Characteristics of Heat Flux Through Slag Film of Mold slag Used for High Al-TRIP Steel Casting

Due to its high content in the Al-TRIP steel, Al] reacts with (SiO2) in the mold slag during the casting process, which results in the increase of w(Al2O3)/w(SiO2) ratio and the Al2O3 content, respectively, the characteristic of heat transfer through the slag film is then changed, which effects the smooth operation of the continuous casting process. In this paper, the mold slag simulator was used to study the change tendency of the heat flux density through slag film and the results were discussed, at the same time, the crystals in the 15# slag were characterized by BSE and XRD. The results obtained show that:(i) Heat flux density decreases with the increase of w(Al2O3)/w(SiO2) ratio; (ii) Heat flux density increases with the increase of Li2O and/or B2O3 content in the mold slag which contain 30% Al2O3; (iii) Compared with the heat flux density of common slag of peritectic steel, an appropriated mold slag contain 4% B2O3 and 4% Li2O is designed. The heat flux density is 0.645MW•m-2 when w(Al2O3)/w(SiO2)=1.46. (iv) In the equilibrium state, mold slag used for Al-TRIP steel precipitates CaF2 crystals.