hong Kong ( MHP/064/20 ). P.K.L. appreciates support from the National Science Foundation ( DMR-1611180 , 1809640 , and 2226508 ) and the US Army Research Office ( W911NF-13\u20131-0438 and W911NF-19\u20132-0049 ). R.F. thanks the Materials and Engineering Initiative at the Spallation Neutron Source (SNS), Oak Ridge National Laboratory (ORNL), for support. A portion of the current research used resources at SNS, a US Department of Energy (DOE) Office of Science User Facility operated by the ORNL. The authors would like to thank Dr. Dunji Yu for assistance with neutron diffraction experiments, Prof. Mingxin Huang for constructive comments on this paper, and Dr. Zuohua Wang and Dr. Tingting Yang for assistance with TEM characterization. This manuscript has been authored by UT-Battelle, LLC under contract DE-AC05-00OR22725 with the US Department of Energy. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes. The Department of Energy will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan ( http://energy.gov/downloads/doe-public-access-plan ).
Keywords
- creep
- ductility
- high-temperature mechanical property
- MAP 1: Discovery
- medium-entropy alloy
- nanoprecipitates
- plastic deformation
- stainless steel
- strength
- superalloy