Effect of continuous reoxidation on inclusions in molten steel during calcium treatment
PENG Kai- yu1,LIU Yang2,ZHANG Li- feng2
（1. Steelmaking Department, Shougang Qian′an Iron and Steel Co., Ltd., Qian′an 064400, Hebei, China 2. School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing 100083, China）
Abstract：The effect of continuous air absorption on inclusions in molten steel during calcium treatment was investigated using the induction furnace. Before reoxidation occurred, the vaporization of calcium significantly influence the composition of inclusions. After reoxidation, the reaction between aluminum, calcium, silicon and oxygen occurred. The evolution of inclusions was CaO- CaS- Al2O3→CaO- (CaS)- Al2O3→ (CaO)- Al2O3→Al2O3→SiO2. The number density of inclusion increased from 10 to 210/mm2, and finally increased to 300/mm2. Based on the measured results of composition of steels, the process was divided to three stages, i.e., the vaporization of calcium, the reoxidation of aluminum and the reoxidation of silicon. The composition of inclusions was predicted accurately via thermodynamic calculation in different stages during the process.
2018, Vol. 28 
