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Effect of ferrite grain size on the estimated true stress–true strain relationship up to the plastic deformation limit in low carbon ferrite–cementite steels

Published online by Cambridge University Press:  13 August 2013

Noriyuki Tsuchida ,
Tadanobu Inoue  and
Haruka Nakano
Noriyuki Tsuchida*
Affiliation:
Graduate School of Engineering, University of Hyogo, Himeji, Hyogo, 671-2280, Japan
Tadanobu Inoue
Affiliation:
National Institute for Materials Science, Tsukuba, Ibaraki, 305-0047, Japan
Haruka Nakano
Affiliation:
Graduate Student, University of Hyogo, Himeji, Hyogo, 671-2280, Japan
*
a)Address all correspondence to this author. e-mail: [email protected]
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Abstract

Grain refinement strengthening in low carbon ferrite–cementite steel was investigated using the estimated true stress (σ)–true strain (ε) relationship up to the plastic deformation limit, i.e., just before fracture. Static and stepwise tensile tests were performed using ferrite–cementite (FC) steels with ferrite grain sizes in the range 0.5–34 μm, and the σ–ε relationships up to the plastic deformation limit were estimated by using the Bridgman equation. In the nominal stress–strain curves, the lower yield stress and tensile strength increased and the uniform and total elongations decreased with a decrease in the ferrite grain size. It was found from the σ–ε relationships of the FC steels that grain refinement strengthening up to 0.8 μm can improve σ and ε at the plastic deformation limit. From the scanning electron microscopy observations of the cross-sectional planes parallel to the tensile direction for the FC steels, voids were observed at the interface between ferrite and cementite in the case where the thickness of elongated ferrite came close to the size of the dispersed cementite.

Keywords

stress/strain relationshipgrain sizesteel
Type
Articles
Information
Journal of Materials Research , Volume 28 , Issue 16 , 28 August 2013 , pp. 2171 - 2179
Copyright
Copyright © Materials Research Society 2013 

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References

REFERENCES

Song, R., Ponge, D., Raabe, D., Speer, J.G., and Matlock, D.K.: Overview of processing, microstructure and mechanical properties of ultrafine grained bcc steels. Mater. Sci. Eng., A 441, 1 (2006).CrossRefGoogle Scholar
Song, R., Ponge, D., and Raabe, D.: Mechanical properties of an ultrafine grained C–Mn steel processed by warm deformation and annealing. Acta Mater. 53, 4881 (2005).CrossRefGoogle Scholar
Inoue, T., Yin, F., Kimura, Y., Tsuzaki, K., and Ochiai, S.: Delamination effect on impact properties of ultrafine-grained low-carbon steel processed by warm caliber rolling. Metall. Mater. Trans. A 41, 341 (2010).CrossRefGoogle Scholar
Inoue, T. and Kimura, Y.: Effect of initial notch orientation on fracture toughness in fail-safe steel. J. Mater. Sci. 48, 4766 (2013).Google Scholar
Tsuji, N. and Maki, T.: Enhanced structural refinement by combining phase transformation and plastic deformation in steels. Scr. Mater. 60, 1044 (2009).CrossRefGoogle Scholar
Lee, T., Park, C-H., Lee, D-L., and Lee, C.S.: Enhancing tensile properties of ultrafine-grained medium-carbon steel utilizing fine carbides. Mater. Sci. Eng., A 528, 6558 (2011).CrossRefGoogle Scholar
Tomota, Y., Narui, A., and Tsuchida, N.: Tensile behavior of fine-grained steels. ISIJ Int. 48, 1107 (2008).CrossRefGoogle Scholar
Sharon, J.A., Padilla, H.A. II, and Boyce, B.L.: Interpreting the ductility of nanocrystalline metals. J. Mater. Res. 28, 1539 (2013).CrossRefGoogle Scholar
Cheng, S., Chooa, H., Zhao, Y.H., Wang, X-L., Zhu, Y.T., Wang, Y.D., Almer, J., Liaw, P.K., Jin, J.E., and Lee, Y.K.: High ductility of ultrafine-grained steel via phase transformation. J. Mater. Res. 23, 1578 (2008).CrossRefGoogle Scholar
Petch, N.J.: The cleavage strength of polycrystals. J. Iron Steel Inst. 174–175, 25 (1953).Google Scholar
Hall, E.O.: The deformation and ageing of mild steel: III discussion of results. Proc. Phys. Soc. London, Sect. B 64, 747 (1951).CrossRefGoogle Scholar
Petch, N.J.: The ductile-brittle transition in the fracture of α-iron: I. Philos. Mag. 3, 1089 (1958).CrossRefGoogle Scholar
Ohmori, A., Torizuka, S., and Nagai, K.: Strain-hardening due to dispersed cementite for low carbon ultrafine-grained steels. ISIJ Int. 44, 1063 (2004).CrossRefGoogle Scholar
Torizuka, S., Muramatsu, E., Murty, S.V.S.N., and Nagai, K.: Microstructure evolution and strength-reduction in area balance of ultrafine-grained steels processed by warm caliber rolling. Scr. Mater. 55, 751 (2006).CrossRefGoogle Scholar
Tsuchida, N., Masuda, H., Harada, Y., Fukaura, K., Tomota, Y., and Nagai, K.: Effect of ferrite grain size on tensile deformation behavior of a ferrite-cementite low carbon steel. Mater. Sci. Eng., A 488, 446 (2008).CrossRefGoogle Scholar
Okitsu, Y., Takata, N., and Tsuji, N.: Dynamic deformation behavior of ultrafine-grained iron produced by ultrahigh strain deformation and annealing. Scr. Mater. 64, 896 (2011).CrossRefGoogle Scholar
Park, K-T., Lee, Y.K., and Shin, D.H.: Fabrication of ultrafine grained ferrite/martensite dual phase steel by severe plastic deformation. ISIJ Int. 45, 750 (2005).CrossRefGoogle Scholar
Calcagnotto, M., Adachi, Y., Ponge, D., and Raabe, D.: Deformation and fracture mechanisms in fine- and ultrafine-grained ferrite/martensite dual-phase steels and the effect of aging. Acta Mater. 59, 658 (2011).CrossRefGoogle Scholar
Calcagnotto, M., Ponge, D., and Raabe, D.: Effect of grain refinement to 1 μm on strength and toughness of dual-phase steels. Mater. Sci. Eng., A 527, 7832 (2010).CrossRefGoogle Scholar
Calcagnotto, M., Ponge, D., and Raabe, D.: Orientation gradients and geometrically necessary dislocations in ultrafine grained dual-phase steels studied by 2D and 3D EBSD. Mater. Sci. Eng., A 527, 2738 (2010).CrossRefGoogle Scholar
Tsuchida, N., Tomota, Y., and Nagai, K.: High-speed deformation for an ultrafine-grained ferrite-pearlite steel. ISIJ Int. 42, 1594 (2002).CrossRefGoogle Scholar
Miyata, K., Wakita, M., Fukushima, S., and Tomida, T.: Microstructures and properties of ultrafine grained C-Mn steel sheets by super short interval multi-pass rolling. Proceedings of the 2nd International Symposium on Steel Science (ISSS-2009), 2009; p. 115.Google Scholar
Dieter, G.E.: Mechanical Metallurgy (McGraw-Hill, London, 1988), pp. 291–295.Google Scholar
Bridgman, P.W.: Studies in Large Plastic Flow and Fracture (McGraw-Hill, New York, 1952), pp. 9–37.Google Scholar
Bridgman, P.W.: The stress distribution at the neck of a tension specimen. Trans. ASM. 32, 553 (1944).Google Scholar
Marshall, E.R. and Shaw, M.C.: The determination of flow stress from a tensile specimen. Trans. ASM. 44, 705 (1952).Google Scholar
Kuwamura, H. and Yamamoto, K.: Criterion for ductile crack initiation in structural steels under triaxial stress state. J. Struct. Eng. 477, 129 (1995).Google Scholar
Ono, T., Sato, A., Yokokawa, T., and Aikawa, N.: The criterion for ductile crack initiation in structural steels. J. Struct. Eng. 565, 127 (2003).Google Scholar
Hancock, J.W. and Mackenzie, A.C.: On the mechanisms of ductile failure in high-strength steels subjected to multi-axial stress-states. J. Mech. Phys. Solids 24, 147 (1976).CrossRefGoogle Scholar
Lankford, G. and Cohen, M.: Strain hardening of iron by severe plastic deformation. Trans. Am. Soc. Met. 62, 623 (1969).Google Scholar
Inoue, T., Yin, F., and Kimura, Y.: Strain distribution and microstructural evolution in multi-pass warm caliber rolling. Mater. Sci. Eng., A 466, 114 (2007).CrossRefGoogle Scholar
Tsuchida, N., Inoue, T., and Enami, K.: Estimations of the true stress and true strain until just before fracture by the stepwise tensile test and Bridgman equation in various metals and alloys. Mater. Trans. 53, 133 (2012).CrossRefGoogle Scholar
Enami, K. and Nagai, K.: Evaluation of true stress-true strain relationship after local necking by stepwise tensile test. Tetsu-to-Hagane 91, 712 (2005).CrossRefGoogle Scholar
MacGregor, C.W.: The true stress-strain tension test – its role in modern materials testing part I. J. Franklin Inst. 238, 111 (1944).Google Scholar
Hollomon, J.H.: Tensile deformation. Trans. AIME 162, 268 (1945).Google Scholar
Inoue, T. and Kinoshita, S.: Observations of ductile fracture processes and criteria of void initiation in spheroidized and ferrite/pearlite steels. Tetsu-to-Hagane 62, 875 (1976).CrossRefGoogle Scholar
Inoue, T. and Kinoshita, S.: Initiation of ductile fracture voids in a spheroidized steel. J. JSTP 14, 291 (1973).Google Scholar
Kozasu, I., Shimizu, T., and Kubota, H.: On the effect of nonmetallic inclusions on ductility and toughness of structural steels. Tetsu-to-Hagane 57, 2029 (1971).CrossRefGoogle Scholar