2021 年 61 巻 5 号 p. 1396-1403
Comprehensive investigation of agglomeration behavior of oxide inclusions in steel-containing rare earth (RE) under different deoxidation conditions is essential for improving the nozzle-clogging problem during continuous casting. The present study first optimized the thermodynamic model by supplementing thermodynamic data of the RE-compound to study the formation of various inclusions in the Ce–Si–Al–O system. On this basis, laboratory-scale experiments with different deoxidation conditions were designed to obtain samples containing one single type of inclusions, viz., SiO2, SiO2–Ce2O3 or SiO2–Al2O3–Ce2O3, respectively. Subsequently, the agglomeration behavior of inclusions was observed in situ by confocal laser scanning microscopy (CLSM), and the corresponding attractive forces were calculated to compare the agglomeration tendency of various inclusions. The results indicate that, in the Si deoxidized samples, SiO2–Ce2O3 inclusions agglomerate to form clusters with the attractive force of 4.3 × 10−17N to 4.2 × 10−15N, which is weaker than that of Al2O3 and Al2O3–Ce2O3 inclusions after Al deoxidation. Although SiO2 inclusions can agglomerate, their attractive force is only 6.3 × 10−19N to 1.2 × 10−16N, which is the weakest of the above inclusions. In the case of Si/Al complex deoxidization, spherical SiO2–Al2O3–Ce2O3 liquid inclusions are formed after Ce treatment, and no agglomeration of such inclusions was observed in situ. The study could provide theoretical guidance for improving the nozzle-clogging problem of RE-containing steel from inclusion-controlling perspective under different deoxidation conditions.
