Effect of calcium content on inclusions during the ladle furnace refining process of AISI 321 stainless steel

Chao Pan; Xiao-jun Hu; Jian-chao Zheng; Ping Lin; Kuo-chih Chou

doi:10.1007/s12613-020-1981-8

Volume 27 Issue 11

Nov. 2020

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Article Navigation > International Journal of Minerals, Metallurgy and Materials > 2020 > 27(11): 1499-1507

Chao Pan, Xiao-jun Hu, Jian-chao Zheng, Ping Lin, and Kuo-chih Chou, Effect of calcium content on inclusions during the ladle furnace refining process of AISI 321 stainless steel, Int. J. Miner. Metall. Mater., 27(2020), No. 11, pp. 1499-1507. https://doi.org/10.1007/s12613-020-1981-8

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Chao Pan, Xiao-jun Hu, Jian-chao Zheng, Ping Lin, and Kuo-chih Chou, Effect of calcium content on inclusions during the ladle furnace refining process of AISI 321 stainless steel, Int. J. Miner. Metall. Mater., 27(2020), No. 11, pp. 1499-1507. https://doi.org/10.1007/s12613-020-1981-8

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Research Article

Effect of calcium content on inclusions during the ladle furnace refining process of AISI 321 stainless steel

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Corresponding author:
Xiao-jun Hu E-mail: huxiaojun@ustb.edu.cn
Received: 3 November 2019; Revised: 3 January 2020; Accepted: 7 January 2020; Available online: 8 January 2020

Abstract

Abstract

The effect of three heat processes with different calcium contents on the evolution of inclusions during the ladle furnace refining process of AISI 321 stainless steel was investigated. The size, morphology, and composition of the inclusions were analyzed by scanning electron microscopy and energy-dispersive X-ray spectroscopy. After the addition of aluminum and titanium, the primary oxide in the AISI 321 stainless steel was an Al₂O₃–MgO–TiO_x complex oxide, in which the mass ratio of Al₂O₃/MgO was highly consistent with spinel (MgO·Al₂O₃). After calcium treatment, the calcium content in the oxide increased significantly. Thermodynamic calculations show that when the Ti content was 0.2wt%, the Al and Ca contents were less than 0.10wt% and 0.0005wt%, respectively, which was beneficial for the formation of liquid inclusions in molten steel. Moreover, the modification mechanism of calcium on TiN-wrapped oxides in combination with temperature changes was discussed.
- inclusions;
- stainless steel;
- calcium treatment;
- thermodynamic calculation

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