Transformation of LaAlO3 Inclusions During Heating in a Solid Non-oriented Electrical Steel

• Published in: Metallurgical and materials transactions. B, Process metallurgy and materials processing science Vol. 53; no. 1; pp. 637 - 649
• Main Authors: Zhang, Yuexin, Ren, Qiang, Kang, Xiaomin, Gao, Julei, Zhang, Lifeng
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.02.2022; Springer Nature B.V
• Subjects: Aluminum oxide; Characterization and Evaluation of Materials; Chemistry and Materials Science; Composition; Dissolved oxygen; Dual phase steels; Electrical steels; Engineering; Experiments; Heating; Inclusions; Liquid metals; Materials Science; Metallic Materials; Molybdenum; Morphology; Nanotechnology; Original Research Article; Steel; Structural Materials; Sulfur; Surfaces and Interfaces; Thin Films; Transformations
• ISSN: 1073-5615; 1543-1916
• DOI: 10.1007/s11663-021-02410-4

The effects of heating temperature (1100 °C, 1200 °C, 1300 °C, 1400 °C, 1500 °C) and heating time (15 minutes, 1, 3, 5 hours) on the transformation of LaAlO 3 inclusions during the heating process in a solid non-oriented electrical steel were studied using laboratory experiments. The composition and morphology of inclusions in the steel before and after heating were analyzed using a scanning electron microscope (SEM) equipped with an energy dispersive spectrum (EDS). Steel samples with single-type LaAlO 3 inclusions were prepared in molten steel at 1600 °C. When solid steel samples were heated at 1100 °C to 1400 °C for 3 hours, LaAlO 3 inclusions were transformed into dual-phase Al 2 O 3 –La 2 S 3 ones and the newly formed Al 2 O 3 and La 2 S 3 phases were increasingly separated with heating temperature increasing. The transformation degree reached the maximum at 1300 °C. When the sample was heated at 1500 °C, LaAl 11 O 18 formed because dissolved oxygen reacted with dissolved aluminum and LaAlO 3 inclusions. The transformation degree increased with heating time increasing at 1200 °C. Thermodynamic analysis was performed using FactSage and was consistent with observed results. A kinetic model was established to predict the composition of inclusions after the transformation of LaAlO 3 .