Study of Micro-Inclusion of 20g Steel

Abstract:

According to the production process of 20g steel(120t BOF→ LF→ CC), some system analysis are introduced to research on the content of T[O] and [N] and the type, source, composition and quantity of micro inclusions in refining process, pouring process and casting billet. The results of the study show: the content of T[O] is 93.2ppm in the normal billet which is 37.8ppm more than that at steady state in the export of tundish. The content of T[O] is 140.5ppm in the compound casting billet which is 70.133ppm more than that at non-steady state in the export of tundish. The secondary oxidation of mould is serious at casting progress. In billet, the quality of CaS-SiO2-Al2O3 complex inclusion is the most, the quality of MnS inclusion is the second, and the quality of Al2O3 inclusion is the least. The sulphur content in micro-inclusion of billet is higher. The sulphur content in CaS-SiO2-Al2O3 complex inclusion is 3~15%, the sulphur content in MnS inclusion is 25%. The particle size of less than 10μm in micro-inclusions is the largest. The particle size of 0~5μm is about 60%, the particle size of 5~10μm is about 35%, the particle size of 10~15μm is about 5%. The average total volume rate of micro-inclusion is 0.149% in normal billet. The average total volume rate of micro-inclusion is 0.184% in compound casting billet which is 1.23 times than normal billet. The number of micro-inclusion is 36.5/ mm2 in normal billet. The number of micro-inclusion is 58.5/ mm2 in compound casting billet which is 60.27% higher than normal billet. The non-steady state casting has serious influence on billet cleanliness.

• Periodical: Advanced Materials Research (Volumes 634-638)
• Pages: 1864-1868
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.634-638.1864
• Online since: January 2013
• Authors: Shuo Ming Wang, Cheng Liang Du, Ju Gao
• Keywords: 20g Steel, Micro-Inclusion, Volume Ratio Distribution

References

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