1 School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing 100083, China 2 Institute of Iron and Steel Technology, TU Bergakademie Freiberg, Freiberg 09599, Germany 3 Department of Metallurgical Process, Research Institute of Technology of Shougang Group Co., Ltd., Beijing 100043, China 4 Jiuquan Iron and Steel (Group) Co., Ltd., Jiayuguan 735100, Gansu, China
In-situ observation and analysis of solidified structure evolution of S50C steel in soaking furnace
1 School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing 100083, China 2 Institute of Iron and Steel Technology, TU Bergakademie Freiberg, Freiberg 09599, Germany 3 Department of Metallurgical Process, Research Institute of Technology of Shougang Group Co., Ltd., Beijing 100043, China 4 Jiuquan Iron and Steel (Group) Co., Ltd., Jiayuguan 735100, Gansu, China
摘要 The evolution of solidified structure of S50C steel during heat treatment in compact strip production process was studied through an ultra-high-temperature confocal scanning laser microscope. It was found that the solidified structure consisted of dendritic crystals with secondary dendrite arm spacing ranging in 32–120 μm, where carbon segregation was evident, and the dendrite arms were α-Fe. The insignificant change was observed at a soaking temperature of 1180 °C, whereas at 1300 °C, the finer structure firstly disappeared, and then, the coarsening decreased, indicating that carbon tended to be homogenized. Therefore, the microsegregation was improved at 1300 °C for 15 min. The phase transformation of αFe→γ-Fe enhanced the carbon diffusion, and the evolution of the equivalent radius req was controlled by carbon diffusion. The diffusion coefficient of carbon (D = 15 μm2/s) was determined by using the inverse problem method.
Abstract：The evolution of solidified structure of S50C steel during heat treatment in compact strip production process was studied through an ultra-high-temperature confocal scanning laser microscope. It was found that the solidified structure consisted of dendritic crystals with secondary dendrite arm spacing ranging in 32–120 μm, where carbon segregation was evident, and the dendrite arms were α-Fe. The insignificant change was observed at a soaking temperature of 1180 °C, whereas at 1300 °C, the finer structure firstly disappeared, and then, the coarsening decreased, indicating that carbon tended to be homogenized. Therefore, the microsegregation was improved at 1300 °C for 15 min. The phase transformation of αFe→γ-Fe enhanced the carbon diffusion, and the evolution of the equivalent radius req was controlled by carbon diffusion. The diffusion coefficient of carbon (D = 15 μm2/s) was determined by using the inverse problem method.
Kai Liu,Shu-sen Cheng,Xing-wen Wei, et al. In-situ observation and analysis of solidified structure evolution of S50C steel in soaking furnace[J]. Journal of Iron and Steel Research International, 2023, 30(10): 1963-1973.
2023, Vol. 30 
