工程科学学报 (Nov 2015)

Effect of BOF slag composition on the end-point[C]content of ultra-low carbon steel

  • ZHANG Ming-bo,
  • QIN Zhe,
  • CHOU Sheng-tao,
  • ZHU Rong,
  • BAI Rui-guo,
  • ZHANG Xing-li

DOI
https://doi.org/10.13374/j.issn2095-9389.2015.11.005
Journal volume & issue
Vol. 37, no. 11
pp. 1422 – 1428

Abstract

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The effect of slag composition on the[C] content of ultra-low carbon steel at the end of smelting was investigated by the coexistence theory,dynamics analysis and experimental verification. A regression model of end-point[C] content was established with temperature and slag composition in a temperature range from 1853 K to 1973 K. The results show that the Fe O activity is little affected by temperature,while it is mainly affected by slag composition. However,the decarburization kinetics is mainly affected by slag composition and temperature. The end-point[C] content increases with increasing slag basicity,but it quickly decreases with increasing Fe O content in slag,so the end-point Fe O mass fraction in slag should be controlled in 12%-18%. In addition,the increment value of[C] is less than 0. 01% with the Mg O mass fraction in slag from 7% to 13%. The results also show that the end-point[C]mass fraction decreases with increasing temperature. Compared with industrial results,the average error rate of the regression model for the end-point[C] content in the ultra-low carbon steel is ±15. 25%,and the hit rate to[C] content predicted by the regression model reaches 69. 19% with a control precision of ±0. 01% for heats of the experiment.

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