Transient influence of cerium on inclusions in an Al-killed non-oriented electrical steel

ABSTRACT

Industrial trials and thermodynamic analysis were performed to investigate the transient influence of cerium on inclusions in an Al-killed non-oriented electrical steel. Inclusions were statistically analyzed using an automatic scanning electron microscope. Without cerium addition, inclusions in the molten steel were predominately MgO·Al₂O₃ ones as well as a small number of Al₂O₃–MgO–CaO ones, and precipitates of AlN and MgS formed in the continuous casting slab. In the steel with approximately 10 ppm total oxygen and 10 ppm total sulphur, inclusions of MgO·Al₂O₃ were modified into homogeneous Ce₂O₂S ones and Ce–Al–Mg–Ca–S–O dual-phase ones by 35 ppm cerium. With increasing time, the content of cerium decreased to 23 ppm in the tundish and dual-phase inclusions of Ce–Al–Mg–Ca–S–O transformed into CeAlO₃ ones. During cooling, inclusions of CeAlO₃ transformed into dual-phase MgO–Ce_xS ones in the steel with approximately 14 ppm total magnesium. Thermodynamic analysis was in good agreement with observed results.

KEYWORDS:

• Non-oriented electrical steel
• cerium
• inclusions
• CeAlO₃
• Ce₂O₂S
• Thermodynamics
• Transformation
• Modification

Acknowledgements

The authors are grateful for support from the National Science Foundation China (Grant No. U1860206 and No. 51725402), the High Steel Center (HSC) at Yanshan University, and Beijing International Center of Advanced and Intelligent Manufacturing of High Quality Steel Materials (ICSM), Beijing Key Laboratory of Green Recycling and Extraction of Metals (GREM) and the High Quality Steel Consortium (HQSC) at University of Science and Technology Beijing (USTB), China.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported by the National Natural Science Foundation of China: [Grant Numbers U1860206 and 51725402].