Microstructural Evolution of a F138 Austenitic Stainless Steel after Deformation by ECAP and HPT

Abstract:

A F138 austenitic stainless steel was solution heat treated, deformed by equal-channel angular pressing (ECAP) at 25, 100, 200, and 300°C. The equivalent strain was ~0.7 per pass and the applied equivalent strain varied from 0.7 to 4.2. The same material was also deformed by high pressure torsion (HPT) at 300 and 480°C, applying 6GPa pressure and 5 turns; the equivalent strain was ~ 4.5 at r/2 and ~5.2 at the vicinity of the disk edge. Microstructure evolution was observed by transmission electron microscopy (TEM) electron back-scattered diffraction (EBSD) and X ray diffraction. The effect of severe plastic deformation was studied at 25 and 300°C: at 25°C further deformation led to the formation of grain subdivision inside deformation bands and the onset of new grains formation after 2 ECAE passes. The deformation at 300 and 400°C up to 6 passes lead to the formation of recrystallized grains of the order of 100 nm size.

• Periodical: Materials Science Forum (Volumes 775-776)
• Pages: 482-486
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.775-776.482
• Online since: January 2014
• Authors: Andrea Madeira Kliauga, Vitor Luiz Sordi, Sergey V. Dobatkin
• Keywords: 316L Stainless Steel, Equal-Channel Angular Pressing (ECAP), High Pressure Torsion, Microstrucure Evolution

References

[1] T.G. Langdon: Mat. Sci. Forum Vol. 667-669 (2011), p.9.

[2] Y. Iwahashi, J. Wang, Z. Horita, M. Nemoto and T.G. Langdon: Scripta Mat. Vol. 35 (1996), p.143.

[3] A.P. Zhilyaev, G.V. Nurislamova, B.K. Kim, M.D. Baró, J.A. Szpunar and TG Langdon: Acta Materialia Vol. 51 (3) (2003), p.753.

DOI: 10.1016/s1359-6454(02)00466-4

[4] M. Greger, L. Kander, R. Kocich: Arch. of Mat. Sci. Eng, Vol. 31 (2008), p.41.

[5] I.Y. Litovchenko, A.N.T. Tyumentsev, N.V. Shevchenko and A.V. Korzinov: The Physics of Metals and Metallography Vol. 112 (2011), p.412.

[6] S. Scheriau, Z. Zhang, S. Kleber and R. Pippan: Mat. Sci. Eng. A Vol. 528 (2011), p.2776.

[7] F. Liu, Y. Zhang and J.T. Wang: Mat. Sci. Forum Vol. 667-669 (2011), p.319.

[8] Y. Zhang, N.R. Tao and K. Lu: Acta Materialia Vol. 59 (2011), p.6048.