Effects of cooling media on the formation of Martensite-Austenite microconstituent in a HSLA steel





Accelerated cooling, Linepipe steel, Martensite-Austenite (MA), Retained Austenite, Selective etching, Scanning electron microscopy (SEM)


The effect of different cooling conditions on the formation of Martensite-Austenite (MA) in a High - Strength Low - Alloy (HSLA) steel was assessed. The MA constituent is detrimental to impact toughness in pipeline applications, so the purpose of this research was to minimize its presence through the choice of effective cooling media and optimal parameters such as the cooling rate and final cooling temperature. The volume fraction, size and morphology of MA was evaluated by selective etching and corroborated trough SEM and EBSD. Vickers hardness testing agreed with the measured MA volume fractions. The sample cooled with helium gas and salt bath with the lowest final cooling temperature of 460 °C, exhibited a fine mixture of ferritic bainite, granular bainite and the lowest volume fraction of MA, along with MA smaller particle average size. A high cooling rate and a decrease in the final cooling temperature resulted in a decrease in the volume fraction and average particle size of MA.


Download data is not yet available.


Belato, D., Waele, W. De, Vanderschueren, D., Hertelé, S. (2013). Latest developments in mechanical properties and metallurgical of high strength line pipe steel. Conference: Int. Journal Sustainable Construction & Design, Vol. 4, pp. 1-10. https://doi.org/10.21825/scad.v4i1.742

Biss, V., Cryderman, R.L. (1971). Martensite and Retained Austenite in Hot-Rolled, Low-Carbon Bainitic Steels. Metall. Mater. Trans. B 2, 2267-2276. https://doi.org/10.1007/BF02917559

Cota, A.B., Santos, D.B. (2000). Microstructural Characterization of Bainitic Steel Submitted to Torsion Testing and Interrupted Accelerated Cooling. Mater. Charact. 44 (3), 291-299. https://doi.org/10.1016/S1044-5803(99)00060-1

Huda, N., Midawi, A.R.H., Gianetto, J., Lazor, R., Gerlich, A.P. (2016). Influence of Martensite-Austenite (MA) on Impact Toughness of X80 Linepipe steels. Mater. Sci. Eng. A 662, 481-491. https://doi.org/10.1016/j.msea.2016.03.095

Kabanov, A., Korpala, G., Kawalla, R., Prahl, U. (2019). Effect of Hot Rolling and Cooling Conditions on the Microstructure, MA Constituent Formation, and Pipeline Steels Mechanical Properties. Steel Res. Int. 90 (6), 1800336. https://doi.org/10.1002/srin.201800336

Konca, E. (2020). Production of 20 mm Thick API PSL 2 X60 and X70 Grade Plates from a Nb-Ti Microalloyed Steel. HJSE 7 (2), 149-155. https://doi.org/10.17350/HJSE19030000183

Liang, X.J., Hua, M.J., DeArdo, A.J. (2014). The Mechanism of Martensite-Austenite Microconstituents Formation During Thermomechanical Controlling Processing in Low Carbon Bainitic Steel. Mater. Sci. Forum 783-786, 704-712. https://doi.org/10.4028/www.scientific.net/MSF.783-786.704

Okatsu, M., Shinmiya, T., Ishikawa, N., Endo, S., Kondo, J. (2005). Development of High Strength Linepipe with Excellent Deformability. Int. Conf. Offshore Mechanics and Arctic Engineering (OMAE2005) 67149, 63-70. https://doi.org/10.1115/OMAE2005-67149

Reichert, J.M., Garcin, T., Militzer, M., Poole, W.J. (2012). Formation of Martensite/Austenite (M/A) in X80 Linepipe Steel. Proceedings IPC2012-90465. Vol. 3, Materials and Joining, pp. 483-489. https://doi.org/10.1115/IPC2012-90465

Rodrigues, P.C.M., Pereloma, E.V., Santos, D.B. (2000). Mechanical Properties of an HSLA Bainitic Steel Subjected to Controlled Rolling with Accelerated Cooling. Mater. Sci. Eng. A 283 (1-2), 136-143. https://doi.org/10.1016/S0921-5093(99)00795-9

Takayama, N., Miyamoto, G., Furuhara, T. (2018). Chemistry and three-dimensional morphology of martensite-austenite constituent in the bainite structure of low-carbon low-alloy steels. Acta Mater. 145, 154-164. https://doi.org/10.1016/j.actamat.2017.11.036

Wang, B., Dong, F., Wang, Z., Rdk, M., Wang, G. (2017). Microstructure and Mechanical Properties of Nb-B bearing Low Carbon Steel Plate: Ultrafast Cooling versus Accelerated Cooling. J. Wuhan Univ. Technol.-Mat. Sci. Edit. 32 (3), 619-624. https://doi.org/10.1007/s11595-017-1643-5

Zhao, H. (2016). Effect of Austenite Deformation and Continuous Cooling on the Microstructural Evolution in a Microalloyed Steel. PhD Thesis, The University of Sheffield, England.

Zhao, M.C., Yang, K., Shan, Y. (2002). The Effects of Thermo-Mechanical Control Process on Microstructures and Mechanical Properties of a Commercial Pipeline Steel. Mater. Sci. Eng. A 335 (1-2), 14-20. https://doi.org/10.1016/S0921-5093(01)01904-9



How to Cite

Moreno-Fabian, Z. ., & Solís-Bravo, G. . (2022). Effects of cooling media on the formation of Martensite-Austenite microconstituent in a HSLA steel. Revista De Metalurgia, 58(1), e214. https://doi.org/10.3989/revmetalm.214




Funding data

Secretaría de Educación Pública
Grant numbers UV-EXB-570