On the microstructure and mechanical properties of an Fe-10Ni-7Mn martensitic steel processed by high-pressure torsion.

Kalahroudi, F.J., Koohdar, H., Jafarian, H., Huang, Y., Langdon, T.G. and Nili-Ahmadabadi, M., 2019. On the microstructure and mechanical properties of an Fe-10Ni-7Mn martensitic steel processed by high-pressure torsion. Materials Science and Engineering: A. (In Press)

Full text available as:

[img] PDF
Kalahroudi-MSE 2019_accepted manuscript.pdf - Accepted Version
Restricted to Repository staff only until 2 February 2020.
Available under License Creative Commons Attribution Non-commercial No Derivatives.

2MB

DOI: 10.1016/j.msea.2019.02.002

Abstract

High-pressure torsion (HPT) processing was applied to an Fe-10Ni-7Mn (wt.%) martensitic steel at room temperature and the grain size was reduced from an initial value of ~5.5 μm to an ultrafine value of ~185 nm for the ferritic phase and around 30 nm for the austenitic phase after 20 HPT turns. The microstructure and mechanical properties of the as-processed material were evaluated using X-ray diffraction (XRD), electron backscatter diffraction (EBSD), field emission scanning electron microscopy (FESEM), microhardness measurements and tensile testing. In addition, annealing of an as-processed specimen was analyzed by differential scanning calorimetry (DSC). The results show that HPT processing increases the hardness and ultimate tensile strength to ~690 Hv and ~2230 MPa, respectively, but the ductility is decreased from ~16.5% initially to ~6.4% and ~3.1% after 10 and 20 turns, respectively. The hardness distributions and EBSD images show that a reasonably homogeneous microstructure is formed when applying a sufficient level of pressure and torsional strain. The DSC results demonstrate that processing by HPT reduces the start and finish temperatures of the reverse transformation of martensite to austenite and there is continuous re-crystallization after the recovery process.

Item Type:Article
ISSN:0921-5093
Uncontrolled Keywords:Fe-Ni-Mn martensitic steel; high-pressure torsion; mechanical properties; microstructural evolution; reverse transformation; severe plastic deformation
Group:Faculty of Science & Technology
ID Code:31724
Deposited By: Unnamed user with email symplectic@symplectic
Deposited On:04 Feb 2019 10:49
Last Modified:04 Feb 2019 10:49

Downloads

Downloads per month over past year

More statistics for this item...
Repository Staff Only -