Effects of the strain rate on the tensile properties of a TRIP-aided duplex stainless steel

Factors influencing the strain-rate dependence of the tensile properties of TRIP-aided lean duplex stainless steel were investigated by employing several characterization techniques of EBSD, TEM, and nanoindentation. The steel exhibited excellent tensile strength over 800MPa and elongation, which ex...

Full description

Saved in:
Bibliographic Details
Published in:Materials science & engineering. A, Structural materials : properties, microstructure and processing Structural materials : properties, microstructure and processing, 2016-06, Vol.666, p.280-287
Main Authors: Choi, Jeom Yong, Lee, Jaeeun, Lee, Keunho, Koh, Ji-Yeon, Cho, Jae-Hyung, Han, Heung Nam, Park, Kyung-Tae
Format: Article
Language:English
Subjects:
Adiabatic flow
Adiabatic heating
Austenite
Duplex stainless steel
Ferrite
Heating
Partitioning
Strain
Strain partitioning
Strain rate
Tensile deformation
Tensile properties
Transformation induced plasticity
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Factors influencing the strain-rate dependence of the tensile properties of TRIP-aided lean duplex stainless steel were investigated by employing several characterization techniques of EBSD, TEM, and nanoindentation. The steel exhibited excellent tensile strength over 800MPa and elongation, which exceeded 70% at a strain rate of 10−3s−1 due to strain-induced martensitic transformation (SIMT), but both values decreased considerably with an increase in the strain rate. The hardness and the maximum shear stress for dislocation nucleation of the austenite were found to be higher than those of the ferrite by sub-grain scale nanoindentation tests. As a result, strain partitioning to the ferrite rather than the austenite was more significant from an early stage of deformation, suppressing the SIMT in the austenite. An EBSD strain analysis on the intra- and inter-grain scale revealed that this strain partitioning became more pronounced as the strain rate increased. Adiabatic heating, which induces austenite stabilization, also became more significant as the strain rate increased. Therefore, the present results indicate that the diminishing TRIP effects at high strain rates can be attributed to preferential strain partitioning to the soft ferrite phase from an early stage of deformation, as well as adiabatic heating.
ISSN:0921-5093
1873-4936
DOI:10.1016/j.msea.2016.04.047