Abstract:Three kinds of low carbon bainitic steels with different silicon contents were designed. The isothermal quenching heat treatment experiments at different temperatures, Xray diffraction and tensile tests were carried out to study the effect of Si content on the kinetics of bainitic transformation and properties of low carbon bainite steels. The results show that the amount of bainite decreases, the kinetic equation parameter b decreases and n increases with the increase of Si content. In addition, with the increase of bainitic transformation temperature, parameter b decreases while n increases. Moreover, at lower phase transition temperatures, the difference in the values of parameters b and n is greater due to the difference in Si content, indicating that the Si content at low temperature has a greater influence on the transformation kinetics of bainite. Moreover, with the lower Si content, the difference in incubation period and completion time of bainitic transformation will gradually increase due to different transformation temperatures, indicating that the impact of Si content on bainitic transformation kinetics decreases with the increase of Si content. Finally, with the increase of Si content, the tensile strength and elongation of specimens increase gradually. The results provide the theoretical reference for optimizing the composition design and controlling its mechanical properties in low carbon banitic steels.
LIU Man,XU Guang,TIAN Jun-yu,WEI Zhi-rui,ZHANG Qing-xiao.
Effect of Si content on kinetics of bainitic transformation and properties of low carbon bainite steels[J]. Journal of Iron and Steel Research, 2019, 31(11): 982-987 https://doi.org/10.13228/j.boyuan.issn1001-0963.20190075