Document Type : Original Reaearch Article

Authors

1 science and engineering, nanotechnology and advanced materials department, Materials and Energy Research Center, Karaj, Iran.

2 materials science and engineering, Materials and Energy Research Center, Karaj, Iran.

3 materials science and engineering, Shahroud University of Technology, Shahroud, Iran.

Abstract

Carbide free bainitic steel, so called supper bainitic or nano-structured bainitic steel has attracted considerable attentions due to its remarkable combination of strength and ductility. Unfortunately, the effect of prior austenite grain size has not been investigated for the low carbon nano-structured bainitic steels. In this research, attempts were made to understand the effect of prior austenite grain size effect on the microstructure of carbide free medium carbon bainitic steel. The steel was cast by using induction furnace under argon gas atmosphere. The ingot was electro-slag-remelted (ESR) to obtain clean steel followed by hot rolling.

Keywords

1. Garcia-Mateo, C., Caballero, F.G., and Bhadeshia, H.K.D.H., Acceleration of Low-temperature Bainite, ISIJ International, 2003, 43(11), 1821-1825.
.2. Garcia-Mateo, C., Caballero, F.G.,  and Bhadeshia, H.K.D.H., Mechanical Properties of Low Temperature Bainite, Materials Science Forum, 2005, 500-501, 495-502.
.3. Caballero, F.G., Bhadeshia, H.K.D.H., Mavella, K.J.A., Jones, D.G., and Brown, P., Very Strong Low Temprature Bainite, Material Science and Technology, 2002, 18, 279-284.
4. Garcia-Mateo, C., Peet, M., Caballero, F. G., and Bhadeshia, H.K.D.H.,  Tempering of hard mixture of bainitic ferrite and austenite, Materials Science and Technology, 2004, 20, 814-818.
5. Bhadeshia, H.K.D.H., Bainite in steels, second editin, London: IOM Communications Ltd, 2001.
6. Caballero, F.G., and Bhadeshia, H.K.D.H.,  Very Strong Bainite, Solid State and Material Science, 2004, 8, 251-257.
7. Garcia-Mateo, C., Caballero, F.G., and Bhadeshia, H.K.D.H., Low temperature bainite, Journal de physique colloque , 2003, 112, 1238-1343.
8. Garcia-Mateo, C., Caballero, F.G., and Bhadeshia, H.K.D.H., Development of Hard Bainite, ISIJ International, 2003, 43(8),1238-1243.
9. Bhadeshia, H.K.D.H., and Edmonds, D.V., Bainite in silicon steels: a new composition property approach I, Metal Science, 1983, 17, 411-419.
10. Wang, T.S., Yang, J., Shang, C.J., Li, X.Y., Zhang, B., and Zhang, F.C. Microstructures and impact toughness of low-alloy high-carbon steel austempered at low temperature, Scripta Materialia, 2009, 61, 434–437.
11. Caballero, F.G., Chao, J., Cornide, J., García-Mateo, C., Santofimia, M.J., Capdevila, C., Toughness deterioration in advanced high strength bainitic steels," Materials Science and Engineering A, 2009, 525, 87–95.
12. Bhadeshia, H.K.D.H.,  High Performance Bainitic Steels, Material Science Forum, 2005, 500-501, 63-74.
13. Lan, L.Y.,  Qiu, C.L., Zhao, D.W., Gao, X.H.,  and Du, L. X., Effect of austenite grain size on isothermal bainite transformation in low carbon microalloyed steel, Materials Science and Technology, 2011, 27(11), 1657-1663.
14. Jiang, T., Liu, H., Sun, J., Guo, S., and Liu, Y., Effect of austenite grain size on transformation of nanobainite and its mechanical properties, Materials Science and Engineering A, 2016, 666, 207-213.
15. Hu, F., Hodgson, P.D., and Wu, K.M., Acceleration of the super bainite transformation through a coarse austenite grain size, Materials Letters, 2014, 122, 240–243.
16. م. ع. گلعذار، اصول و کاربرد عملیات حرارتی فولادها و چدنها، اصفهان: دانشگاه صنعتی اصفهان، چاپ چهارم، 1375.
17. Verhoeven, J.D., steel metallurgy for the non-metallurgist, Materials Park, Ohio 44073-0002: ASM International, 2007.
18. Avishan, B., Mateo, C.G., Yazdania, S., and Caballero, F.G., Retained austenite thermal stability in a nanostructured bainitic steel, Materials Characterization, 2013, 81, 105 –110.
19. Huang, Y., Zhao, A-m., He, J-g., Wang, X-p., Wang, Z-g.,  and Qi, L., Microstructure, crystallography and nucleation mechanism of NANOBAIN steel, International Journal of Minerals, Metallurgy andMaterials, 2013, 20(12), 1155.
20. Lee, Y.K., Shin, H.C., Jang, Y.C., Kim, S.H.,  Choi, C.S.,  Effect of isothermal transformation temperature on amount of retained austenite and its thermal stability in a bainitic Fe–3%Si–0.45%C–X steel, Scripta Materialia, 2002, 47, 805–809.
21. Bhadeshia, H.K.D.H., Nanostructured bainite, Proc. R. Soc. A, 2010, 466, 3–18.