Influence of Coiling on Microstructural Evolution and Mechanical Properties of Strip-Cast Low-Carbon Low-Niobium Steel

Abstract:

As-cast low-carbon low-niobium steels fabricated by direct strip casting (DSC) were treated by simulated coiling in the lab. Coiling temperatures were carefully selected: (1) 900 ̊C (in the austenite); (2) 700 ̊C (during the austenite-to-ferrite transformation); (3) 650 ̊C (in the ferrite). Optical microscopy and transmission electron microscopy were used to examine the microstructure constituents and the precipitates. Mechanical properties were evaluated by Vickers macrohardness measurements. The results show that coiling treatment has a strong influence on the final microstructure and mechanical properties, thus highlighting the necessity to carefully design the coiling treatment. In addition, the differences in hardness for the three coiling temperatures derive from a complex combination of different strengthening mechanisms.

• Periodical: Materials Science Forum (Volume 879)
• Pages: 1182-1187
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.879.1182
• Online since: November 2016
• Authors: Lu Jiang*, Thomas Dorin, Ross Marceau, Nicole Stanford, Peter Hodgson
• Keywords: Direct Strip Casting, Hardening Mechanisms, Low Carbon Steel, Microstructure, Precipitation

References

[1] R. Kopp, F. Hagemann, L. Hentschel, J. Schmitz, D. Senk, Thin-strip casting—modelling of the combined casting/metal-forming process , Journal of Materials Processing Technology, 80 (1998) 458-462.

DOI: 10.1016/s0924-0136(98)00199-x

[2] N. Zapuskalov, Comparison of continuous strip casting with conventional technology, ISIJ international, 43 (2003) 1115-1127.

DOI: 10.2355/isijinternational.43.1115

[3] M. Ferry, Direct strip casting of metals and alloys, Woodhead Publishing, (2006).

[4] Y. Funakawa, T. Shiozaki, K. Tomita, T. Yamamoto, E. Maeda, Development of high strength hot-rolled sheet steel consisting of ferrite and nanometer-sized carbides, ISIJ international, 44 (2004) 1945-(1951).

DOI: 10.2355/isijinternational.44.1945

[5] R. Misra, H. Nathani, J. Hartmann, F. Siciliano, Microstructural evolution in a new 770MPa hot rolled Nb–Ti microalloyed steel, Materials Science and Engineering: A, 394 (2005) 339-352.

DOI: 10.1016/j.msea.2004.11.041

[6] T. Dorin, N. Stanford, A. Taylor, P. Hodgson, Effect of Cooling Rate on Phase Transformations in a High-Strength Low-Alloy Steel Studied from the Liquid Phase, Metall and Mat Trans A, 46 (2015) 5561-5571.

DOI: 10.1007/s11661-015-3173-0

[7] Q. Yong, Secondary phases in steels, Metallurgical Industry Press, Beijing, (2006).

[8] J.H. Jang, Y. -U. Heo, C. -H. Lee, H.K.D.H. Bhadeshia, D. -W. Suh, Interphase precipitation in Ti–Nb and Ti–Nb–Mo bearing steel, Materials Science and Technology, 29 (2013) 309-313.

DOI: 10.1179/1743284712y.0000000131

[9] J.J. Hoyt, The velocity of plate precipitates growing by the ledge mechanism, Acta Materialia, 61 (2013) 4953-4960.

DOI: 10.1016/j.actamat.2013.04.051

[10] F.B. Pickering, Physical metallurgy and the design of steels, Applied Science Publishers, (1978).

[11] H. -J. Kestenbach, S. Campos, E. Morales, Role of interphase precipitation in microalloyed hot strip steels, Materials science and technology, 22 (2006) 615-626.

DOI: 10.1179/026708306x81487

[12] J.T. Busby, M.C. Hash, G.S. Was, The relationship between hardness and yield stress in irradiated austenitic and ferritic steels, Journal of Nuclear Materials, 336 (2005) 267-278.

DOI: 10.1016/j.jnucmat.2004.09.024

[13] E.J. Pavlina, C.J. Van Tyne, Correlation of yield strength and tensile strength with hardness for steels, J. of Materi Eng and Perform, 17 (2008) 888-893.

DOI: 10.1007/s11665-008-9225-5

[14] A. E-112, Standard test methods for determining average grain size, ASTM International USA, (2010).