TY - JOUR
T1 - Microstructural Developments and Tensile Properties of Lean Fe-Mn-Al-C Lightweight Steels
AU - Sohn, S. S.
AU - Lee, S.
AU - Lee, B. J.
AU - Kwak, J. H.
N1 - Funding Information:
This work was supported by the Ministry of Knowledge Economy under a Grant No. 10031723-2011-21. The authors would like to thank Mr. Hyuk-Joong Lee of POSTECH for his help with the correlation between alloying effects and microstructural developments.
Publisher Copyright:
© 2014, The Minerals, Metals & Materials Society.
PY - 2014/9
Y1 - 2014/9
N2 - Concepts of Fe-Al-Mn-C-based lightweight steels are fairly simple, but primary metallurgical issues are complicated. In this study, recent studies on lean-composition lightweight steels were reviewed, summarized, and emphasized by their microstructural development and mechanical properties. The lightweight steels containing a low-density element of Al were designed by thermodynamic calculation and were manufactured by conventional industrial processes. Their microstructures consisted of various secondary phases as κ-carbide, martensite, and austenite in the ferrite matrix according to manufacturing and annealing procedures. The solidification microstructure containing segregations of C, Mn, and Al produced a banded structure during the hot rolling. The (ferrite + austenite) duplex microstructure was formed after the annealing, and the austenite was retained at room temperature. It was because the thermal stability of austenite nucleated from fine κ-carbide was quite high due to fine grain size of austenite. Because these lightweight steels have outstanding properties of strength and ductility as well as reduced density, they give a promise for automotive applications requiring excellent properties.
AB - Concepts of Fe-Al-Mn-C-based lightweight steels are fairly simple, but primary metallurgical issues are complicated. In this study, recent studies on lean-composition lightweight steels were reviewed, summarized, and emphasized by their microstructural development and mechanical properties. The lightweight steels containing a low-density element of Al were designed by thermodynamic calculation and were manufactured by conventional industrial processes. Their microstructures consisted of various secondary phases as κ-carbide, martensite, and austenite in the ferrite matrix according to manufacturing and annealing procedures. The solidification microstructure containing segregations of C, Mn, and Al produced a banded structure during the hot rolling. The (ferrite + austenite) duplex microstructure was formed after the annealing, and the austenite was retained at room temperature. It was because the thermal stability of austenite nucleated from fine κ-carbide was quite high due to fine grain size of austenite. Because these lightweight steels have outstanding properties of strength and ductility as well as reduced density, they give a promise for automotive applications requiring excellent properties.
UR - http://www.scopus.com/inward/record.url?scp=84920201006&partnerID=8YFLogxK
U2 - 10.1007/s11837-014-1128-3
DO - 10.1007/s11837-014-1128-3
M3 - Article
AN - SCOPUS:84920201006
SN - 1047-4838
VL - 66
SP - 1857
EP - 1867
JO - JOM
JF - JOM
IS - 9
ER -