Effects of soaking temperature on the microstructure and mechanical properties of a medium Mn steel for hot/warm forming

Liu，Hui1,2; Li，Jinzhi1; He，Binbin3; Liang，Zhiyuan1

2023-09-01

10.1016/j.jmrt.2023.08.145

Journal of Materials Research and Technology   Impact Factor & Quartile

2238-7854

2214-0697

The increasing demands for better crashworthiness of vehicles require structural components with excellent energy absorption performance and anti-intrusion resistance. Here, we explored the potential of using a medium Mn steel with a 10 wt.% Mn content for hot/warm forming with the aim to produce automotive components with improved strength–ductility combination. The soaking temperature was varied from 670 to 870 °C for tuning the microstructure and the resultant mechanical properties. It is found that a duplex microstructure consisting of ferrite with a high dislocation density and retained austenite with a volume fraction of 53.5% is formed at 720 °C, leading to an exceptional strength–ductility combination (yield strength: 1016 MPa; ultimate tensile strength: 1407 MPa; total elongation: 32.7%). The energy absorbed before fracture is 39.8 GPa·%, which is four times more than that of the widely-used 22MnB5 boron steel. On basis of the experimental results, the effects of soaking temperature on austenite reverse transformation, ferrite recrystallization and martensitic transformation are discussed in depth to provide guidance for optimizing the strength–ductility combination of medium Mn steels processed by hot/warm forming.

Forming Martensitic transformation Medium Mn steel Retained austenite Temperature

SCI

English

Corresponding

National Natural Science Foundation of China-Zhejiang Joint Fund for the Integration of Industrialization and Informatization[52101146];National Outstanding Youth Science Fund Project of National Natural Science Foundation of China[U52071173];

Materials Science ; Metallurgy & Metallurgical Engineering

Materials Science, Multidisciplinary ; Metallurgy & Metallurgical Engineering

WOS:001069612900001

ELSEVIER

2-s2.0-85169792872

Scopus

1.Songshan Lake Materials Laboratory,Dongguan,523808,China
2.Institute of New Materials,Guangdong Academy of Sciences,Guangzhou,510651,China
3.Department of Mechanical and Energy Engineering,Southern University of Science and Technology,Shenzhen,518055,China

Liu，Hui,Li，Jinzhi,He，Binbin,et al. Effects of soaking temperature on the microstructure and mechanical properties of a medium Mn steel for hot/warm forming[J]. Journal of Materials Research and Technology,2023,26:3496-3505.

Liu，Hui,Li，Jinzhi,He，Binbin,&Liang，Zhiyuan.(2023).Effects of soaking temperature on the microstructure and mechanical properties of a medium Mn steel for hot/warm forming.Journal of Materials Research and Technology,26,3496-3505.

Liu，Hui,et al."Effects of soaking temperature on the microstructure and mechanical properties of a medium Mn steel for hot/warm forming".Journal of Materials Research and Technology 26(2023):3496-3505.