Mechanism of MnS Precipitation on Al2O3–SiO2 Inclusions in Non-oriented Silicon Steel

• Published in: Metals and materials international Vol. 24; no. 6; pp. 1394 - 1402
• Main Authors: Li, Fangjie, Li, Huigai, Huang, Di, Zheng, Shaobo, You, Jinglin
• Format: Journal Article
• Language: English
• Published: Seoul The Korean Institute of Metals and Materials 01.11.2018; Springer Nature B.V; 대한금속·재료학회
• Subjects: Aluminum oxide; Characterization and Evaluation of Materials; Chemical precipitation; Chemistry and Materials Science; Diffusion; Energy transmission; Engineering Thermodynamics; Heat and Mass Transfer; Inclusions; Machines; Magnetic Materials; Magnetism; Manganese oxides; Manufacturing; Materials Science; Metallic Materials; Precipitates; Processes; Scanning electron microscopy; Silicon dioxide; Silicon steels; Solid Mechanics; Solid phases; Solidification; Substrates; Transmission electron microscopy; 재료공학; Scanning electron microscopy; Inclusion; Non-oriented silicon steel; Solidification process
• ISSN: 1598-9623; 2005-4149
• DOI: 10.1007/s12540-018-0141-4

This study investigates the mechanism of MnS precipitation on Al 2 O 3 –SiO 2 inclusions during the solidification of non-oriented silicon steel, especially the influence of the phase structures and sizes of the oxides on the MnS precipitation, by scanning electron microscopy and transmission electron microscopy coupled with energy dispersive spectrometry. The investigation results show that MnS tends to nucleate on submicron-sized Al 2 O 3 –SiO 2 inclusions formed by interdendritic segregation and that it covers the oxides completely. In addition, MnS can precipitate on micron-sized oxides and its precipitation behavior is governed by the phase structure of the oxides. The MnS embryo formed in a MnO-containing oxide can act as a substrate for MnS precipitation, thus permitting further growth via diffusion of solute atoms from the matrix. MnS also precipitates in a MnO-free oxide by the heterogeneous nucleation mechanism. Furthermore, MnS is less prone to precipitation in the Al 2 O 3 -rich regions of the Al 2 O 3 –SiO 2 inclusions; this can be explained by the high lattice disregistry between MnS and Al 2 O 3 .