Study on the Mechanical Stability of Retained Austenite in Cold-Rolled Medium-Mn Steel

Abstract:

The mechanical stability of the retained austenite in the cold-rolled medium-Mn steel was studied. Tensile tests were carried out to measure the mechanical properties of the annealed steel. Scanning electron microscopy was applied to characterize the microstructure evolution during the tensile process; X-ray diffraction analysis was used to determine the residual austenite content in the deformed steel. It was found that the volume fraction of retained austenite gradually decreases with strain .The value of the stability coefficient of retained austenite k was small in the test steel, which indicated high mechanical stability of retained austenite. Due to TRIP effect, the high mechanical stability of the retained austenite strongly delays the onset of necking, which resulted in good comprehensive mechanical properties with ultrahigh strength and plasticity.

• Periodical: Advanced Materials Research (Volume 936)
• Pages: 1283-1289
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.936.1283
• Online since: June 2014
• Authors: Jun Hu*, Wen Quan Cao, Jie Shi, Han Dong
• Keywords: Mechanicl Stability, Retained Austenite, Tensile Test, TRIP Effect, Volume Fraction

References

[1] H.K.D.H. Bhadeshia and D.V. Edmonds, The bainite transformation in a silicon steel, Metall. Trans. A. 10(1997)895-907.

DOI: 10.1007/bf02658309

[2] T. Yokoi, K. Kawasaki, M. Takahashi, K. Koyoma and M. Mizui, Fatigue properties of high strength steels containing retained austenite. JSAE Review. 17. 2(1996)210-212.

DOI: 10.1016/0389-4304(95)00063-1

[3] K. Sugimoto, N. Ushi, M. Kobayashi and S. Hashimoto, Effects of Volume Fraction and Stability of Retained Austenite on Ductility of TRIP-aided Dual-phase Steels, ISIJ. 32(1992)1311-1318.

DOI: 10.2355/isijinternational.32.1311

[4] K. Sugimoto, N. Ushi, M. Kobayashi and S. Hashimoto, Ductility and strain-induced transformation in a high-strength transformation-induced plasticity-aided dual-phase steel, Metall. Trans.A. 23(1992)3085-3091.

DOI: 10.1007/bf02646127

[5] H.C. Chen, H. Era and M. Shimizu, Effect of phosphorus on the formation of retained austenite and mechanical properties in Si-containing low-carbon steel sheet, Metall. Trans.A. 20(1989)437-445.

DOI: 10.1007/bf02653923

[6] C.G. Lee and S.J. Kim, Microstructures and mechanical properties of high strength hot-rolled steel plates containing tramp elements, J. Kor. Inst. Met. Mater. 1998; 36. 7(1998) 1024-1031.

[7] G. Frommeyer, U. Brux, P. Neumann, Supra-Ductile and High-Strength Manganese-TRIP/TWIP Steels for High Energy Absorption Purposes, ISIJ. 43(2003)438-446.

DOI: 10.2355/isijinternational.43.438

[8] K. Sugimoto, B. Yu, Y. Mukai, S. Ikeda, Microstructure and Formability of Aluminum Bearing TRIP-Aided Steels with Annealed Martensite Matrix, ISIJ. 45(2005)1194-1200.

DOI: 10.2355/isijinternational.45.1194

[9] L. Bracke, K. Verbeken, L. Kestens andJ. Penning, Microstructure and texture evolution during cold rolling and annealing of a high Mn TWIP steel, Acta Mater. 57(2009)1512-1524.

DOI: 10.1016/j.actamat.2008.11.036

[10] A. A. Gazder, W. Q. Cao, C. H. J. Davies, E. V. Pereloma, An EBSD investigation of interstitial-free steel subjected to equal channel angular extrusion, Mater. Sci. Eng.A. 497(2008)341-352.

DOI: 10.1016/j.msea.2008.07.030

[11] K.X. Tao, H. Choo, and H.Q. Li, Transformation-induced plasticity in an ultrafine-grained steel: An in situ neutron diffraction study, Appl. Phys. Let. 90(2007)101911 - 101911-3.

DOI: 10.1063/1.2711758

[12] Chang Gil Lee, Sung-Joon Kim, Tae-Ho Lee, Sunghak Lee, Effects of volume fraction and stability of retained austenite on formability in a 0. 1C–1. 5Si–1. 5Mn–0. 5Cu TRIP-aided cold-rolled steel sheet, Mater. Sci. Eng.A. 371(2004)16-23.

DOI: 10.1016/s0921-5093(03)00035-2

[13] X.D. Wang a, B.X. Huang, Y.H. Rong, L. Wang, Microstructures and stability of retained austenite in TRIP steels, Mater. Sci. Eng.A. 438-440(2006)300-305.

DOI: 10.1016/j.msea.2006.02.149

[14] Arif Basuki, Etienne Aernoudt, Influence of rolling of TRIP steel in the intercritical region on the stability of retained austenite, Journal of Materials Processing Technology. 89-90(1999)37-43.

DOI: 10.1016/s0924-0136(99)00037-0

[15] N. H. van Dijk, A. M. Butt, L. Zhao, J. Sietsma, S. E. Offerman, J. P. Wright, S. van der Zwaag, Thermal stability of retained austenite in TRIP steels studied by synchrotron X-ray diffraction during cooling, Acta Mater. 53(2005)5439-5447.

DOI: 10.1016/j.actamat.2005.08.017

[16] V. F. Zackay, E. R. Parker, D. Fahr, R. Busch, The enhancement of ductility in high-strength steels, ASM Trans Quart. 60(1967)252-259.

[17] W.Q. Cao, C. Wang, J. Shi, M.Q. Wang, W.J. Hui, H. Dong, Microstructure and mechanical properties of Fe–0. 2C–5Mn steel processed by ART-annealing, Mater. Sci. Eng. A, 528(2011) 6661-6666.

DOI: 10.1016/j.msea.2011.05.039

[18] H.C. Shin, T.K. Ha and Y.W. Chang, A study on the deformation induced martensitic transformation of 304 stainless steel, J. Kor. Inst. Met. Mater. 34. 12(1996)1550-1557.