title: Superstrength of nanograined steel with nanoscale intermetallic precipitates transformed from shock-compressed martensitic steel.
abstract: An increasing number of industrial applications need superstrength steels. It is known that refined grains and nanoscale precipitates can increase strength. The hardest martensitic steel reported to date is C0.8 steel, whose nanohardness can reach 11.9 GPa through incremental interstitial solid solution strengthening. Here we report a nanograined (NG) steel dispersed with nanoscale precipitates which has an extraordinarily high hardness of 19.1 GPa. The NG steel (shock-compressed Armox 500T steel) was obtained under these conditions: high strain rate of 1.2 μs-1, high temperature rise rate of 600 Kμs-1and high pressure of 17 GPa. The mean grain size achieved was 39 nm and reinforcing precipitates were indexed in the NG steel. The strength of the NG steel is expected to be ~3950 MPa. The discovery of the NG steel offers a general pathway for designing new advanced steel materials with exceptional hardness and excellent strength.
authors.affiliation: School of Mechanical, Materials &Mechatronics Engineering, University of Wollongong, NSW 2500, Australia.
authors.forename: Hailiang
authors.initials: H
authors.lastname: Yu
authors.affiliation: Department of Materials Science and Engineering, South University of Science and Technology of China, Shenzhen 518055, China.
authors.forename: Ming
authors.initials: M
authors.lastname: Yan
authors.affiliation: School of Mechanical, Materials &Mechatronics Engineering, University of Wollongong, NSW 2500, Australia.
authors.forename: Cheng
authors.initials: C
authors.lastname: Lu
authors.affiliation: School of Mechanical, Materials &Mechatronics Engineering, University of Wollongong, NSW 2500, Australia.
authors.forename: Anh Kiet
authors.initials: AK
authors.lastname: Tieu
authors.affiliation: School of Mechanical, Materials &Mechatronics Engineering, University of Wollongong, NSW 2500, Australia.
authors.forename: Huijun
authors.initials: H
authors.lastname: Li
authors.affiliation: School of Mechanical, Materials &Mechatronics Engineering, University of Wollongong, NSW 2500, Australia.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Zhu
authors.affiliation: School of Mechanical, Materials &Mechatronics Engineering, University of Wollongong, NSW 2500, Australia.
authors.forename: Ajit
authors.initials: A
authors.lastname: Godbole
authors.affiliation: School of Mechanical, Materials &Mechatronics Engineering, University of Wollongong, NSW 2500, Australia.
authors.forename: Jintao
authors.initials: J
authors.lastname: Li
authors.affiliation: School of Mechanical, Materials &Mechatronics Engineering, University of Wollongong, NSW 2500, Australia.
authors.forename: Lihong
authors.initials: L
authors.lastname: Su
authors.affiliation: Electron Microscope Unit, University of New South Wales, Sydney, NSW 2052, Australia.
authors.forename: Charlie
authors.initials: C
authors.lastname: Kong