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 soli...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 32-120μm,where carbon segregation was evident,and the dendrite arms wereα-Fe.The insignificant change was observed at a soaking temperature of 1180℃,whereas at 1300℃,the finer structure firstly disappeared,and then,the coarsening decreased,indicating that carbon tended to be homogenized.Therefore,the microsegregation was improved at 1300℃for 15 min.The phase transformation ofα-Fe→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=15μm2/s)was determined by using the inverse problem method.展开更多
B2O3 was added to tire cord steel during refining in a carbon tube furnace.The influence of boron on the deformability of oxide inclusions was studied by metallographic and scanning electron microscope（SEM） observat...B2O3 was added to tire cord steel during refining in a carbon tube furnace.The influence of boron on the deformability of oxide inclusions was studied by metallographic and scanning electron microscope（SEM） observations.The melting points of boron-bearing compound oxide inclusions were calculated using Factsage software.The results showed that the main inclusion was a boron-bearing compound oxide and the deformation properties of the inclusions were clearly improved by adding B2O3.As the boron content was increased from 0.0046% to 0.039%,the proportion of long strip type inclusions changed slightly and the number of inclusions decreased.The low-melting point areas of the MnO-SiO2-Al2O3 and CaO-SiO2-Al2O3 ternary system increased with the addition of B2O3.Moreover,the area increased with the increase of B2O3 content.Clear improvements in the deformation ability of the inclusions occurred when the B2O3 mass percent rose to 5% in the CaO-SiO2-Al2O3 inclusion system and to 10% in the MnO-SiO2-Al2O3 inclusion system展开更多
基金The authors would like to thank the National Natural Science Foundation of China(No.62071034)the management of Jiuquan Iron and Steel(Group)Co.,Ltd.,China for the financial support and giving permission to publish this work.
文摘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 32-120μm,where carbon segregation was evident,and the dendrite arms wereα-Fe.The insignificant change was observed at a soaking temperature of 1180℃,whereas at 1300℃,the finer structure firstly disappeared,and then,the coarsening decreased,indicating that carbon tended to be homogenized.Therefore,the microsegregation was improved at 1300℃for 15 min.The phase transformation ofα-Fe→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=15μm2/s)was determined by using the inverse problem method.
文摘B2O3 was added to tire cord steel during refining in a carbon tube furnace.The influence of boron on the deformability of oxide inclusions was studied by metallographic and scanning electron microscope（SEM） observations.The melting points of boron-bearing compound oxide inclusions were calculated using Factsage software.The results showed that the main inclusion was a boron-bearing compound oxide and the deformation properties of the inclusions were clearly improved by adding B2O3.As the boron content was increased from 0.0046% to 0.039%,the proportion of long strip type inclusions changed slightly and the number of inclusions decreased.The low-melting point areas of the MnO-SiO2-Al2O3 and CaO-SiO2-Al2O3 ternary system increased with the addition of B2O3.Moreover,the area increased with the increase of B2O3 content.Clear improvements in the deformation ability of the inclusions occurred when the B2O3 mass percent rose to 5% in the CaO-SiO2-Al2O3 inclusion system and to 10% in the MnO-SiO2-Al2O3 inclusion system
