Effect of Rare-Earth Oxides Containing Refractories on the Cleanliness of Al-Killed Steels

Refractories have a significant impact on the cleanliness of molten steel, especially when utilized as ceramic filters. To explore the feasibility of applying rare-earth oxides in ceramic filters, the interactions between CeO2/CeAlO3 functional refractories and steels with different Al contents are explored, and compared with the microporous magnesia refractory. In the test of CeO2 refractory, the total oxygen (T.O) content significantly increases, while the dissolved Al content obviously decreases in 38CrMoAl steel (0.876 wt% [Al]). Furthermore, the T.O contents in 38CrMoAl and X70 steel (0.040 wt% [Al]) in the test of CeAlO3 refractory are 22.9% and 70.9% of that in the test of microporous magnesia refractory, respectively. Meanwhile, the loss of dissolved Al in steel caused by the interaction between CeAlO3 refractory and steel is relatively small. Therefore, CeAlO3 is relatively stable after contact with molten steel and promising to be applicated in the ceramic filter for improving the cleanliness of molten steel. In the test of CeAlO3 refractory, the total oxygen contents in 38CrMoAl and X70 steel (0.040 wt% [Al]) are 22.9% and 70.9% of that in the test of microporous magnesia refractory, respectively, after holding at 1823 K for 30 min. CeAlO3 is promising to be applied in ceramic filter coating to improving steel cleanliness.image (c) 2023 WILEY-VCH GmbH