An ultrafine-grained steel with an average grain size of about 350 nm was developed. The tensile testing at ambient temperature shows a threefold increase in the yield strength compared to its coarse-grained counterpart. Moreover, the increase in the strength was achieved without the sacrifice of the ductility due to strain-induced martensitic transformation. The evolution of lattice strains and phase fractions of the austenite and martensite phases during the deformation was investigated using in situ neutron diffraction to provide a micromechanical understanding of the transformation-induced plasticity responsible for the combination of high strength and ductility.
Bibliographical noteFunding Information:
This work is supported by the NSF International Materials Institutes (IMI) Program under DMR-0231320. This work has benefited from the use of the Los Alamos Neutron Science Center (LANSCE) at the Los Alamos National Laboratory. LANSCE is funded by the U.S. Department of Energy under Contact No. W-7405-ENG-36.
All Science Journal Classification (ASJC) codes
- Physics and Astronomy (miscellaneous)