Abstract
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.
| Original language | English |
|---|---|
| Pages (from-to) | 1857-1867 |
| Number of pages | 11 |
| Journal | JOM |
| Volume | 66 |
| Issue number | 9 |
| DOIs | |
| Publication status | Published - 2014 Sept |
| Externally published | Yes |
Bibliographical note
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.
ASJC Scopus subject areas
- General Materials Science
- General Engineering