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Dilatometric determination of four critical temperatures and phase transition fraction for austenite decomposition in hypo-eutectoid steels using peak separation method

  • Tao Liu (a1), Mujun Long (a1), Helin Fan (a1), Dengfu Chen (a1), Huabiao Chen (a1), Huamei Duan (a1), Wenxiang Jiang (a1) and Wenjie He (a1)...


This work was aimed to use the peak separation method to directly measure the critical temperatures and phase transition fractions of austenite decomposition products based on experimental dilatometric curves in hypo-eutectoid steels. The results indicated that pearlite transformation start temperature and ferrite transformation finish temperature could be clearly obtained through peak separation processing, which were generally hidden in the overlapped peaks of the linear thermal expansion coefficient curve. Moreover, four critical temperatures of austenite decomposition were retarded to lower temperature with cooling rate increasing. The phase transition fraction for austenite decomposition was quantitated by measuring the area of the corresponding phase transformation peak. The final ferrite phase fraction after austenite decomposition decreased with cooling rate increasing. On the contrary, the final pearlite phase fraction increased with cooling rate increasing. Compared with the lever rule, the calculation result using peak area method can accurately reflect the actual phase fraction change versus the temperature during austenite decomposition.


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1.Thomas, B.: Continuous Casting (Metallurgy). Yearbook of Science and Technology (McGraw-Hill, New York, New York, 2004), pp. 16.
2.Long, M., Dong, Z., Chen, D., Zhang, X., and Zhang, L.: Influence of cooling rate on austenite transformation and contraction of continuously cast steels. Ironmaking Steelmaking 42, 282289 (2015).
3.Kong, J. and Xie, C.: Effect of molybdenum on continuous cooling bainite transformation of low-carbon microalloyed steel. Mater. Des. 27, 11691173 (2006).
4.Chen, J.: Influence of deformation temperature on γ–α phase transformation in Nb–Ti microalloyed steel during continuous cooling. ISIJ Int. 53, 10701075 (2013).
5.Bhadeshia, H.K., and Honeycombe, R.: Steels: Microstructure and properties. (Butterworth-Heineman, Oxford, United Kingdom, 2008).
6.Pfeiler, C., Thomas, B.G., Wu, M., Ludwig, A., and Kharicha, A.: Solidification and particle entrapment during continuous casting of steel. Steel Res. Int. 79, 599607 (2008).
7.Long, M. and Chen, D.: Study on mitigating center macro-segregation during steel continuous casting process. Steel Res. Int. 82, 847856 (2011).
8.Kop, T.A., Sietsma, J., and Zwaag, S.V.D.: Dilatometric analysis of phase transformations in hypo-eutectoid steels. J. Mater. Sci. 36, 519526 (2001).
9.Andrés, C.G.A.D., Caballero, F.G., Capdevila, C., and Álvarez, L.F.: Application of dilatometric analysis to the study of solid–solid phase transformations in steels. Mater. Charact. 48, 101111 (2002).
10.Jian, Z., Dengfu, C., Chengqian, Z., Wengsing, H., and Mingrong, H.: The effects of heating/cooling rate on the phase transformations and thermal expansion coefficient of C–Mn as-cast steel at elevated temperatures. J. Mater. Res. 30, 20812089 (2015).
11.Mintz, B.: Understanding the low temperature end of the hot ductility trough in steels. Mater. Sci. Technol. 24, 112120 (2008).
12.Carpenter, K.R., Dippenaar, R., and Killmore, C.: Hot ductility of Nb-and Ti-bearing microalloyed steels and the influence of thermal history. Metall. Mater. Trans. A 40, 573580 (2009).
13.Ma, F., Wen, G., Tang, P., Yu, X., Li, J., Xu, G., and Mei, F.: In situ observation and investigation of effect of cooling rate on slab surface microstructure evolution in microalloyed steel. Ironmaking Steelmaking 37, 211218 (2010).
14.Dou, K., Meng, L., Liu, Q., Liu, B., and Huang, Y.: Influence of cooling rate on secondary phase precipitation and proeutectoid phase transformation of micro-alloyed steel containing vanadium. Met. Mater. Int. 22, 349356 (2016).
15.Zhao, S., Wu, Y-j., He, M-f., and Zhang, L.: Effects of cooling rates on microstructures and mechanical properties of Nb–Ti microalloyed steel. J. Shanghai Jiaotong Univ. 17, 653657 (2012).
16.Pierson, H.O.: Handbook of Refractory Carbides and Nitrides: Properties, Characteristics, Processing, and Applications (William Andrew, Norwich, New York, 1996).
17.Zarandi, F. and Yue, S.: Failure mode analysis and a mechanism for hot-ductility improvement in the Nb-microalloyed steel. Metall. Mater. Trans. A 35, 38233832 (2004).
18.Ma, F., Wen, G., Tang, P., Xu, G., Mei, F., and Wang, W.: Effect of cooling rate on the precipitation behavior of carbonitride in microalloyed steel slab. Metall. Mater. Trans. B 42, 8186 (2011).
19.Zarandi, F. and Yue, S.: Mechanism for loss of hot ductility due to deformation during solidification in continuous casting of steel. ISIJ Int. 44, 17051713 (2007).
20.Jung, J.G., Park, J.S., Kim, J., and Lee, Y.K.: Carbide precipitation kinetics in austenite of a Nb–Ti–V microalloyed steel. Mater. Sci. Eng., A 528, 55295535 (2011).
21.Chen, J., Lv, M.Y., Tang, S., Liu, Z.Y., and Wang, G.D.: Influence of cooling paths on microstructural characteristics and precipitation behaviors in a low carbon V–Ti microalloyed steel. Mater. Sci. Eng., A 594, 389393 (2014).
22.James, J.D., Spittle, J.A., Brown, S.G.R., and Evans, R.W.: A review of measurement techniques for the thermal expansion coefficient of metals and alloys at elevated temperatures. Meas. Sci. Technol. 12, R1R15 (2001).
23.Banks, K.M., Tuling, A., and Mintz, B.: Influence of thermal history on hot ductility of steel and its relationship to the problem of cracking in continuous casting. Mater. Sci. Technol. 28, 536542 (2012).
24.Li, Y., Chen, X., Liu, K., Wang, J., Wen, J., and Zhang, J.: Reasonable temperature schedules for cold or hot charging of continuously cast steel slabs. Metall. Mater. Trans. A 44, 53545364 (2013).
25.Brimacombe, J.K. and Sorimachi, K.: Crack formation in the continuous casting of steel. Metall. Trans. B 8, 489505 (1977).
26.Santillana, B., Boom, R., Eskin, D., Mizukami, H., Hanao, M., and Kawamoto, M.: High-temperature mechanical behavior and fracture analysis of a low-carbon steel related to cracking. Metall. Mater. Trans. A 43, 50485057 (2012).
27.Zhao, R-j., Fu, J-x., Zhu, Y-y., Yang, Y-j., and Wu, Y-x.: Dilatometric analysis of irreversible volume change during phase transformation in pure iron. J. Iron Steel Res. Int. 23, 828833 (2016).
28.Vázquez-Gómez, O., López-Martínez, E., Gallegos-Pérez, A.I., Santoyo-Avilés, H., Vergara-Hernández, H.J., and Campillo, B.: Kinetic Study of the Austenite Decomposition During Continuous Cooling in a Welding Steel. In Proceedings of the 3rd Pan American Materials Congress (Springer, Cham, Switzerland, 2017), pp. 749760.
29.Yang, H.B., Ma, B.G., Zhu, F.X., and Liu, X.H.: Analysis of continuous cooling transformation and microstructure of hot-formed GCr15 steel. J. Northeast. Univ. 29, 11151117 (2008).
30.Pawłowski, B.: Dilatometric examination of continuously heated austenite formation in hypoeutectoid steels. J. Achiev. Mater. Manuf. Eng. 54, 185193 (2012).
31.Caballero, F.G., Capdevila, C., and Andrés, C.G.D.: Evaluation and review of simultaneous transformation model in high strength low alloy steels. Mater. Sci. Technol. 18, 534540 (2002).
32.Suh, D.W., Oh, C.S., Han, H.N., and Kim, S.J.: Dilatometric analysis of austenite decomposition considering the effect of non-isotropic volume change. Acta Mater. 55, 26592669 (2007).
33.Dong, Z., Chen, D., Long, M., Li, W., Chen, H., and Vitos, L.: Computation of phase fractions in austenite transformation with the dilation curve for various cooling regimens in continuous casting. Metall. Trans. B 47, 15531564 (2016).
34.Li, H., Gai, K., He, L., Zhang, C., Cui, H., and Li, M.: Non-isothermal phase-transformation kinetics model for evaluating the austenization of 55CrMo steel based on Johnson–Mehl–Avrami equation. Mater. Des. 92, 731741 (2016).
35.Long, M., Chen, D., Zhang, L., Zhao, Y., and Liu, Q.: A mathematical model for mitigating centerline macro segregation in continuous casting slab. Metal. Int. 16, 1933 (2011).
36.Wu, D., Liu, G., Sun, R., and Fan, X.: Investigation of structural characteristics of thermally metamorphosed coal by FTIR spectroscopy and X-ray diffraction. Energy Fuels 27, 58235830 (2013).
37.Ibarra, J., Muñoz, E., and Moliner, R.: FTIR study of the evolution of coal structure during the coalification process. Org. Geochem. 24, 725735 (1996).
38.Petkov, P.: Austenite decomposition of low carbon high strength steels during continuous cooling. Master's thesis, Department of Metals and Materials Engineering, University of British Columbia, Vancouver, Canada (2004).



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