Mass Transfer Model of Oriented Silicon Steel Coil during the First Soaking in Annular Furnace

作者：Xia, Tian^*; He, Zhu; Xiang, Zhidong; Shen, Xinyi; Li, Weijie

来源：Silicon, 2023, 15(1): 269-284.

DOI：10.1007/s12633-022-01996-x

• Annular furnace
• Oriented silicon steel
• Mass transfer model
• Magnetic performance
• Surface oxidation

Surface oxidation of the oriented silicon steel usually occurs during the first soaking in annular furnace. It negatively influences the magnetic performance and the MgSO4 coating of the strip. The surface oxidation is closely related to the high H2O content atmosphere between the layers of the strip. As the H2O content within the coil is hard to measure, the mass transfer model of the oriented silicon steel coil during the first soaking in annular furnace is built in this paper. Furthermore the correlations between H2O content and the magnetic performance distribution are also analyzed via experiment in actual production. The result shows that the H2O content within the coil increased as the height declined in axial direction. Plenty of H2O concentrated near the bottom of the coil as a result of the tight joint between the coil and the plate. The maximum H2O content within the coil is about 80 vol%. The magnetic performance of the strip tended to decline while the H2O content rose especially at the edge of the strip. Most magnetic property defects appeared at the outer ring and the bottom of the coil. The oxidizing atmosphere between the layers of the strip could be weakened significantly through improving the diffusion conditions at the bottom surface of the coil.