Research on the Design of Fluoride‐Free Continuous Casting Mold Flux System for High‐Aluminum Steel

To get rid of the restrictions imposed by the components of the original mold flux and minimize fluorides to the largest extent, this article has designed the continuous casting mold flux for high‐aluminum steel with an aluminum content of 1.35% and tested the performance manifestations of the mold flux by integrating equipment like a rotational viscometer, S/DHTT‐TA‐III thermal analyzer, and X‐ray diffraction. The composition of the continuous casting mold flux for high‐aluminum steel is: CaO = 23–43 wt%, SiO 2 = 12–25 wt%, Al 2 O 3 = 14–26 wt%, B 2 O 3 = 13–17 wt%, and Li 2 O = 4–8 wt%. The newly designed mold flux has a lower melting temperature and its performance still satisfies the conditions for continuous casting after the reaction. The crystallization process of the on‐site using mold flux lasts 198 s, with the precipitated phases being Na 2 CaSiO 4 and Ca 3 Si 2 O 7 . The crystallization process of the newly designed mold flux lasts ≈324 s, with the precipitated phase mainly being LiAlO 2 , and the mold flux can maintain a low viscosity and a relatively thick liquid slag layer for a longer period of time.