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Contact experiments between low‐reactivity CaO–BaO–Al2O3‐based mold fluxes, F1 and F2, and 1.4–2.2 mass% of Al‐containing steels are conducted to investigate the effect of interfacial reaction on mold flux properties and the ultimate limit of reaction duration capacity of the developed mold flux. F1 contains 30.76% CaO, 17.03% Al2O3, 13.40% BaO, and 10.70% SiO2, whereas F2 consists of 27.90% CaO, 23.60% Al2O3, 12.90% BaO, and 9.57% SiO2 of the mass. The pre‐ and post‐experimental wettability of slag samples on steel substrates and the lubrication behavior of slags are discussed. The main results reveal that SiO2, Na2O, and B2O3 in the mold flux react with [Al] in the molten steel at steel–slag interface. The variations in slag properties indicate that both reaction durations between F1 reacting with twinning‐induced plasticity (TWIP) and F2 reacting with 20Mn23AlV steel can last for 40 min, whereas F2 has wider potential applicability for the continuous casting of Al‐containing steels. Interfacial reaction deteriorates the wettability of slag F2 on 20Mn23AlV steel substrate and reduces slag consumption, as equilibrium contact angle increases from approximately 3° to 37°, but slag consumption prediction is 0.22 kg m−2, which is likely to meet the requirement for lubrication. [ABSTRACT FROM AUTHOR]

The non-isothermal crystallization behaviors of CaO-BaO-Al 2 O 3 -based mold fluxes in which SiO 2 had been replaced by Na 2 O were investigated, using an infrared furnace combined with digital microscopy as well as X-ray diffraction. The initial crystallization temperatures, crystalline phases generated at different cooling rates, crystallization rates, Ozawa indices N O (as determined using Mo's equation) and effective crystallization activation energies (as determined using the Friedman equation) were evaluated. The initial crystallization temperature increased along with the Na 2 O content in the flux. In addition, the precipitation of CaF 2 crystals was inhibited while the growth of CaAl 2 O 4 crystals was enhanced at Na 2 O concentrations over 4 wt%. Increasing the cooling rate inhibited the precipitation of MgAl 6 O 10 , and of CaSiO 3 , MgAl 2 SiO 6 and NaAlSi 3 O 8 , respectively, in fluxes containing 0, 4 and 8 wt% Na 2 O (NS1, NS2 and NS3 samples). The peak instantaneous and average crystallization rates in these specimens were increased as the Na 2 O level was raised, as a direct result of changes in their N O values. The NS1 flux consistently had the lowest N O value, while the NS2 had the largest value in the primary stage of crystallization but the central value in the secondary stage, and the N O values of the NS3 flux exhibited the opposite trend. The effective crystallization activation energies decreased with increasing Na 2 O levels, and this was evidently an important factor affecting the initial crystallization temperature. [ABSTRACT FROM AUTHOR]