A series of steel-flux reaction experiments was conducted to elucidate the reaction mechanism between high Mn-high Al steel and CaO-\({\text{SiO}}_2\)-type molten mold flux of low MgO content \((({\text{pct MgO}})_0 = 0\) to 1.8) at 1723 K (\(1450\,^\circ \text {C}\)). Composition evolutions in the liquid steel and the molten flux during the reaction and microstructure change in the flux near the steel-flux interface were investigated by employing different experimental techniques. \(4{\underline{{\text{Al}}}} + 3({\text{SiO}}_2) = 3{\underline{\text{Si}}} + 2({{\text{Al}}_2} {{\text{O}}_3}\)) was confirmed as a major reaction in the system. It was found that rate of \({{\text{Al}}_2} {{\text{O}}_3}\) accumulation in the flux was retarded as the initial Al content in the steel (\([{\text{pct Al}}]_0\)) increased from 1 to 5 or 11, approximately. Moreover, keeping the initial content of MgO in the flux (\(({\text{pct MgO}})_0\)) < 1.8) resulted in a slower reaction rate than that with the normal MgO content (\(({\text{pct MgO}})_0 = \sim 2.5\)) reported previously, even at high Al content (\([{\text{pct Al}}]_0 = 4.6 {\text{to}} 5.8\)). From the microstructure analysis in the flux, the \({{\text{Al}}_2} {{\text{O}}_3}\)-rich zone and calcium aluminate layer were observed near the interface. A rapid increase of \({{\text{Al}}_2} {{\text{O}}_3}\) in the flux near the interface was found at the early stage of the reaction. As the reaction proceeded, however, the concentration gradients in the flux did not show noticeable changes. This suggests that mass transport in the flux was hindered by accumulation of the reaction products near the interface. The formation mechanism of the calcium aluminate layer was discussed by considering the measured flux compositions and phase diagram analysis calculated using the CALPHAD technique. Several kinetic analyses indicated that mass transport in the flux significantly affects the overall reaction rate in the high Mn-high Al steel and CaO-\({\text{SiO}}_2\)-type molten mold flux system with high Al \(([{\text{pct Al}}]_0 \ge 5\)) and low MgO content \((({\text{pct MgO}})_0 \le 1.8\)). The formation of a calcium aluminate layer in the low-MgO flux was beneficial to retarding the reaction rate.

一系列的钢磁通反应的实验中进行阐明高Mn-高Al钢和CaO之间的反应机理\（{\文本{的SiO}} _ 2 \）型熔融模具低MgO含量的焊剂\（（（ {\ text {pct MgO}} _ 0 = 0 \）到1.8）在1723 K（\（1450 \，^ \ circ \ text {C} \））。通过采用不同的实验技术，研究了反应过程中钢液和熔液中的成分演变以及钢-熔剂界面附近熔剂的微观结构变化。\（4 {\下划线{{\ text {Al}}}} + 3（{\ text {SiO}} _ 2）= 3 {\ underline {\ text {Si}}}} + 2（{{\ text {Al }} _ 2} {{\ text {O}} _ 3} \））被确认为系统中的主要反应。发现\（{{\ text {Al}} _ 2} {{\ text {O}} _ 3} \）的比率随着钢中的初始Al含量（\（[{{text {pct Al}}] _ 0 \）从1增至5或11，阻滞了焊剂中的累积。此外，保持熔剂中MgO的初始含量（\（{{text {pct MgO}} _ 0 \））<1.8）导致反应速率比正常MgO含量（\（（{文本{PCT的MgO}}）_ 0 = \ SIM 2.5 \） ）以前报道的，甚至在高的Al含量（\（[{\文本{PCT铝}}] _ 0 = 4.6 {\文本{到}} 5.8 \） ）。从焊剂的微观结构分析，在界面附近观察到\（{{\ text {Al}} _ 2} {{\ text {O}} _ 3} \）富集区和铝酸钙层。\（{{\ text {Al}} _ 2} {{\ text {O}} _ 3} \）的快速增长在反应的早期阶段，在界面附近的助焊剂中发现了氟。然而，随着反应的进行，助熔剂中的浓度梯度没有显示出明显的变化。这表明，在界面附近反应产物的积累阻碍了助焊剂中的质量传输。通过考虑测得的焊剂成分和使用CALPHAD技术计算的相图分析，讨论了铝酸钙层的形成机理。几个动力学分析表明在磁通质量传输显著影响高Mn-高Al钢和CaO的总反应速率\（{\文本{的SiO}} _ 2 \）型熔融保护渣与高Al系统\（ （[{\ text {pct Al}}] _ 0 \ ge 5 \））和低MgO含量\（（（（{{text {pct MgO}}）_ 0 \ le 1.8 \））。在低MgO助熔剂中形成铝酸钙层有利于延迟反应速率。