Impacts of Modification of Alloying Method on Inclusion Evolution in RH Refining of Silicon Steel

• Published in: Materials Vol. 10; no. 10; p. 1206
• Main Authors: Li, Fangjie, Li, Huigai, Zheng, Shaobo, You, Jinglin, Han, Ke, Zhai, Qijie
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 19.10.2017; MDPI
• Subjects: Alloy steels; Carbon content; Degassing; Evolution; Inclusions; Industry standards; Iron and steel making; Manganese oxides; RH refining; silicon steel; Silicon steels; Steel production; silicon steel; evolution; inclusions; RH refining
• ISSN: 1996-1944; 1996-1944
• DOI: 10.3390/ma10101206

This study explores the effect of introducing additional alloy elements not only in a different order but also at different stages of the Ruhrstahl-Heraeus (RH) process of low-carbon silicon steel production. A more economical method, described as "pre-alloying", has been introduced. The evolution of MnO-FeO inclusions produced by pre-alloying was investigated. Results show that spherical 3FeO·MnO inclusions form first, then shelled FeO·zMnO (z = 0.7-4) inclusions nucleate on the surface of pre-existing 3FeO·MnO. Spherical FeO·zMnO (z = 3-5) is further evolved from shelled 3FeO·MnO by diffusion. Because these MnO-FeO inclusions float up into the slag before degassing, the pre-alloying process does not affect the quality of the melt in the end. Both carbon content and inclusion size conform to industry standards.