Effect of Mn content on continuous cooling transformation of ultra-low carbon bainitic steel

doi:10.13251/j.issn.0254-6051.2024.12.026

Abstract

Abstract: Phase transition points of three ultra-low carbon bainitic steels with Mn contents of 1.5%, 1.8%, and 2.1%, respectively, were determined using a thermal expansion meter, and the continuous cooling transformation(CCT) curves of the three tested steels were plotted in conjunction with optical microscopy(OM) and scanning electron microscopy(SEM) observation and Vickers hardness measurements. The effects of Mn content on phase transformation points, CCT curves, microstructure and hardness were analyzed. The results show that the change of Mn equivalent caused by the increase of Mn content affects the bainite transformation temperature. In addition, the increase of Mn content makes the Ac₃ of the tested steel show a downward trend, and the hardness is also improved.

Key words: ultra-low carbon bainitic steel, Mn content, CCT curves, granular bainite, lath bainite

CLC Number:

TG142

Mei Tao, Liu Jing, Chai Xiyang. Effect of Mn content on continuous cooling transformation of ultra-low carbon bainitic steel[J]. Heat Treatment of Metals, 2024, 49(12): 157-162.

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