Effect of cooling conditions after rolling on microstructure and properties of a low-carbon bainitic steel
ZOU Hang1,2, LIU Man1, XU Guang1
1. State Key Laboratory of Refractories and Metallurgy, Wuhan University of Science and Technology, Wuhan 430081, Hubei, China; 2. Research and Development Center, Baoshan Iron and Steel Co., Ltd., Wuhan 430080, Hubei, China
Abstract:In order to investigate the effect of different cooling conditions after rolling on microstructure and mechanical properties of a high-strength low-carbon bainitic steel,the dilatometry,field emission SEM,TEM and tensile tests were utilized to clarify the microstructural evolution and property changes of a high-strength low-carbon bainitic steel under different cooling conditions. The results show that,with a final cooling temperature of 510 ℃ and 450 ℃ in the bainite transformation area,the microstructure mainly composed of GB and BF respectively,and more island like martensite was found in the former condition. Moreover,GB and BF microstructure were refined and the portion of island like martensite was reduced as the cooling rate increased. At different cooling conditions,a lower final cooling temperature always led to a higher phase transformation speed,and the highest phase transformation speed acquired at the condition of a cooling rate of 50 ℃/s. With a higher final cooling temperature,better plasticity and smaller strength variation acquired. On the contrary contrast,superior strength acquired,but lower plasticity and remarkably strength fluctuation.
邹航, 刘曼, 徐光. 轧后冷却条件对低碳贝氏体钢组织性能的影响[J]. 钢铁, 2021, 56(9): 144-150.
ZOU Hang, LIU Man, XU Guang. Effect of cooling conditions after rolling on microstructure and properties of a low-carbon bainitic steel[J]. Iron and Steel, 2021, 56(9): 144-150.
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