Effect of Austenite Grain Size on the Mechanical Properties in Air-Cooled 0.1C-5Mn Martensitic Steel


Article Preview

In 0.1C-5Mn steels, 5%Mn addition increases hardening ability and makes 100% martensitic transformation even in air cooling without water quenching. Their Ms and Mf temperatures are in the range of 350-250°C, and subzero treatment is not needed. This makes it possible to measure Ms and Mf temperatures accurately by dilatometry. Utilizing a newly developed experimental technique that makes it possible to examine phase transformation behavior and conduct tensile testing with the same specimen, we examined these relationships with identical specimens and obtained the following results. Ms temperature decreases as much as 40 K with a decrease in austenite grain size from 254 to 30 m. Regarding martensite structure, the packet size and the block length decrease, while the lath width does not change, with the refinement of austenite grain size by about one tenth. True stress - true strain curves obtained up to fracture elucidates that the austenite refinement substantially improves true fracture strength and greatly increases true fracture strain of martensite, potentially invalidating the conventional concept of a trade-off balance between strength and ductility.



Materials Science Forum (Volumes 783-786)

Main Theme:

Edited by:

B. Mishra, M. Ionescu and T. Chandra




T. Hanamura et al., "Effect of Austenite Grain Size on the Mechanical Properties in Air-Cooled 0.1C-5Mn Martensitic Steel", Materials Science Forum, Vols. 783-786, pp. 1027-1032, 2014

Online since:

May 2014




* - Corresponding Author

[1] A.S. Sastri and D.R.F. West, J. of the Iron and Steel Institute (1965) 138.

[2] T. Maki and I. Tamura, Tetsu-to-Hagane 67 (1981) 852-866.

[3] S. Takaki, K. Furunaga, J. Syarif and T. Tshuchiyama, MaterialsTransactions, 45 (2004) 2245-2251.

[4] K. Tomimura, S. Takaki, S. Tanimoto and Y. Tokunaga, ISIJ Int. 31 (1991) 721-727.

[5] T. Furukawa and O. Matsumura, Netsu Shori, 37 (4) (1997), 204.

[6] H. Takechi, JOM December 2008 P. 22.

[7] T. Hanamura, S. Torizuka, A. Sunahara, M. Imagumbai and H. Takechi, ISIJ Int. 51 (2011) 685-687.

DOI: https://doi.org/10.2355/isijinternational.51.685

[8] S. Torizuka and T. Hanamura, Ferrum Vol. 17 (2012) 852-857.

[9] H-S. Yang and H.K.D.H. Bhadeshia, Scripta Materialia, 60 (2009), 493-495.

[10] N. Murayama, S. Torizuka, T. Hanamura and M. Imagumbai: Tetsu-to-Hagané, 98 (2012), 415-424.

[11] F.A. McClintock, Ed. by H. Liebowitz, FractureIII, Academic Press (1971).

[12] J.W. Morris Jr., C.S. Lee and Z. Guo, ISIJ Int., 43 (2003), 410.

[13] A.A. Griffith: Philos. Trans. R. Soc., A221 (1920), 163.

[14] T. Hanamura, F. Yin and K. Nagai, ISIJ Int. 44 (2004), 610-617.

[15] T. Hanamura, M. Zhao, Y. Fuxing, H. Qui and K. Nagai, Tetsu-to-Hagané, 95 (2009), 71.

[16] T. Inoue, S. Matsuda, Y. Okamura and K. Aoki, Trans. ISIJ, 11 (1970), 36.

[17] K. Terasaki and H. Ohtani, Tetsu-to-Hagané, 58 (1972), 436.

Fetching data from Crossref.
This may take some time to load.